Patent Publication Number: US-8974044-B2

Title: Cartridge and printing material supply system

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. application Ser. No. 13/670,997 filed on Nov. 7, 2012, which is a continuation-in-part of U.S. patent application Ser. No. 13/410,528 filed on Mar. 2, 2012 and also claims priority to Japanese Patent Application No. 2012-189836 filed on Aug. 30, 2012, Japanese Patent Application No. 2012-003694 filed on Jan. 12, 2012, Japanese Patent Application No. 2012-003698 filed on Jan. 12, 2012, Japanese Patent Application No. 2012-003653 filed on Jan. 12, 2012 and Japanese Patent Application No. 2012-003652 filed on Jan. 12, 2012 the entire contents of each of which is incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a cartridge, a combination of a cartridge and a printing apparatus (or portion thereof) and/or a printing material supply system including the cartridge and a printing apparatus. 
     BACKGROUND ART 
     Various mechanisms have been proposed for attachment and detachment of a cartridge to a printing apparatus. Examples of such mechanisms are disclosed in U.S. Publication No. 2005/0151811 (which corresponds to JP-A-2007-230249), U.S. Pat. No. 7,008,053 (which corresponds to JP-A-2005-022345), U.S. Pat. No. 6,276,780 (which corresponds to JP-A-2002-019142), U.S. Pat. Nos. 6,955,422, 6,074,042, and U.S. Pat. No. 7,018,030. 
     SUMMARY 
     Technical Problem 
     U.S. Publication No. 2005/0151811 discloses a cartridge with a latching lever 3 and electric contact terminal pads 102. Lever 3 includes an anchoring portion 6 for engaging with the printer. The anchoring portion 6 is disposed far away from the contact pads 102. Because anchoring portion 6 is far away from the cartridge terminals, the engagement with the printer can offer only limited contribution to the accuracy and stability of positioning of the cartridge terminals with respect to the respective printer terminals. 
     In addition, lever 3 in U.S. Publication No. 2005/0151811 needs to be long enough to reach a location accessible by the user so the user can operate it. It also projects far away from the side wall of the cartridge. Such a large lever results in a larger cartridge, which can also result in a large-size printer, in which the cartridge is attached to and detached from, as well as bulky packaging for transportation and distribution of the cartridges, which in turn increases transportation and parts costs. 
     Also, the cartridge structure that connects the anchoring portion 6 to the cartridge-side terminals includes a flexible section of the lever 3. Even though the anchoring portion 6 might be securely engaged with the printer, vibration generated during printing operations can be transmitted through the flexible section of the lever 3 to the cartridge terminals, and so can influence the positioning of the cartridge terminals with respect to the printer terminals. This is particularly a concern for on-carriage type ink cartridges, such as those disclosed of U.S. Publication No. 2005/0151811, because they are mounted on a printer&#39;s carriage, to which the print head is attached. In on-carriage printers, the carriage is scanned back and forth over the print medium during printing operations. The ink cartridges in the carriage undergo great acceleration force with each change in scan direction, in addition to other vibration generated during printing operations. 
     The lever in U.S. Publication No. 2005/0151811 is formed integrally with the cartridge and is elastically deformable. With this configuration, the material used to produce the cartridge is limited to a material with sufficient moldability for making this configuration, and also with sufficient flexibility and durability that is needed for the lever to elastically deform during engagement and disengagement with the printer. 
     The lever might plastically deform under operations by the user. Such plastic deformation of the lever may cause positional misalignment between cartridge-side terminals and printer terminals, which could result in poor electrical communication. Plastic deformation also reduces the durability of the lever. Also, special measures, such as those disclosed in U.S. Pat. No. 7,018,030, must be taken during packaging of the cartridge to prevent creep deformation of the lever while the cartridge is packaged, especially when the cartridge is packaged in a vacuum package. 
     U.S. Pat. No. 6,276,780 discloses a cartridge without any memory or electrical terminals. Because this type of cartridge requires no electrical connection with the printer, there is no need to include structure or configuration for maintaining stable positioning and alignment of cartridge terminals to printer terminals. 
     In addition, the cartridge is attached to the printer by a latch mechanism 132 (in FIGS. 9-16 of U.S. Pat. No. 6,276,780) that is disposed on the printer. Cartridge-side latch ramps 220 that engage the latch mechanism 132 are far away from the pivot axis of the latch mechanism 132, in the direction in which the cartridge is removed from the printer. As a result, when a resilient member 156 or compression force seal 152 applies to the cartridge a force (indicated by arrow X in FIG. 12 U.S. Pat. No. 6,276,780) in the direction in which to the cartridge is removed from the printer, this force can be easily converted into a force that releases engagement of the retainer portion 134 from the cartridge latch ramps 220, so that the cartridge might become separated from the printer during use of the printer. Because the engagement configuration disclosed in U.S. Pat. No. 6,276,780 includes this inherent risk of the cartridge becoming separated from the printer, it is not suitable for use with the configurations disclosed in U.S. Publication No. 2005/0151811, which require proper contact between the cartridge terminals and printer terminals. Moreover, contact between the cartridge and printer terminals in the configurations in U.S. Publication No. 2005/0151811 applies force from the terminals of the printer in lateral direction to the cartridge, so that the cartridge might move in the in lateral direction. The latch mechanism 132 of U.S. Pat. No. 6,276,780 is not suitable for the cartridge of U.S. Publication No. 2005/0151811 at least for the reason that it might not be able to match the lateral direction movement of the cartridge, so that the latch mechanism 132 becomes detached from the cartridge. 
     U.S. Pat. No. 6,074,042 discloses an ink cartridge with electrical contacts 54. As shown in FIGS. 12A to 13B thereof, the electrical contacts 54 are at the leading edge of the direction in which the cartridge is mounted into the printer. With this configuration, when the cartridge is mounted into the printer, the electrical contacts 54 of the cartridge press flat against spring biased electrical contacts 104 of the printer. Metal oxidation, oil, or other non-conductive matter at the outer surface of the metal electrical contacts 54 can become sandwiched between the conductive metal of the cartridge and printer electrical contacts, possibly hindering electrical communication between the cartridge and the printer. 
     U.S. Pat. No. 6,955,422 discloses, for example in FIGS. 2a to 2d thereof, a cartridge 1 that has a memory device 7 with electrodes 7a. The electrodes 7a are aligned substantially parallel to the direction of cartridge insertion into the printer. With this configuration, the printer electrodes 106 slide across the surface of the circuit board (on which the electrodes 7a are formed) for a long distance. The surface of the circuit board is typically covered with an electrically insulating resin material. When the printer electrodes 106 scrape against the circuit board, they can damage this insulation so that fragments of the insulation flake away from the circuit board. The insulation fragments can get caught between the printer electrodes 106 and the cartridge electrodes 7a, and become a cause of poor or otherwise unreliable electrical communication between the printer and the cartridge. 
     As shown in FIGS. 5 to 6B of U.S. Pat. No. 6,955,422, the printer is provided with a leaf spring 103 that exerts an urging force that presses the surface of memory device 7 against the printer electrodes 106 when the cartridge is mounted in the printer, and that moves the cartridge 1 upward when the cartridge is pulled out of the printer. 
     U.S. Pat. No. 7,008,053 discloses in FIG. 5 an elastic piece 40 provided on the printer. When the cartridge is fully mounted in the printer, the lower end 40a of the elastic piece 40 abuts against a flat surface 12a at the upper portion of the projecting portion 12 on which the electrodes 14 are located. The abutment between the lower end 40b and the flat surface 12a restricts upward movement of the projecting portion 12. However, the configuration of U.S. Pat. No. 7,008,053 includes no means located near the projecting portion 12 for restricting downward movement of the projecting portion 12. As a result, projecting portion 12 is fairly free to vibrate vertically during operation of the printer and therefore the electrodes can become misaligned or disconnected from the printer terminals. 
     In the presence of various mechanisms for attachment and detachment, there is a need to reduce the total size of a printer for better usability and ease of installation. For reducing the size of the printer, it is typically necessary to reduce the sizes of a large number of components forming the printer and relevant elements. These components and relevant elements include a cartridge attached to the printer and a cartridge mounting structure for attachment of the cartridge. 
     For improved use of the printer, information regarding the printing material contained in the cartridge (for example, information regarding the remaining amount of the printing material) is often displayed on the monitor of the printer. The cartridge attached to this printer would have a circuit board with a memory for storing the information regarding the printing material. The circuit board has terminals (cartridge-side terminals) used to send and receive information to and from the printer. The information regarding the printing material is transmitted between the memory and a controller of the printer through the contact of these cartridge-side terminals and terminals on the printer (apparatus-side terminals). It is accordingly necessary to maintain stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     As will be described below, there is no known mechanism to meet these requirements in a fully acceptable manner. 
     This problem is not limited to a cartridge containing ink for printing but is also commonly found in any of printing apparatuses and/or cartridges configured to supply or eject various other printing materials (for example, toner) as well as ink. 
     Consequently, there is a need to ensure stable electrical connection between cartridge-side terminals and apparatus-side terminals. There is also a need to attain size reduction of a cartridge, a printer and a printing material supply system including the cartridge attached to the printer. 
     Solution to Problem 
     In order to more suitably achieve at least part of the foregoing, the present invention provides various aspects and embodiments described below. 
     First Aspect: 
     A cartridge detachably attached to a printing apparatus, the printing apparatus comprising a cartridge mounting structure configured to have: (i) a apparatus-side bottom wall member; (ii) a first apparatus-side side wall member, which can be at a front thereof, provided to intersect the apparatus-side bottom wall member; and (iii) a second apparatus-side side wall member, which can be at a rear thereof, provided to intersect the apparatus-side bottom wall member and to be opposed to the first apparatus-side side wall member. The apparatus can include a printing material supply structure, which can be in the form of a tube, structured to have a base end provided on the apparatus-side bottom wall member and a peripheral end to be connected with the cartridge and configured to supply a printing material contained in the cartridge to a head. The cartridge preferable includes a plurality of apparatus-side electrical contact terminals which can be provided in an apparatus-side corner section where the apparatus-side bottom wall member intersects the first (front) apparatus-side side wall member. The cartridge can also include a lever provided on the first (front) apparatus-side side wall member in a rotatable manner to be used for attachment and detachment of the cartridge to and from the printing device. The lever can be oriented such that a Z axis represents an axis parallel to a central axis C of the printing material supply structure/tube, an X axis represents an axis, along which the printing material supply tube and the apparatus-side terminals are arrayed and which is orthogonal to the Z axis, and a Y axis represents an axis orthogonal to both the Z axis and the X axis. A +Z-axis direction represents a direction along the Z axis from the base end to the peripheral end of the printing material supply tube, which can be an upwards direction. A −Z-axis direction represents a reverse direction to the +Z-axis direction. A +X-axis direction represents a direction along the X axis from the printing material supply tube towards the apparatus-side terminals, which can be a frontwards direction. A −X-axis direction represents a reverse direction to the +X-axis direction. A +Y-axis direction represents a direction along the Y axis going to one end, which can be a sideways direction, and −Y-axis direction represents a direction along the Y axis going to the other end. The cartridge can be constructed so that the apparatus-side terminals are in contact with the cartridge to apply a force, which can be a resilient or elastic force, to the cartridge in a specified direction including a +Z-axis direction component in an attached state of the cartridge to the cartridge mounting structure. The lever can have an operating member at the +Z-axis direction end (which can be the top end) and a first apparatus-side restriction element at the −Z-axis direction end (which can be the bottom end) to lock the cartridge and thereby restrict motion of the cartridge in the +Z-axis direction. The lever can be constructed to rotate about a specified position between the operating member and the first apparatus-side restriction element as an axis of rotation, wherein the X axis, the Y axis and the Z axis with respect to the cartridge in the attached state respectively correspond to an X axis, a Y axis and a Z axis of the cartridge. The cartridge can comprise a first face located on the −Z-axis direction side and a second face located on the +Z-axis direction side, as two faces opposed to each other in the Z-axis direction; a third face located on the +X-axis direction side and a fourth face located on the −X-axis direction side, as two faces opposed to each other in the X-axis direction and intersecting the first face and the second face; a corner section arranged to connect the first face with the third face; a sloped surface provided to form part of the corner section and inclined in a specific direction including the +X-axis direction component and the −Z-axis direction component. An ink supply structure can be provided on the first face to be connected with the printing material supply tube. A plurality of cartridge-side terminals can be provided corresponding to the respective apparatus-side terminals and located on the sloped surface to receive a force in a specified direction including the +Z-axis direction component from the apparatus-side terminals. Due to the slope at the area of contact, the force can also have a −X-axis direction component. The cartridge can also include a first cartridge-side restriction element configured to be locked by the first apparatus-side restriction element and thereby restrict motion of the cartridge in the +Z-axis direction. 
     The above configuration can be provided with either or both of two features in the following two embodiments. In one embodiment the added feature is that the first cartridge-side restriction element is provided at a specific position on the third face close to an intersecting part, where the third face intersects the sloped surface, and is located on the −Z-axis direction side of the axis of rotation of the lever. In another embodiment, the cartridge-side terminals comprise a first terminal including a first outer part located at the most +Y-axis direction end; and a second terminal including a second outer part located at the most −Y-axis direction end, wherein the first cartridge-side restriction element is located not outside but inside a range between the first outer part and the second outer part in the Y-axis direction. 
     The cartridge according to a first aspect of the invention has the first cartridge-side restriction element that engages with the lever of the printing device. Because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and greater focus on other properties such as resistance to ink. Thus, different plastics, thermoplastics and resins can be used to make the different components. 
     Also, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. 
     Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing the transportation cost and the parts cost. 
     Because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity compared with the structures described in U.S. Publication No. 2005/0151811. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the apparatus-side terminals and reduces the possibility of poor continuity. In the cartridge of the first aspect, since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This improves the user&#39;s experience and convenience of use. 
     In the cartridge according to the first aspect, the first cartridge-side restriction element is provided on the −Z-axis direction side of the axis of rotation of the lever. Even when the force is applied in the direction including the +Z-axis direction component from the apparatus-side terminals to move the cartridge in the +Z-axis direction, the lever serves to restrict the motion of the cartridge in the +Z-axis direction. This reduces the possibility of the first cartridge-side restriction element becoming unlocked or disengaged from the first apparatus-side restriction element, thus ensuring stable electrical connection between the cartridge-side terminals and the apparatus-side terminals and reducing the possibility of poor continuity. The first apparatus-side restriction element can move about the axis of rotation of the lever with the movement of the cartridge in the −X-axis direction when force in the −X-axis direction is applied from the apparatus-side terminals to the mounted cartridge. This reduces the possibility that the first cartridge-side restriction element is uncoupled from the first apparatus-side restriction element. 
     In the cartridge according to the first aspect, the first cartridge-side restriction element is provided at the specific position on the third face close to the intersecting part. The cartridge can thus be fixed to the cartridge mounting structure at a position near to the contact between the cartridge-side terminals and the apparatus-side terminals. This reduces the possibility of positional misalignment of the cartridge-side terminals relative to the apparatus-side terminals and reduces the poor continuity between the cartridge-side terminals and the apparatus-side terminals. In the event the cartridge falls, the first cartridge-side restriction element prevents the cartridge-side terminals from being directly hit against, for example, the floor surface and thereby helps protect the cartridge-side terminals from being damaged. Especially when the cartridge-side terminals are mounted on the circuit board with a memory unit, this protects the vulnerable memory unit from being damaged and enhances the effect of shock resistance. Providing the first cartridge-side restriction element at the position close to the intersecting part enables the lever of the cartridge mounting structure to be located at the position closer to the first face. This enables size reduction of the cartridge and the printing device in the Z-axis direction. 
     Second Aspect: 
     The cartridge according to the first aspect, wherein the first cartridge-side restriction element is provided at a specific position close to an intersecting part, where the third face intersects the sloped surface. 
     In the cartridge according to the second aspect, the first cartridge-side restriction element is provided at the specific position close to the intersecting part. The cartridge can thus be fixed to the cartridge mounting structure at the position near to the contact between the cartridge-side terminals and the apparatus-side terminals. The first cartridge-side restriction element prevents the positional misalignment of the cartridge-side terminals relative to the apparatus-side terminals. Thus the first cartridge-side restriction element reduces the possibility of poor continuity between the cartridge-side terminals and the apparatus-side terminals. In the event the cartridge falls, the first cartridge-side restriction element reduces the possibility of cartridge-side terminals from being directly hit against, for example, the floor surface and thereby helps protect the cartridge-side terminals from being damaged. Especially when the cartridge-side terminals are mounted on the circuit board with a memory unit, this protects the vulnerable memory unit from being damaged and enhances the effect of shock resistance. When the first cartridge-side restriction element formed as a projection, the effects of shock resistance are further enhanced. Providing the first cartridge-side restriction element at the position close to the intersecting part enables the lever of the cartridge mounting structure to be located at the position closer to the first face. This enables size reduction of the cartridge and the printing device in the Z-axis direction. 
     Third Aspect: 
     The cartridge according to either one of the first aspect and/or second aspect, wherein the first cartridge-side restriction element is provided at a position intersecting a plane (plane Yc), which passes through center of a width or the Y-axis direction length of the cartridge and is parallel to the Z axis and the X axis. 
     When the cartridge is in a mounted condition in the printer, the cartridge receives a force from the printer-side terminal group in a direction that includes a +Z axis direction component, and the first cartridge-side restriction portion is pressed against the first printer-side restriction portion of the lever by this force. By providing the first cartridge-side restriction portion at a location intersected by the plane Yc, the portion of the first cartridge-side restriction portion in the vicinity of the position intersected by the plane Yc would hardly move at all, even if the cartridge were to move about the X axis or Z axis by application of an external force. It should be noted that the first cartridge-side restriction portion is arranged at a position that is near the intersection portion, the edge of the circuit board, or both. By providing the first cartridge-side restriction portion, which hardly moves, at a location extremely near to cartridge-side terminal group, electrical connection between the cartridge-side terminal group and the printer-side terminal group can be stable. 
     Fourth Aspect: 
     The fourth aspect is the embodiment described above where the cartridge-side terminals comprise a first terminal including a first outer part located at the most +Y-axis direction end; and a second terminal including a second outer part located at the most −Y-axis direction end, wherein at least part of the first cartridge-side restriction element is located between the first outer part and the second outer part in the Y-axis direction and as mentioned above can be implemented independent from or together with the above described embodiments of the first aspect addressed above. 
     In the cartridge according to the fourth aspect, at least part of the first cartridge-side restriction element is located between the first outer part and the second outer part. This locates the first cartridge-side restriction element of little motion at the position very close to the cartridge-side terminals, thus ensuring the stable electrical connection between the cartridge-side terminals and the contact mechanism. 
     Fifth Aspect: 
     The cartridge according to the fourth aspect, wherein the first cartridge-side restriction element is located not outside but inside of a range between the first outer part and the second outer part in the Y-axis direction. 
     Some of the printer-side terminals might protrude out farther than the others. In the example shown in  FIG. 31 , the terminal  731  protrudes out further. When the cartridge is mounted within the printer, the cartridge-side terminal group will receive from the printer-side terminal group a force with a +Z axis direction component. If the cartridge is held too securely, then contact with some of the printer-side terminals (terminal  734  in FIG.  31 &#39;s example), might not be proper. By positioning the first cartridge-side restriction portion to completely the inside of the terminals in the widthwise direction, the cartridge can tilt sufficiently to adjust the direction in which the slanted surface faces, so that electrical connection between the cartridge-side terminal group and the printer-side terminal group can be even more stable. These benefits are also relevant to the configurations of the embodiments addressed above. 
     Sixth Aspect: 
     The cartridge according to any one of the first aspect to the fifth aspect, further comprising a second cartridge-side restriction element configured to be locked by a second apparatus-side restriction element provided on the second apparatus-side side wall member and thereby restrict motion of the cartridge in the +Z-axis direction, and the second cartridge-side restriction element is provided on the fourth face. 
     The cartridge according to the sixth aspect has the second cartridge-side restriction element on the fourth face to restrict the motion of the cartridge in the +Z-axis direction, so as to restrict the motion of the cartridge in the +Z-axis direction from both the +X-axis direction end and the −X-axis direction end. This further prevents the positional misalignment of the respective cartridge-side terminals relative to the cartridge mounting structure and further ensures the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Seventh Aspect: 
     The cartridge according to the sixth aspect, wherein the second cartridge-side restriction element is a projection to be inserted in the second apparatus-side restriction element formed as a recess or a through hole. 
     In the cartridge according to the seventh aspect, inserting the second cartridge-side restriction element into the second apparatus-side restriction element provides the pivot point of rotation to turn the cartridge about the vicinity of the second cartridge-side restriction element. This facilitates attachment and detachment of the cartridge to and from the cartridge mounting structure. 
     Eighth Aspect: 
     The cartridge according to any one of the first aspect to the seventh aspect, wherein the first cartridge-side restriction element is located on the −X-axis direction side of the axis of rotation of the lever. 
     In the cartridge according to the eighth aspect, in the attached state, the first cartridge-side restriction element generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the first cartridge-side restriction element is unlocked from the first apparatus-side restriction element and further ensures the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. Even when the cartridge receives the force in the −X-axis direction from the apparatus-side terminals to move in the −X-axis direction, the first apparatus-side restriction element moves in the −X-axis direction with the movement of the cartridge. Such moving reduces the possibility that the first cartridge-side restriction element becomes unlocked from the first apparatus-side restriction element. 
     Ninth Aspect: 
     The cartridge according to the eighth aspect, wherein the first cartridge-side restriction element has a first abutting part that abuts a first portion of the first apparatus-side restriction element to restrict motion of the cartridge in the +Z-axis direction, and a second abutting part that abuts a second portion of the first apparatus-side restriction element to restrict motion of the cartridge in the +X-axis direction. 
     In the cartridge according to the ninth aspect, the first cartridge-side restriction element has the first abutting part and the second abutting part and thus ensures generation of the rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This further reduces the possibility that the first cartridge-side restriction element is unlocked from the first apparatus-side restriction element and more effectively prevents the poor continuity between the cartridge-side terminals and the apparatus-side terminals. 
     Tenth Aspect: 
     The cartridge according to any one of the first aspect to the ninth aspect, further comprising a projection configured to abut the operating member of the lever and receive a force including the +Z-axis direction component during detachment of the cartridge attached to the cartridge mounting structure from the cartridge mounting structure, and the projection is provided on the +Z-axis direction side of the first cartridge-side restriction element on the third face. 
     The cartridge according to the tenth aspect further has the projection. The cartridge can be readily removed from the cartridge mounting structure by using the operating member of the lever and the projection. 
     Eleventh Aspect: 
     The cartridge according to any one of the first aspect to the tenth aspect, wherein the corner section has a step extended from the first face in the +Z-axis direction, the step is located on the −X-axis direction side and the −Z-axis direction side of the sloped surface, and the step has a third cartridge-side restriction element that is in contact with a third apparatus-side restriction element provided on the cartridge mounting structure, so as to restrict motion of the cartridge in the Y-axis direction. 
     In the cartridge according to the eleventh aspect, the third cartridge-side restriction element to restrict the motion of the cartridge in the Y-axis direction is provided in the corner section with the cartridge-side terminals. This restricts the motion of the third face-side of the cartridge in the Y-axis direction in the attached state of the cartridge. 
     Twelfth Aspect: 
     The cartridge according to the eleventh aspect, wherein the third cartridge-side restriction element comprises a pair of projection members configured to receive the third apparatus-side restriction element protruded from the apparatus-side bottom wall member in the +Z-axis direction, and the pair of projection members are protruded from the step in the +X-axis direction. 
     In the cartridge according to the twelfth aspect, the simple structure of providing the pair of projection members protruded in the +X-axis direction from the step effectively restricts the motion of the third face-side of the cartridge in the Y-axis direction in the attached state of the cartridge. 
     Thirteenth Aspect: 
     The cartridge according to either one of the eleventh aspect and the twelfth aspect, wherein part of the third cartridge-side restriction element overlaps the sloped surface, when the cartridge is viewed from the first face side in the +Z-axis direction. 
     In the cartridge according to the thirteenth aspect, the third cartridge-side restriction element and the sloped surface are located to partly overlap with each other. This further restricts the motion of the third face-side of the cartridge in the Y-axis direction about the printing material supply tube. 
     Fourteenth Aspect: 
     The cartridge according to any one of the first aspect to the thirteenth aspect, wherein the ink supply structure is provided at a specific position on the first face closer to the fourth face than the third face. 
     The cartridge according to the fourteenth aspect has the ink supply structure located closer to the fourth face than the third face. This structure lowers the possibility of adhesion of the printing material on the cartridge-side terminals, compared with the structure where the ink supply structure is located closer to the third face than the fourth face. This reduces the poor continuity between the cartridge-side terminals and the apparatus-side terminals. 
     Fifteenth Aspect: 
     The cartridge according to any one of the first aspect to the fourteenth aspect, wherein the first cartridge-side restriction element is a projection. 
     The cartridge according to the fifteenth aspect provides the first cartridge-side restriction element as a projection which can be of a small size and simple structure. 
     Sixteenth Aspect: 
     The cartridge according to any one of the first aspect to the fifteenth aspect, wherein the cartridge-side terminals include a cartridge-side ground terminal that is in contact with a apparatus-side ground terminal of the apparatus-side terminals, which is connected with a ground line, and the cartridge-side ground terminal is provided on center of the width or the Y-axis direction length of the cartridge and is configured to be in contact with the apparatus-side ground terminal before any other cartridge-side terminal is in contact with a corresponding apparatus-side terminal in the course of attachment of the cartridge to the cartridge mounting structure. 
     In the cartridge according to the sixteenth aspect, the force first applied from the cartridge mounting structure to the cartridge-side terminals is generated on the substantial center of the width or the Y-axis direction length of the cartridge. This prevents the force applied to the cartridge-side terminals from acting to tilt the cartridge in the Y-axis direction, thus ensuring stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. The cartridge-side ground terminals are in contact with the corresponding apparatus-side ground terminals, prior to the contact of the other cartridge-side terminals with the corresponding apparatus-side terminals. The grounding function of the cartridge-side ground terminal advantageously prevents or reduces the high voltage-induced troubles and failures, even when an unexpected high voltage is applied to the cartridge. 
     Seventeenth Aspect: 
     The cartridge according to the sixteenth aspect, wherein a Z-axis direction length of the cartridge-side ground terminal is longer than the Z-axis direction length of the other cartridge-side terminal. 
     The cartridge according to the seventeenth aspect ensures the contact between the cartridge-side ground terminal and the apparatus-side ground terminal. 
     Eighteenth Aspect: 
     A cartridge detachably attached to a printing device, the printing device comprising a cartridge mounting structure configured to allow attachment and detachment of the cartridge; a printing material supply tube structured to have a base end provided on a bottom of the cartridge mounting structure and a peripheral end to be connected with the cartridge and configured to supply a printing material contained in the cartridge to a head; a plurality of apparatus-side terminals provided to be in contact with the cartridge; and a lever provided to be used for attachment and detachment of the cartridge, wherein a Z axis represents an axis parallel to a central axis C of the printing material supply tube, an X axis represents an axis, along which the printing material supply tube and the apparatus-side terminals are arrayed and which is orthogonal to the Z axis, and a Y axis represents an axis orthogonal to both the Z axis and the X axis, wherein a +Z-axis direction represents a direction along the Z axis going from the base end to the peripheral end of the printing material supply tube, a −Z-axis direction represents a reverse direction to the +Z-axis direction, a +X-axis direction represents a direction along the X axis going from the printing material supply tube to the apparatus-side terminals, a −X-axis direction represents a reverse direction to the +X-axis direction, a +Y-axis direction represents a direction along the Y axis going to one end, and −Y-axis direction represents a direction along the Y axis going to the other end, wherein the apparatus-side terminals are in contact with the cartridge to apply a force to the cartridge in a specified direction including the +Z-axis direction component in an attached state of the cartridge to the cartridge mounting structure, and the lever has an operating member at the +Z-axis direction end and a first apparatus-side restriction element at the −Z-axis direction end to lock the cartridge and thereby restrict motion of the cartridge in the +Z-axis direction, the lever rotating about a specified position between the operating member and the first apparatus-side restriction element as an axis of rotation, wherein the X axis, the Y axis and the Z axis with respect to the cartridge in the attached state respectively correspond to an X axis, a Y axis and a Z axis of the cartridge. The cartridge comprises an ink supply structure located at the −Z-axis direction end of the cartridge to be connected with the printing material supply tube; a circuit board located on the +X-axis direction side of the ink supply structure and has a surface inclined in a specified direction including the +X-axis direction component and the −Z-axis direction component; a plurality of cartridge-side terminals provided corresponding to the respective apparatus-side terminals and located on the surface of the circuit board to receive a force in a specified direction including the +Z-axis direction component from the apparatus-side terminals; and a first cartridge-side restriction element configured to be locked by the first apparatus-side restriction element and thereby restrict motion of the cartridge in the +Z-axis direction and located on the +X-axis direction side of the printing material supply port, 
     The above configuration can be provided with either or both of the features in the following two embodiments. In one embodiment the added feature is that the first cartridge-side restriction element is provided at a specific position close to a board end and is located on the −Z-axis direction side of the axis of rotation of the lever, the board end being located on the +Z-axis direction side of the surface of the circuit board. In another embodiment, the cartridge-side terminals comprise a first terminal including a first outer part located at the most +Y-axis direction end; and a second terminal including a second outer part located at the most −Y-axis direction end, wherein the first cartridge-side restriction element is located not outside but inside a range between the first outer part and the second outer part in the Y-axis direction. 
     The cartridge according to the eighteenth aspect has the first cartridge-side restriction element locked by the lever of the printing device. The first cartridge-side restriction element is located on the −Z-axis direction side of the axis of rotation of the lever. This structure does not require any engagement member between the axis of rotation and the operating member of the lever like the cartridge according to the first aspect described above and has the similar advantageous effects to those of the cartridge according to the first aspect. For example, the cartridge according to the eighteenth aspect shortens the distance between the lever and the cartridge, thus allowing size reduction in the X-axis direction of the printing device and the whole printing material supply system including the cartridge and the printing device. 
     In the cartridge according to the eighteenth aspect, the first cartridge-side restriction element is provided on the −Z-axis direction side of the axis of rotation of the lever. This enables restriction of the motion of the cartridge in the +Z-axis direction by the lever like the cartridge according to the first aspect and has the similar advantageous effects to those of the cartridge according to the first aspect. For example, this ensures a more stable electrical connection between the cartridge-side terminals and the apparatus-side terminals and reduces the poor continuity. 
     According to the embodiment where the cartridge-side terminals comprise a first terminal including a first outer part located at the most +Y-axis direction end; and a second terminal including a second outer part located at the most −Y-axis direction end, wherein the first cartridge-side restriction element is located not outside but inside a range between the first outer part and the second outer part in the Y-axis direction, the first cartridge-side restriction element is located not outside but inside the range between the first outer part and the second outer part. This enables fine adjustment of the direction of the sloped surface with the cartridge-side terminals provided thereon, like the cartridge according to the first embodiment. Even when the position of each of the apparatus-side terminals or the slope of the first cartridge-side restriction element varies due to the manufacturing error, such fine adjustment of the direction of the sloped surface ensures the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     According to the embodiment where the first cartridge-side restriction element is provided at a specific position close to a board end and is located on the −Z-axis direction side of the axis of rotation of the lever, the board end being located on the +Z-axis direction side of the surface of the circuit board, the first cartridge-side restriction element is provided at the position close to the board end located on the +Z-axis direction side. In other words, the first cartridge-side restriction element is arranged as close as possible to the cartridge-side terminals. Since the first cartridge-side restriction element is locked by the lever, the periphery of the first cartridge-side restriction element has substantially no position shift by application of an external force to the cartridge. Providing the cartridge-side terminals at the location of extremely small position shift effectively prevents the positional misalignment of the respective cartridge-side terminals relative to the cartridge mounting structure, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Nineteenth Aspect: 
     A printing material supply system, comprising a printing device; and the cartridge according to any one of the first aspect to the eighteenth aspect, the printing device comprising a cartridge mounting structure configured to have: (i) a apparatus-side bottom wall member; (ii) a first apparatus-side side wall member provided to intersect the apparatus-side bottom wall member; and (iii) a second apparatus-side side wall member provided to intersect the apparatus-side bottom wall member and to be opposed to the first apparatus-side side wall member; a printing material supply tube structured to have a base end provided on the apparatus-side bottom wall member and a peripheral end to be connected with the cartridge and configured to supply a printing material contained in the cartridge to a head; a plurality of apparatus-side terminals provided in a apparatus-side corner section where the apparatus-side bottom wall member intersects the first apparatus-side side wall member; and a lever provided on the first apparatus-side side wall member in a rotatable manner to be used for attachment and detachment of the cartridge to and from the printing apparatus, wherein a Z axis represents an axis parallel to a central axis C of the printing material supply tube, an X axis represents an axis, along which the printing material supply tube and the apparatus-side terminals are arrayed and which is orthogonal to the Z axis, and a Y axis represents an axis orthogonal to both the Z axis and the X axis, wherein a +Z-axis direction represents a direction along the Z axis going from the base end to the peripheral end of the printing material supply tube, a −Z-axis direction represents a reverse direction to the +Z-axis direction, a +X-axis direction represents a direction along the X axis going from the printing material supply tube to the apparatus-side terminals, a −X-axis direction represents a reverse direction to the +X-axis direction, a +Y-axis direction represents a direction along the Y axis going to one end, and −Y-axis direction represents a direction along the Y axis going to the other end, wherein the apparatus-side terminals are in contact with the cartridge to apply a force to the cartridge in a specified direction including the +Z-axis direction component in an attached state of the cartridge to the cartridge mounting structure, and the lever has an operating member at the +Z-axis direction end and a first apparatus-side restriction element at the −Z-axis direction end to lock the cartridge and thereby restrict motion of the cartridge in the +Z-axis direction, the lever rotating about a specified position between the operating member and the first apparatus-side restriction element as an axis of rotation. 
     The printing material supply system according to the nineteenth aspect includes the cartridge in accordance with any one of the first aspect to the eighteenth aspect, so as to allow size reduction of the printing material supply system in both the X-axis direction and the Z-axis direction and reduce the possibility that the first apparatus-side restriction element is unlocked from the first cartridge-side restriction element. This ensures the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals and reduces the poor continuity. 
     As can be appreciated by one of ordinary skill in the art, the embodiments of the present invention are directed to an ink cartridge, combinations of an ink cartridge with a printing apparatus, or a portion of a printing apparatus, where the ink cartridge is installed on the apparatus and systems adapted to supply ink to a printing apparatus where the system includes the printing apparatus (or portions thereof) and/or where the system does not include the printing apparatus. 
     In one embodiment of the invention, an ink cartridge adapted to be detachably mounted on an ink jet printing apparatus is disclosed wherein the ink jet printing apparatus on which the ink cartridge is mounted includes a lever having an engagement portion. The printing apparatus preferably includes a plurality of apparatus-side contact forming members that are constructed and arranged to apply elastic force to the ink cartridge when the ink cartridge is pressed against the apparatus-side contact forming members after the cartridge is mounted on the printing apparatus. The ink cartridge preferably includes a cartridge body including a front or first surface, a rear or second surface, a top or third surface and a bottom or fourth surface, the front or first surface and rear or second surface are opposite each other and the top or third surface and bottom or fourth surface are opposite each other. The ink cartridge includes an ink chamber for storing ink. The ink cartridge also preferably includes an electrical device. The ink cartridge also includes an ink supply structure positioned at the bottom or fourth surface of the cartridge body having a mounting direction leading edge defining a plane of the ink cartridge where the ink supply structure is adapted and configured to supply ink from the ink chamber to the ink jet printing apparatus. The ink cartridge can also include a terminal bearing structure located proximate to the front or first surface of the cartridge body, the terminal bearing structure having a plurality of electrically conductive terminals coupled to the electrical device therein. The terminals are adapted and arranged on the terminal bearing structure to make contact with and receive elastic force from the contact forming members when the ink cartridge is mounted on the printing apparatus. The terminals are arranged substantially in a terminal plane which is neither parallel nor perpendicular to the plane defined by the leading edge. The ink cartridge preferably includes a first restriction portion that includes an engagement portion adapted to engage with the engagement portion of the lever so as to restrict movement of the ink cartridge in a direction opposite the mounting direction. The engagement portion of the first restriction portion is preferably located adjacent the terminal bearing structure. 
     In one embodiment, the terminal plane is at an angle of about 20 and 50 degrees, preferably from about 25 and 40 degrees to the plane defined by the leading edge. 
     The interaction at the terminal bearing structure to the printing apparatus is important for proper mounting of the cartridge. As described herein, by mating at an angle, the cartridge can receive both upwards and rearward forces. These forces help hold the cartridge in place. 
     In one embodiment, when the front or first surface of the cartridge body is viewed with the ink supply structure facing down, the engagement portion of the first restriction portion is located to the left of a right edge of a rightmost terminal of the plurality of terminals and to the right of a left edge of a leftmost terminal of the plurality of terminals. 
     In one embodiment, the terminals are adapted and arranged on the terminal bearing structure to make contact with and receive elastic force from the contact forming members at contact portions of the terminals. The contact portions are arranged substantially in a contact portion plane. In this embodiment when the front or first surface of the cartridge body is viewed with the ink supply structure facing down, the engagement portion of the first restriction portion can be located to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals. In one embodiment, the contact portion plane is at an angle of between about 25 and 40 degrees to the plane defined by the leading edge. 
     In one embodiment, the ink cartridge further includes a second restriction portion on the rear or second surface of the ink cartridge. The second restriction portion preferably includes an engagement portion adapted and configured to engage with a respective portion of the ink jet printing apparatus. In this embodiment, the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     In one embodiment, when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. The lever may also have two ends where the pivot point is intermediate the two ends. 
     In one embodiment when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the engagement portion of the first restriction portion is to the left of a pivot point of the lever when the cartridge is mounted. 
     In one embodiment when the front or first surface of the cartridge body is viewed with the ink supply structure facing down, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge. 
     In a preferred embodiment, the plane defined by the leading edge is below the bottom or fourth surface. In other embodiments, it is substantially flush with the bottom. In still other embodiments it can be recessed above the bottom surface. 
     In one embodiment an ink supply system adapted to supply ink to an ink jet printing apparatus is disclosed where the ink jet printing apparatus includes a plurality of apparatus-side contact forming members. The ink supply system preferably includes an ink chamber for storing ink and an ink supply structure, adapted and configured to supply ink from the ink chamber to the ink jet printing apparatus. The ink supply structure has a mounting direction leading edge defining a plane. The ink supply system preferably includes an electrical device. The ink supply system can also include a terminal bearing structure having a plurality of electrically conductive terminals, the terminals adapted and arranged on the terminal bearing structure to make contact with and receive elastic force from the contact forming members at contact portions of the terminals when the ink supply system supplies ink to the printing apparatus. The ink supply system can also include a first restriction portion including an engagement portion adapted to engage with the engagement portion of a lever on the printing apparatus so as to restrict movement of the terminal bearing structure and terminals thereon in a direction opposite the mounting direction. The engagement portion of the first restriction portion is preferably positioned adjacent the terminal bearing structure. The terminals can be arranged substantially in a terminal plane which is neither parallel nor perpendicular to the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus. Alternatively, the terminal bearing structure determines the plane and/or the plane is defined by the terminals in contact with the respective structure on the printing apparatus. 
     In one embodiment of the system, the terminal plane is at an angle of between about 20 and 50 degrees, preferably from about 25 and 40 degrees to the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus. 
     In one embodiment of the system, when the ink supply system is in place to supply ink to the printing apparatus, the engagement portion of the first restriction portion is located to the left of a right edge of a rightmost terminal of the plurality of terminals and to the right of a left edge of a leftmost terminal of the plurality of terminals. 
     In one embodiment of the system, the terminals are adapted and arranged on the terminal bearing structure to make contact with and receive elastic force from the contact forming members at contact portions of the terminals. The contact portions are arranged substantially in a contact portion plane. When the ink supply system is in place to supply ink to the printing apparatus, the engagement portion of the first restriction portion can be located to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals. The contact portions can define a plane at an angle over 0 degrees and less than 90 degrees so the plane defined by the leading edge. This plane defined by the contact portions is preferably to the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus. 
     In one embodiment, the ink supply system also includes a body that includes a front or first surface, and a rear or second surface, the front or first surface and rear or second surface opposite each other. The ink supply system can also include a restriction portion proximate to the rear or second surface of the body, referred to as the second restriction portion, the terminal bearing structure proximate to the front or first surface of the body. The second restriction portion can include an engagement portion adapted and configured to engage with a respective portion of the ink jet printing apparatus. The distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     In one embodiment, the second restriction portion can be proximate to the rear or second surface of the body, the terminal bearing structure proximate to the first surface or front of the body, the second restriction portion including an engagement portion adapted and configured to engage with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     In one embodiment, the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     In one embodiment, when the ink supply system supplies ink to the printing apparatus, the engagement portion of the first restriction portion is on the right and the ink supply structure is facing down, the engagement portion of the first restriction portion is to the left of a pivot point of the lever. 
     In one embodiment the ink supply system includes a body proximate the terminal bearing structure and when the ink supply system supplies ink to the printing apparatus, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the body. 
     In one embodiment, the ink supply system can include an adapter where the ink supply structure, the terminal bearing structure and the first restriction portion are positioned on the adapter and the ink chamber is adapted and configured to be mated with the adapter. In another embodiment, the system can include an adapter where the terminal bearing structure and the first restriction portion are positioned on the adapter, the ink supply structure is positioned on the ink chamber and the ink chamber is adapted and configured to be mated with the adapter. Alternatively, the system can include an adapter, an ink tank external from the ink jet printing apparatus, a tube and an auxiliary adapter where the ink supply structure is positioned on the auxiliary adapter, the terminal bearing structure and the first restriction portion are positioned on the adapter and the tube supplies ink from the external tank to the auxiliary adapter when the ink supply system supplies ink to the printing apparatus. 
     In one embodiment, the ink supply system includes a body that includes a top and a bottom, the top and bottom being opposite each other, where the plane defined by the leading edge is substantially flush with the bottom. 
     The present invention is not limited to the cartridge, the combination of the ink cartridge with the printing apparatus or the printing material supply system described above but may be implemented by diversity of other aspects, for example, a liquid cartridge, a liquid container, a printing material container, a cartridge adapter, a circuit board, a printing apparatus, a liquid ejection apparatus, and a liquid supply system including a liquid ejection apparatus and a liquid cartridge. The invention is not limited to the above aspects, but a multiplicity of variations and modifications may be made to these aspects without departing from the scope of the invention. When addressing a combination of an ink cartridge with a printing apparatus and/or an ink jet printing apparatus it should be understood that the ink cartridge is installed attached or mounted on the printing apparatus. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The foregoing summary, as well as the following description of embodiments, will be better understood when read in conjunction with the appended drawings wherein like reference numerals refer to like components. For the purposes of illustrating the apparatus of the present application, there is shown in the drawings certain embodiments. It should be understood, however, that the application is not limited to the precise arrangement, structures, features, embodiments, aspects, and apparatuses shown, and the arrangements, structures, features, embodiments, aspects and apparatuses shown may be used singularly or in combination with other arrangements, structures, features, embodiments, aspects and apparatuses. 
       The drawings are not necessarily drawn to scale and are not in any way intended to limit the scope of this invention, but merely to clarify a single illustrated embodiment of the invention. In the drawings: 
         FIG. 1  is a perspective view illustrating the configuration of a printing material supply system; 
         FIG. 2  is a perspective view illustrating a holder with a cartridge attached thereto; 
         FIG. 3  is a perspective view illustrating a holder with a cartridge attached thereto; 
         FIG. 4  is a top view illustrating a holder with a cartridge attached thereto; 
         FIG. 5  is a sectional view taken on line F 4 -F 4  in  FIG. 4 ; 
         FIG. 5A  is a sectional view illustrating a holder with a cartridge attached thereto; 
         FIG. 6A  shows how the force is applied from the cartridge to a lever; 
         FIG. 6B  shows how the force is applied from the cartridge to a lever; 
         FIG. 7  is a perspective view illustrating the structure of the cartridge; 
         FIG. 8  is a bottom view of the cartridge; 
         FIG. 9  is a sectional view, taken on line F 8 -F 8  in  FIG. 8 ; 
         FIG. 9A  shows a view of the cartridge and the lever when the cartridge is in its mounted position; 
         FIG. 10A  illustrates the detailed structure of a circuit board; 
         FIG. 10B  illustrates the detailed structure of a circuit board; 
         FIG. 11  is a rear view of the cartridge; 
         FIG. 12  is a front view of the cartridge; 
         FIG. 13  is a left side view of the cartridge; 
         FIG. 14  is a perspective view illustrating the structure of the holder; 
         FIG. 15  is a perspective view illustrating the structure of the holder; 
         FIG. 16  is a top view illustrating the structure of the holder; 
         FIG. 17  is a sectional view, taken on line F 16 -F 16  in  FIG. 16 ; 
         FIG. 18  is a perspective view of a contact mechanism; 
         FIG. 19  is a perspective view illustrating the appearance of a lever; 
         FIG. 20  illustrates a cross section of a shaft body of the lever taken on a plane parallel to the X axis and the Z axis; 
         FIG. 21  is a sectional view of the lever; 
         FIG. 22  is an exploded perspective view of a retainer and a perspective view of the lever; 
         FIG. 23  is a sectional view showing the structure of the periphery of the lever in an attached state of the cartridge to the holder; 
         FIG. 24  shows the procedure for attachment of the cartridge to the holder; 
         FIG. 25  shows the procedure for attachment of the cartridge to the holder; 
         FIG. 26  shows the procedure for attachment of the cartridge to the holder; 
         FIG. 27  shows the procedure for attachment of the cartridge to the holder; 
         FIG. 27A  is a close-up view of the cartridge attached to the holder; 
         FIG. 27B  is a close-up view of the cartridge attached to the holder; 
         FIG. 28  is a block diagram illustrating the electrical structure; 
         FIG. 29  illustrates the connection between the circuit board and an attachment detection circuit; 
         FIG. 30  shows the external force applied to the cartridge in the attached state; 
         FIG. 31  shows fine adjustment of the direction of a sloped surface; 
         FIG. 32A  shows one example of advantageous effect; 
         FIG. 32B  shows one example of advantageous effect; 
         FIG. 32C  shows one example of advantageous effect; 
         FIG. 32D  shows one example of advantageous effect; 
         FIG. 32E  shows one example of advantageous effect; 
         FIG. 32F  shows one example of advantageous effect; 
         FIG. 33  illustrates a printer according to a second embodiment; 
         FIG. 34  is a perspective view illustrating the appearance of a cartridge according to a third embodiment; 
         FIG. 35A  is conceptual diagram showing cartridge outer shape according to other embodiment; 
         FIG. 35B  is conceptual diagram showing cartridge outer shape according to other embodiment; 
         FIG. 35C  is conceptual diagram showing cartridge outer shape according to other embodiment; 
         FIG. 35D  is conceptual diagram showing cartridge outer shape according to other embodiment; 
         FIG. 35E  is conceptual diagram showing cartridge outer shape according to other embodiment; 
         FIG. 35F  is conceptual diagram showing cartridge outer shape according to other embodiment; 
         FIG. 35G  is conceptual diagram showing cartridge outer shape according to other embodiment; 
         FIG. 35H  is conceptual diagram showing cartridge outer shape according to other embodiment; 
         FIG. 35I  is a conceptual diagram showing a cartridge that has elongated terminals; 
         FIG. 35J  is a conceptual diagram showing a cartridge that has a contact mechanism disposed to the outside of the circuit board; 
         FIG. 36  is a perspective view illustrating the structure of a cartridge with an adapter according to one embodiment; 
         FIG. 37  is a perspective view illustrating the structure of a cartridge with an adapter according to another embodiment; 
         FIG. 37B  is a perspective view showing a cartridge composed of an adapter and a container assembly; 
         FIG. 38  is a perspective view illustrating the structure of a cartridge with an adapter according to another embodiment; 
         FIG. 39A  illustrates the structure of a lever according to one modification; 
         FIG. 39B  illustrates the structure of a lever according to one modification; 
         FIG. 40  illustrates attachment of the cartridge to a holder according to one modification; 
         FIG. 41A  shows modifications of the terminal shape; 
         FIG. 41B  shows modifications of the terminal shape; 
         FIG. 41C  shows modifications of the terminal shape; 
         FIG. 42A  is a graph showing a relation of wiping amount of a board terminal to a board inclination angle phi. 
         FIG. 42B  shows the wiping amount of a board terminal; 
         FIG. 43A  is a graph showing a relation of upward force by an apparatus-side ground terminal to a board inclination angle phi; 
         FIG. 43B  shows the upward force by the apparatus-side ground terminal; 
         FIG. 44  is a graph showing another relation of wiping amount of the board terminal to a board inclination angle phi; and 
         FIG. 45  is a graph showing another relation of upward force by the apparatus-side ground terminal to a board inclination angle phi. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In order to further clarify the configurations and the operations of the invention, some embodiments of the invention are described below with reference to the accompanied drawings. 
     First Embodiment 
     General Configuration of Printing Material Supply System 
       FIG. 1  is a perspective view illustrating the configuration of a printing material supply system  10 . XYZ axes orthogonal to one another are shown in  FIG. 1 . The XYZ axes in  FIG. 1  correspond to the XYZ axes in the other drawings. In the subsequent drawings, the XYZ axes are shown when needed. The printing material supply system  10  includes cartridges  20  and a printer  50  serving as a printing apparatus. In the printing material supply system  10 , the cartridges  20  are removably attached to a holder  60  of the printer  50  by the user. 
     Each of the cartridges  20  in the printing material supply system  10  contains ink as a printing material. The ink as the printing material contained in the cartridge  20  is supplied through an ink supply structure and a printing material supply tube (described later) to a head  540 . According to this embodiment, a plurality of the cartridges  20  are removably attached to the holder  60  of the printer  50 . More specifically, six cartridges  20  respectively containing six different color inks (i.e., black, yellow, magenta, light magenta, cyan and light cyan) are attached to the holder  60 . It will be appreciated by one of ordinary skill in the art that, although the description herein references ink, any substance that can be used for printing is envisaged to be usable as described in more detail below in connection with the disclosed cartridge, combination and/or supply system and the invention should not be limited thereby. 
     According to other embodiments, the number of cartridges attached to the holder  60  is not limited to six but may be greater than six or less than six. According to other embodiments, the number of different color inks is not limited to six colors but may be greater than six colors or less than six colors. According to other embodiments, two or more cartridges  20  attached to the holder  60  may contain one identical color ink. The detailed structures of the cartridge  20  and the holder  60  will be described later. 
     The printer  50  of the printing material supply system  10  shown in  FIG. 1  is a compact inkjet printer for personal use. The printer  50  has a controller  510  and a carriage  520  including the holder  60 , in addition to the holder  60 . The carriage  520  also includes the head  540 . The printer  50  supplies ink from the cartridge  20  attached to the holder  60  through the printing material supply tube (described later) to the head  540  and ejects ink from the head  540  onto a printing medium  90 , such as printing sheet or label, so as to print various data, such as character strings, figures and images, on the printing medium  90 . Although described in terms of an ink jet printer, one of ordinary skill in the art will appreciate the applicability of the invention to other printer types and printing material supply systems as described in more detail below and the invention should not be limited thereby. 
     The controller  510  of the printer  50  serves to control the operations of the respective parts of the printer  50 . The carriage  520  of the printer  50  is configured to scan the head  540  reciprocally across the printing medium  90 . The head  540  of the printer  50  has an ink ejection mechanism configured to eject ink from the cartridge  20  attached to the holder  60  onto the printing medium  90 . The controller  510  and the carriage  520  are electrically connected via a flexible cable  517 . The ink ejection mechanism of the head  540  is operated by control signals from the controller  510 . 
     According to this embodiment, the carriage  520  has the head  540  and the holder  60 . This type of the printer  50  having the cartridges  20  attached to the holder  60  on the carriage  520  serving to move the head  540  is called “on-carriage type” printer. According to another embodiment, a stationary holder  60  may be provided at a different position from the carriage  520 , and ink may be supplied from each of the cartridges  20  attached to the stationary holder  60  to the head  540  of the carriage  520  through a flexible tube. This type of the printer is called “off-carriage type” printer. 
     According to this embodiment, the printer  50  has a main scan feed mechanism and a sub-scan feed mechanism to move the carriage  520  and the printing medium  90  relative to each other and implement printing on the printing medium  90 . The main scan feed mechanism of the printer  50  includes a carriage motor  522  and a drive belt  524  and serves to transfer the power of the carriage motor  520  to the carriage  520  by means of the drive belt  520 , so as to move the carriage  520  back and forth in a main scanning direction. The sub-scan feed mechanism of the printer  50  includes a feed motor  532  and a platen  534  and serves to transfer the power of the feed motor  532  to the platen  534 , so as to feed the printing medium  90  in a sub-scanning direction orthogonal to the main scanning direction. The carriage motor  522  of the main scan feed mechanism and the feed motor  532  of the sub-scan feed mechanism are operated by control signals from the controller  510 . 
     According to this embodiment, when the printing material supply system  10  is in the orientation typical for use, the X axis represents the axis along the sub-scanning direction (front-rear direction), in which the printing medium  90  is fed. The Y axis represents the axis along the main scanning direction (left-right or side-to-side direction when the system  10  is viewed from the front), in which the carriage  520  is moved back and forth. The Z axis represents the axis in the direction of gravity (vertical direction). The use state of the printing material supply system  10  means the state of the printing material supply system  10  placed on a horizontal plane. In this embodiment, the horizontal plane is a plane parallel to the X axis and the Y axis, i.e., XY plane. 
     According to this embodiment, the +X-axis direction represents the sub-scanning direction (forward direction), the −X-axis direction represents its reverse direction (backward direction) the +Z-axis direction represents the direction going from the bottom to the top of the printing material supply system  10  in the direction opposite to the direction of gravity (upward direction), and the −Z-axis direction represents the reverse to the +Z axis direction, that is, the direction of gravity (downward direction). In this embodiment, the +X-axis direction side (front side) is the front face of the printing material supply system  10 . According to this embodiment, the +Y-axis direction represents the direction going from the right side face to the left side face of the printing material supply system  10  (leftward direction), and the −Y-axis direction represents its reverse direction (rightward direction). In this embodiment, the plurality of cartridges  20  attached to the holder  60  are arrayed in the direction along the Y axis (left-right or side-to-side direction) called the “Y-axis direction”. Similarly the direction along the X axis (front-rear direction) and the direction along the Z axis (vertical direction) are called the “X-axis direction” and the “Z-axis direction”. 
     Structure for Attachment of Cartridge  20  to Holder  60   
       FIGS. 2 and 3  are perspective views illustrating the holder  60  with the cartridge  20  attached thereto.  FIG. 4  is a top view illustrating the holder  60  holder  60  with the cartridge  20  attached thereto. In the state illustrated in  FIGS. 2 to 4 , one cartridge  20  is properly attached at a designed attachment position of the holder  60 . The state of “properly attached at a designed attachment position” and a “mounted” position means that the cartridge  20  is attached, or said differently, mounted, such that cartridge-side terminals are located at positions respectively in contact with corresponding apparatus-side terminals included in a contact mechanism of the printer  50  (described later). 
     As shown in  FIGS. 2 and 3 , the holder  60  of the printer  50  has five wall members  601 ,  603 ,  604 ,  605  and  606 . A recess formed by these five wall members serves as a cartridge chamber or cartridge mounting structure  602 . The cartridge chamber  602  is parted by partition walls  607  into a plurality of slots (mounting spaces) to receive the respective cartridges  20 . The partition walls  607  serve as guides to insert the cartridges  20  into the respective slots, but may be omitted as appropriate. Each slot has a printing material supply tube  640 , a contact mechanism  70 , a lever  80 , a second apparatus-side restriction element  620  and a projection  636  serving as a third apparatus-side restriction element. One side face (+Z-axis direction side face, top face) of each slot is open, and the cartridge  20  is attached to and detached from the holder  60  via this open side face (open top face). 
     The cartridge  20  is attached to the holder  60  in such a state that the cartridge  20  is locked by the lever  80  and the second apparatus-side restriction element  620  and that the ink supply structure (described later) is connected with the printing material supply tube  640 . This state is called “attached state of the cartridge  20  to the holder  60 ” simply “attached” state or alternatively “mounted” state. Connecting the printing material supply tube  640  with the ink supply structure of the cartridge  20  enables ink as the printing material contained in the cartridge  20  to be supplied to the head  540  ( FIG. 1 ). The printing material supply tube  640  has a peripheral end  642  (also called “connection end”) located on the +Z-axis direction side and a base end  645  located on the −Z-axis direction side. The base end  645  is provided on the bottom wall member  601 , and the peripheral end  642  is connected with the ink supply structure of the cartridge  20 . The printing material supply tube  640  has a central axis C parallel to the Z axis. The direction going from the base end  645  to the peripheral end  642  along the central axis C is the +Z-axis direction. 
     As shown in  FIG. 2 , an elastic member  648  is provided around the printing material supply tube  640  to seal the periphery of the ink supply structure of the cartridge  20  in the attached state, so as to prevent leakage of ink from the ink supply structure to the periphery. In the attached state, the elastic member  648  applies a pressing force including a +Z-axis direction component to the cartridge  20 . 
     In the attached (mounted) state, electrical connection between the terminals provided on a circuit board (described later) of the cartridge  20  and those of the contact mechanism  70  in each slot of the holder  60  allows transmission of various information between the cartridge  20  and the printer  50 . 
       FIG. 5  is a sectional view, taken on F 4 -F 4  line of  FIG. 4 . The projection  636  is omitted from the illustration. The printing material supply tube  640  of the printer  50  is connected with an ink supply structure  280  of the cartridge  20 , so that ink is supplied from the cartridge  20  to the head  540  ( FIG. 1 ) via a printing material flow path  282 . 
     According to this embodiment, a porous filter  644  serving to filter the ink supplied from the cartridge  20  is provided at the peripheral end  642  of the printing material supply tube  640 . The porous filter  644  may be made of, for example, stainless steel mesh or stainless steel woven fabric. According to another embodiment, the porous filter may not be located at the peripheral end  642  of the printing material supply tube  640 . 
     The contact mechanism  70  of the printer  50  is located on the +X-axis direction side of the printing material supply tube  640  and is configured to be electrically connectable with the terminals provided on a circuit board  40  of the cartridge  20 . In the attached state of the cartridge  20 , a pressing force Pt including a +Z-axis direction vector component is applied from the terminals of the contact mechanism  70  to the circuit board  40 . In the attached state of the cartridge  20 , a pressing force Ps in the +Z-axis direction is applied from the elastic member  648  to the ink supply structure  280 . 
     A lever  80  used for attachment and detachment of the cartridge  20  has an operating member  830  at a +Z-axis direction end and an engagement portion  810  at a −Z-axis direction end. The first apparatus-side restriction element or engagement portion  810  (more specifically its first apparatus-side locking face described later) is configured to engage with a first cartridge-side restriction portion  210  at a first locking position  810 L in the attached state. The first locking position  810 L is located on the +Z-axis direction side and on the +X-axis direction side of the contact between the terminals provided on the circuit board  40  and the contact mechanism  70 . The engagement portion  810  engages with the first cartridge-side restriction portion  210  to restrict the motion of the cartridge  20  in the +Z-axis direction. 
     The lever  80  pivots around an axis  800   c  at the position between the operating member  830  and the engagement portion  810 . The axis of rotation  800   c  of the lever  80  is located on the +Z-axis direction side and on the +X-axis direction side of the first locking position  810 L. 
     The user uses the operating member  830  of the lever  80  to remove the cartridge  20  from the holder  60 . For removal of the cartridge  20 , the user presses the operating member  830  in the −X-axis direction. This pressing applies a force Pr (called “operating force Pr”) from the +X-axis direction side toward the −X-axis direction side, to the operating member  830 . This operating force Pr turns the lever  80  around the axis  800   c  and moves the engagement portion  810  in the +X-axis direction from the first locking position  810 L. This releases the engagement of the first cartridge-side restriction portion  210  with the engagement portion  810  and enables the cartridge  20  to be removed from the holder  60 . 
     The second apparatus-side restriction element  620  is provided on the side wall member  604  and is configured to engage with a second cartridge-side restriction element  220  at a second locking position  620 L. According to this embodiment, the second apparatus-side restriction element  620  is a through hole formed in the side wall member  604  of the holder  60 . The second locking position  620 L is located on the +Z-axis direction side and on the −X-axis direction side of the printing material supply tube  640 . The second apparatus-side restriction element  620  engages with the second cartridge-side restriction element  220  (which can also be referred to as the second restriction element  220 ) to restrict the motion of the cartridge  20  in the +Z-axis direction. As described above, the motion of the cartridge  20  in the +Z-axis direction is restricted by both its +X-axis direction end and its −X-axis direction end in the attached state. 
     The second locking position  620 L, at which the second cartridge-side restriction element  220  is in contact with the second apparatus-side restriction element  620 , serves as a pivot point, around which the cartridge  20  is turned to be attached to and detached from the holder  60 . In other words, the cartridge  20  is turned around the second locking position  620 L along a plane parallel to the Z axis and the X axis for attachment or detachment. The second cartridge side restriction element  220  and the second apparatus-side restriction element  620  accordingly serve as the pivot point of rotation of the cartridge  20  for attachment or detachment of the cartridge  20 . The attachment and detachment of the cartridge  20  to and from the holder  60  will be described in detail later. 
     As shown in  FIG. 5 , in the attached state, the first locking position  810 L is located on the −Z-axis direction side by a distance Dz from the second locking position  620 L. This reduces the possibility that the first cartridge-side restriction portion  210  is disengaged from the engagement portion  810  by the pressing forces Ps and Pt applied from the holder  60  to the cartridge  20 . The cartridges  20  can thus be stably held at the designed attachment position. 
       FIGS. 6A and 6B  illustrate force applied from the cartridge  20  to the lever  80  at the first locking position  810 L. In the state of  FIG. 6A  where the first locking position  810 L is located on the −Z-axis direction side of the second locking position  620 L, a force F 1  is applied from the cartridge  20  to the lever  80  at the first locking position  810 L. In the state of  FIG. 6B  where the first locking position  810 L is located on the +Z-axis direction side of the second locking position  620 L, a force F 2  is applied from the cartridge  20  to the lever  80  at the first locking position  810 L. The force F 1  shown in  FIG. 6A  has the same magnitude as that of the force F 2  shown in  FIG. 6B . 
       FIGS. 6A and 6B  schematically show the positional relationships of the first locking position  810 L, the second locking position  620 L and the axis of rotation  800   c  (also called “pivot center  800   c ”) to one another on the X axis and on the Z axis. The difference between the two positional relationships shown in  FIGS. 6A and 6B  is the difference of the second locking position  620 L on the Z axis. An arc RT 1  shown in  FIGS. 6A and 6B  shows the rotation locus of the first locking position  810 L around the axis of rotation  800   c . An arc RT 2  shown in  FIGS. 6A and 6B  shows the rotation locus of the first locking position  810 L around the second locking position  620 L. 
     In the example illustrated in  FIG. 6A , the first locking position  810 L is located on the −Z-axis direction side of the second locking position  620 L, so the force F 1 , which is applied in the tangential direction of the arc RT 2  at the first locking position  810 L, has a +X-axis direction vector component and a +Z-axis direction vector component. The force F 1  is accordingly resolved into a vector component F 1   t  in the tangential direction of the arc RT 1  and a vector component F 1   r  in the radial direction of the arc RT 1 . 
     In the example illustrated in  FIG. 6B , the first locking position  810 L is located on the +Z-axis direction side of the second locking position  620 L, so the force F 2 , which is applied in the tangential direction of the arc RT 2  at the first locking position  810 L, has a −X-axis direction vector component and a +Z-axis direction vector component. The force F 2  is accordingly resolved into a vector component F 2   t  in the tangential direction of the arc RT 1  and a vector component F 2   r  in the radial direction of the arc RT 1 . 
     As clearly understood from the comparison between  FIGS. 6A and 6B , when the magnitude of force F 1  is equal to the magnitude of force F 2  (F 1 =F 2 ), the positional relationships of the first locking position  810 L, the second locking position  620 L and the axis of rotation  800   c  to one another result in “F 1   t &lt;F 2   t ” for the vector component in the tangential direction of the arc RT 1  and “F 1   r &gt;F 2   r ” for the vector component in the radial direction of the arc RT 1 . In comparison to the state illustrated in  FIG. 6B , the state in  FIG. 6A  has a larger force vector component from the cartridge  20  towards the axis of rotation  800   c  of the lever  80  and a smaller force vector component in the direction that will turn the lever  80  clockwise, that is, as viewed from the +Y-axis direction, around the axis of rotation  800   c . In other words, locating the first locking position  810 L on the −Z-axis direction side of the second locking position  620 L more effectively reduces the possibility that the first cartridge-side restriction portion  210  is disengaged from the engagement portion  810 , compared with locating the first locking position  810 L on the +Z-axis direction side of the second locking position  620 L. In either state, no force acts in the +X-axis direction to release the engagement at the first locking position  810 L, so both states provide a benefit in reducing the possibility that the first cartridge-side restriction portion  210  will become disengaged from the engagement portion  810 . 
     Detailed Structure of Cartridge 
       FIG. 7  is a perspective view illustrating the structure of cartridge  20  as one example of a cartridge in accordance with one embodiment of the invention.  FIG. 8  is a bottom view of the cartridge  20 .  FIG. 9  is a sectional view, taken on line F 8 -F 8  in  FIG. 8 .  FIGS. 10A and 10B  illustrate the detailed structure of the circuit board  40 .  FIG. 10A  is a view of the circuit board  40  seen from the direction indicated by arrow F 9  in  FIG. 9 , and  FIG. 10B  is a view of the circuit board  40  seen from arrow F 10  in  FIG. 10A . According to this embodiment, the X axis, the Y axis and the Z axis represent the axes on the cartridge  20  in the attached state. The +X-axis direction side in the attached state is the front face of the cartridge  20 . A plane Yc shown in  FIG. 8  is a plane that passes through the center of the width or the Y-axis direction length of the cartridge  20  and is parallel to the Z axis and the X axis (i.e., ZX plane). A plane CX shown in  FIG. 8  is a plane that passes through the central axis C and is parallel to the Z axis and the X axis (i.e., ZX plane). 
     As shown in  FIG. 7 , the cartridge  20  includes an ink chamber  200  containing ink, a housing  22 , the ink supply structure  280 , the circuit board  40  and the first cartridge-side restriction portion  210 . The cartridge  20  is attached to the holder  60  in a mounting direction SD, which is the −Z-axis direction (vertically downward direction in the embodiment). The special orientation or posture of the cartridge  20  is generally not constant during actual insertion of the cartridge  20  to the holder  60 . In the course of attachment of the cartridge  20  to the holder  60 , the cartridge  20  may be inclined with respect to the Z axis. In the state immediately before the attachment and in the attached state, however, the ink supply structure  280  receives the printing material supply tube  640  having the central axis C parallel to the Z axis, so that the special orientation of the cartridge  20  is restricted by the printing material supply tube  640 , and so is substantially aligned in the Z axis direction. For this reason, and because the general direction of movement of the cartridge  20  while being mounted into the holder  60  is in the −Z axis direction, the −Z axis direction can be considered as the mounting direction of the cartridge  20 . For the same reasons, the +Z axis direction can be considered as a removal direction RD ( FIG. 9 ) in which the cartridge  20  is removed from the holder  60 . Because the −Z axis direction and the +Z axis direction are opposite directions, the mounting direction SD and the removal direction RD can be considered opposite directions. 
     The housing  22  (also called “cartridge body  22 ”) defines an inner space including the ink chamber  200  of the cartridge  20 . The housing  22  also forms at least part of the outer wall surfaces of the cartridge  20  and may be made of a synthetic resin, such as polypropylene (PP). The cartridge  20  is in a rectangular prism shape having congruent side faces or in an approximate rectangular parallelepiped shape. Part of the housing  22  may be made of a resin film. 
     The cartridge  20  has a length (X-axis direction length), a width (Y-axis direction length) and a height (Z-axis direction length), wherein the length, the height and the width descend in this order. The magnitude relation of the length, the width and the height of the cartridge  20  is, however, not limited to this order but may be determined arbitrarily; for example, the height, the length and the width may descend in this order or the height, the length and the width may be equal to one another. 
     The housing  22  of the cartridge  20  includes a first wall or a bottom  201 , a second wall or a top  202 , a third wall or a front  203 , a fourth wall or a rear  204 , a fifth wall  205 , a six wall  206  and connection walls  209 . The connection walls  209  include a seventh wall  207  and an eighth wall  208  ( FIG. 9 ). The first to the eighth walls  201  to  208  define the inner space including the ink chamber  200  of the cartridge  20 . In the description below, the symbols  201  to  208  assigned to the first to the eighth walls are also used to represent the outer surfaces of the walls constituting the housing  22  of the cartridge  20  (i.e., first to eighth faces  201  to  208 ). The outer surfaces (first to eighth faces)  201  to  208  of the first to the eighth walls are substantial planes. The “substantial plane” means not only a perfectly flat plane but can include a plane having partial slight irregularity. In other words, the “substantial plane” includes a plane that has partial slight irregularity but is still recognizable as a face or a wall of the housing  22  of the cartridge  20 . The first to the eighth faces  201  to  208  are in rectangular shapes in the planar view. 
     The first face (first wall)  201 , the second face (second wall)  202 , the third face (third wall)  203 , the fourth face (fourth wall)  204 , the fifth face (fifth wall)  205  and the sixth face (sixth wall)  206  are also called bottom face (bottom wall)  201 , top face (top wall)  202 , front face (front wall)  203 , rear face (rear wall)  204 , left side face (left wall)  205  and right side face (right wall)  206 , respectively. The outer surfaces of the walls can also be referred to the front  203 , rear  204 , top  202  and bottom  201 , or as first to fourth surfaces where first surface refers to front  203 , second surface refers to rear  204 , third surface refers to top  202  and fourth surface refers to bottom  201 . 
     The first face  201  and the second face  202  are opposed to each other in the Z-axis direction. The first face  201  is located on the −Z-axis direction side, while the second face  202  is located on the +Z-axis direction side. The third face  203  and the fourth face  204  are opposed to each other in the X-axis direction. The third face  203  is located on the +X-axis direction side, while the fourth face  204  is located on the −X-axis direction side. The fifth face  205  and the sixth face  206  are opposed to each other in the Y-axis direction. The fifth face  205  is located on the +Y-axis direction side, while the sixth face  206  is located on the −Y-axis direction side. 
     According to this embodiment, the first face  201  located on the −Z-axis direction side forms the bottom face in the attached state. The first face  201  is an XY plane parallel to the X axis and the Y axis and perpendicular to the Z axis. The first face  201  is a horizontal face in the attached state. 
     The second face  202  located on the +Z-axis direction side forms the top face in the attached state. The second face  202  is opposed to the first face  201  and is parallel to the first face  201 . The second face  202  is a plane (XY plane) parallel to the X axis and the Y axis and perpendicular to the Z axis. The second face  202  is a horizontal face in the attached state. 
     The third face  203  located on the +X-axis direction side forms a side face in the attached state. The third face  203  is perpendicular to the first face  201  and the second face  202  and is a plane (YZ plane) parallel to the Y axis and the Z axis and perpendicular to the X axis. Among sides of the third face  203 , a side  290  located on the most −Z-axis direction side is called “first side  290 ”, and a side  291  located on the most +Z-axis direction side is called “second side  291 ”. In the specification hereof, the expression that “two faces intersect or cross each other” means not only the state that two faces actually cross each other but the state that an extension of one face intersects the other face and the state that extensions of two faces cross each other. 
     The fourth face  204  located on the −X-axis direction side forms a side face in the attached or mounted state. The fourth face  204  is perpendicular to the first face  201  and the second face  202 . The fourth face  204  is parallel to the third face  203 . The fourth face  204  is a plane (YZ plane) parallel to the Y axis and the Z axis and perpendicular to the X axis. 
     The fifth face  205  located on the +Y-axis direction side and the sixth face  206  located on the −Y-axis direction side form side faces in the attached state. The fifth face  205  and the sixth face  206  are perpendicular to the first to the fourth faces  201  to  204 . The fifth face  205  and the sixth face  206  are planes (XZ planes) parallel to the X axis and the Z axis and perpendicular to the Y axis. The sixth face  206  is parallel to the fifth face  205 . 
     As shown in  FIG. 9 , the connection faces  209  couple the first face  201  with the third face  203 . The seventh face  207  of the connection faces  209  is perpendicular to the first face  201  and is a plane (YZ plane) parallel to the Y axis and the Z axis. The seventh face  207  is vertically-angled relative to the first face  201  and can also be referred to as a “step”. In other words, the seventh face  207  is extended in the +Z-axis direction from the first face  201 . The seventh face  207  is located on the −X-axis direction side and on the −Z-axis direction side of the eighth face  208 . The eighth face  208  couples the seventh face  207  with the third face  203 . The eighth face  208  is a sloped surface inclined in a direction including a +X-axis direction vector component and a −Z-axis direction vector component. The eighth face  208  is inclined to the first face  201  and the third face  203 . The eighth face  208  is perpendicular to the fifth face  205  and the sixth face  206 . In other words, the eighth face  208  is inclined to the XY plane and the YZ plane and is perpendicular to the XZ plane. The eighth face  208  has a board mounting member  208 T protruded outward from the eighth face  208 . 
     The relationships of the first to the sixth faces  201  to  206  indicate that the facing direction of the first face  201  and the second face  202  is the Z-axis direction, the facing direction of the third face  203  and the fourth face  204  is the X-axis direction and the facing direction of the fifth face  205  and the sixth face  206  is the Y-axis direction. 
     As shown in  FIG. 7 , the circuit board  40  is preferably mounted on the board mounting member  208 T of the eighth face  208 . The circuit board  40  has a terminal bearing structure  408  that is inclined, or, said differently, sloped, in the direction including the +X-axis direction vector component and the −Z-axis direction vector component, like the eighth face  208 . In this embodiment, the terminal bearing structure  408  comprises the surface of the circuit board  40 . The terminal bearing structure  408  is inclined to the first face  201  and the third face  203 . The terminal bearing structure  408  is perpendicular to the fifth face  205  and the sixth face  206 . In other words, the terminal bearing structure  408  is inclined to the XY plane and the YZ plane and is perpendicular to the XZ plane. The terminal bearing structure  408  is also called “sloped terminal bearing structure  408 ” or “sloped surface”. As such, in the present embodiment the surface of the circuit board  40  can be considered a “sloped surface”. The terminal bearing structure  408  has cartridge-side terminals  400 , which are in contact with the apparatus-side terminals of the contact mechanism  70  ( FIG. 2 ). The angle of inclination is preferably between 0 degrees and 90 degrees, more preferably between 20 degrees and 50 degrees and most preferably from about 25 degrees to 40 degrees. 
       FIGS. 42A and 42B  shows the relation of a wiping amount of the terminal on the circuit board  40  by an apparatus-side terminal with respect to an inclination angle phi of the circuit board  40 . The inclination angle phi of the circuit board  40  represents an angle between the plane  110   p  extended from the mounting direction leading edge of the ink supply structure  280  and a plane in which the terminals  400  of the circuit board  40  are arranged. The plane defined by the terminals  400  is neither perpendicular nor parallel to the plane  110   p . The inclination angle phi is generally an acute angle (less than 90 degrees). In this embodiment, the plane  110   p  extended from the mounting direction leading edge is parallel to the bottom face  201  of the cartridge  20 . Also, the plane in which the terminals  400  are arranged is parallel to the board surface of the circuit board  40 . Accordingly, in this embodiment, the inclination angle phi is equal to the angle between the bottom face  201  of the cartridge  20  and the board surface of the circuit board  40 . In the present embodiment, the circuit board  40  is about 0.7 mm thick. The terminals  400  are about 5 microns thick, and are provided on the circuit board  40 . The thickness of the terminals  400  are small to a negligible degree, so the surface of the circuit board  40 , including surface of the terminals  400 , is substantially flush. Therefore, the terminal bearing structure  408 , which comprises the surface of the circuit board  40  in this embodiment, is located substantially within a terminal (contact portion) plane TP to be described later. Even if the circuit board  40  were absent, there would only be unevenness equivalent to the thickness of the terminals  400 . Therefore, for simplicity sake, the terminal bearing structure  408  may be used interchangeably with “plane defined by the terminals” or “terminal plane”. When contact portions  431 - 439  are referenced in connection with the terminal bearing structure  408  the term “plane defined by the contact portions” or “contact portion plane” can be used interchangeably as well. In the course of attachment or mounting of the cartridge  20 , as shown in  FIGS. 24-27 , the front face  203  (the first surface) of the cartridge  20  goes down with slight pivotal rotation on the rear face  204  (the second surface) of the cartridge  20 . In this process, the circuit board  40  slightly rotates and comes into contact with the apparatus-side contact forming members  731 - 739  on the terminal base  709 , so that the respective contact portions  431 - 439  are wiped by the apparatus-side contact forming members  731 - 739 . The wiping of the terminal on the circuit board  40  by the corresponding apparatus-side terminal properly removes the dust or oxide coating on the surface of the terminal on the circuit board  40  to enhance the electric conductivity (electrical connection). 
     The plot of  FIG. 42A  shows the wiping length (wiping amount) of the terminal on the circuit board  40  by the corresponding apparatus-side contact forming members as ordinate, and the board inclination angle phi as abscissa. The calculation is on the assumption that distance L 0  in the X direction from the second surface (rear face)  204  of the cartridge  20  to the contact portion of the ground terminal  437  that comes into contact with the corresponding apparatus-side ground terminal  737  is 63 mm. In general, the greater board inclination angle phi causes the board surface to be closer to the vertical plane and increases the wiping amount. In order to sufficiently remove the dust or oxide coating on the surface of the terminal on the circuit board  40 , the wiping amount is preferably not less than 1 mm. According to the graph of  FIG. 42A , the board inclination angle phi is preferably not less than 25 degrees to ensure the wiping amount of not less than 1 mm. 
       FIG. 43A  shows the relation of upward force F by the apparatus-side ground terminal  737  to the board inclination angle phi in consideration of preventing half insertion of the cartridge. The calculation of  FIG. 43A  is also on the assumption that the distance L 0  is equal to 63 mm, like the calculation of  FIG. 42A . The weight of the cartridge (including the weight of ink) is assumed to be 30 grams. This value is the standard weight of the cartridge for inkjet printing apparatuses for household use. The “half insertion of the cartridge” denotes the state where the engagement portion  810  of the lever  80  is located just beside the elastic member  682  as shown in  FIG. 25 , i.e., the state immediately before the complete engagement. This state of half insertion is also called “half engagement”. In this state of half engagement, only the apparatus-side ground terminal  737  among the plurality of apparatus-side contact forming members  731 - 739  applies the upward force to the circuit board  40 . It should be noted that in the printing apparatus shown in  FIG. 1 , the holder  60  does not have a cover. When the user releases the hand in this state of half engagement, the cartridge  20  may be kept in this state of half engagement. The plot of  FIG. 43A  shows the calculation result of the upward force by the apparatus-side ground terminal  737  to prevent such half insertion of the cartridge  20 .  FIG. 43B  shows the relation of the upward force F to the board inclination angle phi. 
     The upward force by the apparatus-side ground terminal  737  is a +Z-direction vector component (vertically upward vector component in this embodiment) of the force applied from the apparatus-side ground terminal  737  to the circuit board  40  (and the cartridge  20 ) in the state of half engagement of  FIG. 25 . When the ground terminal  437  of the circuit board  40  is pressed against the apparatus-side ground terminal  737 , a pressing force in a direction perpendicular to the board surface of the circuit board  40  is applied to the ground terminal  437  by the elastic force of the apparatus-side ground terminal  737 . The calculation of the upward force of  FIG. 43A  is on the assumption that pressing force F 0  of the apparatus-side ground terminal  737  is 0.2 N in the direction perpendicular to the board surface. Since the upward force F (=F 0 ×cos phi) is the +Z-direction vector component of the pressing force F 0 , F=F 0 =0.2 N holds at the board inclination angle phi=0 degree as shown by the broken line in Fig.  FIG. 43B . The upward force F varies according to the curve F=F 0 ×cos phi with a variation in board inclination angle phi. The curve of  FIG. 43A  is the curve F=F 0 ×cos phi. With an increase in board inclination angle phi (phi approaching 90 degrees), the board surface approaches the XZ plane and reduces the upward force F. An upward force FB balancing with the cartridge  20  having the distance L 0  of 63 mm and the weight of 30 grams is approximately 0.15 N (the position of thick horizontal line in  FIG. 43A ). This means that the upward force of not less than 0.15 N enables the cartridge  20  to be pressed vertically upward by the apparatus-side ground terminal  737 . In order to ensure the upward force of not less than 0.15 N, the board inclination angle phi is preferably not greater than 40 degrees, as clearly understood from  FIG. 43A . 
     When the user releases the hand in the state of half engagement of  FIG. 226 , the cartridge  20  may be kept in the state of half engagement. If the board inclination angle phi is set to be not greater than 40 degrees as shown in  FIG. 43A , however, when the user releases the hand in the state of half engagement, the apparatus-side ground terminal  737  presses the front face  203  of the cartridge  20  in the +Z direction (upward direction). This clearly disengages the cartridge from the apparatus—and facilitates the user to find the failed attachment. From this point of view, it is preferable to set the board inclination angle phi to be not greater than 40 degrees. 
       FIGS. 44 and 45  show the characteristics of a cartridge having a greater dimension in the X direction than the dimension of the cartridge in  FIGS. 42 and 43A . Whereas the cartridge is assumed to have the distance L 0 =63 mm in  FIGS. 42 and 43A , it is assumed to have the distance L 0 =80 mm in  FIGS. 44 and 45 . The calculation of the upward force of  FIG. 45  is on the assumption that F 0 =0.2 N and the weight of the cartridge (including the weight of ink) is 30 g, like the calculation of  FIG. 43A . As clearly understood from the result of  FIG. 44 , like the result of  FIG. 42A , in order to ensure the wiping amount of not less than 1 mm, the board inclination angle phi is preferably not less than 25 degrees. Although the distance L 0  is 80 mm in the calculation of  FIG. 45  relative to 63 mm in the calculation of  FIG. 43A , the upward force FB balancing with the cartridge  20  having the weight of 30 grams is almost equal to that of  FIG. 43  and is approximately 0.15 N (the position of thick horizontal line in  FIG. 45 ). As clearly understood from the result of  FIG. 45 , like the result of  FIG. 43A , in order to prevent half engagement of the cartridge, the board inclination angle phi is preferably not greater than 40 degrees. 
     By taking into account the characteristics of  FIGS. 42 through 45 , discussed above, it is preferable to set the board inclination angle phi to be not less than 25 degrees and not greater than 40 degrees. 
     The increased pressing force of the apparatus-side ground terminal  737  ensures the sufficient upward force even at the greater board inclination angle phi. In this case, it is preferable to set the pressing force of the apparatus-side ground terminal  737  and the board inclination angle phi to such values that enable the cartridge  20  to be pressed upward and changed from the state of half engagement to the disengagement state by the pressing force of the apparatus-side ground terminal  737 , when the user release the hand from the cartridge  20  in the state of half engagement. 
     The seventh face  207  and the terminal bearing structure  408  form part of the outer surfaces of the cartridge  20 . More specifically the seventh face  207  and the terminal bearing structure  408  form a portion of a corner section  265  coupling the first face  201  and the third face  203  that form part of the outer surfaces of the cartridge  20 . For better understanding, the corner section  265  is shown by a thick line in  FIG. 9 . The third face  203  and the corner section  265  are opposed to the first apparatus-side side wall member  603  of the holder  60  ( FIG. 14 ) in the attached state of the cartridge  20  to the holder  60  as described later. The third face  203  and the corner section  265  are thus called “first opposed outer wall surface”. The fourth face  204  is opposed to the second apparatus-side side wall member  604  of the holder  60  ( FIG. 15 ) in the attached state as described later. The fourth face  204  is thus called “second opposed outer wall surface”. 
     As shown in  FIG. 10A , the circuit board  40  has a boss groove  401  at a +Z-axis direction end and a boss hole  402  at a −Z-axis direction end. The circuit board  40  is fixed to the eighth face  208  of the cartridge  20  by means of the boss groove  401  and the boss hole  402 . According to this embodiment, the boss groove  401  and the boss hole  402  are provided at positions intersecting the plane Yc passing through the center of the width (Y-axis direction length) of the cartridge  20 . According to another embodiment, at least one of the boss groove  401  and the boss hole  402  may be omitted from the circuit board  40 , and the circuit board  40  may be fixed to the eighth face  208  by an adhesive or by an engagement click (not shown) provided on the eighth face  208 . 
     As shown in  FIGS. 10A and 10B , the circuit board  40  includes the cartridge-side terminals  400  provided on the terminal bearing structure  408  and a memory unit  420  provided on a rear face  409 . The terminal bearing structure  408  and the rear face  409  are planes. A portion or a side of the plane terminal bearing structure  408  located on the most +Z-axis direction side in the mounting state of the circuit board  40  on the cartridge  20  is called a board end  405 . 
     The cartridge-side terminals  400  include nine terminals  431  to  439 . The memory unit  420  stores information regarding ink of the cartridge  20  (for example, remaining amount of ink and ink color). The cartridge-side terminals  400  are electrically conductive and can be coupled to an electrical device that is part of the cartridge  20 . As used herein, electrical device can refer to a resistor, sensor or memory device, or other device that produces or is powered by electricity as can be appreciated by one of ordinary skill in the art. 
     As shown in  FIG. 10A , the nine cartridge-side terminals  431  to  439  are all in approximate rectangular shape and are arrayed in two rows that are substantially perpendicular to the mounting direction SD. The substantially perpendicular rows are extended in the width direction (Y-axis direction) of the cartridge  20 . The row the two row to the rear with respect to the mounting direction SD is called first terminal row R 1  (lower line R 1 ), and the front line along the mounting direction SD is called second terminal row R 2  (upper line R 2 ). The first terminal row R 1  and the second terminal row R 2  have different positions in the Z-axis direction. More specifically, the first terminal row R 1  is located on the −Z-axis direction side of the second terminal row R 2 . Each of the terminals  431  to  439  has a contact portion cp at its center, which is in contact with the contact mechanism  70 . The first terminal row R 1  and the second terminal row R 2  may be regarded as lines formed by a plurality of contact portions cp. 
     The terminals  431  to  439  may be called by the following names corresponding to their functions or applications. For differentiation from the terminals on the printer  50 , the word “cartridge-side” may be prefixed to each name. For example, the “ground terminal  437 ” may be called “cartridge-side ground terminal  437 ”. 
     &lt;First Terminal Row R 1 &gt;
         (1) attachment detection terminal (first terminal)  435 ;   (2) power terminal  436 ;   (3) ground terminal  437 ;   (4) data terminal  438 ; and   (5) attachment detection terminal (second terminal)  439 .       

     &lt;Second Terminal Row R 2 &gt;
         (6) attachment detection terminal (third terminal)  431 ;   (7) reset terminal  432 ;   (8) clock terminal  433 ; and   (9) attachment detection terminal (fourth terminal)  434 .       

     The contact portions cp of the terminals  435  to  439  on the first terminal row R 1  and the contact portions cp of the terminals  431  to  434  on the second terminal row R 2  are arranged alternately or more specifically in zigzag. 
     The four attachment detection terminals  431 ,  434 ,  435  and  439  are used to check the good/poor electrical contact with the corresponding apparatus-side terminals provided in the contact mechanism  70 , so that the printer  50  can detect whether the cartridge  20  is properly attached at the designed attachment position of the holder  60 . These four terminals  431 ,  434 ,  435  and  439  are collectively called “attachment detection terminals”. According to this embodiment, the four cartridge-side terminals  431 ,  434 ,  435  and  439  are electrically connected with one another inside the circuit board  40 . When the cartridge  20  is attached to the holder  60 , these terminals  431 ,  434 ,  435  and  439  are electrically connected with a ground line (not shown) on the printer  50  via the ground terminal  437 . The method of detecting attachment by using the four attachment detection terminals  431 ,  434 ,  435  and  439  will be described later. 
     The other five cartridge-side terminals  432 ,  433 ,  436 ,  437  and  438  are terminals for the memory unit  420 . These five terminals  432 ,  433 ,  436 ,  437  and  438  are thus also called “memory terminals”. 
     The reset terminal  432  receives a reset signal RST, which is to be supplied to the memory unit  420 . The clock terminal  433  receives a clock signal SCK, which is to be supplied to the memory unit  420 . The power terminal  436  receives a power-supply voltage VDD (for example, rated voltage of 3.3 V), which is to be supplied to the memory unit  420 . The ground terminal  437  receives a ground voltage VSS (0V), which is to be supplied to the memory unit  420 . The data terminal  438  receives a data signal SDA, which is to be supplied to the memory unit  420 . 
     The first terminal  435  as one of the attachment detection terminals includes a first outer part  435 P located on the most +Y-axis direction side of the cartridge-side terminals  400 . The second terminal  439  as one of the attachment detection terminals includes a second outer part  439 P located on the most −Y-axis direction side of the cartridge-side terminals  400 . The third terminal  431  as one of the attachment detection terminals includes a third outer part  431 P located on the most +Y-axis direction side of the second terminal line R. The fourth terminal  434  as one of the attachment detection terminals includes a fourth outer part  434 P located on the most −Y-axis direction side of the second terminal line R. In this embodiment, the first to fourth outer parts  435 P,  439 P,  431 P,  434 P are substantially straight edges of the corresponding terminals and extend substantially in the Z axis direction, but this should not be considered a limitation. For example, the edges could be curved and could extend in a direction not parallel to the Z axis direction, such as shown for the terminals  431 ,  434  in the example of  FIGS. 41A and 41B , and the outer part of the terminal could still be understood as the outermost portion of the edge in the Y axis direction. 
     Among the contact portions cp of the cartridge-side terminals  400 , the ground terminal  437  having the contact portion cp on the center in the Y-axis direction is provided at the position intersecting the plane Yc passing through the center of the width (Y-axis direction length) of the cartridge  20 . The contact portions cp of the other terminals  431  to  436 ,  438  and  439  are arranged to be symmetrical with respect to the line of intersection of the plane Yc and the ground terminal  437  as the axis. The ground terminal  437  is configured to be in contact with the contact mechanism  70  prior to the other cartridge-side terminals  431  to  436 ,  438  and  439  in the course of attachment of the cartridge  20  to the holder  60 . The pressing force first applied from the holder  60  to the circuit board  40  is thus generated on the substantial center of the width or the Y-axis direction length of the cartridge  20  both before and after the cartridge is completely mounted. This prevents the pressing force applied to the circuit board  40  from acting to tilt the cartridge  20  in the Y-axis direction and thereby enables the attachment of the cartridge  20  at the designed attachment position. Such contact of the ground terminal  437  with the contact mechanism  70  of the holder  60  prior to the other cartridge-side terminals  431  to  436 ,  438  and  439  advantageously prevents or reduces the high voltage-induced troubles and failures by the grounding function of the ground terminal  437 , even when an unexpected high voltage is applied to the cartridge  20 . 
     According to this embodiment, the ground terminal  437  is formed longer along the Z-axis direction than the other cartridge-side terminals  431  to  436 ,  438  and  439 . This ensures the contact of the ground terminal  437  with the contact mechanism  70  of the holder  60 . According to another embodiment, all the cartridge-side terminals  431  to  439  on the circuit board  40  may be formed in the same size. 
     As shown in  FIG. 9 , the ink supply structure  280  is protruded in the −Z-axis direction from the first face  201 . The ink supply structure  280  communicates with the ink chamber  200  via the printing material flow path  282 . The ink supply structure  280  is connected with the printing material supply tube  640  ( FIG. 5 ) of the printer  50  to supply the ink contained in the ink chamber  200  to the head  540  ( FIG. 1 ). In other words, the ink supply structure  280  is open to the outside, in order to supply the ink contained in the ink chamber  200  to outside of the cartridge  20 . As can be seen in  FIG. 5A , ink supply structure  280  need not protrude from the first face  201 . Rather, in one embodiment, it can be flush or substantially flush with the first face  201 . In such an embodiment, material supply tube  640  is raised so as to be proximate to the first face when the cartridge  20  is mounted. 
     The ink supply structure  280  is provided at the position closer to the fourth face  204  than the third face  203  on the first face  201 . The distance between the outer surface of the ink supply structure  280  and the third face  203  in the X-axis direction is accordingly greater than the distance between the outer surface of the ink supply structure  280  and the fourth face  204 . 
     The ink supply structure  280  has an open peripheral end. The surface at this open peripheral end is referred to as open surface  288 , or alternately a mounting direction leading edge, and defines a horizontal plane in the attached state. That is, the open surface  288  is the leading edge (XY plane) of the cartridge in the mounting direction SD and defines an XY axes plane which is parallel to the X axis and the Y axis. 
     A resin foam  284  is provided inside the ink supply structure  280  at the position on the +Z-axis direction side of the open surface  288  or more specifically at the position in contact with the printing material flow path  282 . According to this embodiment, before shipment of the cartridge  20 , the open surface  288  of the ink supply structure  280  is sealed with a sealing member (not shown), such as a cap or a film. For attachment of the cartridge  20  to the holder  60 , the sealing member (not shown) for sealing the open surface  288  is removed from the cartridge  20 . 
     According to this embodiment, the ink supply structure  280  is protruded in the −Z-axis direction with the center on the central axis C of the printing material supply tube  640 . According to another embodiment, the center of the ink supply structure  280  may be deviated from the central axis C of the printing material supply tube  640 . According to this embodiment, the open surface  288  of the ink supply structure  280  viewed from the −Z-axis direction is formed by the line-symmetrical housing with respect to axes parallel to the X axis and the Y axis. According to another embodiment, the open surface  288  of the ink supply structure  280  may be formed by the asymmetric housing and may have a mounting direction leading edge defining a plane. The open surface  288  viewed from the Z direction is in the rounded rectangular shape according to this embodiment but may be in any other suitable shape, e.g., precise circle, ellipse, oval, square or rectangle according to other embodiments. 
     As shown in  FIG. 9A , plane BP is a plane formed by the mounting direction leading edge of the open surface  288  of ink supply structure  280 . Distance A is the distance between plane BP and the engagement portion  212  of the first restriction portion  210 . Distance B is the distance between plane BP and an engagement portion of the second restriction element  220 . Distance C is the distance between plane BP and the lever  80 &#39;s pivot point around axis  800 C. As can be seen in  FIG. 9A , the distance between plane BP and an engagement portion of the second restriction element  220  is greater than the distance between plane BP and the engagement portion  212  of the first restriction portion  210  when measured in an orthogonal direction to the plane BP. The distance between plane BP and the engagement portion  212  of the first restriction portion  210  is less than the distance between plane BP and the lever  80 &#39;s pivot point around axis  800 C when measured in an orthogonal direction to the plane BP. Additionally as can be seen in  FIG. 9A , plane TP is the plane formed by the sloped terminal bearing structure  408 , which in this embodiment is parallel to the sloped terminal bearing structure  408  itself, and so for simplicity sake, the terminal bearing structure  408  may be used to refer to the plane TP. Plane TP is neither parallel nor perpendicular to plane BP. The terminal bearing structure  408  has cartridge-side terminals  400 , which are in contact with the apparatus-side terminals of the contact mechanism  70  ( FIG. 2 ). 
     As shown in  FIG. 7 , the first cartridge-side restriction portion  210  is provided on the third face  203 . The first cartridge-side restriction portion  210  is located on the +Z-axis direction side and on the +X-axis direction side of the ink supply structure  280  and the circuit board  40 . The first cartridge-side restriction portion  210  is locked by the lever  80  ( FIG. 2 ), so as to restrict the motion of the cartridge  20  in the attached state. The first cartridge-side restriction portion  210  is structured as a projection protruded in the +X-axis direction (outward) from the third face  203 . The first cartridge-side restriction portion  210  is located at the position closer to the first side  290  than the second side  291  along the Z-axis direction. According to this embodiment, the first cartridge-side restriction portion  210  is located adjacent to the first side  290 . 
     The first cartridge-side restriction portion  210  includes a first portion  212  extended in the Y-axis direction (width direction), a second portion  214  extended in the +Z-axis direction (vertically upward direction) from the first portion  212 , and a third portion  215  extended in the −Z-axis direction (vertically downward direction) from the first portion  212 . As described above, the +Z-axis direction (vertically upward direction) is generally the removal direction RD and is opposite the −Z-axis direction (vertically downward direction), which is generally the mounting direction SD. The first or engagement portion  212  cooperates with an engagement portion  810  of the lever  80  to restrict the motion of the cartridge  20  in the attached state. The second portion  214  is provided to lock the first portion  212  by the expected part of the lever  80  in attachment of the cartridge  20  to the holder  60 . 
     The first portion  212  includes a first cartridge-side locking surface  211  as a first abutting part and a second cartridge-side locking surface  213  as a second abutting part. The first cartridge-side locking surface  211  faces in the +Z-axis direction. The second cartridge-side locking surface  213  faces in the +X-axis direction. The third portion  215  is in contact with the first portion  212  and the first side  290 . 
     The cartridge  20  further includes the second cartridge-side restriction element  220  provided on the fourth face  204 , a projection  260  provided on the third face  203  and a third cartridge-side restriction element  250  provided on the seventh face  207 . 
     The second cartridge-side restriction element  220  is structured as a projection protruded in the −X-axis direction from the fourth face  204 . The second cartridge-side restriction element  220  is inserted into the second apparatus-side restriction element  620  ( FIG. 3 ) in the form of the through hole of the holder  60 . The user turns the cartridge  20  around the second cartridge-side restriction element  220  inserted in the second apparatus-side restriction element  620  ( FIG. 3 ) in attachment or detachment of the cartridge  20  to or from the holder  60 . In other words, the second apparatus-side restriction element  620  serves as the guide for attachment or detachment of the cartridge  20  to or from the holder  60 . This facilitates the attachment and detachment of the cartridge  20  to and from the holder  60 . In the attached state of the cartridge  20 , the second cartridge-side restriction element  220  is locked by the second apparatus-side restriction element  620  to restrict the motion of the cartridge  20  in the attached state. The second cartridge-side restriction element  220  is located on the +Z-axis direction side and on the −X-axis direction side of the ink supply structure  280  and the circuit board  40 . 
     The projection  260  on the third face  203  is located on the +Z-axis direction side of the first cartridge-side restriction portion  210 . According to this embodiment, the projection  260  is located at the most +Z-axis direction position (most upward position) including the second side  291  on the third face  203 . 
     The third cartridge-side restriction element  250  is structured as a pair of projection members (restriction walls) protruded in the +X-axis direction from both Y-axis direction sides of the seventh face  207 . The pair of projection members  250  receive the projection  636  ( FIG. 2 ) inserted therebetween and, in cooperation with the projection  636 , restrict the motion of the cartridge  20  in the Y-axis direction in the attached state. 
       FIG. 11  is a rear view of the cartridge  20 . The second cartridge-side restriction element  220  is described in detail with reference to  FIG. 11 . The second cartridge-side restriction element  220  includes a restriction locking surface  222  as a restriction locking element, a sloped surface  224 , a first restriction side face  226  and a second restriction side face  228 . 
     The restriction locking surface  222  faces in the +Z-axis direction and forms a horizontal face in the attached state. The restriction locking surface  222  is in contact with the second apparatus-side restriction element  620  ( FIG. 3 ) to serve as the pivot point of rotation when the cartridge  20  is turned to be detached from the holder  60 . 
     The restriction locking surface  222  is locked by the second apparatus-side restriction element  620  in the attached state, so as to restrict the motion of the cartridge  20  in the +Z-axis direction in the attached state. The restriction locking surface  222  is provided at the position intersecting the plane Yc passing through the center of the width (Y-axis direction length) of the cartridge  20  and perpendicular to this plane Yc. As shown in  FIG. 5 , in the attached state of the cartridge  20 , the cartridge  20  receives the pressing forces Ps and Pt including the +Z-axis direction vector components from the holder  60 . The restriction locking surface  222  is pressed against the second apparatus-side restriction element  620  by these pressing forces Ps and Pt. The second apparatus-side restriction element  620  is thus in contact with the restriction locking surface  222  in parallel with the Y-axis direction. This reduces the possibility that the cartridge  20  is tilted about the X axis in the attached state. 
     The sloped surface  224  is connected with the restriction locking surface  222  and is inclined to the direction including the +Z-axis direction vector component and the −X-axis direction vector component. This enables the restriction locking surface  222  to be smoothly guided to the second apparatus-side restriction element  620  in attachment of the cartridge  20  to the holder  60 . 
     The first restriction side face  226  forms a −Y-axis direction side face of the second cartridge-side restriction element  220 . The second restriction side face  228  forms a +Y-axis direction side face of the second cartridge-side restriction element  220 . The first restriction side face  226  is a plane facing in the −Y-axis direction, and the second restriction side face  228  is a plane facing in the +Y-axis direction. The first restriction side face  226  and the second restriction side face  228  are planes respectively parallel to the X-axis direction and the Z-axis direction. The first and the second restriction side faces  226  and  228  interfere with the second apparatus-side restriction element  620  to restrict the motion of the cartridge  20  in the Y-axis direction in the attached state of the cartridge  20 . 
       FIG. 12  is a front view of the cartridge  20 . The first cartridge-side restriction portion  210  is described more in detail with reference to  FIG. 12 . The first cartridge-side restriction portion  210  is provided at the position intersecting the plane Yc. The first cartridge-side locking surface  211  is provided at the position intersecting the plane Yc and perpendicular to this plane Yc. 
     The first cartridge-side locking surface  211  is located not outside but inside a range  40 Y between the first outer part  435 P and the second outer part  439 P in the Y-axis direction (width direction), when the cartridge  20  is viewed from the third face  203 -side in the −X-axis direction. According to this embodiment, the first cartridge-side restriction portion  210  including the first cartridge-side locking surface  211  is located not outside but inside the range  40 Y. In other words, the first cartridge-side restriction portion  210  is located inside an area defined by a first phantom line  435 PL including the first outer part  435 P and a second phantom line  439 PL including the second outer part  439 P. The first phantom line  435 PL and the second phantom line  439 PL are straight lines extended in the Z-axis direction. 
       FIG. 13  is a left side view of the cartridge  20 . The positional relationship of the respective members of the cartridge  20  is described with reference to  FIG. 13 . An intersection where the third face  203  intersects the sloped terminal bearing structure  408  is called “intersecting part  295 ”. As per the above description about the term “intersection”, the intersection where the third face  203  intersects the sloped terminal bearing structure  408  includes not only the intersection of the actual face  203  and the terminal bearing structure  408 , but also the intersection of one of the face  203  and the terminal bearing structure  408  and an extension of the other of the face  203  and the terminal bearing structure  408 , or the intersection of extensions of both of the face  203  and the terminal bearing structure  408 . The intersecting part  295  is a line parallel to the Y-axis direction. According to this embodiment, the intersecting part  295  is located on a plane extended from the third face  203  in the −Z-axis direction. The intersecting part  295  is accordingly located on the −Z-axis direction side of the third face  203 . The middle point in the Z-axis direction length on the third face  203  (or more specifically, the middle point between an intersection of the third face  203  and the contact portion plane TP and the intersection of the second face  202  and the third face  203 ) is called midpoint  203 P. 
     The first cartridge-side restriction portion  210  is located close to the intersecting part  295 . The first cartridge-side restriction portion  210  can also be considered as located adjacent to the terminal bearing structure  408  and close to the board end  405 . This means that the first cartridge-side restriction portion  210  can be sufficiently closer to the cartridge-side terminals  400 , or more precisely, the portion of the restriction portion  210  that engages with the printer-side lever can be located at a position closer to the contact portions cp than to an intersection of the top face  202  and the front face  203 . The first cartridge-side restriction portion  210  is provided preferably on a specific part of the third face  203  closer to the first side  290  than to the second side  291  or more precisely, the portion of the restriction portion  210  that engages with the printer-side lever is located at a position closer to the intersecting part  295  than to an intersection of the top face  202  and the front face  203 , which is in the range from the midpoint  203 P to the first side  290 . It is especially preferable to provide the first cartridge-side restriction portion  210  at the position sufficiently close or proximate to the first side  290 . As used herein, “proximate” can mean “close to,” “near” or “on.” As described above, the portion of the restriction portion  210  that engages with the printer-side lever is located at a position closer to the intersecting part  295  and/or to the contact portions cp than to an intersection of the top face  202  and the front face  203 . Although in this embodiment the intersection of the top face  202  and the front face  203  is the position indicated by  291  in  FIG. 13 , as mentioned above, the intersection need not be where two surfaces actually cross each other, but could be where one face intersects an extension of the other face, or where extensions of two faces cross each other, as indicated by broken line in the embodiments of  FIGS. 35A and 35D . In this embodiment, the distance between an intersection of the third face  203  and the contact portion plane TP and the intersection of the second face  202  and the third face  203  is about 20 mm. The distance between an intersection of the third face  203  and the contact portion plane TP and the first cartridge-side locking surface  211  of the first cartridge-side restriction portion  210  is about 16 mm. 
     The effective part of the first cartridge-side restriction portion  210  specifically serving to restrict the position of the cartridge-side terminals  400  is the first cartridge-side locking surface  211 . It is thus preferable to locate the first cartridge-side locking surface  211  as close as possible to the cartridge-side terminals  400 . Omitting the third portion  215  of the first cartridge-side restriction portion  210  and locating the first portion  212  in contact with the first side  290  enables the first cartridge-side locking surface  211  to be closer to the intersecting part  295  or the board end  405 . 
       FIG. 13  also shows an X-axis direction range  250 X of the third cartridge-side restriction element  250  and an X-axis direction range  408 X of the sloped terminal bearing structure  408 . As clearly understood from this drawing, part of the third cartridge-side restriction element  250  overlaps with the sloped terminal bearing structure  408  in the X-axis direction, when the cartridge  20  is viewed from the first face  201 -side in the +Z-axis direction. 
     Detailed Structure of Holder  60 : 
     General Structure of Holder  60 : 
       FIGS. 14 and 15  are perspective views illustrating the structure of the holder  60 .  FIG. 16  is a top view illustrating the structure of the holder  60 .  FIG. 17  is a sectional view, taken on line F 16 -F 16  in  FIG. 16 . The projection  636  shown in  FIGS. 14 to 16  is omitted from the illustration of  FIG. 17 . 
     As described above, the holder  60  of the printer  50  has the five wall members  601 ,  603 ,  604 ,  605  and  606  to form the concave cartridge chamber  602  to receive the cartridge  20 . The five wall members  601 ,  603 ,  604 ,  605  and  606  are collectively called “chamber-forming wall members  600 ”. According to this embodiment, the five wall members  601 ,  603 ,  604 ,  605  and  606  are resin plate members and are made of a synthetic resin, more specifically modified polyphenylene ether (m-PPE). 
     The wall member  601  forms the bottom face of the concave cartridge chamber  602 . The wall members  603 ,  604 ,  605  and  606  form the side faces of the concave cartridge chamber  602 . The wall member  601 , the wall member  603 , the wall member  604 , the wall member  605  and the wall member  606  are respectively called “apparatus-side bottom wall member  601 ”, “first apparatus-side side wall member  603 ”, “second apparatus-side side wall member  604 ”, “third apparatus-side side wall member  605 ” and “fourth apparatus-side side wall member  606 ”. 
     Each of the printing material supply tubes  640  and each of the contact mechanisms  70  including the apparatus-side terminals are arrayed in the X-axis direction on the wall member  601 . The printing material supply tube  640  is located on the side of the wall member  604 , and the contact mechanism  70  is located on the side of the wall member  603 . In other words, the printing material supply tube  640  is provided at the position closer to the wall member  604  than the wall member  603 . The contact mechanism  70  is provided at the position closer to the wall member  603  than the printing material supply tube  640 . 
     The elastic member  648  is provided around the printing material supply tube  640  on the wall member  601 . As described above with reference to  FIG. 5 , the elastic member  648  seals the periphery of the ink supply structure  280  the cartridge  20  and thereby prevents leakage of ink from the ink supply structure  280  to the periphery in the attached state of the cartridge  20  to the holder  60 . The elastic member  648  generates the pressing force Ps in the direction of pressing back the ink supply structure  280  of the cartridge  20  (in the +Z-axis direction) in the attached state of the cartridge  20  to the holder  60  ( FIG. 5 ). 
     As shown in  FIGS. 14 to 16 , holder  60  has an opening OP on the upper side opposed to the wall member  601  across the cartridge chamber  602 . The cartridge  20  passes through the opening Op when the cartridge  20  is attached to or detached from the holder  60 . 
     The wall member  603  is vertically-angled relative to the wall member  601  on the +X-axis direction side of the wall member  601 . According to this embodiment, the most +X-axis direction side of the wall member  603  forms an outer wall  603 W. In the use attitude of the printer  50 , the outer wall  603 W forms the front face of the holder  60 . The outer wall  603 W is extended in the direction of the array of the plurality of cartridges  20  (Y-axis direction). A lever  80  used for attachment and detachment of the cartridge  20  is provided on the wall member  603 . A lever  80  is fixed in movable manner, or more precisely, in a rotatable manner to the wall member  603  via a retainer  690 . In other words, lever  80  is fixed to the retainer  690  forming part of the wall member  603 . An axis of rotation of the lever  80  is parallel to the Y-axis direction. 
     The retainer  690  is provided at a corner section (apparatus-side corner section)  600 C ( FIG. 17 ) where the side wall member  603  intersects the bottom wall member  601 . 
     As shown in  FIG. 5 , the operating member  830  is provided on the +Z-axis direction end of the lever  80 . When the user presses this operating member  830  from the +X-axis direction side toward the −X-axis direction side (i.e., when the user applies the operating force Pr to the operating member  830 ), the lever  80  is turned counterclockwise (seen from the +Y-axis direction) about the axis of rotation. The lever  80  is accordingly rotated on the XZ plane parallel to the X-axis direction and the Z-axis direction. 
     The lever  80  is provided as a separate member from the chamber-forming wall members  601 ,  603 ,  604 ,  605  and  606 . The lever  80  is made of a synthetic resin, more specifically polyacetal (POM) according to this embodiment. The lever  80  has a certain level of rigidity sufficient to lock the cartridge  20 . More specifically, the lever  80  preferably has rigidity that causes no substantial deformation of the lever  80  by a force (for example, force of 14.4 N) applied from the cartridge  20  in the attached state. For example, the deformation of the lever  80  by application of an external force of 14.4N from the cartridge  20  is preferably not greater than about 0.5 mm. The lever  80  preferably does not have any elastically deformable portion. This reduces the possibility that the lever  80  is significantly deformed by the force applied from the cartridge  20  in the attached state of the cartridge  20  and ensures the stable electrical connection between the cartridge-side terminals  400  and the apparatus-side terminals of the contact mechanism  70 . Providing the separate lever  80  from the chamber-forming wall members  601 ,  603 ,  604 ,  605  and  606  advantageously increases the degree of freedom in selection of the material for the lever  80 . 
     Referring back to  FIGS. 14 to 17 , the wall member  604  is vertically-angled relative to the wall member  601  on the −X-axis direction side of the wall member  601 . The wall member  604  is opposed to the wall member  603  across the cartridge chamber  602 . According to this embodiment, the wall member  604  forms the rear face of the holder  60  in the use attitude of the printer  50 . The wall member  604  is extended in the direction of the array of the plurality of cartridges  20  (Y-axis direction). The second apparatus-side restriction element  620  is provided on the wall member  604 . The second apparatus-side restriction element  620  is a through hole passing through the X-axis direction ( FIG. 17 ). According to another embodiment, the second apparatus-side restriction element  620  may be a recess open to the cartridge chamber  602 . 
     As described above with reference to  FIG. 5 , the second apparatus-side restriction element  620  is configured to engage with the second cartridge-side restriction element  220 . The second apparatus-side restriction element  620  serves as a guide for attachment and detachment of the cartridge  20  to and from the holder  60 . The second apparatus-side restriction element  620  locks the second cartridge-side restriction element  220  in the attached state of the cartridge  20  to the holder  60 . More specifically, the second apparatus-side restriction element  620  locks the second cartridge-side restriction element  220  at the second locking position  620 L located on the +Z-axis direction side and on the −X-axis direction side of the printing material supply tube  640 . According to this embodiment, the second apparatus-side restriction element  620  is structured as a through hole having the size to receive the second cartridge-side restriction element  220  and has an apparatus-side locking surface  622 . The apparatus-side locking surface  622  is a plane facing in the −Z-axis direction and locks the restriction locking surface  222  of the second cartridge-side restriction element  220  ( FIG. 11 ). A +X-axis direction end  624  of the apparatus-side locking surface  622  is in contact with the second cartridge-side restriction element  220  and accordingly serves as the pivot point of rotation for detachment of the cartridge  20  from the holder  60 . 
     As shown in  FIG. 17 , the second apparatus-side side wall member  604  of the holder  60  has a space  670  provided on the +Z-axis direction side of the second apparatus-side restriction element  620 . The space  670  provides a room to allow rotation of the cartridge  20  about the vicinity of the second apparatus-side restriction element  620  as the pivot point of rotation when the cartridge  20  is attached to or detached from the holder  60 . According to this embodiment, the space  670  is formed by steps recessed in the −X-axis direction stepwise in the +Z-axis direction from the second apparatus-side side wall member  604 . According to another embodiment, the space  670  may be formed by a sloped surface of the wall member  604  lowered in the −X-axis direction gradually in the +Z-axis direction. 
     As shown in  FIGS. 14 to 16 , the wall member  605  is vertically-angled relative to the wall member  601  on the −Y-axis direction side of the wall member  601 . According to this embodiment, the wall member  605  forms the right side face of the holder  60  in the use attitude of the printer  50 . The wall member  605  is connected with the wall members  603  and  604 . The wall member  605  is extended in the X-axis direction and crosses the direction of the array of the plurality of cartridges  20  (Y-axis direction). 
     The wall member  606  is vertically-angled relative to the wall member  601  on the +Y-axis direction side of the wall member  601 . The wall member  606  is opposed to the wall member  605  across the cartridge chamber  602 . According to this embodiment, the wall member  606  forms the left side face of the holder  60  in the use attitude of the printer  50 . The wall member  606  is connected with the wall members  603  and  604 . The wall member  606  is extended in the X-axis direction and crosses the direction of the array of the plurality of cartridges  20  (Y-axis direction). 
     According to the positional relationships of the wall members  601  and  603  to  606  described above, the wall member  601  is perpendicular to the Z-axis direction; the wall member  603  and the wall member  604  are opposed to each other in the X-axis direction; the wall member  605  and the wall member  606  are opposed to each other in the Y-axis direction; and the wall member  601  and the opening OP are opposed to each other in the Z-axis direction. 
     The contact mechanism  70  is provided at the corner section  600 C where the wall member  601  intersects the wall member  603  of the holder  60 . The contact mechanism  70  is located at the position closer to the wall member  603  than the printing material supply tube  640 . The contact mechanism  70  includes a plurality of apparatus-side terminals corresponding to and in contact with the respective terminals  431  to  439  of the cartridge-side terminals  400  ( FIG. 10 ), and a terminal base on which the plurality of apparatus-side terminals are located. 
     Detailed Structure of Contact Mechanism  70 : 
       FIG. 18  is a perspective view of the contact mechanism  70 , which is detached from the holder  60 . 
     The contact mechanism  70  includes a terminal base  709  and apparatus-side terminals or contact forming members  731  to  739  located on the terminal base  709 . Each of the apparatus-side terminals  731  to  739  is an elastic member having electrical conductivity and has a protruded portion from an apparatus-side sloped surface  708 , which is displaced by an external force. The apparatus-side terminals  731  to  739  generate the pressing or elastic force Pt in the direction of pressing back the circuit board  40  of the cartridge  20  (direction including the +Z-axis direction vector component and the −X-axis direction vector component) in the attached state of the cartridge  20  to the holder  60  ( FIG. 5 ). The elastic force Pt is generated as a reaction force when the cartridge  20  presses the apparatus-side terminals  731  to  739  protruded from the apparatus-side sloped surface  708  toward the apparatus-side sloped surface  708 . The resulting vector component of the elastic force PT generated by the apparatus-side terminals  731  to  739  urges the cartridge  20  in the removal direction RD, which is the direction opposite the mounting direction SD as described above. 
     The nine apparatus-side terminals  731  to  739  are provided at the positions corresponding to the nine cartridge-side terminals  431  to  439 . The apparatus-side terminal  731  is called “attachment detection terminal (third terminal)  731 ”. The apparatus-side terminal  732  is called “reset terminal  732 ”. The apparatus-side terminal  733  is called “clock terminal  733 ”. The apparatus-side terminal  734  is called “attachment detection terminal (fourth terminal)  734 ”. The apparatus-side terminal  735  is called “attachment detection terminal (first terminal)  735 ”. The apparatus-side terminal  736  is called “power terminal  736 ”. The apparatus-side terminal  737  is called “ground terminal  737 ”. The apparatus-side terminal  738  is called “data terminal  738 ”. The apparatus-side terminal  739  is called “attachment detection terminal (second terminal)  739 ”. For differentiation from the cartridge-side terminals, the word “apparatus-side” may be prefixed to each name. For example, the “ground terminal  737 ” may be called “apparatus-side ground terminal  737 ”. The nine apparatus-side terminals  731  to  739  are collectively called apparatus-side terminals  700 . 
     The nine apparatus-side terminals  731  to  739  are arrayed in a first apparatus-side terminal line and a second apparatus-side terminal line having different positions in the Z-axis direction. The first apparatus-side terminal line includes the five apparatus-side terminals  735  to  739 , and the second apparatus-side terminal line includes the four apparatus-side terminals  731  to  734 . The first apparatus-side terminal line is located on the −Z-axis direction side of the second apparatus-side terminal line. The number of the apparatus-side terminals is not limited to nine but may be varied to any desired number greater than nine or less than nine according to the structure of the circuit board  40 . 
     Among the nine apparatus-side terminals  731  to  739 , the apparatus-side ground terminal  737  located on the substantial center in the Y-axis direction is electrically connected with a ground line (not shown). The height of the apparatus-side ground terminal  737  protruded from the apparatus-side sloped surface  708  is greater than the height of the other apparatus-side terminals  731  to  736 ,  738  and  739 . The apparatus-side ground terminal  737  is accordingly in contact with the circuit board  40  of the cartridge  20  prior to the other apparatus-side terminals  731  to  736 ,  738  and  739 . 
     According to this embodiment, in order to accelerate assembling the printer, the apparatus-side terminals  731  to  739  are located on the terminal base  709  and are unitized to the contact mechanism  70 , which is incorporated in the holder  60 . The unitized contact mechanism  70  using the terminal base  709  is, however, not essential. According to another embodiment, a suitable structure for receiving the apparatus-side terminals  731  to  739  may be formed integrally with the bottom wall member  601  or the outer wall  603 W of the holder  60 , and the apparatus-side terminals  731  to  739  may be incorporated in the structure. The terminal base  709  is accordingly not essential. 
     Detailed Structure of Lever  80 : 
       FIG. 19  is a perspective view illustrating the appearance of the lever  80 .  FIG. 20  illustrates a cross section of a shaft body  850  taken on the plane parallel to the X axis and the Z axis (XZ plane, plane perpendicular to the Y axis).  FIG. 21  illustrates a cross section of the lever  80  taken on the plane that passes through the central region in the width direction (Y-axis direction) of the lever  80  and is parallel to the X axis and the Z axis (XZ plane, plane perpendicular to the Y axis).  FIG. 21  shows the cross section of the lever  80  in the state that the cartridge  20  is properly attached at the designed attachment position of the holder  60 . 
     As shown in  FIGS. 19 and 21 , the lever  80  includes the operating member  830 , a pair of shaft bodies  850 , a guide member  820 , and the engagement portion  810 . The lever  80  has the operating member  830  on one end (+Z-axis direction end) and the engagement portion  810  on the other side (−Z-axis direction end). The lever  80  has an axis of rotation  800   c  between the operating member  830  and the first apparatus-side restriction member  810 . In other words, the lever  80  pivots around the axis of rotation  800   c  at the position between the operating member  830  and the engagement portion  810 . 
     The operating member  830  of the lever  80  receives the external force applied by the user. As shown in  FIG. 21 , the operating member  830  is provided at the +Z-axis direction end of the lever  80 . The operating member  830  is located on the +Z-axis direction side of the axis of rotation  800   c  in the attached state of the cartridge  20  to the holder  60 . The operating member  830  is located on the +Z-axis direction side of the first apparatus-side side wall member  603  of the holder  60  ( FIG. 15 ). 
     The operating member  830  has an operation surface  835  and an operating-member opposed surface  831 . The operation surface  835  receives the external force (force Pr shown in  FIG. 5 ) applied by the user from the +X-axis direction side to the −X-axis direction side for detachment of the cartridge  20  from the holder  60 . The operating-member opposed surface  831  is a face opposed to the cartridge  20  in the attached state of the cartridge  20  to the holder  60 . 
     As shown in  FIG. 19 , the pair of shaft bodies  850  are provided at the substantially middle position between the ends of the lever  80 . The pair of shaft bodies  850  define the axis of rotation  800   c  of the lever  80 . The axis of rotation  800   c  is parallel to the Y-axis direction (direction of the array of the cartridges  20 ). One shaft body  850   a  of the pair of shaft bodies  850  (called “first shaft body  850   a ”) is protruded in the +Y-axis direction from an outer surface  893  on the +Y-axis direction side of the lever  80 . The other shaft body  850   b  of the pair of shaft bodies  850  (called “second shaft body  850   b ”) is protruded in the −Y-axis direction from an outer surface  891  on the −Y-axis direction side of the lever  80 . The outer surfaces  891  and  893  are also called side faces  891  and  893 . The pair of shaft bodies  850  provided on the lever  80  readily define the axis of rotation  800   c  by using a retainer as described later. 
     According to this embodiment, each of the shaft bodies  850  has an inner arc-shaped surface  852 , an outer arc-shaped surface  854 , and radial side faces  856  and  858 . The respective faces  852 ,  854 ,  856  and  858  form the circumferential surface of the shaft body  850 . The inner arc-shaped surface  852  and the outer arc-shaped surface  854  are respectively called “first curved surface  852 ” and “second curved surface  854 ”. The centers of the inner arc-shaped surface  852  and the outer arc-shaped surface  854  correspond to the axis of rotation  800   c . The inner arc-shaped surface  852  is located at the position closer to the second apparatus-side side wall member  604  than (i.e., on the −X-axis direction side of) the outer arc-shaped surface  854 . 
     As shown in  FIG. 20 , the inner arc-shaped surface  852  forms an arc of radius R 1   a  about the axis of rotation  800   c  on the cross section parallel to the X axis and the Z axis. The outer arc-shaped surface  854  forms an arc of radius R 2   a  about the axis of rotation  800   c  on the cross section parallel to the X axis and the Z axis. The radius R 1   a  is smaller than the radius R 2   a . As described above, each shaft body  850  has the concentric inner arc-shaped surface  852  and outer arc-shaped surface  854 , which is located at the position closer to the second apparatus-side side wall member  604  than the outer arc-shaped surface  854 , as part of the circumferential surface. The axis of rotation  800   c  can thus be located at the closer position to the cartridge  20  in the cartridge chamber  602  without interfering with the cartridge  20 . This enables the engagement portion  212  of the first restriction portion  210  of the cartridge  20  to be locked by the engagement portion  810 , while reducing a deviation from the first locking position  810 L. If the axis of rotation  800   c  were located at the distant position from the cartridge  20 , any shift of the lever  80  from the attachment position designed for the correctly mounted state of the cartridge  20  causes a significant displacement of the engagement portion  810  in the Z-axis direction. Locating the axis of rotation  800   c  at the closer position from the cartridge  20  advantageously reduces the displacement of the engagement portion  810  in the Z-axis direction when the lever  80  is shifted from the standard attitude in the state of the cartridge  20  properly attached at the designed attachment position. Namely such positioning enables the cartridge  20  to be locked by the engagement portion  810  with the less deviation from the first locking position  810 L. Setting the greater radius R 2   a  of the outer arc-shaped surface  854  than the radius R 1   a  of the inner arc-shaped surface  852  advantageously prevents the strength degradation of the shaft body  850 . The “locking position (first locking position)  810 L” means the position where a first apparatus-side locking surface  811  (first part of the engagement portion  810 ) abuts the first cartridge-side locking surface  211  (first abutting part of the first cartridge-side restriction portion  210 ) when the cartridge  20  is attached at the attachment position set as the ideal designed position. 
     The engagement portion  810  serves to lock the cartridge  20  in the attached state and restrict the motion of the cartridge  20 . As shown in  FIG. 21 , the engagement portion  810  is provided on the −Z-axis direction end of the lever  80 . The engagement portion  810  is located on the −Z-axis direction side of the axis of rotation  800   c  in the attached state of the cartridge  20  to the holder  60 . 
     As shown in  FIG. 21 , the engagement portion  810  locks the first cartridge-side restriction portion  210  ( FIG. 5 ) by two parts. The engagement portion  810  includes the first apparatus-side locking surface  811  as the first part (the first apparatus-side restriction element), a groove  815  and a second apparatus-side locking surface  813  as the second part (the second apparatus-side restriction element). According to this embodiment, the two apparatus-side locking surfaces  811  and  813  of the engagement portion  810  are located to intersect each other. 
     The first apparatus-side locking surface  811  is a curved surface in an arc shape around the axis of rotation  800   c . The first apparatus-side locking surface  811  accordingly has the arc shape around the axis of rotation  800   c  on the cross section parallel to the X axis and the Z axis (i.e., cross section parallel to the XZ plane, cross section perpendicular to the Y axis). For attachment of the cartridge  20  to the holder  60 , this structure enables the first apparatus-side locking surface  811  to be smoothly moved to the locking position  810 L and lock the cartridge  20 . For detachment of the cartridge  20  from the holder  60 , this structure enables the first apparatus-side locking surface  811  to smoothly unlock the cartridge  20 . This structure accordingly ensures smooth attachment and detachment of the cartridge  20  to and from the holder  60 . 
     At the locking position (first locking position)  810 L, the first apparatus-side locking surface  811  is close to the axis of rotation  800   c  in the X-axis direction. In other words, at the locking position (first locking position)  810 L, the first apparatus-side locking surface  811  is located approximately beneath the axis of rotation  800   c  according to this embodiment. More specifically, at the locking position (first locking position)  810 L, the first apparatus-side locking surface  811  is located on the slightly −X-axis direction side of the axis of rotation  800   c . At the locking position  810 L, the first apparatus-side locking surface  811  accordingly defines a plane intersecting at an approximately right angle the +Z-axis direction force which the cartridge  20  in the attached state receives from the apparatus-side terminals  700  and the elastic member  648 . According to this embodiment, the plane in contact with the first apparatus-side locking surface  811  as the curved surface is a substantially horizontal plane at the locking position  810 L. This reduces the possibility of releasing the engagement between the first cartridge-side locking surface  211  and the first apparatus-side locking surface  811  while the cartridge  20  is mounted in the printer. The first locking position  810 L in the X-axis direction is thus preferably the position close to the axis of rotation  800   c  and on the −X-axis direction side of the axis of rotation  800   c . This makes the plane in contact with the first apparatus-side locking surface  811  substantially horizontal and prevents application of the +X-axis direction force from the cartridge  20  in the attached state to the first apparatus-side locking surface  811 . Locating the first locking position  810 L close to the axis of rotation  800   c  in the X-axis direction advantageously reduces a deviation of the locking position in the Z-axis direction even when the actual locking position of the first cartridge-side locking surface  211  and the first apparatus-side locking surface  811  is slightly deviated from the first locking position  810 L. In other words, this reduces the deviation of the cartridge  20  in the Z-axis direction relative to the holder  60  and ensures the good electrical connection of the cartridge-side terminals  400  with the apparatus-side terminals  700 . For example, on the cross section of the lever  80  taken on the plane parallel to the X axis and the Z axis, the first locking position  810 L should be located, such that an angle A between the straight line passing through the axis of rotation  800   c  and parallel to the Z-axis direction and the straight line connecting the axis of rotation  800   c  with the first locking position  810 L is preferably not greater than 15 degrees, more preferably not greater than 10 degrees, and further preferably not greater than 5 degrees. The angle A is also preferably not less than 1 degree. 
     As shown in  FIG. 19 , the guide member  820  is provided between the operating member  830  and the engagement portion  810  to be extended from the +Z-axis direction end to the −Z-axis direction end. The guide member  820  serves to guide the first cartridge-side restriction portion  210  (shown in  FIG. 12 ) to the engagement portion  810 , while restricting the motion of the cartridge  20  in the Y-axis direction in the course of attachment of the cartridge  20  to the holder  60 . The cartridge  20  can thus be properly attached at the designed attachment position. 
     The guide member  820  is a recess formed by a guide bottom wall  821  provided along the Y-axis direction and a pair of guide walls  860  being vertically-angled toward the −X-axis direction from the guide bottom wall  821 . The guide bottom wall  821  and the pair of guide walls  860  readily form the recess to receive the first cartridge-side restriction portion  210  structured as the projection. The pair of guide walls  860  include a first guide wall  860   a  provided on the +Y-axis direction side and a second guide wall  860   b  provided on the −Y-axis direction side. The shaft body  850   a  is located on the outer surface  893  of the first guide wall  860   a , whilst the shaft body  850   b  is located on the outer surface  891  of the second guide wall  860   b.    
     The space between the two guide walls  860   a  and  860   b , i.e., the distance between the inner surfaces of the two guide walls  860   a  and  860   b , is less than the Y-axis direction length of the cartridge  20  but is greater than the Y-axis direction length of the first cartridge-side restriction portion  210  (as can be seen in  FIG. 12 ). For attachment of the cartridge  20  to the holder  60 , the first cartridge-side restriction portion  210  is received by the guide member  820  and is readily and securely guided to the engagement portion  810 , while the pair of guide walls  860   a  and  860   b  restrict the motion of the cartridge  20  in the Y-axis direction and the guide bottom wall  821  restricts the motion of the cartridge  20  in the Z-axis direction. 
     One part of the guide bottom wall  821  on the side of the engagement portion  810  has a groove  870  configured to receive the second portion  214  of the first cartridge-side restriction portion  210  ( FIG. 12 ). The groove  870  is recessed from the surface of the guide bottom wall  821  in the +X-axis direction. The groove  870  is extended from the middle in the +Z-axis direction of the guide bottom wall  821  to its −Z-axis direction end. 
     The lever  80  set on the holder  60  is configured to move the first apparatus-side locking surface  811  to the first locking position  810 L by its dead weight. The lever  80  is tilted to locate the first apparatus-side locking surface  811  on the −X-axis direction side of the axis of rotation  800   c  ( FIG. 21 ), when the shaft bodies  850  are retained by the retainer  690 . According to one embodiment, the lever  80  may be tilted by locating the center of gravity of the lever  80  on the −Z-axis direction side and on the −X-axis direction side of the axis of rotation  800   c . According to another embodiment, the lever  80  may be tilted by locating the center of gravity of the lever  80  on the +Z-axis direction side and on the +X-axis direction side of the axis of rotation  800   c.    
     Detailed Structure of Retainer  690 : 
       FIG. 22  is an exploded perspective view of the retainer  690  and a perspective view of the lever  80 . The lever  80  is retained by the retainer  690 , so as to be attached to the holder  60  in a rotatable manner.  FIG. 22  shows partial structure of the retainer  690  to retain the lever  80 . The retainer  690  is structured by a combination of a first retainer member  650  and a second retainer member  680 . The retainer  690  is made of a synthetic resin, more specifically ABS resin according to this embodiment. 
     The first retainer member  650  has a pair of standing portions  651  and a through hole  658 . According to this embodiment, the first retainer member  650  also has the projection  636  serving as the third apparatus-side restriction element. 
     The pair of standing portions  651  of the first retainer member  650  are arranged across a space for receiving the lever  80 . Each of the standing portions  651  has a bearing element  654  to receive the shaft body  850  of the lever  80 . According to this embodiment, each of the standing portions  651  also has an engagement hole  656  serving to engage the second retainer member  680 . 
     The second retainer member  680  has a pair of standing portions  681  and a through hole  688 . According to this embodiment, the second retainer member  680  also has an elastic member  682 . 
     The pair of standing portions  681  of the second retainer member  680  are arranged across the same space as that between the pair of standing portions  651  of the first retainer member  650 . Each of the standing portions  681  has a block surface  684  to block the bearing element  654 , in order to prevent the shaft body  850  of the lever  80  from being unintentionally uncoupled from the bearing element  654 . According to this embodiment, each of the standing portions  681  also has an engagement projection  686  to be fit in the engagement hole  656  of the first retainer member  650 . 
     For attachment of the lever  80  to the holder  60 , the lever  80  is located between the pair of standing portions  651  by setting the respective shaft bodies  850  of the lever  80  into the corresponding bearing elements  654  of the pair of standing portions  651  of the first retainer member  650 . Subsequently the two retainer members  650  and  680  are assembled, so that the bearing elements  654  with the shaft bodies  850  of the lever  80  fit therein are blocked by the corresponding block surfaces  684  of the second retainer member  680 . The first and second retainer members  650  and  680  are then fixed to the wall of the holder  60 , for example, with screws set in the through holes  658  and  688 . This attaches the lever  80  to the holder  60  in a rotatable manner. 
       FIG. 23  is a sectional view showing the structure of the periphery of the lever  80  in the attached state of the cartridge  20  to the holder  60 . The relationship between the shaft body  852  of the lever  80  and the bearing element  654  of the first retainer member  650  is described with reference to  FIG. 23 .  FIG. 23  shows the cross section of the lever  80  locking the cartridge  20  taken on the plane passing through the first apparatus-side locking surface  811  and parallel to the X axis and the Z axis. The broken line in  FIG. 23  shows the projected shape of the shaft body  850  of the lever  80 , and the two-dot chain line shows the projected shape of the bearing element  654  and the block surface  684 . 
     As clearly understood from  FIG. 23 , the axis of rotation  800   c  of the lever  80  is positioned through the contact of the inner arc-shaped surface  852  and the outer arc-shaped surface  854  of the shaft body  850  with the bearing element  654 . Turning the lever  80  counterclockwise (seen from the +Y-axis direction) causes the radial side face  856  of the shaft body  850  to abut the bearing element  654 . This restricts further counterclockwise rotation of the lever  80  (seen from the +Y-axis direction). Turning the lever  80  clockwise (seen from the +Y-axis direction) causes the radial side face  858  of the shaft body  850  to abut the block surface  684 . This restricts further clockwise rotation of the lever  80  (seen from the +Y-axis direction). This ensures stable rotation of the lever  80  and keeps the cartridge  20  at the designed attachment position in the stable state. 
     During rotation of the lever  80 , the elastic member  682  abuts an engagement rear face  880  of the lever  80  located on the −Z-axis direction side of the axis of rotation  800   c . The elastic member  682  accordingly limits the rotatable range of the lever  80  during attachment and detachment of the cartridge  20  to and from the holder  60 . In attachment of the cartridge  20  to the holder  60 , the elastic member  682  abuts the engagement rear face  880  of the lever  80  and is elastically deformed, so as to press the engagement rear face  880  in the direction including the −X-axis direction vector component. This ensures the movement of the engagement portion  810  of the lever  80  to the locking position (first locking position)  810 L. 
     Attachment and Detachment of Cartridge  20  to and from Holder  60 : 
       FIGS. 24 to 27  show the procedure for attachment or mounting of the cartridge  20  to the holder  60  (attachment procedure).  FIGS. 24 to 27  are sectional views corresponding to  FIGS. 5 and 17  and are arranged in time series in this order. 
     For attachment of the cartridge  20  to the holder  60 , the procedure first inserts the cartridge  20  through the top face of the holder  60  as shown in  FIG. 24 . The procedure then moves the cartridge  20  in the −Z axis direction or mounting direction to make the second cartridge-side restriction element  220 -side of the cartridge  20  enter first into the holder  60  and inserts the second cartridge-side restriction element  220  into the second apparatus-side restriction element  620 . In the state of  FIG. 24 , the first cartridge-side restriction portion  210  of the cartridge  20  is located on the +Z-axis direction side of the engagement portion  810  of the lever  80  in the holder  60 . 
     The cartridge  20  is pivoted clockwise (seen from the +Y-axis direction) about the second cartridge-side restriction element  220 , which is inserted in the second apparatus-side restriction element  620 , as the pivot point of rotation from the state of  FIG. 24 , so that the third face  203 -side of the cartridge  20  is moved toward the bottom wall member  601  of the holder  60 . As shown in  FIG. 25 , the first cartridge-side restriction portion  210  then moves in the −Z-axis direction, while the motion of the cartridge  20  in the Y-axis direction and in the X-axis direction is restricted by the guide member  820  of the lever  80 , i.e., the pair of guide walls  860   a  and  860   b , and by the guide bottom wall  821  shown in  FIG. 19 . 
     When the cartridge  20  is further turned from the state of  FIG. 25  to press in its third face  203 -side, the first cartridge-side restriction portion  210  is further pressed in the −Z-axis direction. As shown in  FIG. 26 , the lever  80  is then pressed in the −X-axis direction by the first cartridge-side restriction portion  210  to turn counterclockwise (seen from the +Y-axis direction). The lever  80  abuts the elastic member  682  and receives the pressing force from the elastic member  682  in the direction to press back the lever  80  clockwise (seen from the +Y-axis direction). This pressing force is an external force including a −X-axis direction vector component. The rotatable range of the lever  80  is accordingly limited by the elastic member  682 . This state of  FIG. 26  where the lever  80  abuts the elastic member  682  and is pressed by the elastic member  682  maintains until the cartridge  20  is further pressed in and the first cartridge-side restriction portion  210  rides over the guide member  820  of the lever  80 . 
     When the cartridge  20  is further turned from the state of  FIG. 26  to press in its third face  203 -side, the first cartridge-side restriction portion  210  eventually rides over the guide member  820  of the lever  80 . The lever  80  is then turned to move the first cartridge-side restriction portion  210  in the −X-axis direction as shown in  FIG. 27 . The engagement portion  810  accordingly moves to the first locking position  810 L and locks the first cartridge-side restriction portion  210  at the first locking position  810 L. More specifically, as shown by the lower right close-up view, the first apparatus-side locking surface  811  (first part) of the engagement portion  810  abuts the first cartridge-side locking surface  211  (first abutting part) of the first cartridge-side restriction portion  210 , so as to restrict the motion of the cartridge  20  in the +Z-axis direction. The second apparatus-side locking surface  813  (second part) of the engagement portion  810  also abuts the second cartridge-side locking surface  213  (second abutting part) of the first cartridge-side restriction portion  210 , so as to restrict the motion of the cartridge  20  in the +X-axis direction. Although the first cartridge-side locking surface  211  and second cartridge-side locking surface  213  are shown in the close-up view of  FIG. 27  as being two separate substantially orthogonal surfaces, as can be seen in  FIG. 27A , the first portion  212  of the first restriction portion  210  can be formed with a curved surface so that the first cartridge-side locking surface  211  and second cartridge-side locking surface  213  are configured as separate sections of the same surface. Alternatively, as can be seen in  FIG. 27B , the first portion  212  of the first restriction portion  210  can be formed with a flat slanted surface or other shape so that the first cartridge-side locking surface  211  and second cartridge-side locking surface  213  are configured as separate sections of the same surface. As part of the mounting, the ink supply structure  280  of the cartridge  20  is then connected with the printing material supply tube  640 , while the second cartridge-side restriction element  220  engages with the second apparatus-side restriction element  620  and the first cartridge-side restriction portion  210  engages with the engagement portion  810 . This completes the attachment of the cartridge  20  to the holder  60 . The proper attachment of the cartridge  20  at the designed attachment position makes electrical connection between the cartridge-side terminals  400  and the apparatus-side terminals  700 , so as to allow signal transmission between the cartridge  20  and the printer  50 . 
     According to this embodiment, as shown in  FIGS. 23 and 27 , the elastic member  682  is configured not to abut the lever  80  and thereby not to apply an external force to the lever  80  in the attached state of the cartridge  20  to the holder  60 . This reduces the possibility of plastic deformation of the lever  80  by external force and the possibility of deviation of the engagement portion  810  from the first locking position  810 L. This accordingly ensures stable electrical connection between the cartridge-side terminals  400  and the apparatus-side terminals  700 . 
     According to another embodiment, the elastic member  682  may be designed to abut the lever  80  and thereby apply a force to the lever  80  in the direction including the −X-axis direction vector component in the attached state of the cartridge  20  to the holder  60 . In this application, the elastic member  682  continuously applies the force to the lever  80  in the direction including the −X-axis direction vector component, irrespective of the position of the lever  80 . This moves the engagement portion  810  with sufficient force to the first locking position  810 L for attachment of the cartridge  20  to the holder  60 . This gives the hard click to inform the user of locking the cartridge  20  by the engagement portion  810 . 
     According to another embodiment, the elastic member  682  may be omitted. This application decreases the total number of parts. 
     The procedure of detachment of the cartridge  20  from the holder  60  is described. For detachment of the cartridge  20  from the holder  60 , the user presses the operating member  830  in the −X-axis direction. In other words, the user applies the external force Pr ( FIG. 5 ) to the operating member  830  in the direction including the −X-axis direction vector component. The lever  80  then moves the engagement portion  810  around the axis of rotation  800   c  in the direction including the +X-axis direction vector component. Simultaneously the first cartridge-side locking surface  211  rotates and moves in the direction of arrow Y 22  shown in  FIG. 23 . This disengages the first cartridge-side restriction portion  210  from the engagement portion  810  and eliminates the restriction on the motion of the third face  203 -side of the cartridge  20  in the +Z-axis direction. Eliminating the restriction on the motion of the cartridge  20  in the +Z-axis direction causes the third face  203 -side of the cartridge  20  to move in the +Z-axis direction by the pressing force Pt from the contact mechanism  70 . This moves the cartridge  20  from the state of  FIG. 27  to the state of  FIG. 26 . The cartridge  20  is further turned counterclockwise (seen from the +Y-axis direction) about the second cartridge-side restriction element  220  inserted in the second apparatus-side restriction element  620  as the pivot point of rotation, in order to pull away the third face  203 -side of the cartridge  20  from the bottom wall member  601  of the holder  60 . This moves the cartridge  20  from the state of  FIG. 26  to the state of  FIG. 25  and further to the state of  FIG. 24 . The user may apply force to the projection  260  in the direction including the −X-axis direction vector component, in order to turn the cartridge  20 . This operation turns the third face  203 -side of the cartridge  20  counterclockwise (seen from the +Y-axis direction) and moves the third face  203 -side of the cartridge  20  in the +Z-axis direction. The user holds the third face  203 -side of the cartridge  20  and pulls away the second cartridge-side restriction element  220  from the second apparatus-side restriction element  620 , so as to remove the cartridge  20  from the holder  60 . 
     As shown in the close-up view of  FIG. 27 , the operating member  830  of the lever  80  includes the operating-member opposed surface  831 . For removal of the cartridge  20  in the attached state from the holder  60 , when the user presses the operating member  830 , the operating-member opposed surface  831  is in contact with the projection  260 . The operating-member opposed surface  831  is inclined in a direction including a −X-axis direction vector component and a +Z-axis direction vector component. Turning the lever  80  about the axis of rotation  800   c  in the direction of arrow Y 27  causes the operating-member opposed surface  831  to be in contact with the projection  260  and presses the projection  260  in a direction Yh including the −X-axis direction vector component and the +Z-axis direction vector component. This facilitates detachment of the cartridge  20  from the holder  60 . Even when the cartridge  20  is stuck by some part of the holder  60  and is not moved in the +Z-axis direction through the travel of the first cartridge-side locking surface  211  from the first locking position  810 L in the +X-axis direction, the third face  203 -side of the cartridge  20  can be moved in the +Z-axis direction by using the operating-member opposed surface  831  and the projection  260 . 
     Attachment Detection Method Using Attachment Detection Terminals: 
       FIG. 28  is a block diagram illustrating the electrical structure of the circuit board  40  of the cartridge  20  and the printer  50  according to the first embodiment. The printer  50  includes a display panel  590 , a power circuit  580 , a main control circuit  570  and a sub-control circuit  550 . The display panel  590  serves as a display unit to notify the user of various information, for example, the operating condition of the printer  50  and the attachment state of the cartridge  20 . The display panel  590  may be provided on an operation unit (not shown) visible from outside of the printer  50 . The power circuit  580  includes a first power supply  581  to generate a first power-supply voltage VDD and a second power supply  582  to generate a second power-supply voltage VHV. The first power-supply voltage VDD is the ordinary power-supply voltage (e.g., rated voltage of 3.3 V) used for logic circuits. The second power-supply voltage VHV is the high voltage (e.g., rated voltage of 42 V) used to drive the head  540  ( FIG. 2 ) for ink ejection. These voltages VDD and VHV are supplied to the sub-control circuit  550 , while being supplied to the other circuits as needed basis. The main control circuit  570  includes a CPU  571  and a memory  572 . The sub-control circuit  550  includes a memory control circuit  551  and an attachment detection circuit  552 . The circuit structure including the main control circuit  570  and the sub-control circuit  550  is called “control circuit”. 
     Among the nine terminals provided on the circuit board  40  of the cartridge  20  ( FIG. 10 ), the reset terminal  432 , the clock terminal  433 , the power terminal  436 , the ground terminal  437  and the data terminal  438  are electrically connected with the memory unit  420 . The memory unit  420  is a nonvolatile memory without an address terminal. In the memory unit  420 , a memory cell to be accessed is determined, based on the pulse number of clock signal SCK input from the clock terminal  433  and command data input from the data terminal  438 . The memory unit  420  receives data from the data terminal  438  or sends data to the data terminal  438 , in synchronism with the clock signal SCK. The clock terminal  433  is used to supply the clock signal SCK from the sub-control circuit  350  to the memory unit  420 . The printer  50  applies the power-supply voltage (for example, rated voltage of 3.3 V) for driving the memory unit  420  and the ground voltage (0 V) respectively to the power terminal  436  and to the ground terminal  437 . The power-supply voltage for driving the memory unit  420  may be the first power-supply voltage VDD directly applied by the printer  50  or may be generated from the first power-supply voltage VDD to be lower than the first power-supply voltage VDD. The data terminal  438  is used for transmission of data signal SDA between the sub-control circuit  550  and the memory unit  420 . The reset terminal  432  is used to supply reset signal RST from the sub-control circuit  550  to the memory unit  420 . The four attachment detection terminals  431 ,  434 ,  435  and  439  are interconnected by wiring in the circuit board  40  of the cartridge  20  ( FIG. 3 ) and are all grounded. For example, the attachment detection terminals  431 ,  434 ,  435  and  439  are connected with the ground terminal  437  to be grounded. According to another embodiment, the attachment detection terminals  431 ,  434 ,  435  and  439  may be grounded by any connection path without the ground terminal  437 . As clearly understood from this description, the attachment detection terminals  431 ,  434 ,  435  and  439  may be connected with part of the memory terminals (or memory unit  420 ), but is preferably not connected with any memory terminals other than the ground terminal  437  or the memory unit  420 . Non-connection of the attachment detection terminals with the memory terminal or the memory unit results in application of no signal or voltage other than an attachment check signal to the attachment detection terminals and thus ensures the accurate attachment detection. The four attachment detection terminals  431 ,  434 ,  435  and  439  are interconnected by wiring in the illustrated example of  FIG. 28 , but part of the connection path may be replaced by a resistance. 
     In  FIG. 28 , path names SCK, VDD, SDA, RST, OV 1 , OV 2 , DT 1  and DT 2  are assigned to the respective connection paths connecting the apparatus-side terminals  731  to  739  with the cartridge-side terminals  431  to  439  of the circuit board  40 . The signal names are used for the path names with respect to the connection paths to the memory unit  420 . 
       FIG. 29  illustrates the connection between the circuit board  40  and the attachment detection circuit  552 . The four attachment detection terminals  431 ,  434 ,  435  and  439  of the circuit board  40  are connected with the attachment detection circuit  552  via the corresponding apparatus-side terminals  731 ,  734 ,  735  and  739 . The four attachment detection terminals  431 ,  434 ,  435  and  439  of the circuit board  40  are grounded. The connection paths between the apparatus-side terminals  731 ,  734 ,  735  and  739  and the attachment detection circuit  552  are respectively connected to the power-supply voltage VDD (rated voltage of 3.3 V) in the sub-control circuit  550  via pull-up resistance. 
     In the illustrated example of  FIG. 29 , the three terminals  431 ,  434  and  435  of the four attachment detection terminals  431 ,  434 ,  435  and  439  on the circuit board  40  have good connection with the corresponding apparatus-side terminals  731 ,  734  and  735 . The attachment detection terminal  439 , however, has poor connection with the corresponding apparatus-side terminal  739 . The voltage level of the connection paths for the three apparatus-side terminals  731 ,  734  and  735  in the good connection state is L level (ground voltage level), whilst the voltage level of the connection path for the apparatus-side terminal  739  in the poor connection state is H level (power-supply voltage VDD level). The attachment detection circuit  552  may check the voltage levels of these connection paths, so as to identify the good/poor connection state with respect to each of the four attachment detection terminals  731 ,  734 ,  735  and  739 . 
     The contact portions cp of the four attachment detection terminals  431 ,  434 ,  435  and  439  on the circuit board  40  are located outside a first area  400 P, which includes the contact portions cp of the memory terminals  432 ,  433 ,  436 ,  437  and  438 . The contact portions cp of the four attachment detection terminals  431 ,  434 ,  435  and  439  are located at four corners of a quadrilateral second area  400 T, which includes the first area  400 P. The first area  400 P is preferably a smallest possible quadrilateral including the contact portions cp of the five memory terminals  432 ,  433 ,  436 ,  437  and  438 . The second area  400 T is preferably a smallest possible quadrilateral including all the contact portions cp of the cartridge-side terminals  431  to  439 . 
     In the state of good contact for all the four attachment detection terminals  431 ,  434 ,  435  and  439 , the cartridge  20  has no significant tilt and ensures the good contact for the memory terminals  432 ,  433 ,  436 ,  437  and  438 . In the state of poor contact for any one or more of the four attachment detection terminals  431 ,  434 ,  435  and  439 , on the other hand, the cartridge  20  has a significant tilt and may cause the poor contact for any one or more of the memory terminals  432 ,  433 ,  436 ,  437  and  438 . According to a preferable embodiment, in the state of poor contact for any one or more of the four attachment detection terminals  431 ,  434 ,  435  and  439 , the attachment detection circuit  552  displays information (character string or image) indicating the failed attachment on the display panel  390  to notify the user of the failed attachment. 
     The contact portions cp of the attachment detection terminals  431 ,  434 ,  435  and  439  are arranged at the four corners surrounding the first area  400 P including the contact portions cp of the memory terminals  432 ,  433 ,  436 ,  437  and  438 , because of the following reason. In the attached state of the cartridge  20  to the holder  60 , there is a certain margin for tilting the cartridge  20 , so that the circuit board  40  of the cartridge  20  may be inclined relative to the contact mechanism  70  of the holder  60 . For example, tilting the cartridge  20  to make the terminals  431  to  434  (more specifically their contact portions) in the upper line R 2  ( FIG. 10A ) on the circuit board  40  more distant from the contact mechanism  70  than the terminals  435  to  439  (more specifically their contact portions) in the lower line R 1  ( FIG. 10A ) may result in the poor contact for any of the terminals  431  to  434  in the upper line R 2 . Tilting the cartridge  20  to make the terminals  435  to  439  (more specifically their contact portions) in the lower line R 1  on the circuit board  40  more distant from the contact mechanism  70  than the terminals  431  to  434  (more specifically their contact portions) in the upper line R 2  may result in the poor contact for any the terminals  435  to  439  in the lower line R 1 . Tilting the cartridge  20  to make the left edge of the circuit board  40  ( FIG. 10A ) more distant from the contact mechanism  70  than the right edge may result in the poor contact for any of the terminals  431 ,  432 ,  435 ,  436  and  437  on the left side of the circuit board  40 . Tilting the cartridge  20  to make the right edge of the circuit board  40  more distant from the contact mechanism  70  than the left edge may result in the poor contact for any of the terminals  433 ,  434 ,  437 ,  438  and  439  on the right side of the circuit board  40 . The poor contact may cause an error in reading data from the memory unit  420  or in writing data into the memory unit  420 . Checking the contact portions cp of all the four attachment detection terminals  431 ,  434 ,  435  and  439 , which are arranged at the four corners outside the first area  400 P including the contact portions cp of the memory terminals  432 ,  433 ,  436 ,  437  and  438 , for the good/poor contact advantageously prevents the poor contact and a resulting access error in the memory unit  420  due to such tilting of the cartridge  20 . 
     Advantageous Effects of Embodiment: 
     Certain of the advantageous effects of this embodiment compared with the structures disclosed in U.S. Publication No. 2005/0151811, and U.S. Pat. No. 6,276,780 mentioned previously. 
     In the printing material supply system  10  according to this embodiment, the lever  80  is provided on the holder  60 , and the first cartridge-side restriction portion  210  is provided on the cartridge  20 . The cartridge-side restriction portion  210  is located on the −Z-axis direction side of the axis of rotation  800   c  of the lever  80 . The engagement member for engaging with the holder is not located at the position between the axis of rotation and the operating member of the lever, unlike the structures in U.S. Publication No. 2005/0151811 in which the lever is integral with the cartridge. There is accordingly no need to make a relatively large distance between the lever and the cartridge side face. The structure of the embodiment accordingly shortens the distance between the lever  80  and the third face  203  of the cartridge  20 , i.e., the dimension in the X-axis direction, while shortening the length of the lever, i.e., the dimension in the Z-axis direction. This allows significant size reduction of the printer  50  and the whole printing material supply system  10 , as well as size reduction of packaging for transportation and distribution of the cartridges  20 , which advantageously reduces the transportation cost and the parts cost. This advantageous effect is not achieved by simply providing the lever on the printer holder instead of the cartridge as described in U.S. Pat. No. 6,276,780. This advantageous effect is achieved by providing the axis of rotation  800   c  of the lever  80  between the operating member  830  and the engagement portion  810  and locating the cartridge-side restriction portion  210  on the −Z-axis direction side of the axis of rotation  800   c  of the lever  80 . 
     The printing material supply system  10  according to the embodiment includes the relatively short lever  80  and the first cartridge-side restriction portion  210  of the small size and the simple structure (e.g., projection). This increases the rigidity of the lever  80  and the first cartridge-side restriction portion  210 , compared with the structures described in U.S. Publication No. 2005/0151811, and allows the relatively high-rigidity material to be selected for the lever  80  and the first cartridge-side restriction portion  210  (cartridge  20 ). This results in significantly reducing the possibility of plastic deformation or creep deformation of the lever  80  and the first cartridge-side restriction portion  210 . In the attached state, the cartridge  20  can be kept at the proper position in the holder  60 , which maintains the normal or good contact between the cartridge-side terminals  431  to  439  and the apparatus-side terminals  731  to  739  and reduces the poor continuity. Since the first cartridge-side restriction portion  210  of this embodiment has the small size and the simple structure, no special care to prevent plastic deformation of the lever is required in packaging for transportation and distribution of the cartridges  20 , especially in vacuum packaging, unlike the cartridges of U.S. Publication No. 2005/0151811. This improves the user&#39;s convenience. Providing the projection as the first cartridge-side restriction portion  210  as described in the embodiment is especially preferable for this advantageous effect. 
     In the printing material supply system  10  according to the embodiment, the cartridge-side restriction portion  210  is located on the −Z-axis direction side of the axis of rotation  800   c  of the lever  80 . As described previously, the apparatus-side terminals  731  to  739  generate the pressing force Pt in the direction of pressing back the circuit board  40  (i.e., in the direction including the +Z-axis direction vector component and the −X-axis direction vector component) in the attached state of the cartridge  20 . This pressing force Pt is expected to move the cartridge  20  in the +Z-axis direction in the attached state. In the printing material supply system  10  of the embodiment, however, the axis of rotation  800   c  of the lever  80  is located on the −Z-axis direction side of the first cartridge-side restriction portion  210 , so that the lever  80  restricts the motion of the cartridge  20  from the +Z-axis direction side to the −Z-axis direction side. 
     According to this embodiment, the first cartridge-side restriction portion  210  is located on the −Z-axis direction side and on the −X-axis direction side of the axis of rotation  800   c  of the lever  80 . When the cartridge  20  moves in the +Z-axis direction, rotational moment arises on the lever  80  as shown by arrow M in  FIG. 5 . This moment acts to cause the first cartridge-side restriction portion  210  to be strongly pressed in the −X-axis direction by the engagement portion  810 . This moment also acts to move the engagement portion  810  of the lever  80  in accordance with moving the cartridge  20  in the −X-axis direction by the X-axis direction vector component of the pressing force Pt. The cartridge  20  in the attached state accordingly receives the force to be pressed against the apparatus-side bottom wall member  601  and the second apparatus-side side wall member  604 . This structure of the embodiment prevents the cartridge  20  from being unintentionally uncoupled from the holder  60 , thus maintaining the normal or good contact between the cartridge-side terminals  431  to  439  and the apparatus-side terminals  731  to  739  and reducing the possibility of poor continuity. 
     As shown in  FIG. 27 , the first cartridge-side restriction portion  210  includes the first cartridge-side locking surface  211  that abuts the first part  811  of the engagement portion  810  to restrict the motion of the cartridge  20  in the +Z-axis direction, and the second cartridge-side locking surface  213  that abuts the second part  812  of the engagement portion  810  to restrict the motion of the cartridge  20  in the +X-axis direction. This ensures production of the rotational moment as shown by the arrow M in  FIG. 5  and more effectively reduces the possibility of poor continuity between the cartridge-side terminals  431  to  439  and the apparatus-side terminals  731  to  739 . 
     As shown in  FIG. 12 , according to this embodiment, the first cartridge-side restriction portion  210  has the second portion  214 . The first cartridge-side restriction portion  210  reduces the possibility that the first cartridge-side restriction portion  210  is locked at the position on the −Z-axis direction side of the engagement portion  810  in attachment of the cartridge  20  to the holder  60 . In the course of attachment of the cartridge  20  to the holder  60 , the user may press the cartridge  20  deeper in the −Z-axis direction into the holder  60  than the state of  FIG. 27 . Even in this case, the second portion  214  of the first cartridge-side restriction portion  210  abuts the second apparatus-side locking surface  813  of the lever  80 , so as to prevent the first cartridge-side restriction portion  210  from being located on the −Z-axis direction side of the engagement portion  810 . This reduces the possibility that the first cartridge-side restriction portion  210  is locked by the engagement portion  810  at the unintended locking position. 
     Reduction of Effects of External Force in Attached State of Cartridge: 
       FIG. 30  shows the external force applied to the cartridge  20  in the attached or mounted state. During printing operation of the printer  50 , the holder  60  and the cartridge  20  move reciprocally in the main scanning direction (Y-axis direction or width direction of the cartridge  20 ). The cartridge  20  accordingly receives external force (inertial force) during acceleration and deceleration of the holder  60  in the width direction. The cartridge  20  receiving the external force may turn about the ink supply structure  280  ( FIG. 27 ) and the printing material supply tube  640  in the rotating direction including the width direction vector component (Y-axis direction vector component). More specifically, the third face  203 -side of the cartridge  20  may turn in the direction of arrow YR 1 , while the fourth face  204 -side of the cartridge  20  may turn in the direction of arrow YR 2 . The second face  202 -side of the cartridge  20  may also turn in the direction of arrow YR 3 . The direction of arrow YR 1  and the direction of arrow YR 2  are the rotating direction about the Z axis, which includes the Y-axis direction vector component (width direction vector component). The direction of arrow YR 3  is the rotating direction about the X axis, which includes the Y-axis direction vector component (width direction vector component). 
     Moving the cartridge  20  in the direction of arrow YR 3  causes either the fifth face  205  or the sixth face  206  of the cartridge  20  to be pulled up in the +Z-axis direction. As described previously, however, such motion of the cartridge  20  in the +Z-axis direction is restricted by the lever  80 . According to this embodiment, the first cartridge-side restriction portion  210  is close to the intersecting part  295  as shown in  FIG. 13 . In other words, the first cartridge-side restriction portion  210  is close to the board end  405  of the circuit board  40 . The first cartridge-side restriction portion  210  is arranged as close as possible to the cartridge-side terminals  400 . Since the first cartridge-side restriction portion  210  is locked by the lever  80 , the periphery of the first cartridge-side restriction portion  210  has substantially no position shift by the external force. Providing the cartridge-side terminals  400  at the location of extremely small position shift effectively prevents the positional misalignment of the respective terminals  431  to  439  of the cartridge-side terminals  400  relative to the holder  60 , thus maintaining the stable electrical connection between the cartridge-side terminals  400  and the apparatus-side terminals  700 . In order to ensure this advantageous effect, it is preferable to locate at least part of the first cartridge-side restriction portion  210  (specifically the first cartridge-side locking surface  211 ) between the first outer part  435 P and the second outer part  439 P ( FIG. 10A ) in the Y-axis direction (width direction) (when the cartridge  20  is viewed from the third face  203 -side in the −X-axis direction). 
     As shown in  FIG. 7 , according to this embodiment, the corner section  265  of the cartridge  20  has the step (seventh face)  207  extended in the +Z-axis direction from the first face  201 . The seventh face  207  is located on the −X-axis direction side and on the −Z-axis direction side of the sloped surface (eighth face)  208 . The seventh face  207  has the third cartridge-side restriction element  250 . As shown in  FIG. 2  and  FIGS. 14 to 16 , the holder  60  has the third apparatus-side restriction element (projection)  636 . The third cartridge-side restriction element  250  is in contact with the projection  636 . This further restricts the motion of the third face  203 -side of the cartridge  20  in the width direction about the printing material supply tube  640  and the ink supply structure  280 . The third cartridge-restriction element  250  is structured preferably as the pair of projection members protruded from the seventh face  207  in the +X-axis direction to receive the projection  636  therebetween as described in the embodiment. This simple structure effectively restricts the motion of the third face  203 -side of the cartridge  20  in the width direction about the printing material supply tube  640  and the ink supply structure  280 . 
     As shown in  FIG. 13 , according to this embodiment, the terminal bearing structure  408  of the circuit board  40  and the third cartridge-side restriction element  250  are arranged to partly overlap each other in the X-axis direction (when the cartridge  20  is viewed from the first face  201 -side in the +Z-axis direction). This further effectively restricts the motion of the cartridge  20  in the direction of arrow YR 1  and thereby prevents the motion (deviation) of the cartridge-side terminals  400  relative to the holder  60 . 
     In the above description, the external force in the width direction applied to the cartridge  20  is the inertial force produced by the movement of the cartridge  20  in the main scanning direction. The external force applied to the cartridge  20  is, however, not restricted to such inertial force. For example, in the off-carriage type printer, the print head moves in the main scanning direction, but the cartridge  20  is attached to the stationary holder and so does not move in the main scanning direction. In the off-carriage type printer, however, the cartridge  20  may receive an external force. More specifically, an external force (inertial force) may be applied to the cartridge  20  due to, for example, vibration arising from the movement of the print head in the main scanning direction. 
     Reduction of Tilting of Cartridge  20  in Attached State: 
     As shown in  FIG. 12 , according to this embodiment, the first cartridge-side restriction portion  210  is provided to intersect the plane Yc passing through the center of the width (Y-axis direction length) of the cartridge  20 . As shown in  FIG. 5 , the cartridge  20  in the attached state receives the pressing forces Ps and Pt including the +Z-axis direction vector component from the holder  60 . These pressing forces Ps and Pt press the first cartridge-side restriction portion  210  against the engagement portion  810  of the lever  80 . Even when the cartridge  20  in the attached state is shaken about the X axis or the Z axis by the external force, the first cartridge-side restriction portion  210  hardly moves in the vicinity of the position intersecting the plane Yc. 
     The first cartridge-side restriction portion  210  is located close to the intersecting part  295 , i.e., close to the board end  405 . Providing the first cartridge-side restriction portion  210 , which moves very little at the position very close to the cartridge-side terminals  400  ensures a stable electrical connection between the cartridge-side terminals  400  and the contact mechanism  70 . 
     The effective part of the first cartridge-side restriction portion  210  specifically serving to restrict the position of the cartridge-side terminals  400  is the first cartridge-side locking surface  211 . It is thus preferable to locate the first cartridge-side locking surface  211  as close as possible to the cartridge-side terminals  400 . Omitting the third portion  215  of the first cartridge-side restriction portion  210  and locating the first portion  212  in contact with the first side  290  enable the first cartridge-side locking surface  211  to be closer to the intersecting part  295  or the board end  405 . This further ensures the stable electrical connection between the cartridge-side terminals  400  and the contact mechanism  70 . 
     According to this embodiment, as shown in  FIG. 10 , among the contact portions cp of the respective cartridge-side terminals  400 , the ground terminal  437  having the contact portion cp on the center in the Y-axis direction is provided at the position intersecting the plane Yc. The contact portions cp of the other terminals  431  to  436 ,  438  and  439  are arranged to be symmetrical with respect to the line of intersection of the plane Yc and the ground terminal  437  as the axis. The plane Yc has especially little motion, since the position of the first cartridge-side restriction portion  210  is fixed. The cartridge-side terminals  400  are provided on the plane Yc of little motion or its neighborhood. In addition to providing the first cartridge-side restriction portion  210  at the position very close to the cartridge-side terminals  400 , locating the cartridge-side terminals  400  on the plane Yc or its neighborhood further ensures the stable electrical connection between the cartridge-side terminals  400  and the contact mechanism  70 . 
     Fine Adjustment of Tilted Cartridge  20  in Attached State: 
     According to this embodiment, the first cartridge-side restriction portion  210  (more specifically, the first cartridge-side locking surface  211 ) is located not outside but inside the range  40 Y in the Y-axis direction between the first outer part  435 P located on the most +Y-axis direction side of the cartridge-side terminals  400  and the second outer part  439 P located on the most −Y-axis direction side of the cartridge-side terminals  400 . After the cartridge  20  is attached to the holder  60 , the cartridge-side terminals  400  receive the force of +Z-axis direction vector component from the apparatus-side terminals  700 , so as to finely adjust the tilt of the cartridge  20  or more specifically the direction of the sloped terminal bearing structure  408 , on which the cartridge-side terminals  400  are provided. The manufacturing error may vary the positions of the respective apparatus-side terminals  731  to  739  from the apparatus-side sloped surface  708  or the horizontality of the first cartridge-side locking surface  211  of the first cartridge-side restriction portion  210 . Even in such cases, the fine adjustment of the direction of the sloped terminal bearing structure  408  ensures the stable electrical connection between the cartridge-side terminals  400  and the apparatus-side terminals  700 . 
       FIG. 31  shows fine adjustment of the direction of the sloped terminal bearing structure  408 . The position of the cartridge  20  after fine adjustment of the attitude of the cartridge  20  is shown by the broken line. In this example, the attachment detection terminal  731  of the apparatus-side terminals  700  protrudes from the apparatus-side sloped surface  708  ( FIG. 18 ) in the +Z-axis direction more than the designed amount. In this case, the sloped terminal bearing structure  408  receives force Ph in a direction including the +Z-axis direction vector component from the attachment detection terminal  731 . Locating the first cartridge-side locking surface  211  within the range  40 Y allows more rotation of the cartridge  20  about the X axis. In other words, application of the force Ph to the sloped terminal bearing structure  408  enables fine adjustment of the attitude of the cartridge  20 . In the illustrated example of  FIG. 31 , the attitude of the cartridge  20  is finely adjusted to be tilted toward the sixth face  206 -side. 
     Advantageous Effects of Second Cartridge-Side Restriction Element  220 : 
     The cartridge  20  has the second cartridge-side restriction element  220  on the fourth face  204  ( FIG. 27 ), which serves to restrict the motion of the cartridge  20  from its +X-axis direction sides in the +Z-axis direction. This further ensures the stable electrical connection between the cartridge-side terminals  400  and the apparatus-side terminals  700 . 
     According to this embodiment, the second cartridge-side restriction element  220  is the projection protruded from the fourth face  204  in the −X-axis direction. The second cartridge-side restriction element  220  is inserted into the second apparatus-side restriction element  620  ( FIG. 3 ) in the form of the through hole of the holder  60 . The user turns the cartridge  20  about the vicinity of the second cartridge-side restriction element  220  inserted in the second apparatus-side restriction element  620  ( FIG. 3 ) for attachment and detachment of the cartridge  20  to and from the holder  60 . The second apparatus-side restriction element  620  accordingly serves as the guide for attachment and detachment of the cartridge  20  to and from the holder  60 . This structure facilitates attachment and detachment of the cartridge  20  to and from the holder  60 . The second cartridge-side restriction element  220  in the form of the projection can be readily provided on the fourth face  204  of the cartridge  20 . 
     Advantageous Effects of Projection  260 : 
     As shown in  FIG. 27 , according to this embodiment, the cartridge  20  has the projection  260  on the +Z-axis direction side of the first cartridge-side restriction portion  210  on the third face  203 . For detachment of the cartridge  20  from the holder  60 , applying the force to the operating member  830  of the lever  80  from the +X-axis direction side to the −X-axis direction side causes the operating member  830  to be in contact with the projection  260  and press the projection  260  in the direction Yh including the +Z-axis direction vector component. The projection  260  accordingly receives the force of +Z-axis direction vector component. This facilitates detachment of the cartridge  20  from the holder  60  by using the operating member  830 . Even when the cartridge  20  is stuck by some part of the holder  60  and is not moved in the +Z-axis direction through the travel of the first cartridge-side locking surface  211  from the first locking position  810 L in the +X-axis direction, the third face  203 -side of the cartridge  20  can be moved in the +Z-axis direction by using the projection  260 . 
     Although the external force is directly applied from the operating member  830  to the projection  260  according to the embodiment, the external force may not be applied from the operating member  830  to the projection  260 . Turning the operating member  830  disengages the engagement portion  810  from the first cartridge-side restriction portion  210  and eliminates the restriction on the motion of the third face  203 -side of the cartridge  20  in the +Z-axis direction. Eliminating the restriction on the motion of the cartridge  20  in the +Z-axis direction causes the third face  203 -side of the cartridge  20  to move in the +Z-axis direction by the pressing force Pt from the contact mechanism  70 . The projection  260  of the cartridge  20  simultaneously moves in the direction Yh. The user holds the periphery of the projection  260  moving in the direction Yh and readily detaches the cartridge  20  from the holder  60 . Providing the projection  260  improves the operability for detachment of the cartridge  20  from the holder  60  even without direct application of the external force from the operating member  830  to the projection  260 . 
     Advantageous Effects of Position of Ink Supply Structure  280 : 
     As shown in  FIG. 27 , according to this embodiment, the ink supply structure  280  is provided at the position closer to the fourth face  204  than the third face  203  on the first face  201 . The distance between the outer surface of the ink supply structure  280  and the third face  203  in the X-axis direction is accordingly greater than the distance between the outer surface of the ink supply structure  280  and the fourth face  204 . The cartridge-side terminals  400  are provided on the sloped terminal bearing structure  408  adjacent to the third face  203 . In other words, the ink supply structure  280  is provided at the position away from the cartridge-side terminals  400 . This reduces the possibility that ink adheres to the cartridge-side terminals  400  and prevents the poor contact between the cartridge-side terminals  400  and the apparatus-side terminals  700 . 
     Advantageous Effects of Ground Terminal  437 : 
     According to this embodiment, as shown in  FIG. 10A , among the contact portions cp of the cartridge-side terminals  400 , the ground terminal  437  having the contact portion cp on the center in the Y-axis direction is provided at the position intersecting the plane Yc passing through the center of the width (Y-axis direction length) of the cartridge  20 . The ground terminal  437  is configured to be in contact with the contact mechanism  70  prior to the other cartridge-side terminals  431  to  436 ,  438  and  439  in the course of attachment of the cartridge  20  to the holder  60 . The pressing force first applied from the holder  60  to the circuit board  40  is thus generated on the substantial center of the width or the Y-axis direction length of the cartridge  20 . This prevents the pressing force applied to the circuit board  40  from acting to tilt the cartridge  20  in the Y-axis direction and thereby enables the attachment of the cartridge  20  at the designed attachment position. Such contact of the ground terminal  437  with the contact mechanism  70  of the holder  60  prior to the other cartridge-side terminals  431  to  436 ,  438  and  439  advantageously prevents or reduces the high voltage-induced troubles and failures by the grounding function of the ground terminal  437 , even when an unexpected high voltage is applied to the cartridge  20 . 
     Advantageous Effects of Shape of First Apparatus-side Locking Surface  811 : 
     As shown in  FIG. 21 , the first apparatus-side locking surface  811  is the curved surface in the arc shape about the axis of rotation  800   c  on the cross section parallel to the X axis and the Z axis. This ensures the smooth operations for attachment and detachment of the cartridge  20  to and from the holder  60 . Forming the first apparatus-side locking surface  811  as the curved surface decreases the press-back amount in the +Z-axis direction by the elastic member  648  ( FIG. 27 ) in the course of attachment of the cartridge  20  to the holder  60 . This ensures the good electrical contact between the cartridge-side terminals  400  and the apparatus-side terminals  700 . 
     One example of such advantageous effect is described with reference to  FIGS. 32A to 32F . The vertical direction of  FIGS. 32A to 32F  corresponds to the Z-axis direction; the upward direction of the drawings corresponds to the +Z-axis direction and the downward direction corresponds to the −Z-axis direction which directions are opposite each other.  FIGS. 32A to 32C  show attachment of a cartridge using the first apparatus-side locking surface  811  formed as the curved surface and are arranged in time series in this order.  FIGS. 32D to 32F  show attachment of a cartridge using a first apparatus-side locking surface  811   t  formed as a plane and are arranged in times series in this order. 
     As shown in  FIG. 32A , for attachment of the cartridge  20  to the holder  60 , the first cartridge-side restriction portion  210  moves in the −Z-axis direction while abutting the guide bottom wall  821 . As shown in  FIG. 32B , when the first cartridge-side restriction portion  210  moves through the guide bottom wall  821  further in the −Z axis direction, the first apparatus-side locking surface  811  moves in the direction of arrow Y 32 . When the user strongly presses the cartridge  20  in the −Z-axis direction, the first cartridge-side restriction portion  210  is located on the −Z-axis direction side of the first apparatus-side locking surface  811 . When the user loses hold of the cartridge  20 , the cartridge  20  is pressed upward in the +Z-axis direction by the pressing forces Ps and Pt of the elastic member  648  and the apparatus-side terminals  700 . As shown in  FIG. 32C , the pressed-up amount of the first cartridge-side restriction portion  210  of the cartridge  20  is D 1  when the first apparatus-side locking surface  811  is formed as the curved surface. 
     As shown in  FIGS. 32D to 32F , when the first apparatus-side locking surface  811   t  is formed as the plane, the pressed-up amount of the first cartridge-side restriction portion  210  is D 2 , which is greater than D 1 . 
     In the attached state of the cartridge  20 , the first apparatus-side locking surface  811  formed as the curved surface can be located on the more −Z-axis direction side than the first apparatus-side locking surface  811   t  formed as the plane. This reduces the pressed-up amount of the first cartridge-side restriction portion  210 . 
     According to this embodiment, the first apparatus-side locking surface  811  located at the preset or first locking position  810 L is close to the axis of rotation  800   c  in the X-axis direction ( FIG. 21 ). This reduces the moving distance of the first apparatus-side locking surface  811  in the Z-axis direction even when the actual locking position is deviated in the X-axis direction from the first locking position  810 L. This accordingly prevents deviation of the cartridge  20  in the Z-axis direction relative to the holder  60 . 
     Additional Embodiment: 
       FIG. 33  illustrates a printer  50   a  according to a second embodiment.  FIG. 33  shows the cross section corresponding to the cross section of  FIG. 17  according to the first embodiment. The difference from the printer  50  of the first embodiment is that a retainer  690   a  does not have the elastic member  682 . Otherwise the printer  50   a  of the second embodiment has the same structure as that of the printer  50  of the first embodiment. The like elements are expressed by the like symbols and are not specifically explained here. The cartridge  20  attached to the printer  50   a  has the same structure as the cartridge  20  attached to the printer  50  of the first embodiment. 
     As shown in  FIG. 33 , the retainer  690   a  does not have an elastic member to press the lever  80  in the direction including the −X-axis direction vector component. The lever  80  is, however, designed to locate its first apparatus-side locking surface  811  at the first locking position  810 L by its dead weight, so that the first cartridge-side locking surface  211  of the cartridge  20  is locked by the first apparatus-side locking surface  811  of the lever  80 . 
     The printer  50   a  of the second embodiment has the similar advantageous effects to those of the printer  60  of the first embodiment. Additionally, the structure of the retainer  690  without an elastic member reduces the possible damage or breakage of the retainer  690  and decreases the total number of parts to reduce the manufacturing cost of the printer  50   a.    
     Third Embodiment: 
       FIG. 34  is a perspective view illustrating the appearance of a cartridge  20   b  according to a third embodiment. The difference from the cartridge  20  of the first embodiment ( FIG. 7 ) is the size of the cartridge  20   b . Otherwise the cartridge  20   b  of the third embodiment has the same structure as that of the cartridge  20  of the first embodiment. The like elements are expressed by the like symbols and are not specifically explained here. A printer of the third embodiment is adopted for the cartridge  20   b  but has the same structure as that of the holder  60  and the respective members (for example, lever  80 ) provided on the holder  60  of the first embodiment. 
     The cartridge  20   b  has the greater dimensions than those of the cartridge  20  of the first embodiment and is capable of containing a greater amount of ink. The cartridge  20   b  is attachable to a cartridge mounting structure of a large inkjet printer that is capable of printing large paper (e.g., sizes A2 to A0). The cartridge  20   b  is attached to the cartridge mounting structure of the large inkjet printer in the −Z-axis direction as the mounting direction SD. According to this embodiment, the −Z-axis direction is the horizontal direction. In the attached state of the cartridge  20   b  to the cartridge mounting structure, the X-axis direction is the vertical direction. More specifically, the +X-axis direction is the vertically upward direction, and the −X-axis direction is the vertically downward direction. 
     Modifications of Cartridge Structure: 
       FIGS. 35 to 37  show modifications of cartridge structure. These cartridges are designed for the printer having the same structure as that of the printer  50  according to the first embodiment. The like elements of these cartridges to those of the cartridge  20  of the first embodiment are expressed by the like symbols. 
     Modifications of Cartridge Outer Shape: 
       FIGS. 35A to 35H  are conceptual diagrams showing cartridge outer shapes according to other embodiments. A cartridge  20   c  shown in  FIG. 35A  has a housing of an elliptical or oval side face. The cartridge  20   c  has the first cartridge-side restriction portion  210  and the circuit board  40  provided on the front face. The ink supply structure  280  is formed on the bottom face of the cartridge  20   c , and the second cartridge-side restriction element  220  is provided on the rear face of the cartridge  20   c . This cartridge  20   c  has a fixed width, when the cartridge  20   c  is seen from its front face side. This cartridge  20   c  is compatible with the cartridge  20  shown in  FIG. 7 , as long as the first and second cartridge-side restriction elements  210  and  220 , the circuit board  40  and the ink supply structure  280  are structured to be connectable with the corresponding parts in the printer  50 . 
     A cartridge  20   d  shown in  FIG. 35B  has an approximate rectangular parallelepiped shape like the cartridge  20  shown in  FIG. 7 . One large difference from the cartridge  20  of  FIG. 7  is that the eighth face  208  is not continuous from the lower end of the third face  203 . Cartridge  20 L shown in  FIG. 35G  is similar in shape and design to cartridge  20   d  with the placement of the first cartridge-side restriction element  210  provided closer to the terminal bearing structure  408 . Cartridges  20   e  and  20   f  shown in  FIGS. 35C and 35D  have no seventh face, which is included in the cartridge  20  of  FIG. 7 . A cartridge  20   g  shown in  FIG. 35E  has the circuit board  40  mounted on the eighth face  208  with a spring. A cartridge  20   h  shown in  FIG. 35F  has a hinged or otherwise movable face  208   h , in place of the eighth face  208 , and the circuit board  40  is mounted on the movable face  208   h . While the cartridge  20   h  is being mounted into the printer, the movable face  208   h  moves from the position indicated by broken line to that indicated by solid line. Once the cartridge  20   h  is properly mounted in the printer and the movable face  208   h  is in the position indicated by solid line, the contact portions of terminals on the circuit board  40  are aligned on the contact portion plane TP. These cartridges  20   c  to  20   g  are also compatible with the cartridge  20  shown in  FIG. 7 , as long as the first and second cartridge-side restriction elements  210  and  220 , the circuit board  40  and the ink supply structure  280  are structured to be connectable with the corresponding parts in the printer  50 . A cartridge  20   m  shown in  FIG. 35H  has an elongated member  211  which is connected at one end to the first cartridge-side restriction element  210  and at the other end to the top of the cartridge  202  via a hinge or other appropriate pivotable mechanism. Although the terminals are flat shaped in the above embodiments, the terminals can be elongated, wire shaped, wires or other shapes. For example,  FIG. 35I  shows an embodiment with elongated terminals  400   n , wherein the contact portions CP are aligned on the terminal plane TP when the cartridge  20   j  is mounted into the printer. In the embodiment of the invention shown in  FIG. 35J , a cartridge  20   j  is illustrated, that includes a contact mechanism  70   j  that has substantially the same configuration (including the configuration of the terminals) as the printer-side contact mechanism  70 , which is shown in  FIG. 18 . The contact mechanism  70   j  has resilient terminals with contact portions that, when the cartridge  20   j  is mounted into the printer, make contact with the terminals  700  of the contact mechanism  70  and are substantially aligned on the terminal plane TP. In embodiments such as those of  FIGS. 35I and 35J , where the terminals are not flat shaped, the “terminal bearing structure” can be considered the portion of the cartridge that supports the terminals. Even though these terminals are not flat, the portions of these terminals that make electrical contact with the printer are essentially in the same plane and therefore provide effectively the same contact portions cp and contact portion plane TP as the other embodiments of the invention disclosed herein. Also, the portion of the restriction portion  210  that engages with the printer-side lever is located at a position closer to where the contact portion plane TP intersects the front face  203  and to the contact portions cp themselves than to the intersection of 1) the top face  202  and the front face  203 , 2) one of the top face  202  and the front face  203  and an extension of the other of the top face  202  and the front face  203 , or 3) extensions of both the top face  202  and the front face  203  (such as when the cartridge body has top and front faces shaped as in the embodiments of  FIGS. 35A and 35D ). In the embodiment of  FIG. 35J , the circuit board  40   j  of the cartridge  20   j  is positioned to the inside of the contact mechanism  70   j  and contacts the printer-side contact mechanism  70  via indirect contact through the contact mechanism  70   j.    
     As clearly understood from the examples shown in  FIGS. 35A to 35H , there are various other modifications of cartridge outer shape. In the case of the cartridge having the outer shape other than the approximate rectangular parallelepiped, as shown by the broken lines in  FIGS. 35A and 35D , the six faces of the rectangular parallelepiped, i.e., the bottom face  201  (first face), the top face  202  (second face), the front face  203  (third face), the rear face  204  (fourth face), the left side face  205  (fifth face) and the right side face  206  (sixth face) can be virtually assumed. In the specification hereof, the terms “face” and “plane” mean a virtual plane or the non-existent (imaginary) plane as shown in  FIG. 35A  or  35 D and the actual plane as shown in  FIGS. 7 and 8 . The terms “face” and “plane” include both planar surfaces and curved surfaces. 
     Cartridge with Adapter: 
       FIG. 36  is a perspective view illustrating the structure of a cartridge  20   i  with an adapter according to one embodiment. This cartridge  20   i  is separable into a container assembly  200   i  including the ink chamber  200  and an adapter  299  which can then be mated together for mounting into the holder of the printing apparatus. After the printing material in the ink chamber  200  is used up, the user replaces the container assembly  200   i  with a new one or refills the printing material into the container assembly  200   i . The adapter  299  is reusable. This cartridge  20   i  is compatible with the cartridge  20  of the first embodiment shown in  FIG. 7 . 
     A housing  22   i  for the cartridge  20   i  is structured as a combination of a housing for the container assembly  200   i  and a housing for the adapter  299   i . The container assembly  200   i  includes the ink chamber  200  configured to contain ink, the printing material flow path  282  configured to supply ink or printing material to the ink supply structure and the resin foam  284 . The container assembly  200   i  has a second face  202   i  corresponding to the second face  202  of the cartridge  20   i . The container assembly  200   i  also has a first face  201   i , a third face  203   i , a fourth face  204   i , a fifth face (not shown), a sixth face  206   i , a seventh face  207   i  and an eighth face  208   i  respectively corresponding to the first face  201  and the third to the eighth faces  203  to  208  of the cartridge  20   i . The first face  201   i  and the second face  202   i  are opposed to each other in the Z-axis direction; the first face  201   i  is located on the −Z-axis direction side and the second face  202   i  is located on the +Z-axis direction side. The third face  203   i  and the fourth face  204   i  are opposed to each other in the X-axis direction; the third face  203   i  is located on the +X-axis direction side and the fourth face  204   i  is located on the −X-axis direction side. The fifth face (not shown) and the sixth face  206   i  are opposed to each other in the Y-axis direction; the fifth face (not shown) is located on the −Y-axis direction side and the sixth face  206   i  is located on the +Y-axis direction side. The seventh face  207   i  and the eighth face  208   i  form the connection faces of connecting the first face  201   i  with the third face  203   i . The seventh face  207   i  is perpendicular to the first face  201   i  and forms a plane parallel to the Y axis and the Z axis (YZ plane). The seventh face  207   i  as the step is vertically-angled relative to the first face  201   i . The seventh face  207   i  is accordingly extended from the first face  201   i  in the +Z-axis direction. The seventh face  207   i  is located on the −X-axis direction side and on the −Z-axis direction side of the eighth face  208   i . The eighth face  208   i  connects the seventh face  207   i  with the third face  203   i  and is a sloped surface inclined in the direction including a +X-axis direction vector component and a −Z-axis direction vector component. The eighth face  208   i  is inclined to the first face  201   i  and the third face  203   i  and is perpendicular to the fifth face (not shown) and the sixth face  206   i . In other words, the eighth face  208   i  is inclined to the XY plane and the YZ plane and is perpendicular to the XZ plane. 
     The adapter  299  has the faces corresponding to the first face  201 , the third face  203 , the fourth face  204 , the fifth face  205 , the sixth face  206 , the seventh face  207  and the eighth face  208  of the cartridge  20   i . The face of the adapter  299  corresponding to the second face  202  of the cartridge  20   i  is an opening. The adapter  299  has an inner space to receive the container assembly  200   i . The first face  201  of the adapter  200  has the ink supply structure  280 . Otherwise the cartridge  20   i  has the similar structure to that of the cartridge  20  of the first embodiment sown in  FIG. 7  with our without some variations. The first cartridge-side restriction portion  210  can be on the adapter  299  as shown in  FIG. 36  or on the container assembly  200   i  (not shown). Similarly, circuit board  40  can be can be on the adapter  299  as shown in  FIG. 36  or on the container assembly  200   i  (not shown). The positioning of restriction portion  210  and circuit board  40  need not both be on the cartridge  20   i  or adapter  299 , rather one can be on cartridge  20   i  and the other can be on adapter  299 . The cartridge  20   i  may thus be structured as the combination of the container assembly  200   i  and the adapter  299  as described above. 
       FIG. 37  is a perspective view illustrating the structure of a cartridge  20   j  with an adapter according to another embodiment. This cartridge  20   j  is separable to a container assembly  200   j  including the ink chamber  200  and an adapter  299   j  which can then be mated together for mounting into the holder of the printing apparatus. After the printing material in the ink chamber  200  is used up, the user may replace the container assembly  200   j  with a new one or refill the printing material into the container assembly  200   j . The adapter  299  is reusable. This cartridge  20   j  is compatible with the cartridge  20  of the first embodiment shown in  FIG. 7 . 
     A housing  22   j  for the cartridge  20   j  is structured as a combination of a housing for the container assembly  200   j  and a housing for the adapter  299   j . The container assembly  200   j  includes the ink chamber  200  configured to contain ink and the ink supply structure  280 . The container assembly  200   j  has a second face  202   j  and a sixth face  206   j  respectively corresponding to the second face  202  and the sixth face  206  of the cartridge  20   j . The container assembly  200   j  also has a first face  201   j , a third face  203   j , a fourth face  204   j , a fifth face (not shown), a seventh face  207   j  and an eighth face  208   j  respectively corresponding to the first face  201 , the third face  203 , the fourth face  204 , the fifth face  205 , the seventh face  207  and the eighth face  208  of the cartridge  20   j . The first face  201   j  and the second face  202   j  are opposed to each other in the Z-axis direction; the first face  201   j  is located on the −Z-axis direction side and the second face  202   j  is located on the +Z-axis direction side. The third face  203   j  and the fourth face  204   j  are opposed to each other in the X-axis direction; the third face  203   j  is located on the +X-axis direction side and the fourth face  204   j  is located on the −X-axis direction side. The fifth face (not shown) and the sixth face  206   j  are opposed to each other in the Y-axis direction; the fifth face (not shown) is located on the −Y-axis direction side and the sixth face  206   j  is located on the +Y-axis direction side. The seventh face  207   j  and the eighth face  208   j  form the connection faces of connecting the first face  201   j  with the third face  203   j . The seventh face  207   j  is perpendicular to the first face  201   j  and forms a plane parallel to the Y axis and the Z axis (YZ plane). The seventh face  207   j  as the step is vertically-angled relative to the first face  201   j . The seventh face  207   j  is accordingly extended from the first face  201   j  in the +Z-axis direction. The seventh face  207   j  is located on the −X-axis direction side and on the −Z-axis direction side of the eighth face  208   j . The eighth face  208   j  connects the seventh face  207   j  with the third face  203   j  and is a sloped surface inclined in the direction including a +X-axis direction vector component and a −Z-axis direction vector component. The eighth face  208   j  is inclined to the first face  201   j  and the third face  203   j  and is perpendicular to the fifth face (not shown) and the sixth face  206   j . In other words, the eighth face  208   j  is inclined to the XY plane and the YZ plane and is perpendicular to the XZ plane. 
     The adapter  299   j  has the faces corresponding to the first face  201 , the third face  203 , the fourth face  204  and the fifth face  205  of the cartridge  20   j . The faces of the adapter  299   j  forming the second face  202  and the sixth face  206  of the cartridge  20   j  are openings. The adapter  299   j  has an inner space to receive the container assembly  200   j . The adapter  299   j  also has an opening in part of the first face  201 . The ink supply structure  280  provided in the container assembly  200   j  is exposed on the opening provided on the first face  201  of the adapter  299   j  and is connected with the printing material supply tube  640  ( FIG. 2 ). The cartridge  20   j  has a first cartridge-side restriction portion  210  of the simpler structure than that of the first embodiment ( FIG. 7 ) but may have the first cartridge-side restriction portion  210  of the same structure as that of the first embodiment ( FIG. 7 ). Alternatively, the first cartridge-side restriction portion  210  can be a part of the adapter  299   j  as shown in  FIG. 36  or a part of the container assembly  200   j  (not shown). Similarly, circuit board  40  can be on the adapter  299   j  as shown in  FIG. 36  or on the container assembly  200   j  (not shown). The positioning of restriction portion  210  and circuit board  40  need not both be on the cartridge  20   j  or adapter  299   j , rather one can be on cartridge  20   j  and the other can be on adapter  299   j . The cartridge  20   j  has the third face  203  and the fourth face  204  of the lower heights (shorter Z-axis direction lengths) than those of the third face  203  and the fourth face  204  of the first embodiment but may have the third face  203  and the fourth face  204  of the same heights (same Z-axis direction lengths) as those of the first embodiment. The cartridge  20   j  does not have the projection  260  but may have the projection  260  like the first embodiment. Otherwise the cartridge  20   j  has the similar structure to that of the cartridge  20  of the first embodiment sown in  FIG. 7  with or without some variations. The cartridge  20   j  may thus be structured by the combination of the container assembly  200   j  and the adapter  299   j  as described above. 
       FIG. 37B  shows a cartridge  20   m  configured similar to that shown in the embodiment of  FIG. 7 . However, this embodiment differs in that the cartridge  20   m  is divided into an adapter  299   m  and a container assembly  200   m . The adapter  299   m  fits over an end  201   m  (indicated in dotted line) of the container assembly  200   m  before the cartridge  20   m  is mounted into the printer. Also, the terminals  400   m  are formed directly on the surface of the adapter  299   m . When the terminals are formed on a planer surface, whether the surface of the cartridge as in this embodiment or on the surface of a circuit board as in previous embodiments, the planar surface on which the terminals are formed can be considered a “sloped surface” or “terminal bearing structure”. 
       FIG. 38  is a perspective view illustrating the structure of a cartridge  20   k  with an adapter according to another embodiment. The cartridge  20   k  includes an adapter  299   k , an external tank  200 T, a tube  200 L and an auxiliary adapter  200 S which can all be mated together for mounting into the holder of the printing apparatus. The adapter  299   k  has the same structure as that of the adapter  299   j  described above with reference to  FIG. 37 . The external tank  200 T contains printing material and is located outside the printer  50  shown in  FIG. 1 . The auxiliary adapter  200 S has an ink supply structure  280   k . The tube  200 L is used to supply the printing material from the external tank  200 T to the auxiliary adapter  200 S. The external tank  200 T, the auxiliary adapter  200 S and the tube  200 L serves as a container assembly  200   k  configured to contain ink or printing material. As shown by the broken line in  FIG. 38 , the cartridge  20   k  of this embodiment is thus assumed to have the container assembly  200   k . The cartridge  20   k  of this embodiment is thus separable to the container assembly  200   k  and the adapter  299   k , like the cartridge  20   i  shown in  FIG. 36  and the cartridge  20   j  shown in  FIG. 37 . After the printing material in the external tank  200 T is used up, the user may replace the external tank  200 T with a new one or refill the printing material into the external tank  200 T. The adapter  299   k  is reusable. This cartridge  20   k  is compatible with the cartridge  20  of the first embodiment shown in  FIG. 7 . 
     A housing  22   k  of the cartridge  20   k  is structured as a combination of a housing for the virtual container assembly  200   k  and a housing for the adapter  299   k . The structure of the virtual container assembly  200   k  and the structure of the adapter  299   k  are similar to the structure of the cartridge  20   j  described above with reference to  FIG. 37  with our without some variations. Otherwise the cartridge  20   k  has the similar structure to that of the cartridge  20  of the first embodiment sown in  FIG. 7  with or without some variations. The cartridge  20   k  may thus be structured by the combination of the container assembly  200   k  and the adapter  299   k  as described above. 
     Modification of Lever: 
     According to the above embodiment, the elastic member  682  is provided separately from the lever  80  ( FIG. 22 ). The lever  80  may be made of an elastically deformable material. A modification of the lever is described with reference to  FIGS. 39 and 40 . 
       FIGS. 39A and 39B  illustrate the structure of a lever  80   a  according to one modification.  FIG. 39A  is a perspective view showing the appearance of the lever  80   a , and  FIG. 39B  is a side view showing the appearance of the lever  80   a . The differences from the lever  80  of the first embodiment are that the lever  80   a  additionally has an arm member  890  to be elastically deformable, has an operating member  830   a  of a different shape and does not include the groove  870 . Otherwise the lever  80   a  has the similar structure to that of the lever  80  according to the first embodiment ( FIG. 19 ). The lever  80   a  is made of a synthetic resin, such as polypropylene. 
       FIG. 40  illustrates attachment of the cartridge  20  to a holder  60   a . According to this embodiment, the cartridge  20  has a first cartridge-side restriction portion  210   a  without the second portion  214  ( FIG. 12 ). The shaft body  850  of the lever  80   a  is attached to the first apparatus-side side wall member  603 . When the lever  80   a  is turned about the shaft body  850 , the arm member  890   a  abuts a projection  603   t  formed as part of the first apparatus-side side wall member  603  to be elastically deformed. 
     Modifications of Cartridge-Side Terminals: 
       FIGS. 41A to 41C  show modifications of the terminal shape on the circuit board. The difference from the circuit board  40  shown in  FIG. 10A  is that circuit boards  40   c  to  40   e  have different shapes of the terminals  431  to  439 . The respective terminals on the circuit board  40   c  shown in  FIG. 41A  and on the circuit board  40   d  shown in  FIG. 41B  have irregular shapes, instead of the approximate rectangular shape according to the first embodiment ( FIG. 10A ). In the circuit board  40   e  shown in  FIG. 41C , the nine terminals  431  to  439  are arrayed in one line, wherein the attachment detection terminals  435  and  439  are located on both ends, and the attachment detection terminals  431  and  434  are respectively located between the attachment detection terminal  435  and the power terminal  436  and between the attachment detection terminal  439  and the data terminal  438 . In these circuit boards  40   c  to  40   e , the contact portions cp of these terminals  431  to  439 , which are in contact with the apparatus-side terminals corresponding to these terminals  431  to  439 , have the same arrangement as that of the circuit board  400  shown in  FIG. 10A . The individual terminals may have the shapes of various variations as long as the contact portions cp have the same arrangement. 
     Other Modifications: 
     The foregoing has described the invention in detail with reference to the illustrative embodiments. The invention is, however, not limited to the above embodiments, but a multiplicity of variations and modifications may be made to the embodiments without departing from the scope of the invention. Some examples of possible modifications are described below. 
     First Modification: 
     The second cartridge-side restriction element  220  is provided on the fourth face  204  according to the above embodiment, but may be omitted as appropriate. For example, when there is a relatively small clearance between the cartridge  20  and each slot of the holder  60 , the motion of the fourth face  204 -side of the cartridge  20  in the +Z-axis direction can be restricted without the second cartridge-side restriction element  220  through abutment of the whole or part of the outer surface of the fourth face  204  with the second apparatus-side side wall member  604 . This keeps the cartridge  20  in the holder  60 . According to another embodiment, an elastic member made of, for example, rubber may be provided between the fourth face  204  of the cartridge  20  and the second apparatus-side side wall member  604  of the holder  60 . The motion of the fourth face  204 -side of the cartridge  20  in the +Z-axis direction may be restricted through the friction of the elastic member against the fourth face  204  of the cartridge  20  and the second apparatus-side side wall member  604  of the holder  60 . This elastic member may be a separate member from the cartridge  20  or the holder  60  or may be joined with the fourth face  204  of the cartridge  20  or with the second apparatus-side side wall member  604  of the holder  60 . In the application without the second cartridge-side restriction element  220 , the second apparatus-side restriction element  620  provided on the second apparatus-side side wall member  604  ( FIG. 15 ) may also be omitted. 
     The second cartridge-side restriction element  220  is the projection according to the above embodiment, but may be another form, for example, a recess. In this latter application, the second apparatus-side restriction element  620  provided on the second apparatus-side side wall member  604  may be a projection. According to another embodiment, the holder  60  may have an additional member configured to press the fourth face  204 -side of the second face  202  of the cartridge  20  in the −Z-axis direction. For example, the holder  60  may have a slidable rod member. After the cartridge  20  is placed in the cartridge chamber  602 , the fourth face  204 -side of the second face  202  of the cartridge  20  may be pressed by the rod member. 
     Second Modification: 
     The first cartridge-side restriction portion  210  is provided at the position close to the intersecting part  295  according to the above embodiment, but may be provided at any arbitrary position on the third face  203  within the range  40 Y or may be extended outside of the range  40 Y. ( FIG. 12 ). Locating the first cartridge-side restriction portion  210  within the range  40  enables fine adjustment of the direction of the sloped surface with the cartridge-side terminals mounted thereon. This ensures the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Third Modification: 
     According to the above embodiment, as shown in  FIG. 22 , the lever  80  has the pair of shaft bodies  850 , and the retainer  690  has the bearing elements  654 . According to another embodiment, the lever  80  may have bearing elements, and the retainer  690  may have shaft bodies. According to the above embodiment, the lever  80  and the retainer  690  including the second retainer member  680  are unitized and attached to the holder  60  for easy assembly of the printer. The retainer  690  is, however, not essential. According to another embodiment, bearing members may be formed integrally with the outer wall  603 W of the holder  60  to receive and fix the lever  80 . 
     Fourth Modification: 
     As mentioned above, the present invention is not restricted to the inkjet printer and its ink cartridge but is applicable to any of various liquid ejection apparatuses configured to eject a liquid other than ink and its liquid container, for example, without limitation, the liquid ejection apparatuses and their liquid containers given below: 
     1. image recording apparatus, such as a facsimile machine; 
     2. color material ejection apparatus used to manufacture color filters for image display devices, e.g., liquid crystal displays; 
     3. electrode material ejection apparatus used to form electrodes of, for example, organic EL (electroluminescence) displays and field emission displays (FED); 
     4. liquid ejection apparatus configured to eject a bioorganic material-containing liquid used for manufacturing biochips; 
     5. sample ejection apparatus used as a precision pipette; 
     6. lubricating oil spray apparatus; 
     7. resin solution spray apparatus; 
     8. liquid spray apparatus for pinpoint spray of lubricating oil at precision machinery including watches and cameras; 
     9. liquid ejection apparatus configured to eject transparent resin solution, such as ultraviolet curable resin solution, onto the substrate, so as to manufacture a hemispherical microlens (optical lens) used for, for example, optical communication elements; 
     10. liquid spray apparatus configured to spray an acidic or alkaline etching solution, in order to etch the substrate; and 
     11. (11) liquid ejection apparatus equipped with liquid ejection head for ejecting a very small volume of droplets of another arbitrary liquid. 
     The “liquid droplet” means a state of liquid ejected from the liquid ejection apparatus and may be in a granular shape, a teardrop shape or a tapered threadlike shape. The “liquid” herein may be any material ejectable by the liquid ejection apparatus. The “liquid” may be any material in the liquid phase. For example, liquid-state materials of high viscosity or low viscosity, sols, gel water, various inorganic solvents and organic solvents, solutions, liquid resins and liquid metals (metal melts) are included in the “liquid”. The “liquid” is not restricted to the liquid state as one of the three states of matter but includes solutions, dispersions and mixtures of the functional solid material particles, such as pigment particles or metal particles, solved in, dispersed in or mixed with a solvent. Typical examples of the liquid include ink described in the above embodiment and liquid crystal. The “ink” includes general water-based inks and oil-based inks, as well as various liquid compositions, such as gel inks and hot-melt inks, but is not limited as such. 
     Fifth Modification: 
     The invention may be accomplished by the following variations. The symbols in parentheses after the elements in each of the variations correspond to the symbols of the respective elements described in the first embodiment. 
     First Variation: 
     A cartridge detachably attached to a printing apparatus comprises a first face arranged to form an outer surface of the cartridge, the first face having an ink supply structure to be connected with the printing apparatus; a second face opposed to the first face; a third face arranged to have one side that is connected with the second face and the other side that is opposite to the one side, the third face being located between the first face and the second face with respect to an opposed direction, along which the first face and the second face are opposed to each other; a fourth face opposed to the third face, the fourth face being arranged to connect with the first face and the second face; a corner section arranged to form an outer surface of connecting the first face with the third face; cartridge-side terminals provided on the corner section, the cartridge-side terminals being arranged to receive an external force of pressing up the cartridge from apparatus-side terminals of the printing apparatus in an attached state of the cartridge to the printing apparatus; and a first cartridge-side restriction element provided on the third face and arranged to be locked by a lever of the printing apparatus in the attached state and thereby restrict motion of the cartridge in a press-up direction, wherein the first cartridge-side restriction element is provided at a position close to the cartridge-side terminals. 
     Second Variation: 
     A cartridge detachably attached to a printing apparatus comprises a first face arranged to form an outer surface of the cartridge, the first face having an ink supply structure to be connected with the printing apparatus; a second face opposed to the first face; a third face arranged to have one side that is connected with the second face and the other side that is opposite to the one side and is located between the first face and the second face with respect to an opposed direction, along which the first face and the second face are opposed to each other; a fourth face opposed to the third face, the fourth face being arranged to connect with the first face and the second face; a corner section arranged to form an outer surface of connecting the first face with the third face; cartridge-side terminals provided on the corner section, the cartridge-side terminals being arranged to receive an external force of pressing up the cartridge from apparatus-side terminals of the printing apparatus in an attached state of the cartridge to the printing apparatus; and a first cartridge-side restriction element provided on the third face and arranged to be locked by a lever of the printing apparatus in the attached state and thereby restrict motion of the cartridge in a press-up direction, wherein the first cartridge-side restriction element is located closer to the other side than the one side. 
     Third Variation: 
     A cartridge detachably attached to a printing apparatus comprises a first face arranged to form an outer surface of the cartridge, the first face having an ink supply structure to be connected with the printing apparatus; a second face opposed to the first face; a third face arranged to have one side that is connected with the second face and the other side that is opposite to the one side and is located between the first face and the second face with respect to an opposed direction, along which the first face and the second face are opposed to each other; a fourth face opposed to the third face, the fourth face being arranged to connect with the first face and the second face; a corner section arranged to form an outer surface of connecting the first face with the third face; cartridge-side terminals provided on the corner section, the cartridge-side terminals being arranged to receive an external force of pressing up the cartridge from apparatus-side terminals of the printing apparatus in an attached state of the cartridge to the printing apparatus; and a first cartridge-side restriction element provided on the third face and arranged to be locked by a lever of the printing apparatus in the attached state and thereby restrict motion of the cartridge in a press-up direction, wherein the first cartridge-side restriction element is provided at a position close to the other side. 
     Like the first embodiment described above, any of the first to the third variations advantageously prevents positional misalignment of the cartridge-side terminals relative to the printing apparatus and thereby ensures stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. In any of the first to the third variations, when the direction from the first face side to the second face side in the opposed direction in the attached state is the +Z-axis direction and the direction from the second face side to the first face side is the −Z-axis direction, the first cartridge-side restriction element is preferably located on the −Z-axis direction side of the axis of rotation of the lever. 
     Fourth Variation: 
     A cartridge detachably attached to a printing apparatus comprises an ink supply structure that is connected with the printing apparatus; cartridge-side terminals arranged to receive an external force of pressing up the cartridge from apparatus-side terminals of the printing apparatus in an attached state of the cartridge to the printing apparatus; and a first cartridge-side restriction element located on an identical side with the cartridge-side terminals and arranged to be locked by a lever of the printing apparatus in the attached state and thereby restrict motion of the cartridge in a press-up direction, wherein the first cartridge-side restriction element is located close to the cartridge-side terminals. 
     When the press-up direction is the +Z-axis direction and the opposite direction to the press-up direction is the −Z-axis direction, the first cartridge-side restriction element is preferably located on the −Z-axis direction side of the axis of rotation of the lever. 
     Like the first embodiment described above, the fourth variation advantageously prevents positional misalignment of the cartridge-side terminals relative to the printing apparatus and thereby ensures stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Sixth Modification: 
     The invention may be accomplished by the following variations. The symbols in parentheses after the elements in each of the variations correspond to the symbols of the respective elements described in the first embodiment. 
     First Variation 
     A cartridge detachably attached to a printing apparatus comprises: a first face arranged to form an outer surface of the cartridge, the first face having a printing material supply port that is connected with the printing apparatus; a second face opposed to the first face; a third face arranged to have one side that is connected with the second face and the other side that is opposite to the one side, the third face being located between the first face and the second face with respect to an opposed direction, the opposed direction being a direction along which the first face and the second face are opposed to each other; a fourth face opposed to the third face, the fourth face being arranged to intersect the first face and the second face; a fifth face arranged to intersect the first face, the second face, the third face and the fourth face; a sixth face opposed to the fifth face; a corner section arranged to form an outer surface of connecting the first face with the third face; cartridge-side terminals provided on the corner section, the cartridge-side terminals being arranged to receive an external force of pressing up the cartridge from apparatus-side terminals of the printing apparatus in an attached state of the cartridge to the printing apparatus; and a first cartridge-side restriction element provided on the third face and arranged to be locked by a lever of the printing apparatus in the attached state and thereby restrict motion of the cartridge in a press-up direction, wherein with respect to the opposed direction of the fifth face and the sixth face, the first cartridge-side restriction element is located not outside but inside a range where the cartridge-side terminals are provided. 
     Second Variation 
     A cartridge detachably attached to a printing apparatus comprises: a printing material supply port that is connected with the printing apparatus; cartridge-side terminals provided on an outer surface of the cartridge, the cartridge-side terminals being arranged to receive an external force of pressing up the cartridge from apparatus-side terminals of the printing apparatus in an attached state of the cartridge to the printing apparatus; and a first cartridge-side restriction element provided on the same side of the outer surface as that with the cartridge-side terminals, the first cartridge-side restriction element being arranged to be locked by a lever of the printing apparatus in the attached state to restrict motion of the cartridge in a press-up direction, wherein with respect to a width direction of the cartridge, the first cartridge-restriction element is located not outside but inside a range where the cartridge-side terminals are provided. According to the first or the second variation, the cartridge-side terminals receive the force in the press-up direction from the apparatus-side terminals. This enables fine adjustment of the direction of the part where the cartridge-side terminals are provided and ensures stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. According to the first or the second variation, it is preferable that the first cartridge-side restriction element is located below the axis of rotation of the lever. The term “below” herein corresponds to, for example, −Z-axis direction or a reverse direction to the press-up direction. 
     Seventh Modification: 
     The invention may be accomplished by the following descriptions and variations. The symbols in parentheses after the elements in each of the descriptions correspond to the symbols of the respective elements described in the first embodiment. 
     First Variation 
     An ink cartridge adapted to be detachably mounted on an ink jet printing apparatus, the ink jet printing apparatus comprising a plurality of apparatus-side contact forming members constructed and arranged to apply elastic force to the ink cartridge when the ink cartridge is pressed against the apparatus-side contact forming members, the ink jet printing apparatus also comprising a lever having an engagement portion, the ink cartridge, comprising a cartridge body including a front, a rear, a top and a bottom, the front and rear opposite each other and the top and bottom opposite each other; an electrical device, an ink chamber for storing ink; an ink supply structure positioned at the bottom of the cartridge body, adapted and configured to supply ink from the ink chamber to the ink jet printing apparatus, the ink supply structure having a mounting direction leading edge defining a plane of the ink cartridge; a terminal bearing structure located proximate to the front of the cartridge body, the terminal bearing structure having a plurality of electrically conductive terminals coupled to the electrical device, the terminals adapted and arranged on the terminal bearing structure to make contact with and receive elastic force from the contact forming members at contact portions of the terminals when the ink cartridge is mounted on the printing apparatus, the contact portions arranged substantially in a contact portion plane which is neither parallel nor perpendicular to the plane defined by the leading edge; and a first restriction portion including an engagement portion adapted to engage with the engagement portion of the lever so as to restrict movement of the ink cartridge in a direction opposite the mounting direction, the engagement portion of the first restriction portion located adjacent the terminal bearing structure. 
     Some of the benefits of the above variation of the seventh modification will now be described. The terminals must be precisely positioned and stably fixed while the ink cartridge is mounted in the printer, in order to ensure reliable electrical communication between the cartridge and the printer. Because the engagement portion of the first restriction portion is located adjacent to the terminal bearing structure, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the printer-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to ink. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the printer-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the contact portion plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printer. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the printer terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the printer terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printer, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the printer side terminals serves to both press the printer side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printer when engagement between the first restriction portion and the printer lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is adapted to engage with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printer. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The ink cartridge as described above where the contact portion plane is at an angle of between about 25 and 40 degrees to the plane defined by the leading edge. 
     As discussed with reference to  FIGS. 42A-45 , when the contact portion plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 2: 
     The ink cartridge as described above where when the front of the cartridge body is viewed with the ink supply structure facing down, the engagement portion of the first restriction portion is located to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals. 
     When the ink cartridge is mounted on the printing apparatus, if the cartridge is held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals the ink cartridge can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 3: 
     The ink cartridge as described above further comprising a second restriction portion on the rear of the ink cartridge, the second restriction portion including an engagement portion adapted and configured to engage with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the second restriction portion. 
     Adaptation 4: 
     The ink cartridge as described above where when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, the lever serves to restrict the motion of the cartridge. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted cartridge. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 5: 
     The ink cartridge as described above where when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the engagement portion of the first restriction portion is to the left of a pivot point of the lever when the cartridge is mounted. 
     When the cartridge is mounted so that the engagement portion of the first restriction portion is to the left of a pivot point of the lever when viewing the cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Even when the cartridge receives force, the first restriction portion would move with the cartridge. Such moving reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever. 
     Adaptation 6: 
     The ink cartridge as described above where when the front of the cartridge body is viewed with the ink supply structure facing down, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 7: 
     The ink cartridge as described above where the plane defined by the leading edge is substantially flush with the bottom. 
     Second Variation 
     An ink cartridge adapted to be detachably mounted on an ink jet printing apparatus, the ink jet printing apparatus comprising a plurality of apparatus-side contact forming members constructed and arranged to apply elastic force to the ink cartridge when the ink cartridge is pressed against the apparatus-side contact forming members, the ink jet printing apparatus also comprising a lever having an engagement portion, the ink cartridge, comprising a cartridge body including a front, a rear, a top and a bottom, the front and rear opposite each other and the top and bottom opposite each other; an electrical device, an ink chamber for storing ink; an ink supply structure positioned at the bottom of the cartridge body, adapted and configured to supply ink from the ink chamber to the ink jet printing apparatus, the ink supply structure having a mounting direction leading edge defining a plane of the ink cartridge; a terminal bearing structure located proximate to the front of the cartridge body, the terminal bearing structure having a plurality of electrically conductive terminals coupled to the electrical device, the terminals adapted and arranged on the terminal bearing structure to make contact with and receive elastic force from the contact forming members of the terminals when the ink cartridge is mounted on the printing apparatus, the terminals arranged substantially in a terminal plane which is neither parallel nor perpendicular to the plane of the leading edge; and a first restriction portion including an engagement portion adapted to engage with the engagement portion of the lever so as to restrict movement of the ink cartridge in a direction opposite the mounting direction, the engagement portion of the first restriction portion located adjacent the terminal bearing structure. 
     Some of the benefits of the above variation of the seventh modification will now be described. The terminals must be precisely positioned and stably fixed while the ink cartridge is mounted in the printer, in order to ensure reliable electrical communication between the cartridge and the printer. Because the engagement portion of the first restriction portion is located adjacent to the terminal bearing structure, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the printer-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to ink. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the printer-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the terminal plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printer. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the printer terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the printer terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printer, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the printer side terminals serves to both press the printer side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printer when engagement between the first restriction portion and the printer lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is adapted to engage with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printer. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The ink cartridge as described above where the terminal plane is at an angle of between about 25 and 40 degrees to the plane defined by the leading edge. 
     As discussed with reference to  FIGS. 42A-45 , when the terminal plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 2: 
     The ink cartridge as described above where when the front of the cartridge body is viewed with the ink supply structure facing down, the engagement portion of the first restriction portion is located to the left of a right edge of a rightmost terminal of the plurality of terminals and to the right of a left edge of the leftmost terminal of the plurality of terminals. 
     When the ink cartridge is mounted on the printing apparatus, if the cartridge is held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of a right edge of a rightmost terminal of the plurality of terminals and to the right of a left edge of the leftmost terminal of the plurality of terminals the ink cartridge can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 3: 
     The ink cartridge as described above further comprising a second restriction portion on the rear of the ink cartridge, the second restriction portion including an engagement portion adapted and configured to engage with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 4: 
     The ink cartridge as described above where when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, the lever serves to restrict the motion of the cartridge. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted cartridge. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 5: 
     The ink cartridge as described above where when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the engagement portion of the first restriction portion is to the left of a pivot point of the lever when the cartridge is mounted. 
     When the cartridge is mounted so that the engagement portion of the first restriction portion is to the left of a pivot point of the lever when viewing the cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Even when the cartridge receives force, the first restriction portion would move with the cartridge. Such moving reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever. 
     Adaptation 6: 
     The ink cartridge as described above where when the front of the cartridge body is viewed with the ink supply structure facing down, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 7: 
     The ink cartridge as described above where the plane defined by the leading edge is substantially flush with the bottom. 
     Third Variation 
     An ink cartridge adapted to be detachably mounted on an ink jet printing apparatus, the ink jet printing apparatus comprising a plurality of apparatus-side contact forming members constructed and arranged to apply elastic force to the ink cartridge when the ink cartridge is pressed against the apparatus-side contact forming members, the ink jet printing apparatus also comprising a lever having an engagement portion, the ink cartridge comprising, a cartridge body including a first surface, second surface, third surface and fourth surface, wherein the first surface and second surface are opposite each other and the third surface and fourth surface are opposite each other; an electrical device; an ink chamber for storing ink; an ink supply structure positioned at the fourth surface of the cartridge body, adapted and configured to supply ink from the ink chamber to the ink jet printing apparatus, the ink supply structure having a mounting direction leading edge defining a plane of the ink cartridge; a terminal bearing structure located proximate to the first surface of the cartridge body, the terminal bearing structure having a plurality of electrically conductive terminals coupled to the electrical device, the contact portions adapted and arranged on the contact portion structure to make contact with and receive elastic force from the contact forming members at contact portions of the terminals when the ink cartridge is mounted on the printing apparatus, the contact portions arranged substantially in a contact portion plane which is neither parallel nor perpendicular to the plane of the leading edge; and a first restriction portion including an engagement portion adapted to engage with the engagement portion of the lever so as to restrict movement of the ink cartridge in a direction opposite the mounting direction, the engagement portion of the first restriction portion located adjacent the terminal bearing structure. 
     Some of the benefits of the above variation of the seventh modification will now be described. The terminals must be precisely positioned and stably fixed while the ink cartridge is mounted in the printer, in order to ensure reliable electrical communication between the cartridge and the printer. Because the engagement portion of the first restriction portion is located adjacent to the terminal bearing structure, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the printer-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to ink. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the printer-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the contact portion plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printer. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the printer terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the printer terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printer, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the printer side terminals serves to both press the printer side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printer when engagement between the first restriction portion and the printer lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is adapted to engage with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printer. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The ink cartridge as described above where the contact portion plane is at an angle of between about 25 and 40 degrees to the plane defined by the leading edge. 
     As discussed with reference to  FIGS. 42A-45 , when the contact portion plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 2: 
     The ink cartridge as described above where when the first surface of the cartridge body is viewed with the ink supply structure facing down, the engagement portion of the first restriction portion is located to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals. 
     When the ink cartridge is mounted on the printing apparatus, if the cartridge is held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals the ink cartridge can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 3: 
     The ink cartridge as described above further comprising a second restriction portion on the second surface of the ink cartridge, the second restriction portion including an engagement portion adapted and configured to engage with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 4: 
     The ink cartridge as described above where when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, the lever serves to restrict the motion of the cartridge. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted cartridge. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 5: 
     The ink cartridge as described above where when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the engagement portion of the first restriction portion is to the left of a pivot point of the lever when the cartridge is mounted. 
     When the cartridge is mounted so that the engagement portion of the first restriction portion is to the left of a pivot point of the lever when viewing the cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Even when the cartridge receives force, the first restriction portion would move with the cartridge. Such moving reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever. 
     Adaptation 6: 
     The ink cartridge as described above where when the first surface of the cartridge body is viewed with the ink supply structure facing down, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 7: 
     The ink cartridge as described above where the plane defined by the leading edge is substantially flush with the fourth surface. 
     Fourth Variation 
     An ink cartridge adapted to be detachably mounted on an ink jet printing apparatus, the ink jet printing apparatus comprising a plurality of apparatus-side contact forming members constructed and arranged to apply elastic force to the ink cartridge when the ink cartridge is pressed against the apparatus-side contact forming members, the ink jet printing apparatus also comprising a lever having an engagement portion, the ink cartridge, comprising a cartridge body including a first surface, second surface, third surface and fourth surface, wherein the first surface and second surface are opposite each other and the third surface and fourth surface are opposite each other; an electrical device, an ink chamber for storing ink; an ink supply structure positioned at the fourth surface of the cartridge body, adapted and configured to supply ink from the ink chamber to the ink jet printing apparatus, the ink supply structure having a mounting direction leading edge defining a plane of the ink cartridge; a terminal bearing structure located proximate to the first surface of the cartridge body, the terminal bearing structure having a plurality of electrically conductive terminals coupled to the electrical device, the terminals adapted and arranged on the terminal bearing structure to make contact with and receive elastic force from the contact forming members, when the ink cartridge is mounted on the printing apparatus, the terminals arranged substantially in a terminal plane which is neither parallel nor perpendicular to the plane of the leading edge so that a vector component of the elastic force from the apparatus-side contact forming members urges the ink cartridge in a direction opposite to the mounting direction; and a first restriction portion including an engagement portion adapted to engage with the engagement portion of the lever so as to restrict movement of the ink cartridge in a direction opposite the mounting direction, the engagement portion of the first restriction portion located adjacent the terminal bearing structure. 
     Some of the benefits of the above variation of the seventh modification will now be described. The terminals must be precisely positioned and stably fixed while the ink cartridge is mounted in the printer, in order to ensure reliable electrical communication between the cartridge and the printer. Because the engagement portion of the first restriction portion is located adjacent to the terminal bearing structure, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the printer-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to ink. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the printer-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the terminal plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printer. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the printer terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the printer terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printer, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the printer side terminals serves to both press the printer side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printer when engagement between the first restriction portion and the printer lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is adapted to engage with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printer. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The ink cartridge as described above where the terminal plane is at an angle of between about 25 and 40 degrees to the plane defined by the leading edge. 
     As discussed with reference to  FIGS. 42A-45 , when the terminal plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 2: 
     The ink cartridge as described above where when the first surface of the cartridge body is viewed with the ink supply structure facing down, the engagement portion of the first restriction portion is located to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals. 
     When the ink cartridge is mounted on the printing apparatus, if the cartridge is held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals the ink cartridge can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     The ink cartridge as described above further comprising a second restriction portion on the second surface of the ink cartridge, the second restriction portion including an engagement portion adapted and configured to engage with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 4: 
     The ink cartridge as described above where when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, the lever serves to restrict the motion of the cartridge. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted cartridge. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 5: 
     The ink cartridge as described above where when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the engagement portion of the first restriction portion is to the left of a pivot point of the lever when the cartridge is mounted. 
     When the cartridge is mounted so that the engagement portion of the first restriction portion is to the left of a pivot point of the lever when viewing the cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Even when the cartridge receives force, the first restriction portion would move with the cartridge. Such moving reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever. 
     Adaptation 6: 
     The ink cartridge as described above where when the first surface of the cartridge body is viewed with the ink supply structure facing down, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 7: 
     The ink cartridge as described above where the plane defined by the leading edge is substantially flush with the fourth surface. 
     Fifth Variation 
     A combination of an ink cartridge and a portion of an ink jet printing apparatus, the combination comprising: a portion of an ink jet printing apparatus, the portion comprising: a plurality of apparatus-side contact forming members applying an elastic force to the ink cartridge; and a lever having an engagement portion; an ink cartridge, the ink cartridge, comprising a cartridge body including a front, a rear, a top and a bottom, the front and rear opposite each other and the top and bottom opposite each other; an ink chamber for storing ink; an electrical device, an ink supply structure positioned at the bottom of the cartridge body, adapted and configured to supply ink from the ink chamber to the ink jet printing apparatus, the ink supply structure having a mounting direction leading edge defining a plane of the ink cartridge; a terminal bearing structure located proximate to the front of the cartridge body, the terminal bearing structure having a plurality of electrically conductive terminals coupled to the electrical device, the terminals on the terminal bearing structure contacting with and receiving elastic force from the contact forming members at contact portions of the terminals, the contact portions arranged substantially in a contact portion plane which is neither parallel nor perpendicular to the plane of the leading edge; and a first restriction portion including an engagement portion engaged with the engagement portion of the lever so as to restrict movement of the ink cartridge in a direction opposite the mounting direction, the engagement portion of the first restriction portion located adjacent the terminal bearing structure. 
     Some of the benefits of the above variation of the seventh modification will now be described. The terminals must be precisely positioned and stably fixed while the ink cartridge is mounted in the printer, in order to ensure reliable electrical communication between the cartridge and the printer. Because the engagement portion of the first restriction portion is located adjacent to the terminal bearing structure, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the printer-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to ink. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the printer-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the contact portion plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printer. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the printer terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the printer terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printer, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the printer side terminals serves to both press the printer side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printer when engagement between the first restriction portion and the printer lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is engaged with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printer. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The combination as described above where the contact portion plane is at an angle of between about 25 and 40 degrees to the plane defined by the leading edge. 
     As discussed with reference to  FIGS. 42A-45 , when the contact portion plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 2: 
     The combination as described above where when the front of the cartridge body is viewed with the ink supply structure facing down, the engagement portion of the first restriction portion is located to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals. 
     When the ink cartridge is mounted on the printing apparatus, if the cartridge is held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals the ink cartridge can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 3: 
     The combination as described above further comprising a second restriction portion on the rear of the ink cartridge, the second restriction portion including an engagement portion engaged with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 4: 
     The combination as described above where the lever has two ends and a pivot point intermediate the two ends and when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between the pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, the lever serves to restrict the motion of the cartridge. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted cartridge. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 5: 
     The combination as described above where the lever has two ends and a pivot point intermediate the two ends and when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the engagement portion of the first restriction portion is to the left of the pivot point of the lever. 
     When the cartridge is mounted so that the engagement portion of the first restriction portion is to the left of a pivot point of the lever when viewing the cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Even when the cartridge receives force, the first restriction portion would move with the cartridge. Such moving reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever. 
     Adaptation 6: 
     The combination as described above where when the front of the cartridge body is viewed with the ink supply structure facing down, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 7: 
     The combination as described above where the plane defined by the leading edge is substantially flush with the bottom. 
     Sixth Variation 
     A combination of an ink cartridge and a portion of an ink jet printing apparatus, the combination comprising a portion of an ink jet printing apparatus, the portion comprising: a plurality of apparatus-side contact forming members applying an elastic force to the ink cartridge; and a lever having an engagement portion; an ink cartridge, the ink cartridge comprising: a cartridge body including a front, a rear, a top and a bottom, the front and rear opposite each other and the top and bottom opposite each other; an electrical device, an ink chamber for storing ink; an ink supply structure positioned at the bottom of the cartridge body, adapted and configured to supply ink from the ink chamber to the ink jet printing apparatus, the ink supply structure having a mounting direction leading edge defining a plane of the ink cartridge; a terminal bearing structure located proximate to the front of the cartridge body, the terminal bearing structure having a plurality of electrically conductive terminals coupled to the electrical device, the terminals on the terminal bearing structure contacting with and receiving elastic force from the contact forming members, the terminals arranged substantially in a terminal plane which is neither parallel nor perpendicular to the plane of the leading edge; and a first restriction portion including an engagement portion engaged with the engagement portion of the lever so as to restrict movement of the ink cartridge in a direction opposite the mounting direction, the engagement portion of the first restriction portion located adjacent the terminal bearing structure. 
     Some of the benefits of the above variation of the seventh modification will now be described. The terminals must be precisely positioned and stably fixed while the ink cartridge is mounted in the printer, in order to ensure reliable electrical communication between the cartridge and the printer. Because the engagement portion of the first restriction portion is located adjacent to the terminal bearing structure, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the printer-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to ink. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the printer-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the terminal plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printer. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the printer terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the printer terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printer, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the printer side terminals serves to both press the printer side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printer when engagement between the first restriction portion and the printer lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is engaged with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printer. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The combination as described above where the terminal plane is at an angle of between about 25 and 40 degrees to the plane defined by the leading edge. 
     As discussed with reference to  FIGS. 42A-45 , when the terminal plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 2: 
     The combination as described above where when the front of the cartridge body is viewed with the ink supply structure facing down, the engagement portion of the first restriction portion is located to the left of a right edge of a rightmost terminal of the plurality of terminals and to the right of a left edge of the leftmost terminal of the plurality of terminals. 
     When the ink cartridge is mounted on the printing apparatus, if the cartridge is held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of a right edge of a rightmost terminal of the plurality of terminals and to the right of a left edge of the leftmost terminal of the plurality of terminals the ink cartridge can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 3: 
     The combination as described above further comprising a second restriction portion on the rear of the ink cartridge, the second restriction portion including an engagement portion engaged with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 4: 
     The combination as described above where the lever has two ends and a pivot point intermediate the two ends and when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between the pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, the lever serves to restrict the motion of the cartridge. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted cartridge. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 5: 
     The combination as described above where the lever has two ends and a pivot point intermediate the two ends and when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the engagement portion of the first restriction portion is to the left of the pivot point of the lever. 
     When the cartridge is mounted so that the engagement portion of the first restriction portion is to the left of a pivot point of the lever when viewing the cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Even when the cartridge receives force, the first restriction portion would move with the cartridge. Such moving reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever. 
     Adaptation 6: 
     The combination as described above where when the front of the cartridge body is viewed with the ink supply structure facing down, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 7: 
     The combination as described above where the plane defined by the leading edge is substantially flush with the bottom. 
     Seventh Variation 
     A combination of an ink cartridge and a portion of an ink jet printing apparatus, the combination comprising: a portion of an ink jet printing apparatus, the portion comprising: a plurality of apparatus-side contact forming members applying an elastic force to the ink cartridge; and a lever having an engagement portion; an ink cartridge, the ink cartridge comprising a cartridge body including a first surface, second surface, third surface and fourth surface, wherein the first surface and second surface are opposite each other and the third surface and fourth surface are opposite each other; an electrical device, an ink chamber for storing ink; an ink supply structure positioned at the fourth surface of the cartridge body, adapted and configured to supply ink from the ink chamber to the ink jet printing apparatus, the ink supply structure having a mounting direction leading edge defining a plane of the ink cartridge; a terminal bearing structure located proximate to the first surface of the cartridge body, the terminal bearing structure having a plurality of electrically conductive terminals coupled to the electrical device, the terminals on the terminal bearing structure contacting with and receiving elastic force from the contact forming members at contact portions of the terminals, the contact portions arranged substantially in a contact portion plane which is neither parallel nor perpendicular to the plane of the leading edge; and a first restriction portion including an engagement portion engaged with the engagement portion of the lever so as to restrict movement of the ink cartridge in a direction opposite the mounting direction, the engagement portion of the first restriction portion located adjacent the terminal bearing structure. 
     Some of the benefits of the above variation of the seventh modification will now be described. The terminals must be precisely positioned and stably fixed while the ink cartridge is mounted in the printer, in order to ensure reliable electrical communication between the cartridge and the printer. Because the engagement portion of the first restriction portion is located adjacent to the terminal bearing structure, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the printer-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to ink. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the printer-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the contact portion plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printer. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the printer terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the printer terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printer, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the printer side terminals serves to both press the printer side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printer when engagement between the first restriction portion and the printer lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is engaged with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printer. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The combination as described above where the contact portion plane is at an angle of between about 25 and 40 degrees to the plane defined by the leading edge. 
     As discussed with reference to  FIGS. 42A-45 , when the contact portion plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 2: 
     The combination as described above where when the first surface of the cartridge body is viewed with the ink supply structure facing down, the engagement portion of the first restriction portion is located to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals. 
     When the ink cartridge is mounted on the printing apparatus, if the cartridge is held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals the ink cartridge can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 3: 
     The combination as described above further comprising a second restriction portion on the second surface of the ink cartridge, the second restriction portion including an engagement portion engaged with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 4: 
     The combination as described above where the lever has two ends and a pivot point intermediate the two ends and when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between the pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, the lever serves to restrict the motion of the cartridge. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted cartridge. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 5: 
     The combination as described above where the lever has two ends and a pivot point intermediate the two ends and when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the engagement portion of the first restriction portion is to the left of the pivot point of the lever. 
     When the cartridge is mounted so that the engagement portion of the first restriction portion is to the left of a pivot point of the lever when viewing the cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Even when the cartridge receives force, the first restriction portion would move with the cartridge. Such moving reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever. 
     Adaptation 6: 
     The combination as described above where when the first surface of the cartridge body is viewed with the ink supply structure facing down, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 7: 
     The combination as described above where the plane defined by the leading edge is substantially flush with the fourth surface. 
     Eighth Variation 
     A combination of an ink cartridge and a portion of an ink jet printing apparatus, the combination comprising: a portion of an ink jet printing apparatus, the portion comprising: a plurality of apparatus-side contact forming members applying an elastic force to the ink cartridge; and a lever having an engagement portion; an ink cartridge, the ink cartridge comprising a cartridge body including a first surface, second surface, third surface and fourth surface, wherein the first surface and second surface are opposite each other and the third surface and fourth surface are opposite each other; an electrical device, an ink chamber for storing ink; an ink supply structure positioned at the fourth surface of the cartridge body, adapted and configured to supply ink from the ink chamber to the ink jet printing apparatus, the ink supply structure having a mounting direction leading edge defining a plane of the ink cartridge; a terminal bearing structure located proximate to the first surface of the cartridge body, the terminal bearing structure having a plurality of electrically conductive terminals coupled to the electrical device, the terminals on the terminal bearing structure contacting with and receiving elastic force from the contact forming members, the terminals arranged substantially in a terminal plane which is neither parallel nor perpendicular to the plane of the leading edge; and a first restriction portion including an engagement portion engaged with the engagement portion of the lever so as to restrict movement of the ink cartridge in a direction opposite the mounting direction, the engagement portion of the first restriction portion located adjacent the terminal bearing structure. 
     Some of the benefits of the above variation of the seventh modification will now be described. The terminals must be precisely positioned and stably fixed while the ink cartridge is mounted in the printer, in order to ensure reliable electrical communication between the cartridge and the printer. Because the engagement portion of the first restriction portion is located adjacent to the terminal bearing structure, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the apparatus-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to ink. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the apparatus-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the terminal plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printer. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the printer terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the printer terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printer, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the printer side terminals serves to both press the printer side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printer when engagement between the first restriction portion and the printer lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is engaged with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printer. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The combination as described above where the terminal plane is at an angle of between about 25 and 40 degrees to the plane defined by the leading edge. 
     As discussed with reference to  FIGS. 42A-45 , when the terminal plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 2: 
     The combination as described above where when the front of the cartridge body is viewed with the ink supply structure facing down, the engagement portion of the first restriction portion is located to the left of a right edge of a rightmost terminal of the plurality of terminals and to the right of a left edge of the leftmost terminal of the plurality of terminals. 
     When the ink cartridge is mounted on the printing apparatus, if the cartridge is held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of a right edge of a rightmost terminal of the plurality of terminals and to the right of a left edge of the leftmost terminal of the plurality of terminals the ink cartridge can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 3: 
     The combination as described above further comprising a second restriction portion on the second surface of the ink cartridge, the second restriction portion including an engagement portion engaged with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 4: 
     The combination as described above where the lever has two ends and a pivot point intermediate the two ends and when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between the pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, the lever serves to restrict the motion of the cartridge. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted cartridge. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 5: 
     The combination as described above where the lever has two ends and a pivot point intermediate the two ends and when viewing the ink cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the engagement portion of the first restriction portion is to the left of the pivot point of the lever. 
     When the cartridge is mounted so that the engagement portion of the first restriction portion is to the left of a pivot point of the lever when viewing the cartridge from the side with the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Even when the cartridge receives force, the first restriction portion would move with the cartridge. Such moving reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever. 
     Adaptation 6: 
     The combination as described above where when the first surface of the cartridge body is viewed with the ink supply structure facing down, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the ink cartridge, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 7: 
     The combination as described above where the plane defined by the leading edge is substantially flush with the fourth surface. 
     Ninth Variation 
     An ink supply system adapted to supply ink to an ink jet printing apparatus, the ink jet printing apparatus comprising a plurality of apparatus-side contact forming members, the ink supply system comprising an electrical device, an ink chamber for storing ink; an ink supply structure, adapted and configured to supply ink from the ink chamber to the ink jet printing apparatus, the ink supply structure having a mounting direction leading edge defining a plane; a terminal bearing structure having a plurality of electrically conductive terminals coupled to the electrical device, the terminals adapted and arranged on the terminal bearing structure to make contact with and receive elastic force from the contact forming members  731 - 739 ) at contact portions of the terminals when the ink supply system supplies ink to the printing apparatus so that a vector component of the elastic force from the apparatus-side contact forming members urges the ink chamber in a direction opposite to the mounting direction; and a first restriction portion including an engagement portion adapted to engage with the engagement portion of the lever so as to restrict movement of the terminal bearing structure in a direction opposite the mounting direction; wherein the engagement portion of the first restriction portion is positioned adjacent the terminal bearing structure and the contact portions are arranged substantially in a contact portion plane which is neither parallel nor perpendicular to the plane of the leading edge when the ink supply system supplies ink to the printing apparatus. 
     Some of the benefits of the above variation of the seventh modification will now be described. The terminals must be precisely positioned and stably fixed while the ink cartridge is mounted in the printer, in order to ensure reliable electrical communication between the cartridge and the printer. Because the engagement portion of the first restriction portion is located adjacent to the terminal bearing structure, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the apparatus-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to ink. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the apparatus-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the contact portion plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printer. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the printer terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the printer terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printer, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the printer side terminals serves to both press the printer side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printer when engagement between the first restriction portion and the printer lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is adapted to engage with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printer. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The ink supply system as described above where the contact portion plane is at an angle of between about 25 and 40 degrees to the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus. 
     As discussed with reference to  FIGS. 42A-45 , when the contact portion plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 2: 
     The ink supply system as described above where when the ink supply system supplies ink to the printing apparatus the engagement portion of the first restriction portion is located to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals. 
     When the ink supply system supplies ink to the printing apparatus, if held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals there can be sufficient tilting so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 3: 
     The ink supply system as described above further comprising a body including a front and a rear, the front and rear opposite each other, a second restriction portion proximate to the rear of the body, the terminal bearing structure proximate to the front of the body, the second restriction portion including an engagement portion adapted and configured to engage with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 4: 
     The ink supply system as described above further comprising a body including a first surface and a second surface, the first surface and second surface opposite each other, a second restriction portion proximate to the second surface of the body, the terminal bearing structure proximate to the first surface of the body, the second restriction portion including an engagement portion adapted and configured to engage with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 5: 
     The ink supply system as described above where the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus, the lever serves to restrict motion. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 6: 
     The ink supply system as described above where when the ink supply system supplies ink to the printing apparatus, the engagement portion of the first restriction portion is on the right and the ink supply structure is facing down, the engagement portion of the first restriction portion is to the left of a pivot point of the lever. 
     When the ink supply system supplies ink to the printing apparatus and the engagement portion of the first restriction portion is to the left of a pivot point of the lever and the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Further, the possibility that the engagement portion of the first restriction portion becoming unlocked from the engagement portion of the lever is reduced. 
     Adaptation 7: 
     The ink supply system as described above further comprising a body proximate the terminal bearing structure, wherein when the ink supply system supplies ink to the printing apparatus, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the body. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the body, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 8: 
     The ink supply system as described above further comprising an adapter wherein the ink supply structure, the terminal bearing structure and the first restriction portion are positioned on the adapter and the ink chamber is adapted and configured to be mated with the adapter. 
     Adaptation 9: 
     The ink supply system as described above further comprising an adapter wherein the terminal bearing structure and the first restriction portion are positioned on the adapter, the ink supply structure is positioned on the ink chamber and the ink chamber is adapted and configured to be mated with the adapter. 
     Adaptation 10: 
     The ink supply system as described above further comprising an adapter, an ink tank external from the ink jet printing apparatus, a tube and an auxiliary adapter wherein the ink supply structure is positioned on the auxiliary adapter, the terminal bearing structure and the first restriction portion are positioned on the adapter and the tube supplies ink from the external tank to the auxiliary adapter when the ink supply system supplies ink to the printing apparatus. 
     Adaptation 11: 
     The ink supply system as described above where the further comprising a body including a top and a bottom, the top and bottom opposite each other, where the plane defined by the leading edge is substantially flush with the bottom. 
     Tenth Variation 
     An ink supply system adapted to supply ink to an ink jet printing apparatus, the ink jet printing apparatus comprising a plurality of apparatus-side contact forming members, the ink jet printing apparatus also comprising a lever having an engagement portion, the ink supply system comprising an electrical device, an ink chamber for storing ink; an ink supply structure, adapted and configured to supply ink from the ink chamber to the ink jet printing apparatus, the ink supply structure having a mounting direction leading edge defining a plane; a terminal bearing structure having a plurality of electrically conductive terminals coupled to the electrical device, the terminals adapted and arranged on the terminal bearing structure to make contact with and receive elastic force from the contact forming members when the ink supply system supplies ink to the printing apparatus so that a vector component of the elastic force from the apparatus-side contact forming members urges the ink chamber in a direction opposite to the mounting direction; and a first restriction portion including an engagement portion adapted to engage with the engagement portion of the lever so as to restrict movement of the terminal bearing structure in a direction opposite the mounting direction; wherein the engagement portion of the first restriction portion is positioned adjacent the terminal bearing structure and the terminals are arranged substantially in a terminal plane which is neither parallel nor perpendicular to the plane of the leading edge when the ink supply system supplies ink to the printing apparatus. 
     Some of the benefits of the above variation of the seventh modification will now be described. The terminals must be precisely positioned and stably fixed while the ink cartridge is mounted in the printer, in order to ensure reliable electrical communication between the cartridge and the printer. Because the engagement portion of the first restriction portion is located adjacent to the terminal bearing structure, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the apparatus-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to ink. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the apparatus-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the terminal plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printer. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the printer terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the printer terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printer, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the printer side terminals serves to both press the printer side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printer when engagement between the first restriction portion and the printer lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is adapted to engage with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printer. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The ink supply system as described above where the terminal plane is at an angle of between about 25 and 40 degrees to the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus. 
     As discussed with reference to  FIGS. 42A-45 , when the terminal plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 2: 
     The ink supply system as described above where when the ink supply system supplies ink to the printing apparatus, the engagement portion of the first restriction portion is located to the left of a right edge of a rightmost terminal of the plurality of terminals and to the right of a left edge of the leftmost terminal of the plurality of terminals. 
     When the ink supply system supplies ink to the printing apparatus, if held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of a right edge of a rightmost terminal of the plurality of terminals and to the right of a left edge of the leftmost terminal of the plurality of terminals the ink cartridge can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 3: 
     The ink supply system as described above further comprising a body including a front and a rear, the front and rear opposite each other, a second restriction portion proximate to the rear of the body, the terminal bearing structure proximate to the front of the body, the second restriction portion including an engagement portion adapted and configured to engage with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 4: 
     The ink supply system as described above further comprising a body including a first surface and a second surface, the first surface and second surface opposite each other, a second restriction portion proximate to the second surface of the body, the terminal bearing structure proximate to the first surface of the body, the second restriction portion including an engagement portion adapted and configured to engage with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 5: 
     The ink supply system as described above where the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus, the lever serves to restrict motion. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 6: 
     The ink supply system as described above where when the ink supply system supplies ink to the printing apparatus, the engagement portion of the first restriction portion is on the right and the ink supply structure is facing down, the engagement portion of the first restriction portion is to the left of a pivot point of the lever. 
     When the ink supply system supplies ink to the printing apparatus and the engagement portion of the first restriction portion is to the left of a pivot point of the lever and the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Further, the possibility that the engagement portion of the first restriction portion becoming unlocked from the engagement portion of the lever is reduced. 
     Adaptation 7: 
     The ink supply system as described above further comprising a body proximate the terminal bearing structure, wherein when the ink supply system supplies ink to the printing apparatus, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the body. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the body, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 8: 
     The ink supply system as described above further comprising an adapter wherein the ink supply structure, the terminal bearing structure and the first restriction portion are positioned on the adapter and the ink chamber is adapted and configured to be mated with the adapter. 
     Adaptation 9: 
     The ink supply system as described above further comprising an adapter wherein the terminal bearing structure and the first restriction portion are positioned on the adapter, the ink supply structure is positioned on the ink chamber and the ink chamber is adapted and configured to be mated with the adapter. 
     Adaptation 10: 
     The ink supply system as described above further comprising an adapter, an ink tank external from the ink jet printing apparatus, a tube and an auxiliary adapter wherein the ink supply structure is positioned on the auxiliary adapter, the terminal bearing structure and the first restriction portion are positioned on the adapter and the tube supplies ink from the external tank to the auxiliary adapter when the ink supply system supplies ink to the printing apparatus. 
     Adaptation 11: 
     The ink supply system as described above where the further comprising a body including a top and a bottom, the top and bottom opposite each other, where the plane defined by the leading edge is substantially flush with the bottom. 
     Eleventh Variation 
     An ink supply system adapted to supply ink to a portion of an ink jet printing apparatus, the system comprising: a portion of an ink jet printing apparatus, the portion comprising: a plurality of apparatus-side contact forming members; and a lever having an engagement portion, an electrical device, an ink chamber for storing ink; an ink supply structure, adapted and configured to supply ink from the ink chamber to the ink jet printing apparatus, the ink supply structure having a mounting direction leading edge defining a plane; a terminal bearing structure having a plurality of electrically conductive terminals coupled to the electrical device, the terminals contacting and receiving elastic force from the contact forming members at contact portions of the terminals when the ink supply system supplies ink to the printing apparatus so that a vector component of the elastic force from the apparatus-side contact forming members urges the ink chamber in a direction opposite to the mounting direction; and a first restriction portion including an engagement portion engaged with the engagement portion of the lever so as to restrict movement of the terminal bearing structure in a direction opposite the mounting direction; wherein the engagement portion of the first restriction portion is positioned adjacent the terminal bearing structure and the contact portions are arranged substantially in a contact portion plane which is neither parallel nor perpendicular to the plane of the leading edge when the ink supply system supplies ink to the printing apparatus. 
     Some of the benefits of the above variation of the seventh modification will now be described. The terminals must be precisely positioned and stably fixed while the ink cartridge is mounted in the printer, in order to ensure reliable electrical communication between the cartridge and the printer. Because the engagement portion of the first restriction portion is located adjacent to the terminal bearing structure, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the apparatus-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to ink. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the apparatus-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the contact portion plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printer. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the printer terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the printer terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printer, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the printer side terminals serves to both press the printer side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printer when engagement between the first restriction portion and the printer lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is engaged with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printer. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The ink supply system as described above where the contact portion plane is at an angle of between about 25 and 40 degrees to the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus. 
     As discussed with reference to  FIGS. 42A-45 , when the contact portion plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 2: 
     The ink supply system as described above where when the ink supply system supplies ink to the printing apparatus the engagement portion of the first restriction portion is located to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals. 
     When the ink supply system supplies ink to the printing apparatus, if held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals there can be sufficient tilting so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 3: 
     The ink supply system as described above further comprising a body including a front and a rear, the front and rear opposite each other, a second restriction portion proximate to the rear of the body, the terminal bearing structure proximate to the front of the body, the second restriction portion including an engagement portion engaged with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 4: 
     The ink supply system as described above further comprising a body including a first surface and a second surface, the first surface and second surface opposite each other, a second restriction portion proximate to the second surface of the body, the terminal bearing structure proximate to the first surface of the body, the second restriction portion including an engagement portion engaged with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 5: 
     The ink supply system as described above where the lever has two ends and a pivot point intermediate the two ends and where the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between the pivot point of the lever and the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus, the lever serves to restrict motion. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 6: 
     The ink supply system as described above where the lever has two ends and a pivot point intermediate the two ends and where when the ink supply system supplies ink to the printing apparatus, the engagement portion of the first restriction portion is on the right and the ink supply structure is facing down, the engagement portion of the first restriction portion is to the left of the pivot point of the lever. 
     When the ink supply system supplies ink to the printing apparatus and the engagement portion of the first restriction portion is to the left of a pivot point of the lever and the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Further, the possibility that the engagement portion of the first restriction portion becoming unlocked from the engagement portion of the lever is reduced. 
     Adaptation 7: 
     The ink supply system as described above further comprising a body proximate the terminal bearing structure, wherein when the ink supply system supplies ink to the printing apparatus, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the body. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the body, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 8: 
     The ink supply system as described above further comprising an adapter wherein the ink supply structure, the terminal bearing structure and the first restriction portion are positioned on the adapter and the ink chamber is adapted and configured to be mated with the adapter. 
     Adaptation 9: 
     The ink supply system as described above further comprising an adapter wherein the terminal bearing structure and the first restriction portion are positioned on the adapter, the ink supply structure is positioned on the ink chamber and the ink chamber is adapted and configured to be mated with the adapter. 
     Adaptation 10: 
     The ink supply system as described above further comprising an adapter, an ink tank external from the ink jet printing apparatus, a tube and an auxiliary adapter wherein the ink supply structure is positioned on the auxiliary adapter, the terminal bearing structure and the first restriction portion are positioned on the adapter and the tube supplies ink from the external tank to the auxiliary adapter when the ink supply system supplies ink to the printing apparatus. 
     Adaptation 11: 
     The ink supply system as described above where the further comprising a body including a top and a bottom, the top and bottom opposite each other, where the plane defined by the leading edge is substantially flush with the bottom. 
     Twelfth Variation 
     An ink supply system adapted to supply ink to a portion of an ink jet printing apparatus, the system comprising: a portion of an ink jet printing apparatus, the portion comprising: a plurality of apparatus-side contact forming members; and a lever having an engagement portion; an electrical device, an ink chamber for storing ink; an ink supply structure, adapted and configured to supply ink from the ink chamber to the ink jet printing apparatus, the ink supply structure having a mounting direction leading edge defining a plane; a terminal bearing structure having a plurality of electrically conductive terminals coupled to the electrical device, the terminals contacting and receiving elastic force from the contact forming members when the ink supply system supplies ink to the printing apparatus; and a first restriction portion including an engagement portion engaged with the engagement portion of the lever so as to restrict movement of the terminal bearing structure in a direction opposite the mounting direction; wherein the engagement portion of the first restriction portion is positioned adjacent the terminal bearing structure and the terminals are arranged substantially in a terminal plane which is neither parallel nor perpendicular to the plane of the leading edge when the ink supply system supplies ink to the printing apparatus. 
     Some of the benefits of the above variation of the seventh modification will now be described. The terminals must be precisely positioned and stably fixed while the ink cartridge is mounted in the printer, in order to ensure reliable electrical communication between the cartridge and the printer. Because the engagement portion of the first restriction portion is located adjacent to the terminal bearing structure, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the apparatus-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to ink. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the apparatus-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the terminal plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printer. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the printer terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the printer terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printer, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the printer side terminals serves to both press the printer side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printer when engagement between the first restriction portion and the printer lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is engaged with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printer. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The ink supply system as described above where the terminal plane is at an angle of between about 25 and 40 degrees to the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus. 
     As discussed with reference to  FIGS. 42A-45 , when the terminal plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 2: 
     The ink supply system as described above where when the ink supply system supplies ink to the printing apparatus, the engagement portion of the first restriction portion is located to the left of a right edge of a rightmost terminal of the plurality of terminals and to the right of a left edge of the leftmost terminal of the plurality of terminals. 
     When the ink supply system supplies ink to the printing apparatus, if held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of a right edge of a rightmost terminal of the plurality of terminals and to the right of a left edge of the leftmost terminal of the plurality of terminals the ink cartridge can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 3: 
     The ink supply system as described above further comprising a body including a front and a rear, the front and rear opposite each other, a second restriction portion proximate to the rear of the body, the terminal bearing structure proximate to the front of the body, the second restriction portion including an engagement portion engaged with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 4: 
     The ink supply system as described above further comprising a body including a first surface and a second surface, the first surface and second surface opposite each other, a second restriction portion proximate to the second surface of the body, the terminal bearing structure proximate to the first surface of the body, the second restriction portion including an engagement portion engaged with a respective portion of the ink jet printing apparatus, wherein the distance between the engagement portion of the second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first side restriction portion will become disengaged from the printer engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is farther from the plane defined by the leading edge than is engagement portion of the second restriction portion from the plane defined by the leading edge. 
     Adaptation 5: 
     The ink supply system as described above where the lever has two ends and a pivot point intermediate the two ends and where the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between the pivot point of the lever and the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the ink supply system supplies ink to the printing apparatus, the lever serves to restrict motion. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 6: 
     The ink supply system as described above where the lever has two ends and a pivot point intermediate the two ends and where when the ink supply system supplies ink to the printing apparatus, the engagement portion of the first restriction portion is on the right and the ink supply structure is facing down, the engagement portion of the first restriction portion is to the left of the pivot point of the lever. 
     When the ink supply system supplies ink to the printing apparatus and the engagement portion of the first restriction portion is to the left of a pivot point of the lever and the engagement portion of the first restriction portion to the right and the ink supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Further, the possibility that the engagement portion of the first restriction portion becoming unlocked from the engagement portion of the lever is reduced. 
     Adaptation 7: 
     The ink supply system as described above further comprising a body proximate the terminal bearing structure, wherein when the ink supply system supplies ink to the printing apparatus, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the body. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the body, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 8: 
     The ink supply system as described above further comprising an adapter wherein the ink supply structure, the terminal bearing structure and the first restriction portion are positioned on the adapter and the ink chamber is adapted and configured to be mated with the adapter. 
     Adaptation 9: 
     The ink supply system as described above further comprising an adapter wherein the terminal bearing structure and the first restriction portion are positioned on the adapter, the ink supply structure is positioned on the ink chamber and the ink chamber is adapted and configured to be mated with the adapter. 
     Adaptation 10: 
     The ink supply system as described above further comprising an adapter, an ink tank external from the ink jet printing apparatus, a tube and an auxiliary adapter wherein the ink supply structure is positioned on the auxiliary adapter, the terminal bearing structure and the first restriction portion are positioned on the adapter and the tube supplies ink from the external tank to the auxiliary adapter when the ink supply system supplies ink to the printing apparatus. 
     Adaptation 11: 
     The ink supply system as described above where the further comprising a body including a top and a bottom, the top and bottom opposite each other, where the plane defined by the leading edge is substantially flush with the bottom. 
     Eighth Modification 
     The invention may be accomplished by the following descriptions and variations. The symbols in parentheses after the elements in each of the descriptions correspond to the symbols of the respective elements described in the first embodiment or in the modification of the cartridge with the adapter. 
     First Variation 
     A cartridge adapted to be mounted on an printing apparatus having the following structures: the printing apparatus comprising a plurality of apparatus-side contact forming members arranged to apply elastic force to the cartridge, the printing apparatus also comprising a lever having an engagement portion, the cartridge comprising: a first face, second face, third face, and fourth face, wherein the first face and second face are opposite each other and the third face and fourth face are opposite each other; an electrical device: an liquid chamber for storing liquid; an liquid supply structure positioned at the fourth face, configured to supply liquid from the liquid chamber to the printing apparatus, the liquid supply structure having a mounting direction leading edge defining a plane of the cartridge; electrically conductive terminals located closer to the first face than to the second face and coupled to the electrical device, the terminals arranged to make contact with and to receive elastic force from the contact forming members at contact portions of the terminals when the cartridge is mounted on the printing apparatus, the contact portions of the terminals arranged substantially in a contact portions plane which is neither parallel nor perpendicular to the plane defined by the leading edge; and a first restriction portion including an engagement portion adapted to engage with the engagement portion of the lever so as to restrict movement of the cartridge in a direction opposite the mounting direction, the engagement portion of the first restriction portion located at a position closer to the contact portions than to an intersection of the third face and the first face. 
     Some of the benefits of the above variation of the eighth modification will now be described. The terminals must be precisely positioned and stably fixed while the cartridge is mounted in the printing apparatus, in order to ensure reliable electrical communication between the cartridge and the printing apparatus. Because the engagement portion of the first restriction portion is located at a position closer to the contact portions than to an intersection of the third face and the first face, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the apparatus-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to liquid. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the apparatus-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the contact portion plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printing apparatus. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the apparatus-side terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the apparatus-side terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printing apparatus, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the apparatus-side terminals serves to both press the apparatus side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printing apparatus when engagement between the first restriction portion and the lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is adapted to engage with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printing apparatus. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The cartridge as described above, wherein the engagement portion of the first restriction portion is located at a position closer to the contact portions than to the midpoint between an intersection of the first face and the contact portions plane and an intersection of the third face and the first face. 
     By locating the engagement portion of the first restriction portion at a position closer to the contact portions than to the midpoint, the benefits described above can be brought well. 
     Adaptation 2: 
     The cartridge as described above, wherein the contact portions plane is at an angle of between 25 and 40 degrees to the plane defined by the leading edge. 
     As discussed with reference to  FIGS. 42A-45 , when the contact portion plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 3: 
     The cartridge as described above, wherein when the first face of the cartridge is viewed with the liquid supply structure facing down, the engagement portion of the first restriction portion is located to the left of an extended line of a right edge of a rightmost terminal of the plurality of terminals and to the right of an extended line of a left edge of a leftmost terminal of the plurality of terminals. 
     When the cartridge is mounted on the printing apparatus, if the cartridge is held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals the cartridge can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 4: 
     The cartridge as described above, further comprising a second restriction portion on the second face of the cartridge, the second restriction portion including an engagement portion adapted to engage with a respective portion of the printing apparatus, wherein the distance between the engagement portion of second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first restriction portion will become disengaged from the apparatus-side engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the second restriction portion. 
     Adaptation 5: 
     The cartridge as described above, wherein when viewing the cartridge from the angle with the engagement portion of the first restriction portion to the right and the liquid supply structure facing down, the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, when the distances are measured in an orthogonal direction to the direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, the lever serves to restrict the motion of the cartridge. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted cartridge. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 6: 
     The cartridge as described above, wherein when viewing the cartridge from the angle with the engagement portion of the first restriction portion to the right and the liquid supply structure facing down, the engagement portion of the first restriction portion is to the left of the pivot point of the lever when the cartridge is mounted. 
     When the cartridge is mounted so that the engagement portion of the first restriction portion is to the left of a pivot point of the lever when viewing the cartridge from the side with the engagement portion of the first restriction portion to the right and the liquid supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Even when the cartridge receives force, the first restriction portion would move with the cartridge. Such moving reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever. 
     Adaptation 7: 
     The cartridge as described above, wherein when the first face is viewed with the liquid supply structure facing down, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the cartridge when the cartridge is mounted. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the cartridge, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 8: 
     The cartridge as described above, wherein the plane defined by the leading edge is substantially flush with the fourth face. 
     Adaptation 9: 
     The cartridge as described above, comprising an adapter wherein the contact portions of the terminals and the first restriction portion are positioned on the adapter and the liquid chamber is adapted and configured to be mated with the adapter. 
     Second Variation 
     A cartridge adapted to be mounted on an printing apparatus, the printing apparatus comprising a plurality of apparatus-side contact forming members arranged to apply elastic force to the cartridge, the printing apparatus also comprising a lever having an engagement portion, the cartridge comprising: a first face, second face, third face, and fourth face, wherein the first face and second face are opposite each other and the third face and fourth face are opposite each other; an electrical device; an liquid chamber for storing liquid; an liquid supply structure positioned at the fourth face, configured to supply liquid from the liquid chamber to the printing apparatus, the liquid supply structure having a mounting direction leading edge defining a plane of the cartridge; electrically conductive terminals located closer to the first face than to the second face and coupled to the electrical device, the terminals arranged to make contact with and receive elastic force from the contact forming members at contact portions of the terminals when the cartridge is mounted on the printing apparatus, the contact portions of the terminals arranged substantially in a contact portions plane which is neither parallel nor perpendicular to the plane defined by the leading edge; and a first restriction portion including an engagement portion adapted to engage with the engagement portion of the lever so as to restrict movement of the cartridge in a direction opposite the mounting direction, the first restriction portion provided at a position closer to a first intersection where the first face intersects the contact portions plane than to a second intersection where the first face intersects the third face. 
     Some of the benefits of the above variation of the eighth modification will now be described. The terminals must be precisely positioned and stably fixed while the cartridge is mounted in the printing apparatus, in order to ensure reliable electrical communication between the cartridge and the printing apparatus. Because the engagement portion of the first restriction portion is located at a position closer to a first intersection where the first face intersects the contact portion plane than to a second intersection where the first face intersects the third face, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the apparatus-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to liquid. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the apparatus-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the contact portion plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printing apparatus. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the apparatus-side terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the apparatus-side terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printing apparatus, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the apparatus-side terminals serves to both press the apparatus side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printing apparatus when engagement between the first restriction portion and the lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is adapted to engage with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printing apparatus. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The cartridge as described above, wherein the engagement portion of the first restriction portion is located at a position closer to the first intersection than to the midpoint between the first intersection and the second intersection. 
     By locating the engagement portion of the first restriction portion at a position closer to the contact portions than to the midpoint, the benefits described above can be brought well. 
     Adaptation 2: 
     The cartridge as described above, wherein the contact portions plane is at an angle of between 25 and 40 degrees to the plane defined by the leading edge. 
     As discussed with reference to  FIGS. 42A-45 , when the contact portion plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 3: 
     The cartridge as described above, wherein when the first face of the cartridge is viewed with the liquid supply structure facing down, the engagement portion of the first restriction portion is located to the left of an extended line of a right edge of a rightmost terminal of the plurality of terminals and to the right of an extended line of a left edge of a leftmost terminal of the plurality of terminals. 
     When the cartridge is mounted on the printing apparatus, if the cartridge is held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals the cartridge can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 4: 
     The cartridge as described above, further comprising a second restriction portion on the second face of the cartridge, the second restriction portion including an engagement portion adapted to engage with a respective portion of the printing apparatus, wherein the distance between the engagement portion of second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first restriction portion will become disengaged from the apparatus-side engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the second restriction portion. 
     Adaptation 5: 
     The cartridge as described above, wherein when viewing the cartridge from the angle with the engagement portion of the first restriction portion to the right and the liquid supply structure facing down, the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, when the distances are measured in an orthogonal direction to the direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, the lever serves to restrict the motion of the cartridge. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted cartridge. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 6: 
     The cartridge as described above, wherein when viewing the cartridge from the angle with the engagement portion of the first restriction portion to the right and the liquid supply structure facing down, the engagement portion of the first restriction portion is to the left of the pivot point of the lever when the cartridge is mounted. 
     When the cartridge is mounted so that the engagement portion of the first restriction portion is to the left of a pivot point of the lever when viewing the cartridge from the side with the engagement portion of the first restriction portion to the right and the liquid supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Even when the cartridge receives force, the first restriction portion would move with the cartridge. Such moving reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever. 
     Adaptation 7: 
     The cartridge as described above, wherein when the first face is viewed with the liquid supply structure facing down, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the cartridge when the cartridge is mounted. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the cartridge, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 8: 
     The cartridge as described above, wherein the plane defined by the leading edge is substantially flush with the fourth face. 
     Adaptation 9: 
     The cartridge, as described above comprising an adapter wherein the contact portions of the terminals and the first restriction portion are positioned on the adapter and the liquid chamber is adapted and configured to be mated with the adapter. 
     Third Variation 
     An cartridge adapted to be mounted on an printing apparatus having the following structures: the printing apparatus comprising a plurality of apparatus-side contact forming members arranged to apply elastic force to the cartridge, the printing apparatus also comprising a lever having an engagement portion and a pivot point, the cartridge comprising: a first face, second face, third face, and fourth face, wherein the first face and second face are opposite each other and the third face and fourth face are opposite each other; an electrical device: an liquid chamber for storing liquid; an liquid supply structure positioned at the fourth face, configured to supply liquid from the liquid chamber to the printing apparatus, the liquid supply structure having a mounting direction leading edge defining a plane of the cartridge; electrically conductive terminals located closer to the first face than to the second face and coupled to the electrical device, the terminals arranged to make contact with and to receive elastic force from the contact forming members at contact portions of the terminals when the cartridge is mounted on the printing apparatus, the contact portions of the terminals arranged substantially in a contact portions plane which is neither parallel nor perpendicular to the plane defined by the leading edge; and a first restriction portion including an engagement portion adapted to engage with the engagement portion of the lever so as to restrict movement of the cartridge in a direction opposite the mounting direction, the engagement portion of the first restriction portion is disposed such that when the cartridge is mounted onto the printing apparatus, the engagement portion of the first restriction portion is engaged with the lever at a position beneath the pivot point of the lever. 
     Some of the benefits of the above variation of the eighth modification will now be described. The terminals must be precisely positioned and stably fixed while the cartridge is mounted in the printing apparatus, in order to ensure reliable electrical communication between the cartridge and the printing apparatus. Because the engagement portion of the first restriction portion is located at a position beneath the pivot point of the lever, the lever serves to restrict the motion of the cartridge. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted cartridge. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to liquid. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the apparatus-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the contact portion plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printing apparatus. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the apparatus-side terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the apparatus-side terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printing apparatus, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the apparatus-side terminals serves to both press the apparatus side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printing apparatus when engagement between the first restriction portion and the lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is adapted to engage with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printing apparatus. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The cartridge as described above, wherein the contact portions plane is at an angle of between 25 and 40 degrees to the plane defined by the leading edge. 
     By locating the engagement portion of the first restriction portion at a position closer to the contact portions than to the midpoint, the benefits described above can be brought well. 
     As discussed with reference to  FIGS. 42A-45 , when the contact portion plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 2: 
     The cartridge as described above, wherein when the first face of the cartridge is viewed with the liquid supply structure facing down, the engagement portion of the first restriction portion is located to the left of an extended line of a right edge of a rightmost terminal of the plurality of terminals and to the right of an extended line of a left edge of a leftmost terminal of the plurality of terminals. 
     When the cartridge is mounted on the printing apparatus, if the cartridge is held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals the cartridge can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 3: 
     The cartridge as described above, further comprising a second restriction portion on the second face of the cartridge, the second restriction portion including an engagement portion adapted to engage with a respective portion of the printing apparatus, wherein the distance between the engagement portion of second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first restriction portion will become disengaged from the apparatus-side engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the second restriction portion. 
     Adaptation 4: 
     The cartridge as described above, wherein when viewing the cartridge from the angle with the engagement portion of the first restriction portion to the right and the liquid supply structure facing down, the engagement portion of the first restriction portion is to the left of the pivot point of the lever when the cartridge is mounted. 
     When the cartridge is mounted so that the engagement portion of the first restriction portion is to the left of a pivot point of the lever when viewing the cartridge from the side with the engagement portion of the first restriction portion to the right and the liquid supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Even when the cartridge receives force, the first restriction portion would move with the cartridge. Such moving reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever. 
     Adaptation 5: 
     The cartridge as described above, wherein when the first face is viewed with the liquid supply structure facing down, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the cartridge when the cartridge is mounted. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the cartridge, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 6: 
     The cartridge as described above, wherein the plane defined by the leading edge is substantially flush with the fourth face. 
     Adaptation 7: 
     The cartridge as described above, comprising an adapter wherein the contact portions of the terminals and the first restriction portion are positioned on the adapter and the liquid chamber is adapted and configured to be mated with the adapter. 
     Fourth Variation 
     An cartridge adapted to be mounted on an printing apparatus, the printing apparatus comprising a plurality of apparatus-side contact forming members arranged to apply elastic force to the cartridge, the printing apparatus also comprising a lever having an engagement portion, the cartridge comprising: a front, a rear, a top, and a bottom, wherein the front and rear opposite each other and the top and bottom opposite each other; an electrical device; an liquid chamber for storing liquid; an liquid supply structure positioned at the bottom, configured to supply liquid from the liquid chamber to the printing apparatus, the liquid supply structure having a mounting direction leading edge defining a plane of the cartridge; electrically conductive terminals located closer to the front than to the rear and coupled to the electrical device, the terminals arranged to make contact with and receive elastic force from the contact forming members at contact portions of the terminals when the cartridge is mounted on the printing apparatus, the contact portions of the terminals arranged substantially in a contact portions plane which is neither parallel nor perpendicular to the plane defined by the leading edge; and a first restriction portion including an engagement portion adapted to engage with the engagement portion of the lever so as to restrict movement of the cartridge in a direction opposite the mounting direction, the first restriction portion provided at a position located closer to the contact portions plane than to the top. 
     Some of the benefits of the above variation of the eighth modification will now be described. The terminals must be precisely positioned and stably fixed while the cartridge is mounted in the printing apparatus, in order to ensure reliable electrical communication between the cartridge and the printing apparatus. Because the engagement portion of the first restriction portion is located at a position closer to the contact portion plane than to the top, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the apparatus-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the cartridge-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the cartridge, the material for producing the cartridge can be different from the material used for producing the lever. Also, the material of the cartridge can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to liquid. 
     Additionally, because the lever is not on the cartridge, no special care is needed to prevent creep deformation of the lever in packaging of the cartridge for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the cartridge, the cartridge can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the cartridge for transportation or distribution of the cartridge, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the cartridge, the first cartridge-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first cartridge-side restriction element. In the attached or mounted state, the cartridge can be kept at the proper position in the cartridge mounting structure, which maintains normal or good contact between the cartridge-side terminals and the apparatus-side terminals and reduces the possibility of poor electrical communication. Since the first cartridge-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the cartridge, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the cartridge terminals and the cartridge&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the cartridge terminals, so electrical communication is more stable. 
     Because the contact portion plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the cartridge terminals can be properly wiped during insertion of the cartridge into the printing apparatus. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the apparatus-side terminals scrape for long distances against the circuit board during installation of the cartridge. 
     Because the apparatus-side terminals apply, against the cartridge terminals, an elastic force which includes a vector component in the direction in which the cartridge is detached from the printing apparatus, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the apparatus-side terminals serves to both press the apparatus side and cartridge side terminals together, and also to move the cartridge in the direction for removal from the printing apparatus when engagement between the first restriction portion and the lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is adapted to engage with the engagement portion of the lever so as to restrict movement of the cartridge in the direction opposite to the mounting direction, as a result, the position of the cartridge terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the cartridge is mounted in the printing apparatus. Since the cartridge terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the cartridge terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     Adaptation 1: 
     The cartridge as described above, wherein the engagement portion of the first restriction portion is located at a position closer to the contact portions than to the midpoint between an intersection of the front and the contact portions plane and the intersection of the top and the front. 
     By locating the engagement portion of the first restriction portion at a position closer to the contact portions than to the midpoint, the benefits described above can be brought well. 
     Adaptation 2: 
     The cartridge as described above, wherein the contact portions plane is at an angle of between 25 and 40 degrees to the plane defined by the leading edge. 
     As discussed with reference to  FIGS. 42A-45 , when the contact portion plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     Adaptation 3: 
     The cartridge as described above, wherein when the front of the cartridge is viewed with the liquid supply structure facing down, the engagement portion of the first restriction portion is located to the left of an extended line of a right edge of a rightmost terminal of the plurality of terminals and to the right of an extended line of a left edge of a leftmost terminal of the plurality of terminals. 
     When the cartridge is mounted on the printing apparatus, if the cartridge is held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals the cartridge can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     Adaptation 4: 
     The cartridge as described above, wherein the engagement portion is adapted to engage with a rotatable lever having a pivot point above the engagement portion of the first restriction portion. 
     When the rotatable lever has the pivot point above the engagement portion of the first restriction portion, the lever serves to restrict the motion of the cartridge. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted cartridge. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 5: 
     The cartridge as described above, further comprising a second restriction portion on the rear of the cartridge, the second restriction portion including an engagement portion adapted to engage with a respective portion of the printing apparatus, wherein the distance between the engagement portion of second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first restriction portion will become disengaged from the apparatus-side engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the second restriction portion. 
     Adaptation 6: 
     The cartridge as described above, wherein the second restriction portion is adapted to serve as a pivot point of rotation when the cartridge is turned to be detached from a holder of the printing apparatus. 
     Adaptation 7: 
     The cartridge as described above, wherein when viewing the cartridge from the angle with the engagement portion of the first restriction portion to the right and the liquid supply structure facing down, the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, when the distances are measured in an orthogonal direction to the direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the cartridge is mounted, the lever serves to restrict the motion of the cartridge. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted cartridge. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 8: 
     The cartridge as described above, wherein when viewing the cartridge from the angle with the engagement portion of the first restriction portion to the right and the liquid supply structure facing down, the engagement portion of the first restriction portion is to the left of the pivot point of the lever when the cartridge is mounted. 
     When the cartridge is mounted so that the engagement portion of the first restriction portion is to the left of a pivot point of the lever when viewing the cartridge from the side with the engagement portion of the first restriction portion to the right and the liquid supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Even when the cartridge receives force, the first restriction portion would move with the cartridge. Such moving reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever. 
     Adaptation 9: 
     The cartridge as described above, wherein when the front is viewed with the liquid supply structure facing down, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the cartridge when the cartridge is mounted. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the cartridge, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     Adaptation 10: 
     The cartridge as described above, wherein the plane defined by the leading edge is substantially flush with the bottom. 
     Adaptation 11: 
     The cartridge as described above, comprising an adapter wherein the contact portions of the terminals and the first restriction portion are positioned on the adapter and the liquid chamber is adapted and configured to be mated with the adapter. 
     Adaptation 12: 
     Use of the cartridge as described above, wherein the engagement portion of the cartridge is engaged with a movable lever of a printing apparatus in such a way that the lever has a pivot point above the engagement portion. 
     Adaptation 13: 
     The combination of a cartridge and a printing apparatus, the combination comprising: a cartridge as described above; and a printing apparatus including a plurality of apparatus-side contact forming members applying an elastic force to the cartridge, and a lever having an engagement portion adapted to engage with the engagement portion of the first restriction portion of the cartridge so as to restrict movement of the cartridge in a direction opposite the mounting direction. 
     Adaptation 14: 
     The combination as described above, wherein the lever has two ends and a pivot point intermediate the two ends, the pivot point of the lever is provided above the engagement portion of the first restriction portion of the cartridge. 
     When the rotatable lever has the pivot point above the engagement portion of the first restriction portion, the lever serves to restrict the motion of the cartridge. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted cartridge. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     Adaptation 15: 
     The combination as described above, wherein the pivot point of the lever is provided to the right of the engagement portion of the first restriction portion of the cartridge. 
     When the pivot point of the lever is provided to the right of the engagement portion of the first restriction portion of the cartridge, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Even when the cartridge receives force, the first restriction portion would move with the cartridge. Such moving reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever. 
     Fifth Variation 
     A liquid supply system adapted to supply liquid to a printing apparatus, the printing apparatus comprising a plurality of apparatus-side contact forming members, the liquid supply system comprising: an electrical device; an liquid source; an liquid supply structure adapted and configured to supply liquid from the liquid source to the printing apparatus, the liquid supply structure having a mounting direction leading edge defining a plane; an adapter having: electrically conductive terminals coupled to the electrical device, the terminals arranged to make contact with and receive elastic force from the contact forming members at contact portions of the terminals when the supply system supplies liquid to the printing apparatus, the contact portions of the terminals arranged substantially in a contact portions plane which is neither parallel nor perpendicular to the plane defined by the leading edge; and a first restriction portion provided on a front of the adapter including an engagement portion adapted to engage with the engagement portion of the lever so as to restrict movement of the adapter in a direction opposite the mounting direction, the first restriction portion positioned adjacent the contact portions plane. 
     Some of the benefits of the above variation of the ninth modification will now be described. The terminals must be precisely positioned and stably fixed while the adapter is mounted in the printing apparatus, in order to ensure reliable electrical communication between the adapter and the printing apparatus. Because the engagement portion of the first restriction portion is positioned adjacent the contact portion plane, positioning action of the first restriction portion occurs close to where positioning is most needed (i.e., the terminals of the terminal bearing structure). The elastic force from the apparatus-side terminals can be properly counteracted against. Also, positional shift of the terminals, which can occur due to vibration during printing operations, can be suppressed. Therefore, positioning of the terminals is more stable, thus maintaining the stable electrical connection between the adapter-side terminals and the apparatus-side terminals. 
     Moreover, because the lever is not made integral with the adapter, the material for producing the adapter can be different from the material used for producing the lever. Also, the material of the adapter can be selected with less concern for flexibility and durability requirements, and with greater focus on other properties such as resistance to liquid. 
     Additionally, because the lever is not on the adapter, no special care is needed to prevent creep deformation of the lever in packaging of the adapter for transportation and distribution. This simplifies packaging requirements and improves the user&#39;s convenience. Because the lever is not an integral part of the adapter, the adapter can be made smaller. This further allows size reduction of the packaging material, such as paper or box, used to package the adapter for transportation or distribution of the adapter, thus advantageously reducing transportation and parts costs. Also because the lever is not integral with the adapter, the first adapter-side restriction element can be made with a small size and simple structure, and with higher rigidity, compared with the structures described in U.S. Publication No. 2005/0151811, for example. This results in significantly reducing the possibility of plastic deformation of the first adapter-side restriction element. In the attached or mounted state, the adapter can be kept at the proper position in the adapter mounting structure, which maintains normal or good contact between the adapter-side terminals and the apparatus-side terminals and reduces the possibility of poor electrical communication. Since the first adapter-side restriction element can have a small size and simple structure, no special care to prevent creep deformation of the lever is required in packaging for transportation and distribution of the adapter, unlike the cartridges of U.S. Publication No. 2005/0151811. This reduces packaging requirements and also improves the user&#39;s convenience. 
     It is possible for the structure that connects the adapter terminals and the adapter&#39;s engagement portion to each other, to be only rigid structure (which is not the case with the flexible levers of U.S. Publication No. 2005/0151811). In this case, less vibration is transmitted from the engagement portion to the adapter terminals, so electrical communication is more stable. 
     Because the contact portion plane of the terminals is neither parallel nor perpendicular to the plane defined by the leading edge, the surface of the adapter terminals can be properly wiped during insertion of the adapter into the printing apparatus. In addition, this configuration reduces or eliminates insulation fragments (dust) that can be generated if the apparatus-side terminals scrape for long distances against the circuit board during installation of the adapter. 
     Because the apparatus-side terminals apply, against the adapter terminals, an elastic force which includes a vector component in the direction in which the adapter is detached from the printing apparatus, there is no need to provide a spring like the spring 103 described in U.S. Pat. No. 6,955,422. In other words, the elastic force from the apparatus-side terminals serves to both press the apparatus side and adapter side terminals together, and also to move the adapter in the direction for removal from the printing apparatus when engagement between the first restriction portion and the lever is released. So there is no need to provide an additional spring as in the case of the U.S. Pat. No. 6,955,422, which enables a simpler structure and reduced costs. 
     Because the first restriction portion is adapted to engage with the engagement portion of the lever so as to restrict movement of the adapter in the direction opposite to the mounting direction, as a result, the position of the adapter terminals will be maintained in place with respect to the mounting direction by the elastic force of the apparatus-side contact forming members, and with respect to the direction opposite to the mounting direction by the first restriction portion, when the adapter is mounted in the printing apparatus. Since the adapter terminals are “sandwiched” in this way, they are firmly fixed from moving in both the mounting direction and the direction opposite from the mounting direction. There is thus less likelihood of misalignment or disconnection between the adapter terminals and the apparatus-side contact forming members, compared with the one-sided restriction by the elastic piece 40 and related configuration of U.S. Pat. No. 7,008,053. 
     The liquid supply system as described above, wherein the contact portions plane is at an angle of between 25 and 40 degrees to the plane defined by the leading edge. 
     As discussed with reference to  FIGS. 42A-45 , when the contact portion plane is at an angle between about 25 and 40 degrees relative to the plane defined by the leading edge, excessive wiping is prevented and sufficient force to prevent half-insertion can be applied. 
     The liquid supply system as described above, wherein when the front of the adapter is viewed with the liquid supply structure facing down, the engagement portion of the first restriction portion is located to the left of an extended line of a right edge of a rightmost terminal of the plurality of terminals and to the right of an extended line of a left edge of a leftmost terminal of the plurality of terminals. 
     When the adapter is mounted on the printing apparatus, if the adapter is held too securely, then contact with some of the apparatus-side contact forming members, might not be secure. By locating the engagement portion of the first restriction portion to the left of the rightmost contact portion of the plurality of terminals and to the right of the leftmost contact portion of the plurality of terminals the adapter can tilt sufficiently so that the electrical connection between the plurality of terminals and the apparatus-side contact forming members can be even more stable. 
     The liquid supply system as described above, further comprising a second restriction portion on an rear of the adapter, the second restriction portion including an engagement portion adapted to engage with a respective portion of the printing apparatus, wherein the distance between the engagement portion of second restriction portion and the plane defined by the leading edge is more than the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge, when the distances are measured in an orthogonal direction to the plane defined by the leading edge. 
     When the engagement portion of the second restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the first restriction portion, the possibility that the first restriction portion will become disengaged from the apparatus-side engagement portion can be more effectively reduced, compared with the case when the engagement portion of the first restriction portion is located farther from the plane defined by the leading edge than is the engagement portion of the second restriction portion. 
     The liquid supply system as described above, wherein when viewing the adapter from the angle with the engagement portion of the first restriction portion to the right and the liquid supply structure facing down, the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the adapter is mounted, when the distances are measured in an orthogonal direction to the direction to the plane defined by the leading edge. 
     When the distance between the engagement portion of the first restriction portion and the plane defined by the leading edge is less than the distance between a pivot point of the lever and the plane defined by the leading edge when the adapter is mounted, the lever serves to restrict the motion of the adapter. This reduces the possibility of the first restriction portion becoming unlocked or disengaged from the engagement portion of the lever, thus creating a stable electrical connection between the plurality of terminals and the contact forming members and reducing the possibility of poor continuity. The first restriction portion can move about the axis of rotation of the lever when force is applied from the contact forming members to the mounted adapter. This reduces the possibility that the engagement portion of the first restriction portion becomes uncoupled from the engagement portion of the lever. 
     The liquid supply system as described above, wherein when viewing the adapter from the angle with the engagement portion of the first restriction portion to the right and the liquid supply structure facing down, the engagement portion of the first restriction portion is to the left of the pivot point of the lever when the adapter is mounted. 
     When the adapter is mounted so that the engagement portion of the first restriction portion is to the left of a pivot point of the lever when viewing the adapter from the side with the engagement portion of the first restriction portion to the right and the liquid supply structure facing down, the first restriction portion generates rotational moment on the lever to turn the lever about the axis of rotation of the lever in the reverse direction to the unlocking direction. This reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever and further ensures the stable electrical connection between the plurality of terminals and the apparatus side contact forming members. Even when the adapter receives force, the first restriction portion would move with the adapter. Such moving reduces the possibility that the engagement portion of the first restriction portion is unlocked from the engagement portion of the lever. 
     The liquid supply system as described above, wherein when the front of the adapter is viewed with the liquid supply structure facing down, at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the adapter when the adapter is mounted. 
     By providing the first restriction portion in such a position so that at least a portion of the engagement portion of the first restriction portion is located substantially at the widthwise center of the adapter, the first restriction portion is located extremely near to the plurality of terminals so that the electrical connection between the plurality of terminals and the apparatus side contact forming members can be stable. 
     The liquid supply system as described above, further comprising a container assembly having the liquid source therein and adapted to be mated with the adapter. 
     The liquid supply system as described above, wherein the liquid supply structure is provided on the container assembly. 
     The liquid supply system as described above, further comprising: a tank having the liquid source therein; an auxiliary adapter having the liquid supply structure; and a tube connecting the tank and the auxiliary adapter. 
     It should also be appreciated that the features described herein can be part of a cartridge itself, as part of a combination of a cartridge and a printing apparatus or in other words when the cartridge is installed and/or as part of a system adapted to supply ink or other printing material to a printing apparatus without departing from the spirit of the invention. 
     The matters described in the respective aspects according to any parts of the invention may be added to any of the various variations described above. 
     Those skilled in the art will recognize that the present invention has many applications, may be implemented in many manners and, as such is not to be limited by the foregoing embodiments and examples. Any number of the features of the different embodiments described herein may be combined into one single embodiment and alternate embodiments having fewer than or more than all of the features herein described are possible. Functionality may also be, in whole or in part, distributed among multiple components, in manners now known or to become known. 
     It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims. While there had been shown and described fundamental features of the invention as applied to being exemplary embodiments thereof, it will be understood that omissions and substitutions and changes in the form and details of the disclosed invention may be made by those skilled in the art without departing from the spirit of the invention. Moreover, the scope of the present invention covers conventionally known, future developed variations and modifications to the components described herein as would be understood by those skilled in the art. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein disclosed and all statements of the scope of the invention that, is a matter of language, might be said to fall there between.