Abstract:
A cartridge is detachably mountable to a holder of an ink jet recording apparatus, so as to be freely reciprocatable to scan across a recording medium and record thereon by discharging ink. The cartridge is defined by a cartridge main body, and is provided with a recording head for discharging ink from plural nozzles formed in parallel on a lower face of the cartridge main body facing the recording medium. A front face of the cartridge main body is provided with an electrical connection portion having cartridge electrodes, which are electrically connectable with corresponding electrodes of the holder. A rear face opposite to the front face is provided with an ink connection portion connectable to corresponding supply ports which supply ink to the recording head from a main tank installed elsewhere on the ink jet recording apparatus. With the cartridge thus structured, the force exerted for connection to the supply port does not affect the precision with which the cartridge is mounted on the holder.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to the structure of fixing a cartridge to the carriage of an ink jet recording apparatus, and also, relates to the structure of the cartridge. 
   Here, in order to describe the relationship between the fixing point and the fixing force when the cartridge is mounted on the carriage, it is defined in the specification hereof that the thrust direction of the guide shaft that guides the carriage as the direction X; the carrying direction of a recording medium as the direction Y; and the direction perpendicular to the surface of the recording medium as the direction Z, and that the rotational directions centering on these three axes as θX, θY, and θZ, respectively. 
   Also, in the specification hereof, the phrase “electrical connection” indicates the state where electrical connection is made, and the phrase “ink connection” indicates the state where the ink receiving portion of a cartridge and a needle are connected in order to supply ink to the cartridge. 
   2. Related Background Art 
   The ink jet recording technology is such as to record characters and images directly on a recording medium (such as paper, cloth, plastic sheet) by discharging ink from fine nozzles thereto. Conventionally, the recording apparatus having a recording head of ink jet recording type has been utilized as a printer serving as the output terminal of a copying machine, a facsimile equipment, a printer, a word processor, a work station, or the like or as a handy or potable printer used for such an information processing system as a personal computer, a host computer, an optical disc device, a video apparatus. For the conventional ink jet recording apparatus of the kind, there has been known the one in which an ink jet recording head and an ink tank are formed integrally or the one that uses the ink jet cartridge provided with an ink tank arranged to be detachably mountable on the cartridge. The cartridge of the kind is fixedly supported on the carriage mounted on the ink jet recording apparatus main body to be able to perform scanning reciprocation, while being arranged to be of disposable type, which is detachably mountable on the carriage. 
     FIG. 16  is a perspective view that schematically shows one example of the vicinity of the carriage of the conventional ink jet recording apparatus.  FIGS. 17A and 17B  are perspective view that illustrate one structural example of the conventional cartridge of disposable type.  FIG. 18  is a perspective view that shows the cartridge represented in  FIGS. 17A and 17B , observed from the lower front side thereof. 
   The carriage  152  of the conventional ink jet recording apparatus is structured to support the cartridge  151  to be detachably mountable. Then, on the inner wall thereof, there are arranged plural electrodes  161 . Also, the carriage  152  reciprocates along the guide shafts  154  and  159  for scanning in the direction X which is substantially at right angles to the direction Y in which a recording medium  160  is being carried by use of conveyance means (not shown). 
   The cartridge  151  comprises plural ink tanks  171 , each of which is independently arranged to contain color ink mostly inside thereof each corresponding to color print; a holder  170  that holds the ink tanks  171 ; and the recording head  172  that discharges ink. 
   As the recording head  172 , there is the one that uses electromechanical converting element, such as piezoelectric element, the one that uses electrothermal converting element, such as heat generating resistive element, or the one that uses magnetic wave mechanical converting element or magnetic wave thermal converting element, such as electric wave or laser, which can be utilized for discharging ink droplets from nozzles. Of the heads of the kinds, the one adopting the method to utilize thermal energy for discharging ink droplets is advantageous in that recording is executable in high resolution, because this method makes it possible to arrange nozzles in high density. 
   The front face  174  of the holder  170  has a head base plate  173  fixed thereto with plural electric connectors  175  connected electrically with the flexible cable that supplies electric energy to the recording head  172 . For the holder  170 , plural ribs  176  are formed to be extended in the direction substantially perpendicular to the head base plate  173  fixed to the front face  174 . 
   The cartridge  151  is inserted into the carriage  152  from the opening portion  177 , and fixed inside the carriage  152  by rotating the head set lever  153  in the direction indicated by an arrow a. Then, the abutting point  166  of the cartridge  151  abuts against the θZ rotation stop point  163  each arranged at two locations, the left and right sides of the inner wall of the carriage  152 , and the head base plate  173  is received with the reaction force of the electrodes  161  being depressed to the electrodes  161  centering on them. The cartridge  151  is drawn into the electrode  161  side by the toggle mechanism by rotating the head set lever  153  further in the direction indicated by the arrow a, and abuts against the θX rotation stop point  162  to fix the carriage  152 . The conventionally exemplified cartridge  151  is fixed to the carriage  152  at these three points, the θZ rotation stop points  163  on the left and right sides, and the θX rotation stop point  162 . 
   The holder  170  of the cartridge  151  thus fixed to the carriage  152  receives reaction force from the electrodes  161 , but the ribs  176  prevent the holder  170  from being deformed by such reaction force. Then, with the support by the ribs  176  over the front face  174 , the head base plate  173  is not deformed to make it possible to connect electrically the electric connectors  175  and the electrodes  161  of the carriage  152  stably. 
   In recent years, however, the multiple use of ink for a color printer has advanced in order to record in higher quality, and the numbers of recording element to be used is increased, while the length of nozzles is made larger to implement higher recording. As a result, the recording area of the recording head is expanded. Along with this, the area of the head base plate is expanded with the increased numbers of electric connectors corresponding to the increased numbers of nozzles. However, it becomes more difficult for a plate member like the head base plate to keep robustness, as the area thereof is made wider. Also, in order to receive the supply of electric power through the pressurized contact with the electrodes of the carriage, it may be impossible to receive the electric supply stably unless suppressed with reaction force of as much as approximately 69 kN at the maximum if each pin is suppressed with reaction force of 490 N. 
   Fundamentally, ribs are provided for the inside of the holder in order to suppress the deformation of the head base plate and the head partition wall that serves as the front face of the holder, which may be caused by the pressure thus added. However, the ribs are extended from the bottom face of the inner wall of the holder toward the head partition wall, and the power that supports the head base plate is small. There is no problem if a head base plate is small even if ribs are extended from the bottom face of the holder only to a portion nearby. If the area of head base plate becomes larger than the conventional one, the area of the head partition wall that should be supported becomes larger accordingly as a matter of course, and it becomes extremely difficult to support the head base plate including the wide area of the partition wall only by the ribs extending from the bottom face of the head without creating any deformation. 
   Also, as described above, if the cartridge having the head base plate that needs a large fixing force, as it becomes larger, should be fixed to a carriage, the power added to the head set lever should be larger or the head set laver should be made larger in order to implement the exertion of pressure over the reaction force received by the carriage from the electrodes of the carriage. Nevertheless, if the force that should be added to the head set lever is made larger, its operability becomes unfavorable due to the increased force needed for operation or there is a fear that such force exceeds the limit of stress of the head set lever that has been formed by molding. On the other hand, if the arm of the head set lever is made longer while setting the force to be added to the head set lever at an appropriate value, the size of the cartridge should be made larger to ensue in making the apparatus larger accordingly. Also, if the force that should be added to the head set lever becomes larger, there is a fear that the deformation of the cartridge and head base plate is made greater. 
   Also, the main body portion of the cartridge is often molded for formation, and along with the trend that it becomes larger, molding deformation is no longer negligible. 
   Further, in recent years, the number of nozzles of the discharge unit is made larger in order to shorten the recording time, and the length of nozzle is made larger, the amount of ink per discharge becomes as fine as several pl, which requires the precise installation of cartridge of several tens micron order with respect to a recording medium. 
   The preciseness of the kind is determined by the precision of the mechanism for carrying a recording medium, the precision of the guide shaft for the carriage that reciprocates across the recording medium, the precision of the positioning point of the carriage with respect to the cartridge, and the precision with which the cartridge is made. 
   Particularly, the deviation of impact of ink on a recording medium in the direction with the vertical axis as the center of rotation generates the displacement of ruled lines or deviation of color formation. The precision in different directions may also contribute to the aforesaid impact deviation as a matter of course, but the greatest cause for this impact deviation is the precision with which nozzles are installed in the rotational direction centering on a recording medium and the vertical axis. 
   For the conventional head, the θX rotation stop is arranged only at one point in the center above the electric connectors. This location is the center of beam, observed from the cartridge main body, and the portion where deformation becomes greatest. Positioning at the location where the deformation is greatest itself is unfavorable, and worst if some unexpected event may take place or it should be taken into consideration that deformation may possibly exceed the limit of elasticity. 
   Even at present, there is a need for providing the parallelism of approximately 20 micron if the receiving portion of the carriage is taken into the measurement criterion with respect to the guide shaft for a printer of high image quality. However, this precision is a limit even now, and it takes a long time to achieve the degree of this precision, and also, it tends to be unstable to make the control complicated. Therefore, it is extremely difficult to attain any higher precision in this respect. 
   Also, for the high image quality printer, not only high speed recording is required, but also, the design consideration begins to be needed for the use thereof at a site where a large scale recording is executed. Consequently, such a disposable type as exemplified for the conventional art presents disadvantage in terms of the weight when an ink tank of a large capacity should be mounted on a movable unit. To cope with the situation, it becomes necessary to adopt the mode in which an ink tank of a large capacity is not mounted on a carriage, but use a tube to connect them, through which ink is supplied from the ink tank to a recording head.  FIG. 19  is a perspective view that schematically shows one example of the ink jet recording apparatus structured to have such an ink tank of large capacity fixed on the recording apparatus main body side. As shown in  FIG. 19 , the structure is arranged so that ink is supplied from the main tank  104  fixed to the recording apparatus main body side to the cartridge  101  mounted on the carriage  102  through the tube  106 . 
   For a recording apparatus of the kind, there is disclosed the recording apparatus in the specification of Japanese Patent Application Laid-Open No. 10-128992, which is structured to connect the tube at the same time when cartridges are replaced. The recording apparatus thus disclosed in the specification thereof makes it possible to complete the connection of the tube simultaneously with the insertion of the cartridge into the carriage. However, since the electrical connection and the tube connection are executed at the same time, the direction in which pressure is exerted to position the cartridge and the direction in which the inserting force is exerted together with the electrical connection are caused to vary. Also, in accordance with the example disclosed in the aforesaid specification, the cartridge is structured to be one line/one color, and there is no problem as to the robustness of the cartridge. For example, however, if six-line nozzles are mounted on one piece of cartridge, the electrical connection and ink connection portions are increased, and the load is increased accordingly, while the span of the robust wall face of the member that forms the cartridge is elongated to make it conceivably difficult to keep the required robustness. In other words, the precision with the cartridge should be installed is inevitably reduced, and it is conceivable that a problem is encountered that the impact precision is degraded eventually. 
   SUMMARY OF THE INVENTION 
   Here, therefore, it is an object of the present invention to provide a cartridge with enhanced robustness, a carriage capable of fixing the cartridge reliably with a small force of operation, and a cartridge and a carriage having high positioning precision, as well as to provide a recording apparatus and a recording head. 
   In order to achieve the object describes above, a cartridge of the invention is detachably mountable on holding means of an ink jet recording apparatus, which is freely reciprocatable to scan for recording by discharging ink to a recording medium, and provided with a recording head for discharging ink from plural nozzles formed in parallel on the lower face of the cartridge main body facing the recording medium. For this cartridge, the front face of the cartridge main body, an electrical connection portion having an electrode on the cartridge side is provided and electrically connected with an electrode of the holding means on holding means side, and for the rear face opposite to the front face, an ink connection portion having supply means connected thereto is provided to supply ink to he recording head from the main tank installed on the main body of the ink jet recording apparatus. 
   The cartridge of the invention thus structured has the front face on which reaction force is exerted at the time of electrodes on the cartridge side being electrically connected with the electrodes of this holding means on holding means side with mechanical pressure exerted thereon, and the rear face on which reaction force given by supply means is exerted when the supply means for supplying ink is physically connected with the ink connection portion. Therefore, with the cartridge being positioned to holding means against the force exerted by the electrical connection, the force exerted for connecting the supply means is in the same direction as the force exerted for positioning. Then, the force exerted for connecting the supply means does not weaken the force exerted on the holding means for positioning. As a result, there is no possibility that the force exerted for connecting the supply means produces any unfavorable effect on the precision with which the cartridge is positioned with respect to the holding means. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view that shows schematically an ink jet recording apparatus in accordance with one embodiment of the present invention. 
       FIG. 2  is a side sectional view that shows a cartridge in accordance with one embodiment of the present invention. 
       FIG. 3  is a front view that shows the cartridge in accordance with one embodiment of the present invention, observed from the needle receptive side. 
       FIG. 4  is an exploded perspective view that shows the cartridge in accordance with one embodiment of the present invention. 
       FIG. 5  is a perspective view that shows the cartridge in accordance with one embodiment of the present invention, observed from above in a state of the face cover being removed. 
       FIGS. 6A ,  6 B,  6 C,  6 D and  6 E are perspective views that illustrate the face cover in accordance with one embodiment of the present invention, observed from the side where ribs are formed. 
       FIG. 7  is a perspective view that shows the cartridge in accordance with one embodiment of the present invention in a state before the head base plate is fixed to the front face of the cartridge. 
       FIG. 8  is a partially broken plan view that shows needle retaining portion. 
       FIG. 9  is a perspective view that shows the cartridge in a state of both the head set lever and the ink connection lever being open. 
       FIG. 10  is a perspective view that shows the cartridge in the state where only the head set lever is closed. 
       FIG. 11  is a perspective view that shows the state where both the head set lever and the ink connection lever are closed. 
       FIGS. 12A ,  12 B,  12 C,  12 D,  12 E, and  12 F are views that illustrate each step of the procedure in which the cartridge is mounted on the carriage. 
       FIG. 13  is a view that illustrates each force exerted on the cartridge and the positioning unit. 
       FIG. 14  is a view that shows the relations between pressure P 1  from the carriage to the cartridge, pressure P 2  from the cartridge to the carriage, and pressure P 3  providing auxiliary pressure for the pressure P 2  in terms of the rotational torques. 
       FIGS. 15A ,  15 B, and  15 C are views that illustrate each step of the procedure in which the cartridge is removed from the carriage. 
       FIG. 16  is a perspective view that shows schematically one example of the vicinity of the carriage of the conventional ink jet recording apparatus. 
       FIGS. 17A and 17B  are perspective views that illustrate one structural example of the conventional cartridge of disposable type. 
       FIG. 18  is a perspective view that shows the cartridge represented in  FIGS. 17A and 17B , observed from the lower front side. 
       FIG. 19  is a perspective view that shows schematically one example of the ink jet recording apparatus structured to fix an ink tank of large capacity on the recording apparatus main body side. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Next, with reference to the accompanying drawings, the embodiments will be described in accordance with the present invention. 
   With reference to  FIG. 1 , the description will be made of one example of an ink jet recording apparatus embodying the present invention. 
   The ink jet recording apparatus shown in  FIG. 1  is the serial type recording apparatus in which the reciprocation (main scanning) of the ink jet recording head  69  (see  FIG. 2 ) and the conveyance (sub-scanning) of a general recording paper sheet, a special paper sheet, an OHP film, or other recording sheet S per designated pitch are repeated, and in synchronism with such movement, ink is selectively discharged from the ink jet recording head  69  to enable it to adhere to the recording sheet S for the formation of characters, symbols, images, or the like. 
   In  FIG. 1 , the cartridge  3  provided with the ink jet recording head  69  is detachably mounted on the carriage  1  slidably supported by two guide shafts  70  and  71 , which reciprocates along the guide shafts  70  and  71  by driving means such as a motor (not shown). The recording sheet S is carried in the direction intersecting with the traveling direction of the carriage  1  (the orthogonal direction indicated by an arrow A, for example) by means of the carrying roller  72  in such a manner that it faces the ink discharge surface of the ink jet recording head  69 , and maintains a constant distance to the ink discharge surface. 
   The ink jet recording head  69  is provided with plural nozzle arrays in order to discharge ink of different colors, respectively. Plural independent ink tanks  2  are detachably mounted on the ink supply unit  73  corresponding to ink of each color discharged from the ink jet recording head  69 . For the ink supply unit  73  and the ink jet recording head  69 , plural tubes  28  are connected with the cartridge  3  corresponding to ink of each color, and when the main tank  2  is installed on the ink supply unit  73 , it becomes possible to supply ink of each color retained in the main tank  2  independently to each nozzle array of the ink jet recording head  69 . 
   Within the range of the reciprocation of the ink jet recording head  69 , but the non-recording area that is the area outside the passing range of the recording sheet S, a recovery unit  74  is arranged to face the ink discharge surface of the ink jet recording head  69 . The recovery unit  74  is provided with a capping portion for capping the ink discharge surface of the ink jet recording head  69 ; a suction mechanism for sucking ink compulsorily from the ink jet recording head  69  in a state of the ink discharge surface being capped; and a cleaning blade for wiping off stains from the ink discharge surface, among some others. 
   Here, in  FIG. 1 , the example of the serial type ink jet recording apparatus is illustrated for description, but the present invention is applicable to the ink jet recording apparatus that has a line type ink jet recording head mounted thereon, in which the nozzle array is arranged over the entire widthwise direction of a recording medium. 
   Next,  FIG. 2  is a side sectional view that shows a cartridge in accordance with the present embodiment of the present invention.  FIG. 3  is a front view that shows the cartridge in accordance with the present embodiment, observed from the needle receptive side.  FIG. 4  is an exploded perspective view that shows the cartridge in accordance with the present embodiment.  FIG. 5  is a perspective view that shows the cartridge in accordance with the present embodiment, observed from above in a state of the face cover being removed. 
   The configuration of the cartridge  3  of the present embodiment is formed almost by six faces, the upper face  40 , lower face  41 , front face  42 , rear face  43 , and the right side  45 , and the left side  46 , and with the exception of the upper face  40  side, these are formed integrally. Also, the cartridge  3  of the present embodiment is capable of discharging ink of six colors, and the structure is arranged in such a manner that ink of each color is supplied from the main tank  2  to each of six portions (hereinafter, also referred to as sub-tank)  36 , which is formed with partitions arranged by use of the partition wall  50 , through the needle  30  (see  FIG. 8 ) of the needle holding member  24  connected with the needle receptive portion  23  per color. Ink supplied to this sub-tank  36  is once retained in the ink retainer  21  through the filter  5  that filters impurities, and then, flows into the liquid chamber  20  through the communicative portion  37  and flow path  6 . The ink that has flown into the liquid chamber  20  is discharged from plural discharge ports  29  (see  FIG. 7 ) arranged in parallel in the direction X per color by means of bubble energy generated by the electrothermal element (not shown) that converts electric energy supplied from the heater board  26  arranged on the lower face  41  to thermal energy. 
   For the upper part of the sub-tank  36 , there is provided a pressure adjustment chamber  8  communicated with the inside of the sub-tank  36  through the air hole  38  formed for the sub-tank cover  9 , which is formed by elastic material, such as rubber, to absorb the abrupt changes of pressure in the sub-tank  36 . To protect this pressure adjustment chamber  8 , there are provided for the upper face  40  of the cartridge  3 , which is the upper part of the pressure adjustment chamber  8  as shown in  FIG. 6A , ribs  15  integrally formed in the direction Y from the front face  42  toward the rear face  43  of the cartridge  3 ; and the face cover  7  that has reinforcement ribs  14  integrally formed in the direction X intersecting with the ribs  15 . The coupling portion  39  of the face cover  7 , which is formed to extrude to the end portion of the ribs  15 , is guided by the taper portion  51  formed for the inner wall of the cartridge  3  to open to the upper face  40  side to slid into the vertical portion  52 , which is substantially in parallel to the head base plate  35  to be described later, which is positioned between the taper portion  51  and the abutting portion  76  upon which abuts the end portion of the ribs  15 , and then, both end faces of the coupling portion  39  are fitted into the cartridge  3  at this vertical portion  52 , while being pressed to be in contact with the inner walls thereof. Further, the nail portion  53  is fixed to engage with the coupling hole  31  of the cartridge  3 . 
   Also, the heights of the taper portion  51  and the vertical portion  52  in the vertical direction is made higher than that of the ribs  15 , while the ribs  15  and the reinforcement ribs  14  are arranged not to interfere with any parts of the cartridge  3  with the exception of the taper portion  51  or the vertical portion  52 . In this way, the face cover  7  can be fixed by abutting it against the opening end face  76 . At this juncture, the ribs  15  function and correct the warping, deformation, or the like of the cartridge main body that may have been caused at the time of molding. 
   The ribs  15 , and the partition walls  50  that partition not only the sub-tank  36 , but also, the ink retainer  21 , flow path  6 , and liquid chamber  20  per color are given function to make robustness of the cartridge  3  higher in the direction Y. Also, the robustness of the cartridge  3  in the direction X, that is, the side direction, is secured by the presence of the reinforcement ribs  14  of the face cover  7  and the sub-tank cover  9 . 
   As shown in  FIG. 6B , the face cover may be formed to provide curved surface at the intersecting point of the rib  15  and the reinforcement rib  14  in order to make robustness higher in the direction Y. Also, as shown in  FIG. 6C , the structure may be arranged to reinforce the intersecting point with the C-letter chamfering so as to make robustness in the direction Y higher. Further, as shown in  FIG. 6D , the structure may be arranged to configure the rib  15  so that it becomes thicker as it is located nearer to the central portion, and to make robustness higher in the direction Y. Also, as shown in  FIG. 6E , the rib-type face is arranged on the end face of the rib  15 , with which it is in contact with the inner wall of the cartridge  3  under pressure. Also, these configurations can be combined as a matter of course. 
   Also, the partition wall  50  is integrally formed with the cartridge  3  main body to link the front face  42  and the rear face  43 . Further, the partition wall  50  is structured to be almost orthogonal to the scanning direction of the carriage  1  in the longitudinal direction thereof. As a result, it becomes possible to minimize the swinging of ink in the sub-tank  36  or the liquid chamber  20  due to vibrations of the carriage  1  at the time of scanning. 
   The head base plate  35  is fixed to the front face  42  of the cartridge  3 , which is the opposite side of the rear face  43  where the needle receptive portion  23  is arranged, and which also becomes the depth end side when the recording apparatus main body is installed. For this head base plate  35 , the electrodes  4  on the plural cartridge side are provided, which are electrically connected by means of depression to the plural electrodes  27  provided for the inner wall of the carriage  1 . Also, this head base plate  35  is supported by the end faces of plural front ribs  44  formed on the front face  42  of the cartridge  3  from the rear face  33  on the rear side of the base plate, that is, the rear face of the area having the arrangement of the electrodes  4  on the cartridge side. In other words, the head base plate  35  is fixed to the front face  42  of the cartridge  3  with the robustness in the direction Y on the upper face  40  side being secured by the ribs  15  of the face cover  7  serving as a member material, and also, with the robustness in the direction Y being secured by the partition wall  50  connected with the front face  42  in the position intersecting with the projected face in the direction of the reaction P 1  (see  FIG. 13 ) received from the electrode  27  on the arrangement area of the electrodes  4  on the cartridge side provided for the head base plate  35 . Further, the head base plate  35  is supported by the front face ribs  44  from the rear face  33  side of the base plate as described above. For the head base plate  35 , therefore, the flatness is secured against the pressure in the direction Y from the front face  42  toward the rear face  43 , which is exerted by the electrodes  27  to be pressed when mounted on the carriage  1  so that each electrode  27  is connected with each of the electrodes  4  on the cartridge side by means of substantially equal pressure. Here, for the present embodiment, in order to prevent the head front face from being deformed by the contact with the electrodes on the cartridge side, the corresponding portion is made thicker. Also, there is a possibility in general that the so-called “sink mark” is created at the time of molding if thickness is made larger. Therefore, as shown in  FIGS. 6A  to  6 E, the corresponding portions are configured to be “lightening sections”. 
   Further, it is required to make the contacting portions to be flat in order to keep its contact in good condition. For that matter, the corresponding portions are latticed to enhance the flatness thereof (see FIG.  2 ). Also, as shown in  FIG. 7 , the head base plate  35  is electrically connected with the heater board  26  by use of a flexible board  16 . Here,  FIG. 7  shows the state before the head base plate  35  is fixed to the front face  42  of the cartridge  3 . 
   For the right side face  45  and left side face  46  of the cartridge  3 , there are provided a first Y directionnal-positioning portion  11 , a second Y directional-positioning portion  17 , and a Z directional-positioning portion  13 , respectively, for positioning the cartridge  3  to the carriage  1  when the carriage  1  is mounted on the carriage. In other words, all the positioning portions are provided for the two side faces, that is, the right side face  45  and left side face  46 , which are aside from the front face  42  where electrical connection is made, the rear face  43  serving as the ink connection face where the needle receptive portion  23  and needle  30  are connected, the lower face  41  where the discharge ports  29  are formed, and the upper face  40 , hence arranging the structure to eliminate the exertion of force in the direction (perpendicular to the side wall) in which the structural wall on the side face is caused to be warped so as to enable the force that may collapse the structural wall to face them, hence minimizing the deformation of each positioning portion. 
   Also, on the upper end side of the right side face  45  and left side face  46 , a first pressure portion  12  and second pressure portion  19  are formed, which are portions to receive pressure for fixing the cartridge  3  to the carriage  1 . The first pressure portion  12  is inclined to the front face  42  in a state of the cartridge  3  being mounted on the carriage  1 , while the second pressure portion  19  is almost in parallel to the front face  42 . Between the first pressure portion  12  and the second pressure portion  19 , an inclined portion  18  is formed to allow the head set unit  54  (see  FIG. 13 ) to slide thereon. Also, between the first pressure portion  12  and the inclined portion  18 , a hook  66  is formed to hook the head set unit  54  so as to hold the pressure exerted by the head set unit  54  on the first pressure portion  12 . 
   In this respect, the positioning by means of the first Y directional-positioning portion  11 , second Y directional-positioning portion  17 , and Z directional-positioning portion  13 , and the fixation by means of the first pressure portion  12  and second pressure portion  19  will be described later. 
   Next, the needle holding portion will be described. Here,  FIG. 8  is a partially broken plan view that shows the needle holding portion.  FIG. 11  is a perspective view that shows the cartridge in a state of both the head set lever and the ink connection lever being closed.  FIGS. 15A ,  15 B, and  15 C are views that illustrate each step of the procedure to remove the cartridge from the carriage, and the description will be made with reference thereto. 
   For the needle holding member  24  there are provided plural needles  30  to be inserted into each of the needle receptive portion  30  of the cartridge  3 ; the guiding boss  47  inserted into the boss hole  48  of the cartridge  3 , which guides the insertion of the needle  30  into the needle receptive portion  23 ; and plural tube receptive portions  75  arranged on the rear face side of the surface where these needles  30  and guide boss  47  are provided, which are communicated with each of the needles  30  independently. At the corners of the guiding boss  47 , the C-letter chamfering portion  81  is provided, and also, the C-letter chamfering portion  80  is provided for the boss hole  48  of the cartridge  3 . Here, the structure is arranged so that when the needle holding member  24  is installed on the cartridge  3 , the guiding boss  47  abuts against the boss hole  48  at first for guiding. The C-letter chamfering portion may be radially configured. In the needle holding member  24  the ink flow path is formed to communicate the needle  30  with the needle receptive portion  75  in such a manner that the tube  28  can be arranged on a position arbitrarily with respect to the needle  30 . Also, with the tube receptive portion  75 , is connected the other end of the tube  28  the one end of which is connected the main tank  2 . 
   With the structure thus arranged, it becomes easier to connect each needle  30  with the needle receptive portion  23  provided for the cartridge  3  per color, while securing the bending area for the tube  28 , thus contributing to minimizing the size of the main body. Also, with no unwanted force being exerted on the cartridge, the deformation of the cartridge can be prevented. 
   Also, the needle holding member  24  is slidably installed on the rail  62  provided for the carriage  1  by rotating the ink connection lever  22  as shown in  FIGS. 15A ,  15 B, and  15 C. The link  49  that enables the rotation of the ink connection lever  22  and needle holding member  24  to be interlocked is fixed to the pins  60  installed on both ends of the needle holding member  24 . In other words, the structure is arranged so that with the rotation of the ink connection lever  22  in the CCW direction (in the order of  FIGS. 15C ,  15 B and  15 A), the needle  30  is inserted into the needle receptive portion  23 . Then, with the rotation CW direction (in the order of  FIGS. 15A ,  15 B, and  15 C), the needle  30  is withdrawn from the needle receptive portion  23 . 
   Further, as shown in  FIG. 13 , on the upper part of the needle holding member  24 , the pressure lever  58  that depresses the head set lever  25  downward. The pressure lever  58  is biased by a pressure spring  59  to depress the pressure lever  58  from the top to the bottom, that is, to bias the head set lever  25 . 
   Here, in  FIG. 8 , the example is shown to insert four needles  30  into the needle receptive portion  23  of the cartridge  3 , but the needles are not necessarily limited to that number. As described above, six needles can be provided without any problem in order to correspond to the six tubes  28  from the six main tanks  2 . In this case, the numbers of tube receptive portions  75  become six corresponding to each of the needles  30  as a matter of course. 
   Next, in conjunction with  FIG. 9  to  FIGS. 15A ,  15 B, and  15 C, the description will be made of the procedure to mount the cartridge  3  on the carriage  1 . Here, in  FIG. 9  to  FIG. 11 , which are perspective views, the cartridge  3  is omitted to simplify the representation. 
   At first, the positioning of the cartridge  3  to the carriage  1  will be described. 
     FIG. 9  shows the state of both the head set lever  25  for fixing the cartridge  3  to the carriage  1 , and the ink connection lever  22  to insert the needle  30  of the needle holding member  24  into the needle receptive portion  23  by sliding the needle holding member  24  being open. This state shown in  FIG. 9  corresponds to the state shown in  FIG. 12A  of those which illustrate the procedure to mount the cartridge  3  on the carriage  1  per step. 
   When the cartridge  3  slides into the carriage  1 , the extrusion  61  abuts, at first, against the bottom face of the carriage  1 , while the support nail  63  of the head set lever  25  abuts upon the abutting portion  64  of the cartridge  3 . In this state, the cartridge  3  is inclined to the carriage  1  with an inclination of −θX (in the CW (clockwise) direction in FIG.  12 A), that is, it is inclined to the circumference of the axis X. 
   Then, as shown in  FIG. 12B , with the rotation of the head set lever  25  in the CW direction, the Z directional-positioning portion  13  near the bottom face of the carriage  1 , the second Y directional-positioning portion  17 , and the rotational center  10  of the cartridge  1  are in contact with the carriage  3 . Also, the electrodes  4  of the head base plate  35  are partly in contact with the electrodes  27 . However, even at this juncture, there exists the reaction force of the electrodes  27 , and the cartridge  3  is still inclined at −θX inside the carriage  1  as shown in FIG.  12 B. 
   Next, from the state shown in  FIG. 12B , the head set lever  25  further rotates in the CW direction. Then, pressure P 2  is exerted on the inclined portion  18  by means of the head set spring  57 . This pressure P 2  is divided, as shown in  FIG. 13 , into a component P 2 Y in the direction Y and a component P 2 Z in the direction Z. (However, in  FIG. 13 , the head set lever  25  is positioned at the first pressure portion  12 .) Then, the cartridge  3  begins to rotate around the rotational center  10  of the head set portion when the rotational torque (CCW, θX direction) around the rotational center  10  by means of the component P 2 Y in the direction Y generated by the further rotation of the head set lever  25  becomes larger than the rotational torque (CW, −θX direction) around the rotational center  10  created by means of the reaction force of the electrodes  27 . When the cartridge  3  makes this rotational motion, the head set portion  57 , which is arranged inside the head set lever  25  rotatively around the rotational center  67  of the head set portion, and biased by the head set spring  57  in the cartridge  3  direction, slides on the inclined portion  18  while pressing the inclined portion  18  of the cartridge  3 . 
   When the head set portion  57  moves over the hooking  66  to arrive at the position of the first pressure portion  12 , the head set portion  57  presses the first pressure portion  12  that has been inclined by the pressure P 2  exerted by the head set spring  57 . Since the first pressure portion  12  is also inclined, the pressure P 2  exerted by the head set spring  57  is, as shown in  FIG. 13 , divided into a component P 2 Y in the direction Y and a component P 2 Z in the direction Z. The component P 2 Z in the direction Z presses the cartridge  3  in the direction toward the lower face  41  of the carriage  1 . With the component P 2 Z in the direction Z, the Z directional-positioning portion  13  of the cartridge  3  is pressed to the upper face of the first fixing portion  55  of the carriage  1  to determine the position of the cartridge  3  in the direction Z with respect to the carriage  1 . Also, the component P 2 Y in the direction Y works in the −Y direction to rotate the cartridge  3  in the direction θX (CCW). 
   The position of the cartridge  3  in the direction θX is determined in such a manner that in the state where the rotational torque (CCW, θX direction) around the rotational center  10  exerted by the component P 2 Y in the direction Y becomes sufficiently over the rotational torque (CW, −θX direction) around the rotational center  10  exerted by the reaction force P 1  of the electrodes  4  on the cartridge side, the first Y directional-positioning portion  11  serving as the rotation stopper for the θX abuts against the second fixing portion  56  of the carriage  1 , and also, the second Y directional-positioning portion  17  is pressed to the first fixing portion  55  of the carriage  1 . Here, with the first Y directional-positioning portion  11 , which is provided for both sides, the right face side  45  and the left side face  46  of the cartridge  3 , respectively, the position in the direction θZ is also determined at the same time that the position in the θX is set. 
   In this respect, the direction of the reaction force P 1  received from the electrodes  27  and the force exerted by the second fixing portion  56  on the first Y directional-positioning portion  11  is almost equally directed. 
   In this manner, with the exception of the X direction, the position of the cartridge  3  is determined with respect to the carriage  1 , but for the present embodiment, the structure is arranged so as to determine the position in the direction X approximately by removing looseness between the cartridge  3  and the carriage  1  to a certain extent. This is because when the cartridge  3  is positioned, the relations between each of the forces at X, Y, and Z should be such as to become weaker in the fixing order, and then, positioning is impeded unless such difference is sufficient. 
   As described above, the cartridge  3  is positioned with respect to the carriage  1 . 
   Next, the description will be made of the procedure to insert the needle  30  into the needle receptive portion  23  by means of the auxiliary pressure P 3  that acts upon the cartridge  3  positioned to the carriage  1 , and the sliding of the needle holding member  24  as well. 
   When the cartridge  3  is positioned with respect to the carriage  1  in the procedure described above, the head set lever  25  is closed, but as shown in  FIG. 10  or  FIG. 15C , the ink connection lever  22  is in a state of being open. The positional relation between the needle  30  and the needle receptive portion  23  is such as to make them apart as shown in  FIG. 10 ,  FIG. 12C  or FIG.  15 C. 
   When the ink connection lever  22  in the state of being open rotates in the CCW direction, the needle holding member  24 , which is coupled with the ink connection lever  22  by use of the link  49 , slides on the rail  62  as shown in  FIG. 10  in the direction −Y as shown in FIG.  12 E. Then, at first, the guiding boss  47  of the needle holding member  24  is inserted into the boss hole  48  of the cartridge  3 . Subsequently, the insertion of the needle  30  into the needle receptive portion  23  begins, while being guided by the guiding boss  47  to the boss hole  48 . The direction of the reaction force that the cartridge  3  receives from the needle  30  at the time of the insertion of the needle  30  is the one opposite to the direction of the reaction force that the cartridge  3  received from the electrodes  27  of the carriage  1 . also, the directions of these reaction forces are almost in parallel to the arrangement direction of the discharge ports  29 . 
   Here, the problem is that the reaction force that the cartridge  3  receives with the insertion of the needle  30  is the one exerted by the user&#39;s force. Therefore, if the needle is inserted forcefully, it is conceivable that an extreme force is exerted. However, this force is in the same −Y direction as those of the P 2 Y and P 3 Y. In other words, the force in the −Y direction is not allowed to become factors that may disorder the positioning of the cartridge  1  even if such force is exerted beyond them. Also, when withdrawing the cartridge  3  for removal, the opposite force is exerted as a matter of course, but this occurs along with the removal of the head, which does not present any problem. 
   Now, form the state shown in  FIG. 12E , the ink connection lever  22  further rotates in the CCW direction. Then, as shown in  FIG. 12F , the needle  30  is completely inserted into the needle receptive portion  23 . Also, the ink connection lever  22  arrives at the closed position as shown in FIG.  11 . In this closed position of the ink connection lever  22 , the pressure lever  58  biased by the pressure spring  59  of the needle holding member  24  depresses the pressure portion  68  of the head set lever  25  downward as shown in FIG.  13 . With this depression, the head set lever  25  tends to rotate in the CW direction. As a result, the fixing auxiliary member  34  of the head set lever  25  depressed the second pressure portion  19  of the cartridge  3 . The Y directional component P 3 Y of the pressure P 3  exerted by the fixing auxiliary member  34  on the second pressure portion  19  becomes the auxiliary force that enables the first Y directional-positioning portion  11  to abut upon the second fixing portion  56  of the carriage  1 . This pressure P 3  is auxiliary, and the intensity thereof is smaller than that of the pressure P 2 . 
   As described above, two forces, P 2  and P 3 , are used for fixing the cartridge  3 . This use of two forces aims at making the apparatus smaller. In accordance with the conventional art, only the P 2  is used for completing the fixation of a cartridge in general. However, as shown in  FIG. 14 , it is necessary for the fixation of the cartridge  3  to make the rotational torque generated by the exertion of the P 2  for fixing the cartridge  3  on the position away from the fulcrum by the distance L 2  greater than the rotational torque exerted by the P 1  to cause the cartridge  3  to part from the carriage  1  on the position away from the rotational center  10  by the distance L 1 . In order to make the rotational torque for fixing the cartridge  3  greater, it is conceivable to make the P 2  greater or to make the L 2  greater. If the P 2  is made greater, the operational force should become greater to invite the unfavorable operability or invite deformation, because this force may exceed the limit of stress of the head set lever  25  or the head set portion  54 , which are formed by molding. On the other hand, if the L 2  is made greater while setting the P 2  at an appropriate value, the size of the cartridge  3  should be made larger to ensue in the larger size of the apparatus eventually. 
   In contrast, the present embodiment is such that the cartridge  3  is not fixed only by means of the P 2 , but the structure is arranged to add the P 3  that is the auxiliary force, hence making it unnecessary to make the P 2  or L 2  greater. As a result, the cartridge  3  can be made smaller. Also, the P 3  is exerted by the utilization of the needle holding structure formed by the needle holding member  24 , the ink connection lever  22 , and others. Therefore, the increase part is only the pressure spring  59 . 
   For removing the carriage  3  thus fixed from the carriage  1 , the ink connection lever  22  rotates in the CW direction at first as shown in  FIG. 15A  to  FIG. 15C  to withdraw the needle  30  of the needle holding member  24  from the needle receptive portion  23 . At this juncture, the needle holding member  24  slides on the rail  62  in the +Y direction, but it is slidably installed on the carriage  1  by use of the spring  37  that biases the needle holding member  24  in the −Y direction. Therefore, the needle holding member  24  is not caused to fall off from the rail  62 . After the needle  30  is withdrawn from the needle receptive portion  23  and the ink connection lever  22  is in the state of being open, the head set lever  25  moves in the CCW direction as shown in  FIG. 12C  to  FIG. 12A  to be in the state of being released, thus conditioning the cartridge  3  to be removed from the carriage  1 . 
   As described above, the cartridge  3  of the present embodiment secures robustness in the direction Y by use of the partition wall  50  that serves as the beam in the direction Y, and the ribs  15  of the face cover  7 . As a result, it is made possible to secure the flatness of the head base plate  35  against the reaction force that it receives from the electrodes  27  in the direction Y, hence obtaining the stabilized electrical connection between the electrodes  27  and the electrodes  4  on the cartridge side. 
   Also, the cartridge  3  of the present embodiment is structured to receive the reaction force exerted by the insertion of the needle  30  with the rear face  43  opposite to the front face  42  that received the reaction force from the electrodes  27 . Therefore, the direction of the reaction force that the cartridge  3  received by the insertion of the needle  30  is the one opposite to the direction of reaction force that the cartridge  3  receives from the electrodes  27 , that is, the −Y direction in which the positioning force of the cartridge  3  is exerted. As a result, it becomes possible to suppress the lowering of the precision with which the ink jet recording head  69  should be positioned by the insertion of the needle  30 . Also, the front face  42  that serves as the electrical connection face and the rear face  43  serving as the ink connection face are away from each other. Therefore, even if there is ink leakage from the needle receptive portion  23 , it is possible to minimize the danger that the electrodes  27  and the electrodes  4  on the cartridge side are wetted by such ink leakage. Further, the plate member having the ribs of the cartridge in accordance with the present invention is effective in collecting the deformation of the cartridge that may result from molding or assembling. 
   Further, all the positioning portions are installed on the right side face  45  and the left side face  46 . Then, the major face is substantially in parallel with each direction of the force needed for fixing the cartridge  3 , and the reaction force exerted from the electrodes  27  along with this fixation, thus making it possible to minimize the deformation of the cartridge  3  even if these forces may be exerted on the cartridge. In this way, the lowering of the positioning precision that may be caused by the deformation of the cartridge  3  can be suppressed for the ink jet recording head  69 . 
   Also, the cartridge  3  of the present embodiment can simply protect the pressure adjustment chamber  8 , but with the installation of the face cover  7  having the function as a member material with ribs  15 , it becomes possible to suppress effectively the deformation of the cartridge  3  still more. 
   Also, the force needed for fixing the cartridge  3  to the carriage  1  is divided into the main pressure P 2  and the pressure P 3  that supports the pressure P 2 , not exerted only one means at a time. Thus, it is made possible to avoid such problems as to deteriorate the operability due to the increased operational force, to cause the head set lever  25  or head set portion  54  to be deformed, or to make the apparatus larger. 
   As described above, the cartridge is positioned to holding means against the force exerted on the front face by the electrical connection between the electrodes on the cartridge and the electrodes on holding means. Then, the force needed for connecting supply means on the rear face opposite to the front face is exerted in the same direction of the positioning force for the cartridge of the present invention. As a result, the force needed for connecting supply means does not produce any unfavorable effect on the precision with which the cartridge should be positioned to holding means, hence securing highly precise positioning. 
   Also, the cartridge of the present invention provides the partition wall that becomes the beam for linking the front face and rear face, and the plate member having ribs for the upper surface of the cartridge main body, thus securing robustness against the force exerted on the front face by the electrical connection. 
   Further, the carriage of the present invention applies the force needed for fixing the cartridge to the carriage by dividing it into two, each applied to first fixing means and second fixing means, respectively, making it unnecessary to exert a large force at a time for such fixation. As a result, the operability of the fixation is improved, while preventing fixing means, and the apparatus itself, from being made larger.