Patent Publication Number: US-8967780-B2

Title: Liquid cartridge

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a Continuation-In-Part application of International Application No. PCT/JP2011/004264 filed Jul. 28, 2011. The entire disclosure of the prior application is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The invention relates to a liquid cartridge that stores liquid. 
     BACKGROUND 
     According to a known liquid cartridge, when an ink cartridge is mounted on a main unit of an inkjet recording apparatus, an electrode provided at a mounting section and a resistance label provided at the cartridge make contact with each other so that electrical connection is obtained. Thus, it is detected that the cartridge is mounted on the mounting section. 
     SUMMARY 
     According to the above-mentioned technology, however, although it can be detected that the liquid cartridge is mounted on the mounting section, fluid communication between the liquid storing section and a liquid ejecting head cannot be detected appropriately. Also, it is expected to improve space efficiency of wiring for detection. 
     In view of the foregoing, the invention provides a liquid cartridge including a housing, a liquid storing section, a channel member, a movable member, a sensor, a sensor-signal output terminal, and a wiring line. The housing has a space therein. The liquid storing section is provided in the housing and is configured to store liquid. The channel member is provided in the housing and is formed with a liquid channel having one end and another end. The one end is in fluid communication with the liquid storing section. The another end is in fluid communication with outside to serve as a discharge port for discharging liquid to the outside. The movable member is movable in the liquid channel. The sensor is configured to generate a signal based on a position of the movable member in the liquid channel. The sensor-signal output terminal is connected electrically with the sensor and is configured to output the signal to the outside. The wiring line connects the sensor with the sensor-signal output terminal. The housing includes a first outer surface, a second outer surface, and a third outer surface. The second outer surface and the third outer surface each connects to the first outer surface and intersects the first outer surface. The second outer surface and the third outer surface are spaced from and in confrontation with each other. The sensor-signal output terminal is disposed on the first outer surface. The discharge port is disposed on the second outer surface. The channel member is disposed at a position closer to the second outer surface than the liquid storing section is. The liquid storing section is disposed at a position closer to the third outer surface than the channel member is. A first direction is defined as a direction perpendicular to the first outer surface. A second direction is defined as a direction perpendicular to the second outer surface. A third direction is defined as a direction perpendicular to both the first direction and the second direction. When the space in the housing is divided by an imaginary line parallel to the first direction, as viewed from the third direction, into a first region in which the channel member is disposed and a second region in which the liquid storing section is disposed, the sensor and the sensor-signal output terminal are disposed in the first region. The liquid channel extends linearly in the second direction. The sensor and the sensor-signal output terminal are arranged to be aligned in the first direction. 
     According to another aspect, the invention also provides a liquid cartridge including a housing, a liquid storing section, a channel member, a movable member, a sensor, a sensor-signal output terminal, and a wiring line. The housing has a space therein. The liquid storing section is provided in the housing and is configured to store liquid. The channel member is provided in the housing and is formed with a liquid channel having one end and another end. The one end is in fluid communication with the liquid storing section. The another end is in fluid communication with outside to serve as a discharge port for discharging liquid to the outside. The movable member is movable in the liquid channel. The sensor is configured to generate a signal based on a position of the movable member in the liquid channel. The sensor-signal output terminal is connected electrically with the sensor and is configured to output the signal to the outside. The wiring line connects the sensor with the sensor-signal output terminal The housing includes a first outer surface, a second outer surface, and a third outer surface. The second outer surface and the third outer surface each connects to the first outer surface and intersects the first outer surface. The second outer surface and the third outer surface are spaced from and in confrontation with each other. The sensor-signal output terminal is disposed on the first outer surface. The discharge port is disposed on the second outer surface. The channel member is disposed at a position closer to the second outer surface than the liquid storing section is. The liquid storing section is disposed at a position closer to the third outer surface than the channel member is. A first direction is defined as a direction perpendicular to the first outer surface. A second direction is defined as a direction perpendicular to the second outer surface. When the space in the housing is divided by an imaginary line parallel to the second outer surface, as viewed from a direction parallel to both the first outer surface and the second outer surface, into a first region in which the channel member is disposed and a second region in which the liquid storing section is disposed, the sensor and the sensor-signal output terminal are disposed in the first region. The liquid channel extends linearly in the second direction. The sensor and the sensor-signal output terminal are arranged to be aligned in the first direction. With this arrangement, effects similar to those described above are obtained. 
     According to still another aspect, the invention also provides a liquid cartridge including a housing, a liquid storing section, a channel member, a sensor, a sensor-signal output terminal, and a wiring line. The housing has a space therein. The liquid storing section is provided in the housing and is configured to store liquid. The channel member is provided in the housing and is formed with a liquid channel having one end and another end. The one end is in fluid communication with the liquid storing section. The another end is in fluid communication with outside to serve as a discharge port for discharging liquid to the outside. The channel member is so configured that a hollow member can be inserted through the discharge port. The sensor is configured to generate a signal based on a position of the hollow member in the liquid channel. The sensor-signal output terminal is connected with the sensor and is configured to output the signal to the outside. The wiring line connects the sensor with the sensor-signal output terminal. The housing includes a first outer surface, a second outer surface, and a third outer surface. The second outer surface and the third outer surface each connects to the first outer surface and intersects the first outer surface. The second outer surface and the third outer surface are spaced from and in confrontation with each other. The sensor-signal output terminal is disposed on the first outer surface. The discharge port is disposed on the second outer surface. The channel member is disposed at a position closer to the second outer surface than the liquid storing section is. The liquid storing section is disposed at a position closer to the third outer surface than the channel member is. A first direction is defined as a direction perpendicular to the first outer surface. A second direction is defined as a direction perpendicular to the second outer surface. A third direction is defined as a direction perpendicular to both the first direction and the second direction. When the space in the housing is divided by an imaginary line parallel to the first direction, as viewed from the third direction, into a first region in which the channel member is disposed and a second region in which the liquid storing section is disposed, the sensor and the sensor-signal output terminal are disposed in the first region. The liquid channel extends linearly in the second direction. The sensor and the sensor-signal output terminal are arranged to be aligned in the first direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments in accordance with the invention will be described in detail with reference to the following figures wherein: 
         FIG. 1  is a perspective view showing the exterior of an inkjet printer according to an embodiment of the invention; 
         FIG. 2  is a schematic cross-sectional view showing the internal structure of the printer; 
         FIG. 3  is a perspective view showing the cartridge; 
         FIG. 4  is a schematic view showing the internal structure of the cartridge; 
         FIGS. 5A and 5B  are partial cross-sectional views of a region V shown in  FIG. 4 , wherein  FIG. 5A  shows a case in which a hollow needle of the printer is not inserted in a plug and a valve is in a closed state, and  FIG. 5B  shows a case in which the hollow needle of the printer is inserted in the plug and the valve is in an open state; 
         FIG. 6  is a partial cross-sectional view taken along a line VI-VI shown in  FIG. 5A ; 
         FIG. 7  is a partially enlarged view of a region VII shown in  FIG. 4 ; 
         FIG. 8  is a diagram as viewed from a direction VIII shown in  FIG. 7 , for illustrating a terminal of the cartridge according to the embodiment; 
         FIGS. 9A and 9B  show the configuration of wiring in the cartridge, wherein  FIG. 9A  is a schematic side view and  FIG. 9B  is a schematic plan view each showing the configuration of wiring in the cartridge; 
         FIGS. 10A through 10C  are schematic plan views showing a process in which the cartridge is mounted onto the printer, wherein  FIG. 10A  shows a state before the cartridge is mounted onto the printer,  FIG. 10B  shows a state in which the cartridge is inserted to a position where the terminal of the cartridge contacts a terminal of the printer, and  FIG. 10C  shows a state in which a hollow needle supported by a support body has moved in a direction of a filled arrow and penetrated the plug of the cartridge; 
         FIG. 11  is a block diagram showing the electrical configuration of the cartridge and the printer; 
         FIG. 12  is a functional block diagram showing each section constructed by a controller of the printer; 
         FIG. 13  is a flowchart showing controls performed by the controller of the printer when the cartridge is mounted on the printer; 
         FIG. 14  is a graph showing relationship between travel distances of the valve and output values from a Hall element of the cartridge; 
         FIG. 15  is a diagram as viewed from a mounting direction shown in  FIG. 10 , for illustrating a terminal of the printer; and 
         FIG. 16  is a partial cross-sectional view taken along a line XVI-XVI shown in  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION 
     A liquid cartridge according to some aspects of the invention will be described while referring to the accompanying drawings. In the following description, the expressions “upper” and “lower” are used to define the various parts when a liquid ejecting device on which a liquid cartridge is mounted is disposed in an orientation in which it is intended to be used. 
     First, the overall configuration of an inkjet-type printer  1  according to an embodiment will be described while referring to  FIG. 1 . 
     The printer  1  has a housing  1   a  having a rectangular parallelepiped shape. A paper discharging section  31  is provided on a top plate of the housing  1   a . Three openings  10   d ,  10   b , and  10 C are provided on a front surface (the surface on the near left side in the drawing of  FIG. 1 ) of the housing  1   a  in this order from the top. The opening  10   b  is for inserting a paper supplying unit  1   b  inside the housing  1   a . The opening  10   c  is for inserting a cartridge unit  1   c  inside the housing  1   a . The opening  10   d  is fitted with a door  1   d  that can open and close pivotally about a horizontal axis on its lower end. The door  1   d  is disposed in confrontation with a conveying unit  21  (see  FIG. 2 ) in a main scanning direction X (the direction perpendicular to the front surface of the housing  1   a ) of the housing  1   a.    
     Next, the internal structure of the printer  1  will be described with reference to  FIG. 2 . 
     The internal space of the housing  1   a  can be divided into spaces A, B, and C in this order from the top, for description purposes. In the space A, two heads  2 , the conveying unit  21 , and a controller  100  are disposed. The two heads  2  eject black ink and pre-coat liquid (hereinafter, these may be collectively referred to as “liquid”), respectively. The conveying unit  21  conveys paper P. The controller  100  controls operations of each section of the printer  1 . In the space B, the paper supplying unit  1   b  is disposed. In the space C, the cartridge unit  1   c  is disposed. Within the printer  1 , a paper conveying path along which paper P is conveyed is formed from the paper supplying unit  1   b  to a paper discharging section  31  along thick arrows in  FIG. 2 . 
     The controller  100  includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory: including non-volatile RAM), I/F (Interface), and the like. The ROM stores programs executed by the CPU, various constant data, and the like. The RAM can temporarily store data (image data etc.) that are required when the programs are executed. The controller  100  performs data transmission and reception with a memory  141  and Hall elements  71  of a cartridge  40 , data transmission and reception with an external device (a personal computer connected with the printer  1  etc.), and the like, via the I/F. 
     The paper supplying unit  1   b  includes a paper supplying tray  23  and a paper supplying roller  25 . Of these, the paper supplying tray  23  is detachable from the housing  1   a  in the main scanning direction X. The paper supplying tray  23  is a box which is opened upward, and can accommodate paper P in a plurality of sizes. The paper supplying roller  25  rotates by driving of a paper supplying motor  125  (see  FIG. 11 ) under controls by the controller  100 , and picks up paper P at the topmost position in the paper supplying tray  23 . The paper P picked up by the paper supplying roller  25  is sent to the conveying unit  21  while being guided by guides  27   a  and  27   b  and being nippingly held by a pair of feed rollers  26 . 
     The conveying unit  21  includes two belt rollers  6  and  7 , an endless-type conveying belt  8  looped around the both rollers  6  and  7 . The belt roller  7  is a drive roller and, under controls by the controller  100 , rotates in the clockwise direction in  FIG. 2  by driving of a conveying motor  127  (see  FIG. 11 ) connected with its shaft. The belt roller  6  is a follow roller, and rotates in the clockwise direction in  FIG. 2  by following the movement of the conveying belt  8  caused by rotation of the belt roller  7 . 
     A platen  19  having a rectangular parallelepiped shape is disposed within the loop of the conveying belt  8  so as to confront the two heads  2 . The upper loop of the conveying belt  8  is supported by the platen  19  from the inner peripheral surface side, so that an outer peripheral surface  8   a  of the conveying belt  8  extends parallel to lower surfaces  2   a  (ejecting surfaces in which a large number of ejection ports for ejecting liquid is formed) of the two heads  2  with a predetermined gap therebetween. 
     A silicone layer with slight adherence is formed on the outer peripheral surface  8   a  of the conveying belt  8 . The paper P sent from the paper supplying unit  1   b  to the conveying unit  21  is pressed against the outer peripheral surface  8   a  of the conveying belt  8  by a pressing roller  4 , and is subsequently conveyed in a sub-scanning direction Y along the thick arrows while being held on the outer peripheral surface  8   a  by adhesive force. 
     Here, the sub-scanning direction Y is a direction parallel to the conveying direction of paper P by the conveying unit  21 . The main scanning direction X is a direction perpendicular to the sub-scanning direction Y and parallel to a horizontal surface. Each of the main scanning direction X and the sub-scanning direction Y is perpendicular to a vertical direction Z. 
     When the paper P passes a position directly below each head  2 , the heads  2  are driven under controls by the controller  100  so that liquid (black ink, and pre-coat liquid depending on situations) is ejected toward the top surface of the paper P from the lower surface  2   a  of each head  2 , thereby recording a desired image on the paper P. Then, the paper P is separated from the outer peripheral surface  8   a  of the conveying belt  8  by a separation plate  5 , is conveyed upward while being guided by guides  29   a  and  29   b  and being nippingly held by two pairs of rollers  28 , and is discharged onto the paper discharging section  31  through an opening  30  formed at an upper section of the housing  1   a . One roller of each pair of rollers  28  rotates by driving of a feed motor  128  (see  FIG. 11 ) under controls by the controller  100 . 
     The pre-coat liquid is liquid having, for example, an effect of improving density (an effect of improving density of ink ejected on paper P), an effect of preventing running of ink and permeation of ink (a phenomenon that ink ejected on the top surface of paper P penetrates the layer of paper P and runs on the bottom surface), an effect of improving chromogenic characteristics and quick drying characteristics, an effect of suppressing wrinkles and curl of paper P subsequent to ejection of ink, and the like. As the pre-coat liquid, for example, liquid containing multivalent metal salt such as cationic polymer, magnesium salt, etc. may be used. 
     The head  2  that ejects pre-coat liquid is disposed at an upstream side of the head  2  that ejects black ink with respect to the conveying direction of paper P. 
     Each head  2  is a line-type head having substantially a rectangular parallelepiped shape elongated in the main scanning direction X (the direction perpendicular to the drawing sheet of  FIG. 2 ). The two heads  2  are arranged in the sub-scanning direction Y with a predetermined pitch, and are supported by the housing  1   a  via a frame  3 . A joint to which a flexible tube is attached is provided on the upper surface of each head  2 . A large number of ejection ports is formed on the lower surface  2   a  of each head  2 . A channel is formed inside of each head  2  so that liquid supplied from a corresponding reservoir  42  of the cartridge  40  can reach the ejection ports via the flexible tube and the joint. 
     The cartridge unit  1   c  includes a tray  35  and one cartridge  40  disposed within the tray  35 . The cartridge  40  includes two reservoirs  42  that accommodate black ink and pre-coat liquid, respectively (see  FIG. 4 ). Liquid accommodated in each reservoir  42  of the cartridge  40  is supplied to a corresponding one of the heads  2  via the flexible tube and the joint. 
     The tray  35  is detachable from the housing  1   a  in the main scanning direction X in a state in which the cartridge  40  is disposed inside. Accordingly, a user of the printer  1  can replace the cartridge  40  in the tray  35  in a state in which the tray  35  is removed from the housing  1   a.    
     The configuration of the cartridge  40  will be described with reference to  FIGS. 3 through 9B . 
     As shown in  FIGS. 3 and 4 , the cartridge  40  includes a housing  41 , a black ink unit  40 B for black ink, a pre-coat liquid unit  40 P for pre-coat liquid, the memory  141 , and a board  142 . Each of the black ink unit  40 B and the pre-coat liquid unit  40 P includes the reservoir  42 , a supply pipe  43 , a plug  50 , a valve  60 , a sensor unit  70 , and the like, and has the same configuration (see  FIGS. 4 ,  5 A, and  5 B). 
     As shown in  FIG. 3 , the housing  41  has a rectangular parallelepiped shape. As shown in  FIG. 4 , the inner space of the housing  41  is divided to form two chambers  41   a  and  41   b . The reservoir  42  of each of the units  40 B and  40 P is disposed in the chamber  41   a  at the right side in  FIG. 4 . The supply pipe  43  of each of the units  40 B and  40 P is disposed in the other chamber  41   b . As shown in  FIGS. 3 and 9A , the units  40 B and  40 P are arranged at different positions with respect to the vertical direction Z. The pre-coat liquid unit  40 P is disposed at a higher position than the black ink unit  40 B is. 
     As shown in  FIG. 4 , the housing  41  includes a first outer surface  41   x , a second outer surface  41   y , and a third outer surface  41   z.    
     The first outer surface  41   x  is a surface at a downstream side in a mounting direction (hereinafter, referred to simply as “mounting direction”) M, the surface being one of outer surfaces of the housing  41 . Here, the mounting direction M is a direction in which the cartridge  40  moves into the space C when the cartridge  40  is mounted into the space C. The first outer surface  41   x  is perpendicular to the mounting direction M. In the present embodiment, the mounting direction M is parallel to the main scanning direction X. A concave section  41   c  is formed at a portion of the first outer surface  41   x  corresponding to the chamber  41   b  in the main scanning direction X. 
     The second outer surface  41   y  and the third outer surface  41   z  are surfaces parallel to both the mounting direction M and the vertical direction Z. Each of the second outer surface  41   y  and the third outer surface  41   z  connects to the first outer surface  41   x , and is perpendicular to the first outer surface  41   x . The second outer surface  41   y  and the third outer surface  41   z  are spaced away from and in confrontation with each other in the sub-scanning direction Y. 
     The board  142  is disposed on the first outer surface  41   x . An opening  43   b  (see  FIGS. 5A and 5B ) of the supply pipe  43  is disposed on the second outer surface  41   y . The supply pipe  43  is disposed at a position closer to the second outer surface  41   y  than the reservoir  42  is. The reservoir  42  is disposed at a position closer to the third outer surface  41   z  than the supply pipe  43  is. 
     The reservoir  42  is a pouch that stores liquid. The reservoir  42  of the black ink unit  40 B stores black ink, and the reservoir  42  of the pre-coat liquid unit  40 P stores pre-coat liquid. An opening section of the reservoir  42  is connected with a base end of the supply pipe  43 . 
     The supply pipe  43  is formed with a supply channel  43   a  (see  FIGS. 5A and 5B ) for supplying the head  2  with liquid stored in the reservoir  42 . 
     As shown in  FIG. 4 , a distal end of the supply pipe  43  protrudes outside of the housing  41 . The distal end of the supply pipe  43  is provided with the plug  50  made of elastic material such as rubber in a compressed state, so as to close the opening  43   b  of the supply channel  43   a  at the opposite side from the reservoir  42  (see  FIGS. 5A and 5B ). A cap  46  is provided outside of the distal end of the supply pipe  43  and the plug  50 . An opening  46   a  is formed at the center of the cap  46 , so that a front surface (the surface at the opposite side from a back surface in confrontation with the valve  60 ) of the plug  50  is exposed through the opening  46   a.    
     As shown in  FIGS. 5A and 5B , the valve  60  is disposed at the supply channel  43   a  and includes an O-ring  61  and a valve main body  62 . 
     As shown in  FIGS. 5A ,  5 B, and  6 , the valve main body  62  is a magnetic body of a cylindrical shape having an axis in the sub-scanning direction Y. 
     As shown in  FIG. 6 , a portion of the supply pipe  43  at which the valve main body  62  is disposed has a cylindrical shape having flat upper and lower walls and having a cross-section elongated in the main scanning direction X, the cross-section being perpendicular to the sub-scanning direction Y. Each of inner surfaces of the supply pipe  43  at both sides in the main scanning direction X is formed with a protrusion  43   p  that protrudes inward in the main scanning direction X. Each protrusion  43   p  extends in the sub-scanning direction Y over a range in which the valve main body  62  is movable. The valve main body  62  is supported by the protrusions  43   p  and the upper and lower walls of the supply pipe  43 , and is positioned at the center of the supply channel  43   a  in the cross-section. A channel is secured between the valve main body  62  and the supply pipe  43  at portions except contact portions where the valve main body  62  is in contact with the protrusions  43   p  and the upper and lower walls of the supply pipe  43 . 
     The O-ring  61  is made of elastic material such as rubber, and is fixed to a front surface of the valve main body  62  (the surface that faces the plug  50 ). 
     The valve  60  is urged toward an opening  43   y  by a coil spring  63 . The coil spring  63  has one end fixed to a base end of the supply pipe  43  and another end in contact with a back surface of the valve main body  62 . 
     As shown in  FIG. 5A , when the valve  60  is in a closed position for closing the supply channel  43   a , the O-ring  61  is in contact with a portion (valve seat)  43   z  that protrudes from one end (the end closer to the opening  43   b ) of a small diameter portion  43   x  of the supply pipe  43  toward the center of the supply pipe  43  in a radial direction, so that the opening  43   y  of one end of the small diameter portion  43   x  is sealed. With this arrangement, fluid communication between the reservoir  42  and the outside via the supply channel  43   a  is blocked. At this time, the O-ring  61  is deformed elastically by urging force of the coil spring  63 . 
     The sensor unit  70  includes the Hall element  71  and a magnet  72 . The magnet  72  is for generating a magnetic field. The Hall element  71  is a magnetic sensor that converts inputted magnetic field into an electric signal, thereby generating the electric signal. In the present embodiment, the Hall element  71  generates an electric signal indicative of a voltage value proportional to magnitude of a magnetic field that changes due to movement of the valve main body  62 . The Hall element  71  is disposed at a position at which a magnetic field created by the magnet  72  and the valve main body  62  is inputted (see  FIG. 5A ). 
     As shown in  FIG. 5A , the Hall element  71  and the magnet  72  are fixed to upper and lower walls of the supply pipe  43 , respectively, and confront each other in the vertical direction Z. 
     As shown in  FIG. 5A , when the valve  60  is in a closed position, the Hall element  71  and the magnet  72  confront each other with the valve main body  62  interposed therebetween. That is, the valve main body  62  is at a position between the Hall element  71  and the magnet  72 . In other words, the valve main body  62  is aligned with a center of the Hall element  71  in the sub-scanning direction Y. At this time, a magnetic field generated by the magnet  72  reaches the Hall element  71  effectively via the valve main body  62 . Accordingly, the magnetic field (magnetic flux density) detected by the Hall element  71  is strong, and the Hall element  71  generates a signal indicative of a high voltage value. Here, the valve main body  62  serves as an interacting portion configured to magnetically interact with the Hall element  71  to change the magnetic field (magnetic flux density) at the Hall element  71 . 
     When the valve  60  moves from the closed position shown in  FIG. 5A  to an open position shown in  FIG. 5B  where the supply channel  43   a  is opened, the valve main body  62  moves to a position that does not confront the Hall element  71  and the magnet  72  in the vertical direction Z. That is, the valve main body  62  is located at a position that is not between the Hall element  71  and the magnet  72 . In other words, the valve main body  62  is not aligned with the center of the Hall element  71  in the sub-scanning direction Y. At this time, the magnetic field (magnetic flux density) detected by the Hall element  71  is weak (small), and the Hall element  71  generates a signal indicative of a low voltage value. 
     The controller  100  receives a signal generated by the Hall element  71 , and determines whether a position of the valve  60  is open or closed based on a voltage value indicated by the signal. 
     As shown in  FIG. 7 , the board  142  is disposed on a bottom surface  41   c   1  of the concave section  41   c  (an innermost surface of the concave section  41   c ). 
     The memory  141  is disposed at the back side of the board  142 . The memory  141  is an EEPROM or the like, and stores data relating to the cartridge  40 . Specifically, the memory  141  preliminarily (that is, at the time of manufacture) stores data such as a liquid amount (an amount of liquid within each reservoir  42  in a brand-new cartridge  40 ), sensor output values (output values Vmax and Vmin from each Hall element  71 ; see  FIG. 14 ), and a manufacturing date (date, month, and year on which the cartridge  40  is manufactured). Further, when the cartridge  40  is mounted on the printer  1 , the controller  100  can write, in the memory  141 , data relating to a used amount of liquid (a used amount of liquid within each reservoir  42 , that is, an amount of liquid ejected from each head  2 ), a number of insertion of hollow needle (a number by which a hollow needle  153  is inserted in the plug  50 ), a number of recorded sheets (a number of sheets of paper P on which recording is performed with liquid within the cartridge  40 ), a cumulative usage period (a time period during which the cartridge  40  is mounted on the printer  1 , and is the same as a time period during which the hollow needle  153  is inserted in the supply channel  43   a ), and the like. When the cartridge  40  is mounted on the printer  1 , the controller  100  can also read data stored in the memory  141 . 
     As shown in  FIG. 8 , eight terminals  170   c  through  177   c  are provided on a surface of the board  142 . All of the terminals  170   c  through  177   c  have the same size and shape, and are exposed on an outer surface of the cartridge  40 . Each of the terminals  170   c  through  177   c  has a rectangular shape with two short sides parallel to the sub-scanning direction Y and two long sides parallel to the vertical direction Z. The terminals  170   c  through  177   c  are arranged in two rows. 
     Center-to-center distances x 0 -x 3  between each terminal  170   c - 173   c  and the terminal  174   c  have relationship of x 1 &lt;x 0 &lt;x 2 &lt;x 3 . Shortest distances y 0 -y 3  between outer edges of each terminal  170   c - 173   c  and the terminal  174   c  have relationship of y 1 &lt;y 0 &lt;y 2 &lt;y 3 . Here, xn (n=0-3) denotes a center -to-center distance between a terminal  17   nc  and the terminal  174   c , and yn (n=0-3) denotes a shortest distance between the outer edges of the terminal  17   nc  and the terminal  174   c.    
     As shown in  FIG. 11 , a sensor-signal output terminal (SB)  170   c  is electrically connected with the Hall element  71  of the black ink unit  40 B. A sensor-signal output terminal (SP)  171   c  is electrically connected with the Hall element  71  of the pre-coat liquid unit  40 P. A data output terminal (DO)  172   c  and a data input terminal (DI)  173   c  are electrically connected with the memory  141 . A power input terminal (V)  174   c  is electrically connected with the two Hall elements  71  and the memory  141 . Three ground terminals (G)  175   c ,  176   c , and  177   c  are electrically connected with the memory  141 , the Hall element  71  of the pre-coat liquid unit  40 P, and the Hall element  71  of the black ink unit  40 B, respectively. 
     As shown in  FIG. 9A , the board  142  is connected with one end  180   a  of a flexible cable  180 . The flexible cable  180  is an elongated cable extending from the one end  180   a  to another end  180   b  substantially in the main scanning direction X. The flexible cable  180  is accommodated in the chamber  41   b  of the housing  41  (see  FIG. 4 ). On the flexible cable  180 , boards  191  and  192  are fixed at positions spaced away from each other between the one end  180   a  and the another end  180   b . The memory  141  is electrically connected with the one end  180   a  via wiring provided on the board  142 . The boards  191  and  192  correspond to the black ink unit  40 B and the pre-coat liquid unit  40 P, respectively, and are fixed on a top surface of the supply pipe  43  of the corresponding unit. The Hall element  71  is attached to the back side of each of the boards  191  and  192 . 
     As shown in  FIG. 9B , the flexible cable  180  is formed with eight wiring lines  181  that are connected with respective ones of the terminals  170   c  through  177   c . The wiring line  181  connected with the data input terminal (DI)  173   c  and the wiring line  181  connected with the data output terminal (DO)  172   c  connect to the memory  141 . The wiring line  181  connected with the sensor-signal output terminal (SB)  170   c  extends from the one end  180   a  to the board  191  and connects to the Hall element  71  of the black ink unit  40 B. The wiring line  181  connected with the sensor-signal output terminal (SP)  171   c  extends from the one end  180   a  via the board  191  to the board  192  and connects to the Hall element  71  of the pre-coat liquid unit  40 P. The wiring line  181  connected with the power input terminal (V)  174   c  extends from the one end  180   a  via the board  191  to the board  192 , and branches off so as to connect to each of the memory  141 , the Hall element  71  of the black ink unit  40 B, and the Hall element  71  of the pre-coat liquid unit  40 P. The three wiring lines  181  connected with respective ones of the three ground terminals (G)  175   c ,  176   c , and  177   c  are combined to a single line (that is, two lines of the three lines connect to the other one line) near the one end  180   a . This single line extends from the one end  180   a  via the board  191  to the board  192 , and branches off so as to connect to each of the memory  141 , the Hall element  71  of the black ink unit  40 B, and the Hall element  71  of the pre-coat liquid unit  40 P. 
     Note that the terminals  170   c  through  177   c  are arranged in a row in  FIG. 9B  in order to show connection configuration between the terminals  170   c  through  177   c  and elements (the memory  141  and the Hall elements  71 ) by the wiring lines  181 . However, the actual arrangement of the terminals  170   c  through  177   c  is as shown in  FIG. 8 . 
     Here, as shown in  FIG. 4 , the space in the housing  41  can be divided by an imaginary line L parallel to the main scanning direction X, as viewed from the vertical direction Z, into a first region R 1  in which the supply pipes  43  are disposed and a second region R 2  in which the reservoirs  42  are disposed. The chamber  41   a  in the housing  41  belongs to the second region R 2 , and the chamber  41   b  belongs to the first region R 1 . 
     The Hall elements  71  and the board  142  (the terminals  170   c  through  177   c ) are arranged in the first region R 1 . The memory  141 , the flexible cable  180 , the wiring lines  181 , the boards  191  and  192  are also arranged in the first region R 1  (see  FIG. 9B ). 
     As shown in  FIGS. 10A through 10C , a board  182  is provided on a wall surface perpendicular to the mounting direction M (the main scanning direction X), the wall surface being one of wall surfaces defining the space C of the housing  1   a.    
     The board  182  has substantially the same size as the board  142 , and is disposed at a position confronting the board  142  when the cartridge  40  is mounted to a predetermined position in the space C (see  FIG. 10B ). As shown in  FIGS. 15 and 16 , a base material  201  is provided on a surface of the board  182 . Eight terminals  170   p  through  177   p  corresponding to eight terminals  170   c  through  177   c , respectively, are provided on the base material  201 . 
     As shown in  FIG. 16 , each of the terminals  170   p  through  177   p  includes a leaf spring having substantially a C-shape in cross-section. One end  205  of each of the terminals  170   p  through  177   p  is a fixed end that is fixed to the board  182 , and is electrically connected with the board  182 . Another end  203  of each of the terminals  170   p  through  177   p  is a free end that can bend with a part  204  as a fulcrum. The another end  203  is urged upward in  FIG. 16  (that is, the direction approaching the terminals  170   c  through  177   c  of the cartridge  40  mounted at the predetermined position in the space C). 
     The terminals  170   p  through  177   p  are arranged in a mirror symmetry pattern with the pattern of the terminals  170   c  through  177   c  shown in  FIG. 8 , so as to make contact with the terminals  170   c  through  177   c , respectively, when the cartridge  40  is mounted at the predetermined position in the space C. 
     Each of the terminals  170   p  through  177   p  is arranged so that each top portion  202  makes contact with the center of a corresponding one of the terminals  170   c  through  177   c.    
     As shown in  FIG. 11 , a sensor-signal receiving terminal (SB)  170   p , a sensor-signal receiving terminal (SP)  171   p , a data receiving terminal (DO)  172   p , and a data transmitting terminal (DI)  173   p  are electrically connected with the controller  100 . A power output terminal (V)  174   p  is electrically connected with a power source  158 . Three ground terminals (G)  175   p ,  176   p , and  177   p  are connected with ground. The power source  158  is provided in the housing  1   a.    
     Next, a process in which the cartridge  40  is mounted to the printer  1  will be described with reference to  FIGS. 5A through 16 . In  FIGS. 10A through 10C , illustration of the tray  35  is omitted. In  FIG. 11 , power supply lines are indicated by thick lines, and signal lines are indicated by thin lines. 
     Before the cartridge  40  is mounted to the printer  1 , in each of the units  40 B and  40 P, the hollow needle  153  is not inserted in the plug  50 , and the valve  60  is held in a closed position (see  FIG. 5A ). At this stage, electrical connection between the terminals  170   c  through  177   c  and the terminals  170   p  through  177   p , respectively, are not achieved. Accordingly, the Hall elements  71  and the memory  141  are not supplied with electrical power, and the controller  100  cannot perform transmission and reception of signals with the Hall elements  71  and the memory  141 . 
     When the cartridge  40  is mounted to the printer  1 , the user of the printer  1  moves the tray  35  in the main scanning direction X (the direction indicated by a blanked arrow in  FIG. 10A ) in a state where the cartridge  40  is placed in the tray  35  (see  FIG. 2 ), thereby inserting the cartridge  40  into the space C of the housing  1   a . At this time, as shown in  FIG. 10B , the cartridge  40  is inserted to a position at which the board  182  is inserted in the concave section  41   c  (see  FIG. 7 ) to make contact with the board  142  so that the terminals  170   c  through  177   c  and the terminals  170   p  through  177   p  are in contact with each other. 
     At the stage of  FIG. 10B , the centers of the terminals  170   c  through  177   c  make contact with the top portions  202  of the terminals  170   p  through  177   p , respectively, so as to be connected electrically. With this operation, electrical power is supplied from the power source  158  to the Hall elements  71  and the memory  141  via the terminals  174   p  and  174   c . The controller  100  can then perform reception of signals from the Hall element  71  of the black ink unit  40 B via the terminals  170   c  and  170   p , reception of signals from the Hall element  71  of the pre-coat liquid unit  40 P via the terminals  171   c  and  171   p , reading of data from the memory  141  via the terminals  172   c  and  172   p , and writing of data to the memory  141  via the terminals  173   c  and  173   p.    
     In a process in which the cartridge  40  is mounted to the printer  1 , immediately before mounting is completely finished, the centers of the terminals  170   c  through  177   c  make contact with the top portions  202  of the terminals  170   p  through  177   p . Subsequently, before mounting is completely finished, the terminals  170   p  through  177   p  are pressed by the terminals  170   c  through  177   c  so that the another end  203  bends downward with the part  204  as the fulcrum, thereby shifting from a state shown by solid lines in  FIG. 16  to a state shown by double-dot chain lines. The top portions  202  of the terminals  170   p  through  177   p  contact the terminals  170   c  through  177   c  in contact regions (regions surrounded by single-dot chain lines in  FIG. 8 ) including the centers of the terminals  170   c  through  177   c  when mounting is completely finished. From a state immediately before mounting is completely finished to a state when mounting is completely finished, the contact regions of the top portions  202  on the terminals in the upper row (the terminals  175   c ,  170   c ,  171   c , and  174   c ) slide upward gradually from positions slightly below the regions surrounded by single-dot chain lines in  FIG. 8 , whereas the contact regions of the top portions  202  on the terminals in the lower row (the terminals  176   c ,  173   c ,  172   c , and  177   c ) slide downward gradually from positions slightly above the regions surrounded by single-dot chain lines in  FIG. 8 . 
     A support body  154  is disposed on a wall surface perpendicular to the sub-scanning direction Y and confronting the two caps  46  when the cartridge  40  is mounted to the predetermined position in the space C, the wall surface being one of wall surfaces defining the space C of the housing  1   a . The support body  154  supports the two hollow needle  153  and is movable in the sub-scanning direction Y relative to the housing  1   a . The two hollow needles  153  correspond to the head  2  that ejects black ink and the head  2  that ejects pre-coat liquid, respectively, and are in fluid communication with the flexible tube attached to the joint of the corresponding head  2 . 
     At the stage of  FIG. 10B , the cartridge  40  is separated from the hollow needles  153 , and each reservoir  42  is not in fluid communication with the channel of the corresponding head  2 . 
     The printer  1  includes a mounting detection switch  159  (see  FIG. 11 ) that detects that the cartridge  40  is mounted at the predetermined position in the space C. The mounting detection switch  159  has a convex section (not shown) provided on a wall surface perpendicular to the mounting direction M, the wall surface being one of the wall surfaces defining the space C of the housing  1   a . The convex section is provided near the board  182 , for example. The convex section is in a protruding state before the cartridge  40  is mounted to the space C and, when the cartridge  40  is inserted in the space C to reach a position shown in  FIG. 10B , retracts in the wall surface by being pressed by the housing  41  of the cartridge  40 . The mounting detection switch  159  outputs an OFF signal when the convex section is in a protruding state, and outputs an ON signal when the convex section is retracted in the wall surface. 
     The controller  100  determines whether the cartridge  40  is mounted at the predetermined position in the space C, based on a signal received from the mounting detection switch  159  (S 1  in  FIG. 13 ). If the controller  100  determines that the cartridge  40  is mounted at the predetermined position in the space C by reception of an ON signal from the mounting detection switch  159  (S 1 : YES), the controller  100  stores time at that time (mount time) in the RAM of the controller  100  (S 2 ). Subsequent to S 2 , the controller  100  reads data stored in the memory  141  of the cartridge  40  (data relating to the liquid amount, the sensor output value, the manufacturing date, the used amount of liquid, the number of insertion of hollow needle, the number of recorded sheets, the cumulative usage period, and the like) (S 3 ). 
     Subsequent to S 3 , the controller  100  determines whether reading in S 3  is abnormal (S 4 ). If reading is not performed normally in S 3 , the controller  100  determines that reading in S 3  is abnormal (S 4 : YES) and controls an output section  160  (see  FIG. 11 ) such as a display, a speaker, etc. of the printer  1  to report an error (S 5 ). Subsequent to S 5 , the controller  100  stops operations of each section of the printer  1  (S 6 ). 
     If reading is abnormal, it is presumed that the memory  141  is damaged by short circuit between the terminal  172   c  and the terminal  174   c , or that a failure occurs with communication function of the controller  100  by short circuit between the terminal  173   c  and the terminal  174   c.    
     If reading is performed normally in S 3 , the controller  100  determines that reading is not abnormal (S 4 : NO) and controls a moving mechanism  155  (see  FIG. 11 ) to move the support body  154  together with the two hollow needles  153  supported by the support body  154  in the sub-scanning direction Y (the direction indicated by a filled arrow in  FIG. 10C ) (S 7 ). 
     With movement of the hollow needle  153  in S 7 , as shown in  FIG. 5B , in each of the units  40 B and  40 P, first, the hollow needle  153  penetrates a substantial center of the plug  50  via the opening  46   a  in the sub-scanning direction Y. 
     At this time, an opening  153   b  formed at the distal end of the hollow needle  153  is located in the supply channel  43   a , so that a channel  153   a  in the hollow needle  153  and the supply channel  43   a  are in fluid communication with each other via the opening  153   b . Although a hole is formed in the plug  50  by the hollow needle  153  at this time, a portion of the plug  50  around the hole closely contacts the outer circumferential surface of the hollow needle  153  by elasticity. This suppresses liquid leakage from between the hole in the plug  50  and the hollow needle  153 . 
     Subsequently, the distal end of the hollow needle  153  abuts the valve main body  62 . Then, further penetration of the hollow needle  153  into the supply channel  43   a  causes the valve main body  62  to move together with the O-ring  61  and causes the O-ring  61  to separate from the valve seat  43   z  (see  FIG. 5B ). At this time, the position of the valve  60  changes from a closed position to an open position. 
     When the valve  60  is in the open position, fluid communication between the reservoir  42  and the outside is allowed via the supply channel  43   a . That is, as shown in  FIG. 5B , when the plug  50  is penetrated by the hollow needle  153  and the valve  60  is in the open position, the reservoir  42  is in fluid communication with the channel of the head  2  via the supply channel  43   a , the channel  153   a , and the like. 
     Subsequent to S 7 , the controller  100  receives a signal from the Hall element  71  of each of the units  40 B and  40 P (S 8 ). Subsequent to S 8 , the controller  100  determines whether the valve  60  is disposed at the open position in each of the units  40 B and  40 P (that is, whether fluid communication is formed between the reservoir  42  and the head  2  so that liquid can be supplied from the reservoir  42  to the head  2  via the hollow needle  153 ), based on the output values Vmax and Vmin read from the memory  141  in S 3  and on the signal received in S 8  (S 9 ). In the present embodiment, determination in S 9  is performed as described below. 
       FIG. 14  shows relationship between travel distances of the valve  60  and output values from the Hall element  71 . The horizontal axis indicates the travel distance of the valve  60  from the closed position shown in  FIG. 5A  in a direction away from the plug  50  in the sub-scanning direction Y. The output values Vmax and Vmin are output values from the Hall element  71  when a predetermined driving voltage is applied to the Hall element  71  in a state where the valve  60  is in the closed position and in the open position, respectively. The controller  100  determines that the valve  60  is in the open position if the output value from the Hall element  71  received in S 8  is less than or equal to a threshold value Vt (for example, Vt=(Vmax+Vmin)/2) calculated based on the output values Vmax and Vmin read in S 3 , and determines that the valve  60  is in the closed position if the output value from the Hall element  71  is greater than the threshold value Vt. In the present embodiment, the output values Vmax and Vmin are measured during a manufacturing process of each cartridge  40  and are stored in the memory  141 . 
     If a predetermined period elapses while the valve  60  of each of the units  40 B and  40 P is not disposed in the open position (S 10 : YES), the controller  100  reports an error (S 5 ) and stops operations of each section of the printer  1  (S 6 ). 
     In this case, it is presumed that the Hall element  71  of the black ink unit  40 B is damaged by short circuit between the terminal  170   c  and the terminal  174   c , that the Hall element  71  of the pre-coat liquid unit  40 P is damaged by short circuit between the terminal  171   c  and the terminal  174   c , that a failure occurs with communication function of the controller  100  by short circuit between the terminal  173   c  and the terminal  174   c , or that a failure occurs with the plug  50 , the valve  60 , the hollow needle  153 , and the moving mechanism  155  of the printer  1 , etc. 
     If the controller  100  determines that the valve  60  of each of the units  40 B and  40 P is disposed in the open position (S 9 : YES), the controller  100  writes, in the memory  141 , data indicative of a value obtained by adding one to the number of insertion of hollow needle read in S 3  (S 11 ). Subsequent to S 11 , the controller  100  determines whether a print command from an external device has been received (S 12 ). 
     If a print command is received (S 12 : YES), the controller  100  controls driving of a paper supplying motor  125 , a conveying motor  127 , the feed motor  128 , the head  2 , and the like to perform recording for each page of paper P (S 13 ). Subsequent to S 13 , the controller  100  calculates the used amount of liquid for each page of paper P (that is, the amount of each liquid of black ink and pre-coat liquid ejected for one page of the paper P that is recorded this time) (S 14 ). 
     Subsequent to S 14 , the controller  100  writes, in the memory  141 , data indicative of the used amount of each liquid (the amount of liquid in each reservoir  42  that has been used since the cartridge  40  is a brand-new cartridge, that is, a value obtained by adding the used amount of liquid for each page calculated in S 14  to the used amount of liquid read in S 3 ) and the number of recorded sheets (the number of sheets of paper P on which recording has been performed with the cartridge  40  since the cartridge  40  is a brand-new cartridge, that is, a value obtained by adding one to the number of recorded sheets read in S 3 ) (S 15 ). 
     Subsequent to S 15 , the controller  100  determines whether writing in S 15  is abnormal (S 16 ). If writing is not performed normally in S 15 , the controller  100  determines that writing in S 15  is abnormal (S 16 : YES), reports an error (S 5 ), and stops operations of each section of the printer  1  (S 6 ). 
     If writing is abnormal, it is presumed that the memory  141  is damaged by short circuit between the terminal  172   c  and the terminal  174   c , or that a failure occurs with communication function of the controller  100  by short circuit between the terminal  173   c  and the terminal  174   c.    
     If writing is performed normally in S 15 , the controller  100  determines that writing is not abnormal (S 16 : NO), and determines whether there are recording data for the next page, based on image data included in the print command received in S 12  (S 17 ). 
     If there are recording data for the next page (S 17 : YES), the controller  100  returns to S 13  and repeats the above-described series of steps S 13  through S 16 . On the other hand, if there are no recording data for the next page (S 17 : NO), the controller  100  returns to S 12  and waits until a print command is received again. 
     Note that the printer  1  includes a lock mechanism (not shown) for locking the cartridge  40 . If the controller  100  determines that the cartridge  40  is mounted at the predetermined position in the space C (S 1 : YES), the controller  100  drives the lock mechanism concurrently with the process in S 2 , for example, to lock the cartridge  40  together with the tray  35  at the predetermined position. 
     In order to dismount the cartridge  40  from the printer  1 , the user of the printer  1  presses a lock release button. If the controller  100  detects pressing of the lock release button, the controller  100  first controls the moving mechanism  155  (see  FIG. 11 ) to move the support body  154  in the direction opposite from the filled arrow in  FIG. 10C  so that the support body  154  returns from the position of  FIG. 10C  to the position of  FIG. 10B . At this time, in each of the units  40 B and  40 P, as the hollow needle  153  moves in the leftward direction in  FIG. 5B , urging force of the coil spring  63  causes the valve  60  to move in the leftward direction in  FIG. 5B  to make contact with the valve seat  43   z . With this operation, the position of the valve  60  shifts from the open position to the closed position. The controller  100  determines that the valve  60  is in the closed position when the output value from the Hall element  71  exceeds the threshold value Vt in each of the units  40 B and  40 P and, based on that time (dismount time) and mount time stored in S 2 , calculates the cumulative usage period (a time period from the mount time until the dismount time). The controller  100  writes, in the memory  141 , data indicative of a value obtained by adding the cumulative usage period read in S 3  to the calculated cumulative usage period (that is, the value is the cumulative usage period during which the cartridge  40  is mounted on the printer  1  since the cartridge  40  is a brand-new cartridge). Subsequently, the hollow needle  153  is pulled out of the plug  50 . At this time, a hole formed in the plug  50  by the hollow needle  153  becomes small to an extent that liquid leakage is suppressed, due to elasticity of a portion of the plug  50  around the hole. 
     Subsequently, the controller  100  drives the lock mechanism to unlock the cartridge  40 . In this state, the user can pull the tray  35  out of the space C. When the tray  35  is pulled out of the space C, the board  142  separates from the board  182 . Thus, electrical connections between the terminals  170   c  through  177   c  and the terminals  170   p  through  177   p , respectively, are disconnected, which stops power supply to the Hall elements  71  and the memory  141  and which prevents the controller  100  from performing transmission and reception of signals with the Hall elements  71  and the memory  141 . 
     Note that the controller  100  displays a value obtained by subtracting the used amount of liquid written in the memory  141  in S 15  from the liquid amount read in S 3 , as the remaining amount of each liquid, on the display of the printer  1 . 
     As shown in  FIG. 12 , the controller  100  serves as a communication section that communicates with the cartridge  40  mounted in the space C, and also serves as each section corresponding to processes in  FIG. 13 . 
     In the present embodiment, a mount detecting section M 1  corresponds to S 1 , a reading section M 2  corresponds to S 3 , an abnormal-reading determining section M 3  corresponds to S 4 , a reporting section M 4  corresponds to S 5 , a recording prohibiting section M 5  corresponds to S 6 , a moving section M 6  corresponds to S 7 , a receiving section M 7  corresponds to S 8 , an abnormal-reception determining section M 8  corresponds to S 9  and S 10 , a writing section M 9  corresponds to S 11  and S 15 , an abnormal-writing determining section M 10  corresponds to S 16 , a recording controlling section M 11  corresponds to S 13 , and a fluid-communication determining section M 12  corresponds to S 9 . 
     As described above, according to the present embodiment, it is possible to determine whether the hollow needle  153  is inserted in the supply channel  43   a  appropriately, based on signals from the Hall element  71 . Accordingly, fluid communication between the reservoir  42  and the head  2  can be detected appropriately and correctly. 
     In the housing  41  of the cartridge  40 , the first region R 1  tends to be a dead space. However, because the Hall elements  71  and the sensor-signal output terminals  170   c  and  171   c  are arranged in the first region R 1 , the space within the housing  41  can be utilized efficiently. In addition, the length of the wiring line  181  connecting the Hall elements  71  and the sensor-signal output terminals  170   c  and  171   c  can be shortened. 
     The first outer surface  41   x , on which the terminals  170   c  through  177   c  are disposed, and the second outer surface  41   y , on which the openings  43   b  are disposed, intersect each other. With this configuration, a contact operation between the terminals  170   c  through  177   c  and the terminals  170   p  through  177   p , respectively, (see  FIG. 10B ) and an inserting operation of the hollow needle  153  into the supply channel  43   a  through the opening  43   b  (see  FIG. 10C ) can be performed independently from each other. 
     The Hall element  71  detects the valve  60  that moves by being pressed by the hollow needle  153 . Thus, insertion of the hollow needle  153  into the supply channel  43   a  can be detected appropriately by using the valve  60 . 
     As shown in  FIGS. 4 ,  5 A, and  5 B, the supply pipe  43  extends linearly in the sub-scanning direction Y. Thus, the configuration of the cartridge  40  can be simplified. 
     As shown in  FIG. 4 , the Hall elements  71  and the sensor-signal output terminals  170   c  and  171   c  are arranged in the main scanning direction X. Thus, the length of the wiring lines  181  connecting the Hall elements  71  and the sensor-signal output terminals  170   c  and  171   c  can be shortened reliably. Further, bending of the wiring line  181  can be suppressed. 
     As shown in  FIG. 9B , as viewed from the vertical direction Z, the wiring lines  181  are arranged in the first region R 1  where the Hall elements  71  and the sensor-signal output terminals  170   c  and  171   c  are arranged. Thus, the length of the wiring lines  181  can be shortened more reliably. 
     As shown in  FIG. 7 , the board  142  on which the terminals  170   c  through  177   c  are provided is disposed on the bottom surface  41   c   1  of the concave section  41   c  formed in the first outer surface  41   x . Further, when the cartridge  40  is mounted to the space C, the first outer surface  41   x  is a surface of the housing  41  at the downstream side in the mounting direction M. When the cartridge  40  is mounted to the space C, the concave section  41   c  guides the board  182 . With this configuration, both of a mounting operation of the cartridge  40  to the space C and a contacting operation of the terminals  170   c  through  177   c  and the terminals  170   p  through  177   p  can be performed reliably at substantially the same timing (see  FIG. 10B ). 
     The two boards  191  and  192  are connected with each other via the single flexible cable  180 . Thus, the number of terminals and the wiring lines  181  can be reduced and the configuration can be simplified, compared with a case in which, for example, a flexible cable is provided for each of the boards  191  and  192  (that is, a cable connecting the board  142  and the board  191 , and a cable connecting the board  142  and the board  192 ). 
     As shown in  FIG. 9B , the Hall elements  71  of the units  40 B and  40 P share the power input terminal (V)  174   c  and the ground terminals (G)  175   c ,  176   c , and  177   c . Thus, it is not necessary to provide the power input terminal (V)  174   c  and the ground terminals (G)  175   c ,  176   c , and  177   c  for each Hall element  71 . Accordingly, the number of terminals and the wiring lines  181  can be reduced and the configuration can be simplified. 
     Further, as shown in  FIG. 9B , the wiring line  181  (the wiring line shown at the lowermost side in  FIG. 9B ) corresponding to the Hall element  71  (the Hall element  71  of the pre-coat liquid unit  40 P) attached to the board  192  closer to the another end  180   b  (among the two boards  191  and  192 ) extends to the board  192  via the board  191  which is closer to the one end  180   a  than the board  192  is. Hence, the configuration of the wiring lines  181  can be simplified more efficiently. 
     While the invention has been described in detail with reference to the above aspects thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the claims. 
     &lt;Modifications Regarding Terminals of the Cartridge&gt; 
     The terminals may be provided separately on a plurality of boards. 
     The shapes of the terminals are not limited to rectangular shapes but may be any shape (for example, the shapes may be circular shapes or the like). 
     Distances between the terminals need not be equal, and distance relationship between the terminals may be changed arbitrarily. Further, the arrangement and sizes of the terminals may be changed arbitrarily. For example, in  FIG. 8 , the positions of the data input terminal  173   c  and the data output terminal  172   c  may be switched. The positions of the sensor-signal output terminals  170   c  and  171   c  may be switched. The power input terminal  174   c  may be arranged at the right-lower end, the left-upper end, the left-lower end, or the like, not the right-upper end, or may be arranged at a position other than an end of a row. Further, the number of rows in which terminals are arranged, the number of terminals included in each row, and the like are also arbitrary. Additionally, terminals may be arranged in a circular shape, or in a random shape, not in rows. 
     The surface on which terminals are arranged (the first outer surface) is not limited to a surface at the downstream side in the mounting direction of the cartridge onto the mounting section, but may be a surface at the upstream side in the mounting direction. Further, the first outer surface is not limited to a surface perpendicular to the mounting direction, but may be a surface parallel to the mounting direction, for example. 
     The sensor-signal output terminal need not be disposed on the bottom surface of the concave section formed in the first outer surface. 
     The number of the sensor-signal output terminals may be changed in accordance with the number of sensors. 
     The number of ground terminals is arbitrary, and a ground terminal may be omitted. 
     It is sufficient that the power input terminal is electrically connected with at least one of a sensor (the Hall element  71 , for example) and a storage section (the memory  141 , for example) so that the power input terminal can input power to the at least one of the sensor and the storage section (for example, power may be inputted into the storage section via the data input terminal). Further, two or more power input terminals may be provided, or a power input terminal may be omitted. 
     A data output terminal and a data input terminal may be omitted. 
     &lt;Modifications Regarding Terminals of the Apparatus Main Unit&gt; 
     The terminals of the apparatus main unit may have the same size as or a larger size than the terminals of the cartridge. 
     The number or arrangement of the terminals of the apparatus main unit may partially correspond to the terminals of the cartridge. For example, in a case where the terminals of the cartridge are arranged in two rows each including three terminals, the terminals of the apparatus main unit may be arranged in two rows each including four terminals, as shown in  FIG. 8 . In this case, the terminals of the apparatus main unit include terminals that do not contact the terminals of the cartridge. 
     Similarly, the number or arrangement of the terminals of the cartridge may partially correspond to the terminals of the apparatus main unit. For example, the terminals of the cartridge may include terminals that do not contact the terminals of the apparatus main unit. 
     The terminals of the apparatus main unit may be terminals of a leaf-spring type (terminals urged by leaf springs in a direction toward the terminals of the cartridge) or may be other than a leaf-spring type. 
     The terminals of the apparatus main unit and the terminals of the cartridge may be so designed that positions other than centers of the terminals serve as contact portions. 
     &lt;Modifications Regarding Other Configuration of the Cartridge&gt; 
     The sensor is not limited to a magnetic sensor such as the Hall element  71 , but may be sensors of various types (for example, a reflective-type optical sensor, a transmission-type optical sensor, a mechanical sensor that detects an existence of an object based on a contact with the object, or the like). 
     In the above-described embodiment, the sensor detects a movable member that moves in a channel by being pressed by a hollow member. However, the sensor may detect a position of the hollow member in the channel directly or indirectly. For example, in the above-described embodiment, the Hall elements  71  (as the sensor) are used for detecting whether the valve  60  is open or closed. However, if the hollow member is inserted into the channel substantially concurrently with mounting of the liquid cartridge onto the mounting section, a mounting detection sensor may be used for detecting that the liquid cartridge has been mounted on the mounting section. As the mounting detection sensor, the mounting detection switch  159  in the above-described embodiment, an optical sensor, or the like may be used. 
     The number of sensor(s) provided on the cartridge may be one or more. 
     It is sufficient that the second and third outer surfaces intersect the first outer surface, and the second and third outer surfaces need not be perpendicular to the first outer surface. Further, the second and third outer surfaces need not be parallel to each other. 
     The direction in which the channel extends is not limited to the second direction. Further, the channel is not limited to a linear shape, but may be a shape having a bent portion such as L-shape, for example. 
     The configurations of the wiring lines and the flexible cable are arbitrary. For example, it is not necessary that two or more sensors be connected with each other by a single flexible cable, but a flexible cable may be provided individually for each sensor. A portion of the wiring line may be disposed outside the first region. 
     In the above-described embodiment, the cartridge stores two kinds of liquid (black ink and pre-coat liquid). However, the cartridge may store only one kind of liquid. 
     Data stored in the storage section are not limited to particular kinds of data. As data relating signals generated by the sensor, the amount of liquid within the liquid storing section, and the like, the storage section need not store output values of the sensor and the amount of liquid within the liquid storing section themselves. Instead, the storage section may store data form which the output values and the amount of liquid can be derived. 
     In addition, without departing from the scope of the claims, the configurations (shapes, positions, etc.) of each part (the housing  41 , the reservoir  42 , the supply pipe  43 , the plug  50 , the valve  60 , the sensor unit  70 , the memory  141 , the board  142 , etc.) of the cartridge may be changed appropriately. Further, other parts may be added, and some parts may be omitted. 
     &lt;Modifications Regarding Controls Performed by the Apparatus Main Unit&gt; 
     The apparatus main unit may stop an operation of each section of the apparatus main unit (an ejecting operation of the head, etc.), without reporting an error. 
     Timing at which transmission and reception of signals are allowed between the cartridge and the apparatus main unit and timing at which power supply is allowed from the apparatus main unit to the cartridge are not limited to those described above. The timings can be changed arbitrarily. 
     In the above-described embodiment, the mounting detection switch  159  of a mechanical-sensor type is used as the mounting detection section for detecting that the cartridge is mounted on the mounting section. However, another component may be used. For example, an optical sensor, a switch that outputs an ON signal when the printer and the cartridge are electrically connected, or the like may be used. 
     Writing of data by the writing section and determination of abnormality by the abnormal-writing determining section may be performed prior to reception of a print command from an external device. 
     Timing at which each section performs a function, such as timing at which the reading section reads data stored in the storage section of the cartridge, timing at which the writing section writes data in the storage section of the cartridge, timing at which the receiving section receives a signal from the sensor, timing at which the abnormal-writing determining section determines abnormal writing, timing at which the abnormal-reception determining section determines abnormal reception, timing at which the moving section moves the hollow member, and the like may be changed appropriately, without departing from the scope of the claims. 
     The hollow member may have a tip that is not acicular like a needle. 
     Liquid stored in the liquid cartridge is not limited to ink and pre-coat liquid. For example, the liquid may be post-coat liquid that is ejected onto a recording medium subsequent to recording in order to improve image quality, cleaning liquid for cleaning the conveying belt, and the like. 
     The number of the cartridge(s) included in a liquid ejecting device may be one or more. 
     The number of the liquid ejecting head(s) included in a liquid ejecting device is not limited to two, but may be one or more. For example, the liquid ejecting device may be a color inkjet printer including heads that eject black ink and ink in three colors (magenta, cyan, and yellow). The liquid ejecting device may be a line type or a serial type. Further, the liquid ejecting device is not limited to a printer, but may be any liquid ejecting device such as a facsimile apparatus, a copier, and the like.