Patent Publication Number: US-8113637-B2

Title: Liquid supply device and liquid ejecting apparatus

Description:
BACKGROUND 
     The entire disclosure of Japanese Patent Application No. 2008-190202, filed Jul. 23, 2008, is expressly incorporated herein by reference. 
     1. Technical Field 
     The present invention relates to a liquid supply device including a supply pump provided in a liquid supply passage, a first unidirectional valve provided on the upstream side of the supply pump, and a second unidirectional valve provided on the downstream side of the supply pump, and a liquid ejecting apparatus. 
     2. Related Art 
     In the past, an ink jet printer as a liquid ejecting apparatus printed a text, an image, or the like by ejecting ink droplets onto a target (a sheet, etc.) as a liquid from a printing head. An ink cartridge (a liquid storing member) as an ink supply source supplying ink to the printing head is mounted on such a kind of printer. As an ink supplying method of supplying ink from the ink cartridge to the printing head, there is known a method of using a water head difference based on a difference between an ink surface of the ink cartridge and the height of nozzles of the printing head or a method of supplying ink by use of a pump. 
     In the ink supply device (a liquid supply device) using the pump, there is known a pressurizing supply method (for example, JP-A-2002-192751 (FIG. 2, etc.)) of supplying ink by sending air pressurized by a pressurizing pump to an ink cartridge and pressurizing an ink pack accommodated in the ink cartridge or a method (JP-A-2006-272661 (FIGS. 2, 4, 6, 8, 10, etc.)) of supplying ink by driving a pump provided in an ink passage and ejecting the ink sucked from an ink cartridge located on the upstream side of the ink passage toward the downstream side of the ink passage. 
     An ink supply device disclosed in JP-A-2006-272661 includes a pulsation type pump such as a diaphragm type pump and a pair of unidirectional valves (check valves) provided in the upstream side (an input side) and the downstream side (an output side) of the pump, respectively. The unidirectional valve (a first unidirectional valve) on the upstream side is opened by depressurization of the ink upon the sucking drive of the pump, and maintains a valve-closed state when the pressure of the ink is increased upon the ejecting drive of the pump. On the other hand, the unidirectional valve (a second unidirectional valve) on the downstream side maintains a valve-closed state upon the sucking drive of the pump and is opened when the pressure of the ink is increased upon the ejecting drive of the pump. 
     However, in the ink supply device disclosed in JP-A-2006-272661, since the pump and the first and second unidirectional valves are separate elements, it is necessary to connect these separate elements to each other through pipes such as an ink introducing pipe, an ink outputting pipe, and an air supply tube. For this reason, when the known ink supply device is used, a problem occurs in that the pipes such as tubes are complicated. In particular, since the ink supply devices have to be disposed according to the number of ink colors, the liquid ejecting apparatus such as an ink jet printer has the problem that the number of pipes increases in proportion to the number of ink colors, the pipes become complex, and thus a piping work becomes difficult. 
     SUMMARY 
     An advantage of some aspects of the invention is that it provides a liquid supply device which includes a supply pump and unidirectional valves provided in the upstream side and the downstream side of the supply pump and which is capable of reducing a piping work without complicated pipes, and a liquid ejecting apparatus. 
     According to an aspect of the invention, there is provided a liquid supply device including: a supply pump which is provided in a liquid supply passage; a first unidirectional valve which is provided on the upstream side of the supply pump; a second unidirectional valve which is provided on the downstream side of the supply pump; and a plurality of constituent members which each include a single passage forming member provided with a part or the whole of the liquid supply passage and are laminated and which are formed such that a partial passage of the liquid supply passage permitting the first unidirectional valve to communicate with the supply pump and a partial passage thereof permitting the supply pump to communicate with the second unidirectional valve are formed in the laminated state. The supply pump and the first and second unidirectional valves are disposed on the substantially same plane by laminating the plurality of constituent members, the first unidirectional valve communicates with the supply pump by the partial passage, and the supply pump communicates with the second unidirectional valve by the partial passage. In addition, the number of single passage forming members is not limited to one, but two or more single passage forming members may be included in the plurality of constituent elements. It is not necessary to form a part of the liquid supply passage in all the plurality of constituent members. The constituent member in which a part of the liquid supply passage is not formed may be included as long as a part or the whole of the liquid supply passage is formed at least in the passage forming member. Both the two “partial passages” may be formed as the single passage forming member or only one of the partial passages may be formed as the single passage forming member. In the single passage forming member, parts of the two “partial passages” may be formed or one of the parts of the “partial passages” may be formed. In short, it is sufficient that the two “partial passages” are formed in the state where the plurality of constituent members is laminated. Here, the plurality of constituent members refers to a member forming each layer of the lamination structure. It is preferable that the constituent member forming one layer is a single member. However, another constituent member other than the single passage forming member does not necessarily have to be formed as a single (one) member and one layer may be formed of a plurality of members. The plurality of constituent members includes members serving as the constituent elements which are laminated to construct the supply pumps and the unidirectional valves. However, as long as the single passage forming member is shared, a configuration is also included in which the shape or material of the members laminated on a part of the supply pump and a part of the unidirectional valve is different. 
     According to this aspect of the invention, by laminating the plurality of constituent members, the supply pumps and the first and second unidirectional valves are disposed on the substantially same plane. In addition, the first unidirectional valve communicates with the supply pump by the partial passage of the liquid supply passage and the supply pump communicates with the second unidirectional valve by the partial passage of the liquid supply passage. With such a configuration, the liquid supply device is formed as a relatively thin element which includes the supply pump, the first and second unidirectional valves, and the liquid supply passage including two kinds of passages (the partial passages) each permitting the supply pump to communicate with second unidirectional valves. Accordingly, since a piping work for connecting the two pipes (for example, a pipe such as a tube or hose) for permitting the supply pump to communicate with second unidirectional valves is not required, it is possible to reduce the piping work required for the liquid supply device. 
     The liquid supply device according to this aspect of the invention may further include: a first passage forming member in which a part of the liquid supply passage is formed; a flexible member which has a diaphragm forming the supply pump; and a second passage forming member in which another part of the liquid supply passage is formed. The single passage forming member may be at least one of the first passage forming member and the second passage forming member. The first and second passage forming members may be laminated with the flexible member interposed therebetween. 
     According to this aspect of the invention, by laminating the first and second passage forming members with the flexible member interposed therebetween, the diaphragm type supply pump and the first and second unidirectional valves are formed as one element. Accordingly, the liquid supply device can be made relatively thin. 
     In the liquid supply device according to this aspect of the invention, at least one of the first and second passage forming members may have a groove on a surface thereof opposite to the flexible member. By fixing a blocking member in a sealed state onto the surface in which the groove is formed, a part of the liquid supply passage may be formed by a spatial area surrounded by the groove and the blocking member. 
     According to this aspect of the invention, the blocking member is fixed to the surface of at least one of the first and second passage forming members opposite to the flexible member in the sealed state. Accordingly, since a part of the liquid supply passage is formed by the spatial area surrounded by the groove and the blocking member, the size of the liquid supply device viewed in the lamination direction can be reduced. 
     In the liquid supply device according to this aspect of the invention, the blocking member may be a film welded on the surface in which the groove is formed. 
     According to this aspect of the invention, the film is welded to form the liquid supply passage. Accordingly, the liquid supply device can be made thin. 
     In the liquid supply device according to this aspect of the invention, the first and second passage forming members may be fixed by fastening a fastening member in a laminated state with the flexible member interposed therebetween. The liquid supply device may further include a regulating unit ensuring a gap between the first and second passage forming members so that the flexible member is not excessively pressed and deformed in a state of being fastened by the fastening member. 
     According to this aspect of the invention, upon fastening the fastening member, the regulating unit ensures the gap between the first and the second passage forming members so that the flexible member is not excessively pressed and deformed. Accordingly, even when the fastening member is fastened too strongly, the flexible member between the first and the second passage forming members is not excessively pressed and deformed. As a consequence, it is possible to prevent problems caused by the excessive pressing and deformation of the flexible member. 
     In the liquid supply device according to this aspect of the invention, the single passage forming member may include a concave section for forming a chamber of the supply pump, a concave section for forming a valve chamber of the first unidirectional valve, and a concave section for forming a valve chamber of the second unidirectional valve. In each of the concave sections forming the valve chambers of the first and second unidirectional valves, a communication port communicating with the liquid supply passage may be opened to a portion other than a valve seat coming in contact with valve portions of the first and second unidirectional valves upon closing the valves. 
     According to this aspect of the invention, in the concave sections forming the valve chambers of the first and second unidirectional valves, the communication port communicating with the liquid supply passage is opened to the portion other than the valve seat coming in contact with the valve portions of the first and second unidirectional valves upon closing the valves. Accordingly, since the valve portions receives the pressure in the pressure receiving surface broader than the communication port to be opened or closed, the first and second unidirectional valves can be opened or closed by a relatively small variation in the liquid pressure. In addition, since the concave sections are formed in the single passage forming member, the liquid supply device can be made thin. 
     In the liquid supply device according to this aspect of the invention, a metal plate may be laminated on a surface opposite to the flexible member in at least one of the first and second passage forming members. 
     According to this aspect of the invention, even when the first and second passage forming members are made of a plastic material, for example, the first and the second passage forming members can be prevented from being deformed in a rippling shape thanks to the rigidity of the laminated metal plate even though the first and the second passage forming members are pressurized at the fastened positions more strongly than in the other positions and the distribution of the force occurs. As a consequence, even in the fastened state, the flatness of the first and second passage forming members can be guaranteed and the sealing property with the flexible member can be ensured. 
     In the liquid supply device according to this aspect of the invention, a metal plate may be laminated on the surface of the first and second passage forming members to which the film is attached. 
     According to this aspect of the invention, even when the first and second passage forming members are made of a plastic material, for example, the first and the second passage forming members can be prevented from being deformed in the rippling shape thanks to the rigidity of the laminated metal plate even though the first and the second passage forming members are pressurized at the fastened positions more strongly than in the other positions and the distribution of the force occurs. As a consequence, even in the fastened state, the flatness of the first and second passage forming members can be guaranteed and the sealing property with the flexible member can be ensured. Moreover, since the film used as the blocking member is protected by the metal plate, it is easy to prevent the damage of the film. 
     The liquid supply device according to this aspect of the invention may further include a plurality of liquid supply units which each include the supply pump and the first and second unidirectional valves. The supply pumps and the first and second unidirectional valves included in the plurality of liquid supply units may be disposed on the substantially same plane and are formed by laminating the plurality of constituent members each including the single passage forming member. 
     According to this aspect of the invention, the plurality of liquid supply units including the supply pump and the first and the second unidirectional valves are formed as one element, it is possible to reduce a piping work for connecting a working fluid pipe (for example, a tube or a hose) such as a passage for sending the working fluid to the supply pumps, for example, for permitting the liquid supply units to communicate each other. 
     In the liquid supply device according to this aspect of the invention, a plurality of connection sections connecting a plurality of liquid storing members may be provided on a surface opposite to the flexible member in at least one of the first and second passage forming members. The connection sections and the supply pumps may be laid out such that all the central points of the plurality of supply pumps fall within a projection range obtained by projecting an area for disposing the plurality of liquid storing members connected to the plurality of connection sections in a lamination direction. 
     According to this aspect of the invention, when the plurality of liquid storing members is mounted on the connection sections of the liquid supply device, the plurality of liquid storing members is disposed so that all the central points of the plurality of supply pumps fall within the projection range of the area for disposing the plurality of liquid storming members in the lamination direction. Accordingly, the space required to dispose the liquid supply device mounted with the plurality of liquid storing members can be restrained so as to be relatively small. 
     According to another aspect of the invention, there is provided a liquid ejecting apparatus including the liquid supply device having the above-described configuration and a liquid ejecting unit which ejects a liquid supplied from the liquid supply device. 
     According to this aspect of the invention, since the liquid ejecting apparatus includes the liquid supply device according to the aspect of the invention to supply the liquid to the liquid ejecting unit, the same advantages as those of the liquid supply device according to the aspect of the invention can be obtained. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a schematic sectional view illustrating an ink jet printer according to an embodiment. 
         FIG. 2A  is a schematic sectional view illustrating an ink supply device upon suction drive and  FIG. 2B  is a schematic sectional view illustrating the ink supply device upon ejection drive. 
         FIG. 3  is a perspective view illustrating an ink supply system mounted with ink cartridges. 
         FIG. 4  is a perspective view illustrating the ink supply system. 
         FIG. 5  is an exploded perspective view illustrating the ink supply system. 
         FIG. 6  is a plan view illustrating a cover. 
         FIG. 7  is a perspective view illustrating the rear surface of the cover. 
         FIG. 8  is a bottom view illustrating the cover. 
         FIG. 9  is a perspective view illustrating a diaphragm forming member and a coil spring. 
         FIG. 10  is a plan view illustrating the diaphragm forming member. 
         FIG. 11  is a perspective view illustrating the rear surface of the diaphragm forming member. 
         FIG. 12  is a bottom view illustrating the diaphragm forming member. 
         FIG. 13  is a perspective view illustrating the upper surface (the front surface) of a passage forming plate. 
         FIG. 14  is a plan view illustrating the passage forming plate. 
         FIG. 15  is a bottom view illustrating the passage forming plate. 
         FIG. 16  is an exploded perspective view illustrating the passage forming plate and a film. 
         FIG. 17  is a partial bottom view for explaining an ink passage of the passage forming plate. 
         FIG. 18  is a partial bottom view for explaining an air passage of the passage forming plate. 
         FIG. 19  is an exploded perspective view illustrating a receiving plate and a protective plate. 
         FIG. 20  is a plan view illustrating the ink supply system mounted with the ink cartridge. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, an ink jet printer (hereinafter, referred to as “a printer”) which is an example of a liquid ejecting apparatus according to an embodiment of the invention will be described with reference to  FIGS. 1 to 20 . 
     As shown in  FIG. 1 , a printer  11  according to this embodiment includes a printing head unit  12  as a liquid ejecting unit which ejects ink (liquid) onto a target (for example, a print medium such as a sheet) (not shown) and an ink supply device  14  (a liquid supply unit) which supplies the ink stored in an ink cartridge  13  as a liquid storing member (liquid supply source) to the printing head unit  12 . When the upstream end of the ink supply device is connected to the ink cartridge  13  and the downstream end of the ink supply device is connected to the printing head unit  12 , a part of an ink passage  15  supplying the ink from an upstream side, which is the ink cartridge  13 , to a downstream side, which is the printing head unit  12 , is formed in the ink supply device  14 . 
     The printer  11  according to this embodiment is an ink jet type serial printer or line printer and known as an off-carriage type printer in which the ink cartridge  13  is mounted on a printer main body. As described in  FIG. 1 , the printing head unit  12  connected to the ink supply device  14  through an ink supply tube  15   e  includes a head unit body  56  and a printing head  57 . In the serial printer, for example, the head unit body  56  is formed by a carriage which reciprocates in a main scanning direction (right and left directions in  FIG. 1 ), while being guided by a guiding mechanism by the power of an electric motor (carriage motor) (none of which are shown). On the other hand, in the line printer, the head unit body  56  is fixed so as to extend in a width direction perpendicular to a sheet transporting direction, and the printing head  57  is configured such that the nozzles for each color are arranged over the whole of the maximum sheet width at a predetermined nozzle pitch. Of course, in the serial printer, the ink supply device  14  may be used in a kind of printer known as an on-carriage type printer in which an ink cartridge is mounted on a carriage. 
     The printer  11  according to this embodiment is provided with plural the ink supply devices  14  to correspond to the number (kinds) of ink colors to be used for the printer  11 . In this case, since the ink supply devices have the same configuration, one ink supply device  14  supplying one kind of ink, the printing head unit  12 , and one ink cartridge  13  are shown in  FIG. 1 . Hereinafter, a case in which tone ink supply device  14  shown in  FIG. 1  supplies the ink from the ink cartridge  13  to the printing head unit  12  will be described as an example. In the ink supply device  14  shown in  FIG. 1 , the cross-section of passages or valves is schematically shown to explain the principle of an ink supply mechanism. A preferable shape including the layout of the passages or the valves is described below with reference to separate drawings. 
     As shown in  FIG. 1 , in the printing head  57 , plural nozzles  16  (in this embodiment, six nozzles) corresponding to the number of ink supply devices  14  are opened on a nozzle forming surface  12   a  which faces a platen (not shown). The ink supplied from each of the ink supply devices  14  to an ink passage  12   d  formed in the printing head unit  12  through the ink passage  15  is supplied to the nozzles  16  via a valve unit  17  and a defoaming unit  58  formed in the ink passage  12   d . That is, a pressure chamber  17   a  temporarily storing the ink flowing from the ink passage  15  is formed in the valve unit  17  to communicate with the nozzles  16 . Upon ejecting the ink from the nozzles  16 , an amount of ink corresponding to an amount of ink consumed upon ejecting the ink flows from the ink passage  15  to the pressure chamber  17   a  appropriately in accordance with an opening or closing operation of a passage valve  17   d . The configuration of the valve unit  17  and the defoaming unit  58  is described. The six nozzles  16  form nozzle rows such that the plural nozzles are disposed at a uniform nozzle pitch in a direction perpendicular to the surface of  FIG. 1 . A direction of the nozzle row (the direction perpendicular to the surface of  FIG. 1 ) is equal to the sheet transporting direction in the serial printer and a sheet width direction in the line printer. 
     The printer  11  is provided with a maintenance unit  18  which performs a cleaning operation on the printing head  57  so as to solve clogging or the like of the nozzles  16  of the printing head  57 . The maintenance unit  18  includes a cap  19  which comes in contact with the nozzle forming surface  12   a  of the printing head  57  to surround the nozzles  16 , a sucking pump  20  which is driven upon sucking the ink from the cap  19 , and a waste liquid tank  21  to which the ink sucked from the cap  19  with the drive of the sucking pump  20  is discharged as waste ink. In addition, upon performing the cleaning operation, the thickened ink or the ink mixed with bubbles is discharged from the printing head  57  to the waste liquid tank  21  by driving the sucking pump  20  in the state where the cap  19  is moved from the state shown in  FIG. 1  and comes in contact with the nozzle forming surface  12   a  of the printing head  57  and by generating a negative pressure in the inner space of the cap  19 . In addition, the maintenance unit  18  is disposed at a location corresponding to a home position in which the printing head unit  12  is located in non-printing in the serial printer and disposed directly below the printing head  57  in the line printer. 
     On the other hand, the ink cartridge  13  includes a substantial box-like case  22  serving as an ink chamber  22   a  storing ink therein. A pipe unit  23  communicating with the inside of the ink chamber  22   a  is formed downward on the lower wall of the case  22 . An ink supply port  24  through which the ink can lead out is formed on the front end of the pipe unit  23 . When the ink cartridge  13  is connected to the ink supply device  14 , a supply needle  25  protruding from the ink supply device  14  to form the upstream end of the ink passage  15  is inserted into the ink supply port  24 , an air communication hole  26  allowing the inside of the ink chamber  22   a  storing the ink to communicate to the air is formed through the upper wall of the case  22  so that the air pressure is exerted to the liquid surface of the ink stored in the ink chamber  22   a.    
     Next, the configuration of the ink supply device  14  will be described in detail. 
     As shown in  FIG. 1 , the ink supply device  14  includes a first passage forming member  27  made of a resin material and serving as a base body, a second passage forming member  28  made of a resin material and laminated on the first passage forming member  27  to be assembled, and a flexible member  29  formed of a rubber plate or the like and interposed between both the passage forming members  27  and  28  upon the assembly. A film  120  is adhered onto the surface (rear surface) on the first passage forming member  27  opposite to the flexible member  29 . Moreover, a protective plate  130  and a receiving plate  140  are laminated on the lower surface of the film  120 . Here, concave sections  30 ,  31 , and  32  having a circular shape in a plan view are formed at plural positions (in this embodiment, three positions) on the upper surface of the first passage forming member  27 . That is, the concave sections  30  to  32  are formed parallel in order of the concave sections  30 ,  31 , and  32  from the right side to the left side in  FIG. 1 . 
     On the other hand, concave sections  33 ,  34 , and  35  having a circular shape in a plan view and vertically facing the concave sections  30 ,  31 , and  32  formed on the surface of the first passage forming member  27  are formed at plural positions (in this embodiment, three positions) on the lower surface of the second passage forming member  28  laminated on the first passage forming member  27 . That is, the concave sections  33  to  35  are formed parallel in order of the concave sections  33 ,  34 , and  35  from the right side to the left side in  FIG. 1 . An air communication hole  35   a  communicating to the air is on the bottom of the concave section  35  formed at the most left side in the second passage forming member  28  in  FIG. 1 . 
     The flexible member  29  is interposed between the first passage forming member  27  and the second passage forming member  28  such that plural locations (three locations in this embodiment) of the flexible member  29  are vertically separated between the concave sections  30  to  32  of the first passage forming member  27  and the concave sections  33  to  35  of the second passage forming member  28 . As a consequence, a portion of the flexible member  29  interposed between the concave section  30  of the first passage forming member  27  and the concave section  33  of the second passage forming member  28  functions as a sucking valve body (valve body)  36  which can elastically displace between the concave sections  30  and  33 . 
     Likewise, a portion of the flexible member  29  interposed between the concave section  31  of the first passage forming member  27  and the concave section  34  of the second passage forming member  28  functions as a diaphragm  37  which can elastically displace between the concave sections  31  and  34 . Likewise, a portion of the flexible member  29  interposed between the concave section  32  of the first passage forming member  27  and the concave section  35  of the second passage forming member  28  functions as an ejecting valve body (valve body)  38  which can elastically displace between the concave sections  32  and  35 . 
     As shown in  FIG. 1 , a first passage  15   a  permitting the ink supply needle  25  protruding from the upper surface of the second passage forming member  28  to communicate with the concave section  30  of the first passage forming member  27  is formed in the first passage forming member  27  and the second passage forming member  28  so as to form a part of the ink passage  15  of the ink supply device  14 . Likewise, a second passage  15   b  permitting the concave section  33  of the second passage forming member  28  to communicate with the concave section  31  of the first passage forming member  27  is formed in the first passage forming member  27 , the second passage forming member  28 , and the flexible member  29  so as to form a part of the ink passage  15  of the ink supply device  14 . Likewise, a third passage  15   c  permitting the concave sections  31  and  32  of the first passage forming member  27  to communicate with each other is formed in the first passage forming member  27  so as to form a part of the ink passage  15  of the ink supply device  14 . 
     Likewise, a fourth passage  15   d  permitting the concave section  32  of the first passage forming member  27  to communicate with the upper surface of the second passage forming member  28  is formed in the first passage forming member  27 , the second passage forming member  28 , and the flexible member  29  so as to form a part of the ink passage  15  of the ink supply device  14 . An ink display port  64  which is a passage opening end of the fourth passage  15   d  opened to the upper surface of the flexible member  29  is connected to one end (upstream end) of the ink supply tube  15   e , which forms a part of the ink passage  15 , through a pipe connection tool  59  attached to the end of the ink supply device  14 . In addition, the other end (downstream end) of the ink supply tube  15   e  is connected to the valve unit  17  on the side of the printing head unit  12 . In this embodiment, the first passage  15   a  to the fourth passage  15   d  form a liquid supply passage. 
     As shown in  FIG. 1 , the passages  15   a ,  15   b ,  15   c , and  15   d  are in a passage passing through the rear surface of the first passage forming member  27 . Therefore, through-holes  90   a  and  30   b  forming the first passage  15   a  and a groove permitting the through-holes  90   a  and  30   b  to communicate with each other, through-holes  90   b  and  31   a  forming the second passage  15   b  and a groove permitting the through-holes  90   b  and  31   a  to communicate with each other, through-holes  31   b  and  32   b  forming the third passage  15   c  and a groove permitting the through-holes  31   b  and  32   b  to each other, and through-holes  32   c  and  91   a  forming the fourth passage  15   d  and a groove permitting the through-holes  32   c  and  91   a  to communicate with each other are formed in the first passage forming member  27 . In addition, parts of the passages  15   a ,  15   b ,  15   c , and  15   d  are surrounded by a film  120  welded on the rear surface of the passage forming member  27  and the respective grooves, respectively. 
     As shown in  FIG. 1 , a portion which serves as the sucking valve body  36  of the flexible member  29  of the ink supply device  14  is provided with a through-hole  36   a  in the middle thereof and urged toward the inner bottom surface of the lower-side concave section  30  by an urging force of a coil spring  40  (an urging member) disposed in the upper-side concave section  33 . In this embodiment, the concave sections  30  and  33 , the sucking valve body  36 , and the coil spring  40  constitute a sucking valve  41  (a sucking check valve) as a first unidirectional valve provided in the ink passage  15  so as to open and close the ink passage  15 . The sucking valve  41  includes a valve chamber  41   a  communicating with an opening (an ink sucking port) on the downstream end of the first passage  15   a  and a valve chamber  41   b  communicating with an opening (an ink discharging port) on the upstream end of the second passage  15   b . The valve chamber  41   a  is formed as a spatial area with a ring shape surrounded by the concave section  30  and the sucking valve body  36  in a valve closed state where the middle of the sucking valve body  36  comes in contact with a valve seat  30   a  in the middle of the bottom surface of the concave section  30 . With such a configuration, during the openness and closeness of the sucking valve  41 , the ink pressure of the valve chambers  41   a  and  41   b  is applied to the sucking valve body  36  with an area sufficiently broader than the opening area of the passages  15   a  and  15   b , and the sucking valve  41  can be opened and closed with good sensitivity even by a relatively small differential pressure between the valve chambers  41   a  and  41   b . That is, the sucking valve  41  can be opened and closed with good sensitivity, compared to a case of using the sucking valve  41  having a structure in which the coil spring  40  urges the sucking valve body  36  in a valve closing direction. 
     Likewise, a portion which becomes a diaphragm  37  of the flexible member  29  of the ink supply device  14  is urged toward the inner bottom surface of the lower-side concave section  31  by the urging force of a coil spring  42  (an urging member) disposed in the upper-side concave section  34 . In this embodiment, the concave sections  31  and  34 , the diaphragm  37 , and the coil spring  42  constitute a pulsation type pump  43 . A volume variable spatial area surrounded by the diaphragm  37  and the lower-side concave section  31  functions as a pump chamber  43   a  in the pump  43 . 
     Likewise, a portion which becomes the ejecting valve body  38  of the flexible member  29  of the ink supply device  14  is urged toward the inner bottom surface of the lower-side concave section  32  by the urging force of a coil spring  44  (an urging member) disposed in the upper-side concave section  35 . In this embodiment, the concave sections  32  and  35 , the ejecting valve body  38 , and the coil spring  44  constitute an ejecting valve  45  (an ejecting check valve) as a second unidirectional valve provided in the ink passage  15  on the more downstream side than the pump  43  so as to open and close the ink passage  15 . The ejecting valve  45  includes a valve chamber  45   a  (an ink chamber) communicating with an opening (an ink inflow port) on the downstream end of the third passage  15   c  and a valve chamber  45   b  (an air chamber) opened to the air through an air communication hole  35   a . The valve chamber  45   a  is formed as a spatial area with a ring shape surrounded by the concave section  32  and the ejecting valve body  38  in a valve closed state where the middle of the ejecting valve body  38  comes in contact with a valve seat  32   a  in the middle of the bottom surface of the concave section  32 . With such a configuration, during the openness and closeness of the ejecting valve  45 , the ink pressure of the valve chamber  45   a  is applied to the ejecting valve body  38  with an area sufficiently broader than the opening area of the third passage  15   c , and the ejecting valve  45  can be opened and closed with good sensitivity even by a relatively small variation in pressure between the valve chamber  45   a . That is, the ejecting valve  45  can be opened and closed with good sensitivity in comparison to using the ejecting valve  45  having a structure in which the coil spring  44  urges the ejecting valve body  38  in the valve closing direction. In this embodiment, the second passage  15   b  forms a part of the liquid supply passage permitting the first unidirectional valve to communicate with a supply pump, and the third passage  15   c  forms a part of the liquid supply passage permitting the supply pump to communicate with the second unidirectional valve. 
     As shown in  FIG. 1 , a negative pressure generating device  47  constituted by the sucking pump or the like and an air opening mechanism  48  are connected to the concave section  34  of the second passage forming member  28  via an air passage  46  having a shape diverged in both directions. The negative pressure generating device  47  is driven by a driving force, which is transferred via a one-way clutch (not shown) when a driving motor  49  capable of forward and backward rotation is driven to rotate forward, to generate negative pressure. Likewise, the negative pressure generating device can also generate negative pressure in the concave section  34  of the second passage forming member  28  connected via the air passage  46 . Accordingly, the volume variable spatial area surrounded by the concave section  34  of the second passage forming member  28  and the diaphragm  37  is configured to function as a negative pressure chamber  43   b  which becomes a negative pressure state with the drive of the negative pressure generating device  47 . 
     On the other hand, the air opening mechanism  48  has a configuration in which an air opening valve  53  formed by adding a sealing member  52  to the side of an air opening hole  50  in a box  51  provided with the air opening hole  50  is accommodated and the air opening valve  53  typically urges the air opening hole  50  by the urging force of the coil spring  54  in the valve closing direction in which the air opening hole  50  is sealed. In addition, the air opening mechanism  48  is configured such that a cam mechanism  55  operating on the basis of the driving force transferred via the one-way clutch (not shown) operates when the driving motor  49  is driven to rotate backward and the air opening valve  53  is displaced against the urging force of the coil spring  54  in a valve opening direction by the operation of the cam mechanism  55 . That is, the air opening mechanism  48  opens the inside of the negative pressure chamber  43   b  to the air to release a negative pressure state by allowing the air opening valve  53  to perform a valve opening operation when the negative pressure chamber  43   b  connected via the air passage  46  becomes the negative pressure state. 
     One negative pressure generating device  47 , one air opening mechanism  48 , and one driving motor  49  driving the negative pressure generating device and the air opening mechanism are provided and shared by the plural ink supply devices  14 . That is, an air passage pipe  46   a  forming the air passage  46  which connects between the negative pressure generating device  47 , the air opening mechanism  48 , and each ink supply device  14  is connected to an air passage  46   b  formed in each ink supply device  14 . The air passage  46   b  is diverged in the midway thereof and the front end of the diverged passage is connected to the negative pressure chamber  43   b  of the pump  43  of each ink supply device  14 . With such a configuration, since the ink supply devices  14  can be driven just by providing one negative pressure generating device  47 , one air opening mechanism  48 , and one driving motor  49  in the plural ink supply devices  14 , it is possible to reduce the size of the printer  11 . The air passage  46   b  connected to the pressure chamber  43   b  of each pump  43  is opened to the upper surface of the flexible member  29  via the rear surface of the first passage forming member  27  and forms a negative pressure lead-out port  65 . The negative pressure lead-out port  65  is connected to one end (the upstream end) of an air supply tube  46   c  through the pipe connection tool  59 . In addition, the other end (the downstream end) of the air supply tube  46   c  is connected to the printing head unit  12  and negative pressure can be introduced to the defoaming unit  58 . 
     Here, the configurations and functions of the valve unit  17  and the defoaming unit  58  provided within the printing head unit  12  will be described. As shown in  FIG. 1 , an air chamber  12   c  communicating to the air via the air communication hole  12   b  is provided within the printing head unit  12 . The valve unit  17  includes the pressure chamber  17   a  which temporarily stores the ink flowing to the ink passage  12   d  formed in the printing head unit  12 , a partition wall  17   b  partitioning the pressure chamber  17   a  and the air chamber  12   c , and a passage valve  17   d  which is urged in the valve closing direction by a spring  17   c  to come in contact with the partition wall  17   b . The partition wall  17   b  is formed of a film (or a sheet) made of a flexible material (for example, synthetic resin or rubber), and a metal piece (for example, a metal piece having a pectinate shape, for example) (not shown) having a portion displaceable together with, for example, a film is disposed at the contact position of the passage valve  17   d . In addition, an ink storing chamber  12   e  which temporarily stores ink is formed in the ink passage  12   d  formed from the pressure chamber  17   a  to the nozzles  16 . 
     When the ink from the nozzles  16  is ejected and consumed, the actual pressure of the pressure chamber  17   a  is depressurized by a decrease in the ink and the partition wall  17   b  is bent and deformed toward the pressure chamber  17   a  on the basis of a differential pressure between the depressurized pressure chamber  17   a  and the air chamber  12   c , so that the passage valve  17   d  is moved to a valve opened position against the urging force of the spring  17   c  and the ink flows to the pressure chamber  17   a . When the ink flows into the pressure chamber  17   a  and the actual pressure of the pressure chamber is increased, the passage valve  17   d  is again moved to a valve closed position since the actual pressure exceeds the urging force of the spring  17   c . When the passage valve  17   d  of the valve unit  17  opens and closes the passage in accordance with the consumption of the ink, the ink is configured to appropriately flow from the ink supply tube  15   e  to the printing head unit  12 . 
     The defoaming unit  58  includes a depressurizing chamber  58   a  communicating with the air supply tube  46   c  via the negative pressure passage  12   f  formed in the printing head unit  12 , a partition wall  58   b  partitioning the depressurizing chamber  58   a  and the air chamber  12   c , a passage valve  58   d  urged by the spring  58   c  to come in contact with the partition wall  58   b , and a negative pressure chamber  58   e  communicating with the depressurizing chamber  58   a  upon valve openness of the passage valve  58   d . The two partition walls  17   b  and  58   b  are formed of a common film (or a sheet) and a metal piece (not shown) having a piece displaceable together with the contact position of the passage valve  58   d  is disposed in the partition wall  58   b.    
     The negative pressure chamber  58   e  and the ink storing chamber  12   e  are partitioned through a partition wall  58   f  formed of a synthetic resin material having a gas permeable property. When a negative pressure is introduced to the depressurizing chamber  58   a  via the air supply tube  46   c  and the negative pressure passage  12   f  upon the sucking drive of the pump  43 , the partition wall  58   b  is bent and deformed toward the depressurizing chamber  58   a  on the basis of the differential pressure between the depressurizing chamber  58   a  and the air chamber  12   c  and the negative pressure of the depressurizing chamber  58   a  is introduced to the negative pressure chamber  58   e  by moving the passage valve  58   d  to the valve opened position against the urging force of the spring  58   c . On the other hand, the depressurizing chamber  58   a  is opened to the air through the air supply tube  46   c  and the negative pressure passage  12   f  upon the ejecting drive of the pump  43 . At this time, however, since the passage valve  58   d  is maintained at the valve closed position by the urging force of the spring  58   c , the negative pressure chamber  58   e  maintains the negative pressure state. That is, after the sucking drive of the pump  43  is performed at least one time after the activation of the printer  11 , the negative pressure chamber  58   e  maintains a negative pressure state to some extent or more, and bubbles or dissolved air in the ink stored in the ink storing chamber  12   e  permeate through the partition wall  58   f  to be collected to the side of the negative pressure chamber  58   e . In this way, the defoaming unit  58  defoams the ink. 
     Next, the operation of the printer  11  having the above-described configuration will be described particularly focusing the operation of the ink supply device  14 .  FIG. 2A  is a diagram illustrating the cross-section of the ink supply device upon the sucking drive and  FIG. 2B  is a diagram illustrating the cross-section of the ink supply device upon the ejecting drive. 
     First, it is assumed that the state shown in  FIG. 1  shows the state immediately after an old ink cartridge is replaced by a new ink cartridge, and the sucking valve body  36  of the sucking valve  41 , the diaphragm  37  of the pump  43 , and the ejecting valve body  38  of the ejecting valve  45  are pressed down and attached onto the inner bottom surface of the lower-side concave sections  30 ,  31 , and  32  by the urging forces of the coil springs  40 ,  42 , and  44 , respectively. In addition, it is assumed that the air opening mechanism  48  is in the valve closed state where the air opening valve  53  seals the air opening hole  50 . 
     When the ink supply device  14  supplies the ink from the ink cartridge  13  to the printing head unit  12  in the state shown in  FIG. 1 , the driving motor  49  is first driven to rotate forward to drive the pump  43 . Then, the negative pressure generating device  47  generates the negative pressure and the negative pressure chamber  43   b  of the ink supply device  14  connected to the negative pressure generating device  47  via the air passage  46  becomes the negative pressure state. Accordingly, the diaphragm  37  of the pump  43  is elastically deformed (displaced) toward the negative pressure chamber  43   b  against the urging force of the coil spring  42  to decrease the volume of the negative pressure chamber  43   b  (see  FIG. 2A ). Then, the volume of the pump chamber  43   a  partitioned with the negative pressure chamber  43   b  through the diaphragm  37  is conversely increased with the decrease in the volume of the negative pressure chamber  43   b.    
     That is, the pump  43  displaces the diaphragm  37  in a direction increasing the volume of the pump chamber  43   a  to perform the sucking drive. Specifically, the diaphragm  37  is displaced from a bottom dead point shown in  FIG. 1  to a top dead point shown in  FIG. 2A . Accordingly, the pump chamber  43   a  becomes a negative pressure state, the negative pressure is applied to the upper-side valve chamber  41   b  of the sucking valve  41  through the second passage  15   b , and the sucking valve body  36  is elastically deformed (displace) toward the upper side (that is, in the valve opening direction) against the urging force of the coil spring  40  on the basis of the pressure difference with the ink pressure of the lower-side valve chamber  41   a . As a consequence, the first passage  15   a  and the second passage  15   b  becomes a communication state one another through the through-hole  36   a  of the sucking valve body  36 , and the ink is sucked from the ink cartridge  13  to the pump chamber  43   a  via the first passage  15   a , the valve chamber  41   a , the through-hole  36   a , the valve chamber  41   b , and the second passage  15   b.    
     On the other hand, upon the sucking drive of the pump  43 , the negative pressure of the pump chamber  43   a  is also applied to the more downstream side of the ink passage  15  than the pump chamber  43   a , that is, the third passage  15   c  through the third passage  15   c . However, the lower-side valve chamber  45   a  of the ejecting valve  45  communicating with the downstream side of the third passage  15   c  is configured so as not to become the valve opened state, as long as the ejecting valve body  38  is urged in the valve closing direction by the coil spring  44  and an ink ejection pressure of a predetermined positive pressure (for example, a pressure of 13 kPa or more) is not applied from the upstream side of the third passage  15   c  to the ejecting valve body  38  by the ejecting drive of the pump  43  in the valve closed state. Accordingly, in this case, the ejecting valve body  38  of the ejecting valve  45  maintains the valve closed state, since the negative pressure is applied. 
     Next, the driving motor  49  is driven to rotate backward in the state shown in  FIG. 2A . Then, the air opening valve  53  performs the valve opening operation against the urging force of the coil spring  54  by the operation of the cam mechanism  55  of the air opening mechanism  48  and opens the negative pressure chamber  43   b , which has been in the negative pressure state, to the air. Accordingly, the diaphragm  37  of the pump  43  is elastically deformed (displaced) toward the lower side (that is, the inner bottom surface of the pump chamber  43   a ) and the volume of the negative pressure chamber  43   b  is increased by the urging force of the coil spring  42  (see  FIG. 2B ). On the contrary, the volume of the pump chamber  43   a  of the pump  43  partitioned with the negative pressure chamber  43   b  through the diaphragm  37  decreases with the increase in the volume of the negative pressure chamber  43   b.    
     That is, the pump  43  displaces the diaphragm  37  in a direction decreasing the volume of the pump chamber  43   a  to perform the ejecting drive. Specifically, as shown in FIG.  2 B, the diaphragm  37  is displaced from the top dead point to the bottom dead point, and the ink which has been sucked in the pump chamber  43   a  is pressurized at a predetermined pressure (for example, about a pressure of 30 kPa). Accordingly, the ink in the pump chamber  43   a  is ejected, the ejection pressure is applied to the upper-side valve chamber  41   b  of the sucking valve  41  via the second passage  15   b  on the more upstream side than the pump chamber  43   a , and the ejection pressure elastically deforms (displaces) the sucking valve body  36  toward the lower side (that is, the valve closing direction) in cooperation with the urging force of the coil spring  40 . As a consequence, the first passage  15   a  and the second passage  15   b  become a non-communication state by a valve closing operation of the sucking valve body  36 , the suction of the ink from the ink cartridge  13  to the pump chamber  43   a  via the sucking valve  41  stops, and the ink ejected from the pump chamber  43   a  with the ejecting drive of the pump  43  is regulated so as not to flow backward to the ink cartridge  13  via the sucking valve  41 . 
     On the other hand, upon the ejecting drive of the pump  43 , the pressure (for example, about a pressure of 30 kPa) of the ink ejected from the pump chamber  43   a  is also applied to the downstream side of the ink passage  15  via the third passage  15   c . Accordingly, the ejecting pressure of the pump  43  permits the ejecting valve body  38  in the valve closed state to perform the valve opening operation, so that the third passage  15   c  and the fourth passage  15   d  communicate with each other through the lower-side valve chamber  45   a  in the ejecting valve  45 . As a consequence, the pressurized ink from the pump chamber  43   a  is supplied to the valve unit  17  via the third passage  15   c , the valve chamber  45   a , the fourth passage  15   d , and the ink supply tube  15   e . In addition, the urging force of the coil spring  44  in the ejecting valve  45  is set to about 13 kPa, for example, so that the ejecting valve body  38  is elastically deformed toward the upper side by the ejection pressure of the ink, when the ink flows to the valve chamber  45   a  of the ejecting valve  45  upon the ejecting drive of the pump  43 . 
     Thereafter, the ejection pressure of the ink pressurized by the diaphragm  37  and ejected from the pump chamber  43   a  remains in balance in the respective passage areas (which include the pump chamber  43   a  and the valve chamber  45   a  of the ejecting valve  45 ) on the downstream side including the valve chamber  41   b  of the sucking valve  41  in the ink passage  15 . Thereafter, when the ink is ejected from the printing head  57  to a target (not shown), an amount of the ink corresponding to the amount of ink consumed upon the ejection of the ink is supplied from the ink passage  15  to the printing head unit  12  upon the valve openness of the valve unit  17 . Accordingly, as the ink is consumed in the downstream side (the printing head unit  12 ), the amount of ink corresponding to the amount of ink consumed is supplied in the pressurized state to the printing head unit  12  (on the downstream side) on the basis of the pressurizing force of the diaphragm  37  urged in a direction decreasing the volume of the pump chamber  43   a  by the urging force of the coil spring  42 . 
     As a consequence, the volume of the pump chamber  43   a  and the volume of the valve chamber  45   a  of the ejecting valve  45  gradually decrease. Finally, the diaphragm  37  is displaced up to the vicinity of the bottom dead point and the ejecting valve body  38  is displaced up to the vicinity of the valve closed position at which the fourth passage  15   d  is closed. In this embodiment, the diaphragm  37  is pressurized at this time point and the ejection pressure of the ink ejected from the pump chamber  43   a  becomes about 13 kPa. 
     Then, the driving motor  49  is again driven to rotate forward, the air opening valve  53  is displaced in the air opening mechanism  48  to the valve closed position at which the air opening hole  50  is closed. In addition, the negative pressure generating device  47  generates the negative pressure, so that the negative pressure chamber  43   b  becomes the negative pressure state and the diaphragm  37  is elastically deformed (displaced) toward the negative pressure chamber  43   b  against the urging force of the coil spring  42 . That is, the pump  43  again starts the sucking drive. As a consequence, since the diaphragm  37  is displaced to the top dead point to increase the volume of the pump chamber  43   a  and the pump chamber  43   a  becomes the negative pressure state, the sucking valve body  36  is elastically deformed (displaced) in the valve opening direction. Accordingly, the first passage  15   a  and the second passage  15   b  becomes the communication state through the through-hole  36   a  of the sucking valve body  36 , and the ink is sucked from the ink cartridge  13  to the pump chamber  43   a . Thereafter, the ejecting drive of the pump  43  is performed and the pressurized ink is supplied from the pump chamber  43   a  to the printing head unit  12  via the ink passage area on the downstream side. 
     Next, an example of an ink supply system in which the plural ink supply devices  14  having the above-described configuration are made into one unit will be described with reference to  FIGS. 3 to 20 . 
       FIG. 3  is a perspective view illustrating the ink supply system mounted with plural ink cartridges.  FIG. 4  is a perspective view illustrating the ink supply system when the ink cartridges are not mounted. Hereinafter, in the following description, a direction parallel to an arrangement direction of the ink supply needles  25  is denoted by an X direction, a direction perpendicular to the arrangement direction of the ink supply needles is denoted by a Y direction, and an upper direction which is perpendicular to the XY plane and a protruding direction of the ink supply needles  25  is denoted by a Z direction. 
     An ink supply system  61  which is a liquid supply device shown in  FIG. 3  is disposed at a predetermined position within the printer  11  and functions as a cartridge holder on which the ink cartridges  13  are mounted. The ink supply system  61  has a lamination structure with a substantially rectangular plate. The ink supply needles  25  (see  FIG. 4 ) arranged in plural rows (in this embodiment, six rows) are disposed in one row in the x direction on the upper surface of the ink supply system so as to protrude perpendicularly (in the Z direction) from the upper surface thereof. The plural (in this embodiment, six) ink cartridges  13  are mounted on the upper side of the ink supply system  61  so as to be nearly adjacent to each other in one row in the X direction by inserting the ink supply needles  25  into the ink supply ports  24  (see  FIG. 1 ) of the pipe unit  23 , respectively. 
     The ink supply system  61  according to this embodiment has a structure in which the six ink supply devices  14  capable of individually supplying six colors such as cyan, magenta, yellow, light cyan, light yellow, and black respectively stored in the six ink cartridges  13  are made into one unit. That is, the ink supply system  61  is capable of using the lamination structure in which plural constituent members having a plate shape are laminated by disposing six pumps  43  (supply pumps), six sucking valves  41  (first unidirectional valves), and six ejecting valves  45  (second unidirectional valves) respectively forming the six ink supply devices  14  on the same plane. In addition, the ink supply system  61  made into one component (one unit) is realized by configuring at least one of the plural constituent members to a single (common) passage forming member and laminating the other constituent members (where the single passage forming member is not necessarily required and the constituent members may be formed in each of the ink supply device). In this embodiment, however, as described below, all the plural constituent members laminated to form the ink supply system  61  are formed as the single forming members that are common to the six ink supply devices  14 . The number of the ink supply devices  14  made into one unit as the ink supply system  61  is not limited to six. For example, plural ink supply devices such as two to ten ink supply devices or ten or more ink supply devices may be used. It is not necessary to match with the number of colors (the number of ink cartridges) of the printer  11 . For example, two ink supply systems each formed by making three ink supply devices  14  into one unit may be mounted in the printer  11 . That is, the plural ink supply systems may be mounted in one printer  11 . 
     As shown in  FIGS. 3 and 4 , the ink supply system  61  includes a main body  62  which has a rectangular plate shape and includes plural (for example, six) pump  43 , sucking valves  41 , and ejecting valves  45  corresponding to the number of colors and a pipe connection section  63  which has a plate shape horizontally extending from one end of the main body  62 . 
     As shown in  FIG. 4 , the main body  62  has the six ink supply needles  25  which protrude from the upper surface of the main body vertically (in the Z direction) so as to be arranged in one row in the X direction therein, the six pumps  43  which are arranged in two rows in the X direction so that each three pumps are arranged in one row, the six sucking valves  41  which are arranged in one row in the X direction, and the six ejecting valves  45  which are arranged in one row in the X direction. 
     As shown in  FIGS. 3 and 4 , six ink discharging ports  64  and one negative pressure lead-out port  65  are opened on the upper surface of the pipe connection section  63 . The six ink discharging ports  64  each serve as a discharging port which pressurizes and supplies the ink sucked from each ink cartridge  13  by each pump  43  to the outside with a predetermined ejection pressure. The one negative pressure lead-out port  65  serves as a lead-out port which leads out the negative pressure introduced into the ink supply system  61  from the negative pressure generating device  47  (see  FIG. 1 ) to permit the pulsation type pump  43  to perform the sucking drive for another usage (in this embodiment, the defoaming unit  58 ). 
     The pipe connection tool  59  (see  FIG. 1 ), which is fixed to one end of a flexible pipe plate in which the six ink supply tubes  15   e  and the one air supply tube  46   c  (see  FIG. 1 ) connected to the printing head unit  12  are bundled onto a flexible plate, is connected to the pipe connection section  63 . The ink discharged from each of the ink discharging ports  64  is pressurized and supplied to each of the valve units  17  formed in the printing head unit  12  via each of the ink supply tubes  15   e . On the other hand, the negative pressure led out from the negative pressure lead-out port  65  upon the sucking drive of the pump  43  is supplied to the defoaming unit  58  formed in the printing head unit  12  via the air supply tube  46   c  (see  FIG. 1 ). In the ink supply system  61  according to this embodiment, a connection tube  106  (see  FIG. 16 ) connected to the air passage pipe  46   a  (see  FIG. 1 ) protrudes from the rear surface. In addition, the air passage  46   b  formed within the ink supply system  61  passes through the inside of a path formed from the connection tube  106  to the negative pressure lead-out port  65  via the negative pressure chamber  43   b  of each pump  43 . 
     The ink supply system  61  has the lamination structure in which the six members  70 ,  80 ,  90 ,  120 ,  130 , and  140  are laminated. The upper five members  70 ,  80 ,  90 ,  120 , and  130  forming the ink supply system  61  are fixed at plural positions in a pressurized state in the lamination direction by fastening screws  66  of plural rows (in this embodiment, nineteen screws) by a predetermined fastening force in the lamination direction from the upper side. On the lower side of the lamination structure in which the five members  70 ,  80 ,  90 ,  120 , and  130  are fixed by screws  66  of the plural rows, the receiving plate  140  is fixed to the lowermost layer of the lamination structure by fastening two screws  67  in the lamination direction from the lower side. 
     Hereinafter, the detailed configuration of the ink supply system  61  will be described.  FIG. 5  is an exploded perspective view illustrating the ink supply system  61 . In  FIG. 5 , some of the screws are shown. As shown in  FIG. 5 , the ink supply system  61  includes the cover  70  which has a rectangular plate shape and corresponds to the second passage forming member  28 , the diaphragm forming member  80  which corresponds to the flexible member  29 , the passage forming plate  90  which corresponds to the first passage forming member  27 , the film  120 , the protective plate  130 , and the receiving plate  140  in this order from the upper side. The film  120  is welded in advance on the rear surface of the passage forming plate  90  before the assembly. Upon the assembly, the coil springs  40 ,  42 , and  44  respectively corresponding to the upper sides of the sucking valve body  36 , the diaphragm  37 , and the ejecting valve body  38  incorporated into the diaphragm forming member  80  are set. Then, the upper five members  70 ,  80 ,  90 ,  120 , and  130  having the rectangular plate shape are fastened with a predetermined tightening force in a vertical direction (the lamination direction) of  FIG. 5  by use of the screws  66  of the plural rows (in this embodiment, nineteen screws). By the fastening, it is possible to assemble the lamination structure in which the cover  70 , the diaphragm forming member  80 , the passage forming plate  90 , the film  120 , and the protective plate  130  are fixed in the laminated state with the coil springs  40 ,  42 , and  44  accommodated between the cover  70  and the diaphragm forming member  80  in a compressed state. The ink supply system  61  shown in  FIG. 4  is formed by disposing the receiving plate  140  on the bottom surface of the lamination structure in which the members  70 ,  80 ,  90 ,  120 , and  130  are fixed and fastening the two screws  67  from the lower side to fix the receiving plate  140  on the lowermost layer. 
     Here, the cover  70 , the passage forming plate  90 , and the receiving plate  140  are made of a plastic material and formed in a predetermined rectangular plate shape by metal molding (ejection molding, etc.), for example, using a synthetic resin material. The diaphragm forming member  80  is made of elastomer or rubber and formed in a predetermined rectangular plate shape by metal molding (ejection molding, etc.), for example. The film  120  is formed of a laminated film which has a surface made of a synthetic resin material which can be welded with the synthetic resin material of the passage forming plate  90  and is cut in a predetermined substantially rectangular shape. The protective plate  130  is made of a metal material and is punched in a predetermined rectangular plate shape to form plural holes  130   a ,  130   b , and  132 . 
     The cover  70 , the diaphragm forming member  80 , and the passage forming plate  90  are constituent members which are laminated in the state where the coil springs  40 ,  42 , and  44  are accommodated and in which the six pumps  43 , the six sucking valves  41 , and the six ejecting valves  45  are disposed on the same plane. The cover  70  is also used as a board provided with the ink supply needles  25 . 
     Plural grooves  101  to  105  (see  FIGS. 15 and 16 ) for forming the first passage  15   a , the second passage  15   b , the third passage  15   c , the fourth passage  15   d , and the air passage  46   b  (see  FIG. 1  and  FIGS. 2A and 2B ) are formed on the rear surface of the passage forming plate  90 . By welding the film  120  on the rear surface of the passage forming plate  90 , the passages  15   a ,  15   b ,  15   c , and  15   d  and the air passage  46   b  connecting between the ink supply needles  25 , the sucking valves  41 , the pumps  43 , and the ejecting valves  45  are formed on the rear surface of the passage forming plate  90 . 
     The reason to use the sucking valves  41 , the ejecting valves  45 , and the coil springs  40  and  44  is to ensure the closed state of the check valves (the unidirectional valve). For example, when the ejecting valve  45  is not fully closed and thus the ink leaks, the amount of ink flowing in the ink passage of each color becomes irregular. Moreover, when the sucking valve  41  is not fully closed and thus the ink leaks, the ink flowing backward comes out unnecessarily from the ink supply needle  25  in a case where the ink cartridge  13  is detached, for example. In this way, when the ink is unnecessarily consumed, a difference in the amounts of ink of respective colors consumed occurs. For this reason, the check valves of the sucking valve body  36  and the ejecting valve body  38  require a configuration for preventing the ink from leaking. In this embodiment, the urging coil springs  40  and  44  are provided in addition to the diaphragm type valve bodies  36  and  38 . Of course, when this configuration is used, it is necessary to broaden the diaphragm areas of the valve bodies  36  and  38  so as to open the valves against the urging force of the coil springs  40  and  44 , and the valves  41  and  45  are required to have the broad disposition area. 
     In this embodiment, the check valve structure requiring this broad disposition area is used to ensure reliability, but other structures may be realized to save a space. One exemplary configuration is realized such that almost all of the pumps  43  and the valves  41  and  45  are disposed within a projection range of the ink cartridges  13  before the ink cartridges are mounted on the ink supply system  61  and the ink supply system  61  is formed in the substantially same plane size as that of the projected area. 
     In the ink supply system  61  according to this embodiment, the pumps  43  and the valves  41  and  45  are disposed very precisely within a predetermined rectangular area by arranging the six pumps  43  having a relatively large diameter in two rows so as to be nearly adjacent to each other and arranging the six sucking valves  41  and the six ejecting valves  45  having a relatively small diameter, which is the substantially half of the diameter of the pump  43 , in one row so as to be nearly adjacent to each other in the adjacent area of the pumps. In addition, each of the ink supply needles  25  is disposed in the gap between the rows of the pumps  43 . With such a layout, the ink supply system  61  can be configured so as to have a small thickness and a small plane size. However, when the precise layout is used, the ink supply needle  25  and the sucking valve  41 , the sucking valve  41  and the pump  43 , and the pump  43  and the ejecting valve  45  are relatively distant from each other, respectively. Moreover, the passage lengths of the first passage  15   a , the second passage  15   b , the third passage  15   c , the fourth passage  15   d , and the air passage  46   b  may be relatively long. Accordingly, by disposing the first passage  15   a , the second passage  15   b , the third passage  15   c , the fourth passage  15   d , and the air passage  46   b  on the rear surface of the passage forming plate  90 , the effective layout of the lengthened passages  15   a ,  15   b ,  15   c ,  15   d , and  46   b  can be achieved without sacrificing the precise layout (that is, the reduction in the plane size) of the pumps  43  and the valves  41  and  45 . 
     Next, the configuration of each member of the ink supply system  61  will be described. 
       FIG. 6  is a plan view illustrating the front surface of the cover.  FIG. 7  is a perspective view illustrating the rear surface of the cover.  FIG. 8  is a bottom view illustrating the rear surface of the cover. 
     As shown in  FIGS. 4 and 6 , the cover  70  includes a board  71  which has a rectangular plate shape and in which the ink supply needles  25  of the plural rows protrude from the upper surface (the front surface). In a substantially ⅔ area of the upper surface of the board  71  in the vicinity of the location where the ink supply needles  25  are arranged in row, six pump housing sections  72  swelled in a substantially conic frustum shape toward the upper side (in the Z direction) are arranged in two rows at a uniform interval in the X direction so that three pump housing sections are arranged in one row. 
     The six ink supply needles  25  are arranged in gap areas, which correspond to row spaces between the pump housing pumps  72  arranged in two rows, at a uniform pitch (a pitch slightly broader than the width of the ink cartridge  13  in the X direction) in the X direction. At this time, the six ink supply needles  25  are located on both sides interposing the line segments connecting the central points of the three pairs of pump housing sections  72  each paired in the Y direction in a plan view of  FIG. 6 . 
     Through-holes  68  perforated through the cover  70  in a vertical direction are formed in the peripheral of each of the ink supply needles  25 . In addition, when the ink leaks to the peripherals of the ink supply needles  25  upon mounting or detaching the ink cartridges  13  on the ink supply needles  25  of the ink supply system  61 , the leaking ink is discharged from the front surface of the cover  70  to the rear surface via the through-holes  68 . In this embodiment, two through-holes  68  are formed for each one of the ink supply needles  25 . 
     In the substantially remaining ⅓ area of the upper surface of the board  71 , six sucking valve housing sections  73  swelled in the substantially conic frustum shape having a diameter smaller than that of the pump housing section  72  and six ejecting valve housing sections  74  swelled in a substantially conic frustum shape having almost the same diameter as that of the sucking valve housing section are respectively arranged in one row so as to be nearly adjacent in the X direction. The six sucking valve housing sections  73  are arranged in the vicinity of the rows of the second pump housing sections  72  from the upper side in  FIG. 6  and the six ejecting valve housing sections  74  are arranged in the vicinity of the row of the sucking valve housing sections  73 . The six sucking valve housing sections  73  and the six ejecting valve housing sections  74  are located so as to be also nearly adjacent in the Y direction. 
     On the front surface of the cover  70 , an extension section  71   a  having a predetermined height is formed on nearly four sides so as to surround the circumference. Plural (nineteen) boss sections  75  having a screw insertion hole  75   a  protrude at positions where the screws  66  are fastened in the board  71 . In addition, plural (two) boss sections  76  having a screw insertion hole  76   a  protrude at positions where the screws  67  are fastened in the board  71 . The plural boss sections  75  are arranged at the positions on the inside of the extension section  71   a  at almost the same interval along the inner circumference and at the positions corresponding to the row spaces of the housing sections  72  to  74  at almost the same interval in the X direction. One pair of boss sections  76  are formed at the positions of the both sides interposing the second pump housing sections  72  in X direction. 
     As shown in  FIGS. 7 and 8 , on the rear surface of the cover  70 , the six concave sections  34  having a concave shape and forming the negative chamber  43   b  are formed at the positions corresponding to the pump housing sections  72 . In addition, on the rear surface of the cover  70 , six concave sections  33  having a concave shape are formed at the positions corresponding to the sucking valve housing sections  73  and six concave sections  35  having a concave shape are formed at the positions corresponding to the ejecting valve housing sections  74 . The concave sections  33 ,  34 , and  35  are formed in the substantially conic frustum shape on the inner circumferential surface having a concave shape. The concave sections  33  and  35  have a smaller diameter which is the substantial half of the diameter of that of the concave sections  34 . 
     Columnar convex portions  34   a  into which the upper end of the coil spring  42  (see  FIGS. 1 and 9 ) is inserted outwardly protrude from the bottoms of the concave sections  34 . The inner diameter of the bottom of the concaves  33  and  35  is slightly larger than the outer diameter of the coil springs  40  and  44 , and the upper end of the coil springs  40  and  44  coming in contact with the bottom of the concaves can be positioned at the substantial middle of the concave sections  33  and  35 . An air communication hole  35   a  having a small diameter is formed at the middle of the bottom surface of the concave  35 . Due to the presence of the air communication hole  35   a , the ejecting valve  45  functions as a choke valve for increasing the negative pressure of the downstream area by closing the valve when the ink is forcibly sucked from the nozzles  16  upon cleaning the printing head  57 . 
     On the rear surface of the cover  70 , six through-holes  25   a  individually communicating with the ink supply needles  25  are formed at the positions individually corresponding to the ink supply needles  25  at a uniform pitch in X direction. 
     A groove  77  permitting the two concave sections  34  adjacent to each other to communicate with each other in the Y direction is formed on the rear surface of the cover  70 . The groove  77  forms a part of the air passage  46   b  for introducing the negative pressure into the two concave sections  34  (that is, the negative pressure  43   b ) located at the positions on both the sides in the length direction. In addition, a groove  33   a  extending by a predetermined distance from each concave section  33  to the outside in a diameter direction is formed on the rear surface of the cover  70 . The groove  33   a  forms a part of the second passage  15   b  for supplying the ink in the sucking valve  41  to the pump chamber  43   a.    
     A sealing portion  78   a  which has a substantially 8-shape and extends in a strip shape having a nearly uniform width along the circumference of the two concave sections  34  adjacent to each other in the Y direction and the circumference of the groove  77  permitting both the concave sections  34  to communicate with each other is formed on the rear surface of the cover  70 . A sealing portion  78   b  which extends in a strip shape with a nearly uniform width along the circumference of the concave section  33  and the groove  33   a  is formed. Moreover, a sealing portion  78   c  which extends in a strip shape with a nearly uniform width along the circumference of the concave section  35  is formed. A sealing portion  78   d  having a ring shape surrounding a long elliptical area is formed in the most left concave section  34  located in the first row in  FIG. 8  so as to be conjunctive to the sealing portion  78   a . A sealing portion  78   e  having a ring shape with a uniform width is also formed in the circumference of each through-hole  25   a . The sealing portions  78   a  to  78   e  are formed in a convex shape with a height of the range from about several 10 μm to about several 100 μm from the bottom surface of the cover  70 . A pair of positioning pins  79  protrude from the rear surface of the cover  70  at both the sides interposing the concave sections  34  located in the first row in the X direction. These pins  79  are used to position the cover  70  to the passage forming plate  90 . 
     Next, the configuration of the diaphragm forming member  80  will be described. 
       FIG. 9  is a perspective view illustrating the diaphragm forming member when viewed from the upper side.  FIG. 10  is a plan view illustrating the diaphragm forming member.  FIG. 11  is a perspective view illustrating the diaphragm forming member when viewed from the rear surface.  FIG. 12  is a bottom view illustrating the diaphragm forming member. 
     The diaphragm forming member  80  shown in  FIGS. 9 to 12  is made of rubber having rubber elasticity or elastomer. The diaphragm forming member  80  includes a sheet main body  81  which has a substantially rectangular shape having almost the same size as that of the cover  70  and an extension section  82  which extends from one end (the left lower end in  FIG. 10 ) of the sheet main body  81  and forms a sealing portion of the pipe connection section  63 . The sheet main body  81  is provided with the six diaphragms  37  which each have a circular disk shape and are disposed at the positions corresponding to the concave sections  34  of the cover  70 , the six sucking valve bodies  36  which are disposed at the positions corresponding to the concave sections  33 , and the six ejecting valve bodies  38  which are disposed at the positions corresponding to the concave sections  35 . The diaphragm  37  has a large diameter to correspond to the concave section  34 . The sucking valve body  36  and the ejecting valve body  38  have a small diameter which is the about half of that of the diaphragm  37  to correspond to the concave sections  33  and  35 , respectively. 
     As shown in  FIGS. 9 and 10 , the diaphragm  37  has a flat columnar convex portion  37   a  at the middle of the upper surface. One end (the lower end) of the coil spring  42  is inserted outwardly into the convex portion  37   a  to position the coil spring. 
     As shown in  FIGS. 9 to 12 , in the gap areas which are the row spaces between the diaphragms  37  arranged in two rows in the diaphragm forming member  80 , six through-holes  81   a  are formed at the positions corresponding to the through-holes  25   a  of the ink supply needles  25  of the cover  70 . Three through-holes  81   b  are formed at the positions between the through-holes  81   a  in the X direction, that is, the positions corresponding to the lines connecting the central points of the three pairs of diaphragms  37  arranged in the Y direction, respectively. The three through-holes  81   b  forms a part of the air passage  46   b  for introducing the negative pressure into the negative pressure chamber  43   b  together with the grooves  77  of the cover  70 . 
     Six through-holes  81   c  are formed in the vicinities of the sucking valve bodies  36  in the diaphragm forming member  80 , respectively. The through-holes  81   c  form a part of the second passage  15   b  permitting the sucking valve  41  to communicate with the pump  43  and individually communicate with the front end of the grooves  33   a  (see  FIGS. 7 and 8 ) formed on the rear surface of the cover  70 . 
     As shown in  FIGS. 9 and 10 , a cylindrical portion  36   b  having the through-hole  36   a  (see  FIG. 1 ) protrudes at the middle of the sucking valve body  36 . The lower end of the coil spring  40  urging the sucking valve body  36  toward the lower side is inserted inwardly into the cylindrical portion  36   b  to position the coil spring. A cylindrical portion  38   a  having a bottom surface protrudes at the middle of the ejecting valve body  38 . The lower end of the coil spring  44  urging the ejecting valve body  38  toward the lower side is inserted inwardly into the cylindrical portion  38   a  to position the coil spring. 
     As shown in  FIGS. 9 and 10 , the upper surface (the front surface) of the diaphragm forming member  80  is provided with a sealing portion  83   a  which seals the circumference of the two diaphragms  37  arranged in the Y direction and the circumference of the through-hole  81   b , a sealing portion  84   a  which seals the circumferences of the sucking valve body  36  and the through-hole  81   c , and a sealing portion  85   a  which seals the circumference of the ejecting valve body  38 . As shown in  FIGS. 11 and 12 , the rear surface (the lower surface) of the diaphragm forming member  80  is provided a sealing portion  83   b  which seals the circumference of the two diaphragms  37  arranged in the Y direction and the circumference of the through-hole  81   b , a sealing portion  84   b  which seals the circumferences of the sucking valve body  36  and the through-hole  81   c , and a sealing portion  85   b  which seals the circumference of the ejecting valve body  38 . 
     As shown in  FIGS. 9 to 12 , on the upper surface and the lower surface of the diaphragm forming member  80 , sealing portions  86   a  and  86   b  having a ring shape are formed in the circumference of each through-hole  81   a , respectively. On the upper surface and the lower surface of the diaphragm forming member  80 , sealing portions  87   a  and  87   b  are formed at the positions corresponding to the sealing portion  78   d  of the cover  70 . In addition, the sealing portions  83   a  to  87   a  and the sealing portions  83   b  to  87   b  are formed in a convex shape with the height of about several 10 μm to about several 100 μm, for example, from the bottom surface, and formed so as to be thinner than the corresponding sealing portions of the cover  70  and located in correspondence with the nearly middle in the width direction of the corresponding sealing portions of the cover  70 . The sealing portions  83   a  to  87   a  on the front surface of the diaphragm forming member  80  and the sealing portions  83   b  to  87   b  on the rear surface thereof are formed so as to be plane-symmetry, respectively. 
     On the front and rear surfaces of the diaphragm forming member  80 , a sealing portion  88  having a convex shape extending vertically from the front and rear surfaces is formed in the nearly whole circumference along the circumference of the sheet main body  81 . A notch  88   a  is formed at one position in the circumferential direction of the sealing portion  88 . The circumference between the cover  70  and the diaphragm forming member  80  and the circumference between the diaphragm forming member  80  and the passage forming plate  90  are sealed by the sealing portion  88  so that a liquid does not leak in portions other than the notch  88   a . The ink leaking from the seal of the ink passages is accumulated at a gap between the cover  70  and the diaphragm forming member  80  or a gap between the diaphragm forming member  80  and the passage forming plate  90 , but the accumulated waste ink flows and drops from the notch  88   a  to the outside. 
     The extension section  82  of the diaphragm forming member  80  is provided with six through-holes  81   c  serving as the ink discharging ports  64  and one through-hole  82   b  serving as the negative pressure lead-out port  65 . The diaphragm forming member  80  is provided with plural screw insertion holes  89   a , into which the screws  66  and  67  are inserted and concave portions  89   b . Plural pin holes  89   c  are formed in the peripherals of the diaphragms  37  located in the first row. 
     Next, the configuration of the passage forming plate  90  will be described.  FIG. 13  is a perspective view illustrating the passage forming plate when viewed from the upper surface side.  FIG. 14  is a plan view illustrating the upper surface of the passage forming plate.  FIG. 15  is a bottom view illustrating the rear surface (the bottom surface) of the passage forming plate.  FIG. 16  is an exploded perspective view illustrating the passage forming plate and a film. In addition, in  FIG. 15 , reference numerals of passages corresponding to grooves are also given. 
     The passage forming plate  90  shown in  FIGS. 13 to 16  includes an extension section  91  at the position corresponding to the extension section  82  of the diaphragm forming member  80  and has the substantially same rectangular plate shape as that of the diaphragm forming member  80  in a plan view. The passage forming plate  90  according to this embodiment is made of a plastic material such as polypropylene (PP). The reason to use the polypropylene is because the polypropylene has a relatively high gas barrier performance (that is, a low gas permeable property) among plastic materials and is a material (a thermoplastic material) which easily welds the film  120 . 
     As shown in  FIGS. 13 and 14 , on the upper surface of the passage forming plate  90 , the six concave sections  31  are formed in the concave shape at the positions corresponding to the diaphragms  37 , the six concave sections  30  are formed in the concave shape at the positions corresponding to the sucking valve bodies  36 , and the six concave sections  32  are formed in the concave shape at the positions corresponding to the ejecting valve bodies  38 . In the passage forming plate  90 , the through-holes  90   a  are formed at the positions corresponding to the ink supply needles  25 . The six through-holes  90   a  are arranged in one row at a uniform pitch in the X direction in the gap areas which are the row spaces between the concave sections  31  arranged in two rows. Through-holes  90   a  form a part of the first passage  15   a  and the ink supplied from the ink supply needles  25  are sent to the rear surface of the passage forming plate  90  via the through-holes  90   a.    
     As shown in  FIGS. 13 and 14 , the through-hole  30   b  formed at the eccentric position located outside the valve seat  30   a  protruding at the middle of the concave section is formed in each of the concave sections  30 . The through-hole  30   b  forms a part of the first passage  15   a  (see  FIGS. 1 and 2 ) and serves as an inflow passage of the ink flowing from the rear surface of the passage forming plate  90  to the inside (the valve chamber  41   a ) of the sucking valve  41 . The through-hole  90   b  is formed in the vicinity of each concave section  30 . The through-hole  90   b  forms a part of the second passage  15   b  (see  FIGS. 1 and 2 ) and serves as an outflow passage of the ink from the valve chamber  41   b  of the sucking valve  41  to the rear surface of the passage forming plate  90 . 
     As shown in  FIGS. 13 and 14 , one pair of through-holes  31   a  and  31   b  are formed in the concave section  31  forming the pump chamber  43   a . The through-hole  31   a  forms a part of the second passage  15   b  (see  FIGS. 1 and 2 ) and serves as an outflow passage of the ink sucked into the pump chamber  43   a . On the other hand, the through-hole  31   b  forms a part of the third passage  15   c  (see  FIGS. 1 and 2 ) and serves as an inflow passage of the ink ejected from the pump chamber  43   a . In each concave section  32 , the through-hole  32   b  is formed at the position located in the outer circumference of the valve seat  32   a  located at the middle of the bottom surface of the concave section  32  and having a circular plate shape and the through-hole  32   c  is formed at the middle of the valve seat  32   a . The through-hole  32   b  forms a part of the third passage  15   c  (see  FIGS. 1 and 2 ) and serves as an inflow passage through which the ink ejected from the pump  43  flows into the ejecting valve  45 . On the other hand, the through-hole  32   c  forms a part of the fourth passage  15   d  (see  FIGS. 1 and 2 ) and serves as an outflow passage of the ink flowing from the ejecting valve  45 . 
     As shown in  FIGS. 13 and 14 , the six through-holes  91   a  (ink discharging holes) and one negative pressure lead-out hole  91   b  are formed in the extension section  91 . The six through-holes  91   a  form a part of the fourth passage  15   d  (see  FIGS. 1 and 2 ) and the one negative pressure lead-out hole  91   b  forms a part of the air passage  46   b  (see  FIGS. 1 and 2 ). 
     In the right upper end of the passage forming plate  90  shown in  FIG. 14 , a pair of through-holes  90   e  and  90   f  and a groove  90   g  permitting both the through-holes  90   e  and  90   f  to communicate with each other are formed in the vicinity of the right concave section  31  located in the first row. The through-holes  90   e  and  90   f  and the groove  90   g  form a part of the air passage  46   b  (see  FIG. 1 ) for introducing the negative pressure into the negative pressure chamber  43   b.    
     In the gap areas which are the row spaces between the concave sections  31  arranged in the two rows, three through-holes  92  are individually formed at the positions corresponding to the nearly central points of the line segments connecting the central points of the three concave sections  31  each paired in the Y direction. The through-holes  92  form a part of the air passage  46   b  and serves as a passage for introducing the negative pressure. The introduced negative pressure reaches the grooves  77  on the rear surface of the cover  70  via the through-holes  81   b  of the diaphragm forming member  80  to be introduced to the two negative pressure chambers  43   b  located on both the side in Y direction via the grooves  77 . 
     As shown in  FIGS. 13 and 14 , in the peripherals of the concave sections  30 ,  31 , and  32 , sealing portions  93   a ,  93   b ,  93   c ,  93   d , and  93   e  extending in a strip shape so as to be nearly plane-symmetric with the sealing portions  78   a ,  78   b ,  78   c ,  78   d , and  78   e  of the cover  70  protrude so as to have a width of about 0.5 mm to about 2 mm and a height of about several 10 μm to about several 100 μm, for example. The sealing portions  93   a ,  93   b ,  93   c ,  93   d , and  93   e  are located to correspond to the sealing portions  83   b ,  84   b ,  85   b ,  86   b , and  87   b  formed on the rear surface of the diaphragm forming member  80 . Upon the assembly of the ink supply system  61 , the sealing portions of the diaphragm forming member  80  having rubber elasticity are put and come in pressing contact between the sealing portions of the cover  70  and the sealing portions of the passage forming plate  90  to ensure the sealing property of the concave sections  30 ,  31 , and  32 . 
     Boss sections  94  and  95  having screw insertion holes  94   a  and  95   a  protrude at the positions where the screws  66  and  67  are fastened in the passage forming plate  90 , respectively. In the passage forming plate  90 , columnar pins  96  having an outer diameter slightly smaller than the inner diameter of the pin hole  89   c  protrude at the positions corresponding to the pin holes  89   c  of the diaphragm member  80 . In the passage forming plate  90 , positioning holes  97  having an inner diameter slightly larger than the outer diameter of the pin  79  are formed at the positions corresponding to the pins  79  of the cover  70 . 
     The plural (in this embodiment, nineteen) boss sections  94  are inserted into the screw insertion holes  89   a  of the diaphragm forming member  80  and the pins  96  are inserted into the pin holes  89   c , so that the diaphragm forming member  80  is positioned to the passage forming plate  90  in a state where the sucking valve bodies  36 , the diaphragms  37 , and the ejecting valve bodies  38  face the concave sections  30 ,  31 , and  32 , respectively. In addition, the pins  79  of the cover  70  are inserted into the positioning holes  97 , so that the cover  70  is positioned to the passage forming plate  90  and the diaphragm forming member  80  is positioned to the passage forming plate  90 . 
     Here, the protruding height of the boss sections  94  and  95  are set such that a gap between the passage forming plate  90  and the cover  70  is regulated to a predetermined value by bringing the upper end surface of the boss sections  94  and  95  into contact with the rear surface of the cover  70  upon fastening the screws  66 . That is, when the screws  66  are fastened, the sealing portions  83   a ,  83   b ,  84   a ,  84   b ,  85   a ,  85   b ,  86   a ,  86   b ,  87   a , and  87   b  of the diaphragm forming member  80  are put and come in pressing contact between the sealing portions  93   a ,  93   b ,  93   c ,  93   d , and  93   e  of the passage forming plate  90  and the sealing portions  78   a ,  78   b ,  78   c ,  78   d , and  78   e  of the cover  70  to ensure the sealing property. At this time, the boss sections  94  and  95  regulate distortion of the sealing portions so that the sealing portions  83   a ,  83   b ,  84   a ,  84   b ,  85   a ,  85   b , and the like of the diaphragm forming member  80  are deformed due to excessive pressing even when the screws  66  are fastened too strongly. That is, the protruding height of the boss sections  94  and  95  is set to a value which does not cause the excessive pressing and deformation of the sealing portions  83   a ,  83   b ,  84   a ,  84   b ,  85   a ,  85   b , and the like, by regulating the gap of the sealing portions of the passage forming plate  90  and the cover  70  so as not to be a value smaller than a predetermined value upon bringing the boss sections  94  and  95  into contact with the rear surface of the cover  70  even when the screws  66  are fastened by an excessive fastening force. Moreover, the protruding height of the boss sections  94  and  95  is set so as to compress the sealing portions  83   a ,  83   b ,  84   a ,  84   b ,  85   a ,  85   b , and the like of the diaphragm forming member  80  to an appropriate deforming degree to ensure an appropriate sealing property until the end surfaces of the boss sections  94  and  95  come in contact with the rear surface of the cover  70  during fastening the screws  66 . 
     In the passage forming plate  90 , a notch  98  is formed at the position corresponding to the notch  88   a  of the diaphragm forming member  80 . An inclined surface inclined at a predetermined angle and gradually extending outward on the lower side is formed on the bottom surface of the notch  98 . 
     Next, the configuration of the rear surface (the bottom surface) of the passage forming plate  90  will be described. As shown in  FIG. 15 , on the rear surface of the passage forming plate  90 , a partition wall  100  forming side walls of the passages  15   a  to  15   d  and  46   b  (see  FIGS. 1 and 2 ) extends along a predetermined passage path. The partition wall  100  is closed in the shape of a blind passage in all passages  15   a  to  15   d  and  46   b . Plural grooves (hereinafter, referred to as “a first groove  101  to a fifth groove  105 ) formed such that a gap (which is a gap of adjacent portions extending substantially parallel) is a groove width are formed in the partition wall  100 . In this embodiment, as shown in  FIG. 16 , by welding the film  120  onto the passage forming surface (the bottom surface) of the passage forming plate  90 , the spatial areas surrounded by the first groove  101  to the fifth groove  105  and the film  120  serve as passages  111  to  115  passing through the rear surface of the passage forming plate  90 . At this time, the four kinds of first groove  101  to fourth groove  104  serve as the first ink passage  111  to the fourth ink passage  114 , respectively, and are provided in each of the six ink supply devices  14 . The other one kind of fifth groove  105  serves as the air passage  115  and one groove is provided in a passage passing through the vicinity of the negative pressure chamber  43   b  of each of the six ink supply devices  14 . 
     In one corner of the rear surface of the passage forming plate  90 , one negative pressure introducing tube  106  protrudes vertically from the rear surface. One end of the air passage pipe  46   a  connected to the negative pressure generating device  47  is connected to the negative pressure introducing tube  106 . The negative pressure introducing tube  106  serves as a port for introducing negative pressure to the ink supply system  61 . The air passage groove  105  extends in a passage formed from the negative pressure introducing tube  106  to the negative pressure lead-out hole  91   b  via three through-holes  92 . 
     A pair of pins  107  positioning the protective plate  130  to the passage forming plate  90  protrude at the upper right and left positions of the rear surface of the passage forming plate  90  in  FIG. 15 . An extension section  108  having the substantially same height of that of the partition wall  100  is formed in the nearly whole circumference of the rear surface of the passage forming plate  90 . 
     As shown in  FIG. 16 , the film  120  is formed in a substantially rectangular shape having almost the same circumference as that of the passage forming plate  90 , and welded to the end surfaces (the upper end surface in  FIG. 16 ) of the partition wall  100  and the extension section  108 . The film  120  is formed of a lamination film formed by interposing a metal plate between resin layers. A gas barrier property is improved due to the metal plate (for example, an aluminum plate) and the welding to the passage forming plate  90  is ensured due to the resin layer (for example, thermoplastic resin such as polypropylene) of the surface. Moreover, the film  120  includes an extension section  121  corresponding to the extension section  91  of the passage forming plate  90  and concave portions  120   a  and  120   b  for avoiding the tube  106  and the pins  107  of the passage forming plate  90 , respectively. 
       FIG. 17  is a partial bottom view illustrating a portion associated with an ink passage on the rear surface of the passage forming plate.  FIG. 18  is a partial bottom view mainly illustrating the air passage on the rear surface of the passage forming plate. In  FIGS. 17 and 18 , the portions (the boss sections, etc.) other than the passages (the grooves) are not illustrated. In  FIG. 17 , the portions corresponding to the two ink supply devices  14  are illustrated. Here, like  FIG. 15 , in  FIGS. 17 and 18 , reference numerals are given to the passages corresponding to the grooves. In the following description, the groove  101  is considered to be the passage formed after the film welding for explanation. 
     As shown in  FIGS. 15 and 17 , the first ink passage groove  101  to the fourth ink passage groove  104  are surrounded by spaces with the film  120  welded onto the rear surface of the passage forming plate  90  to serve as the first ink passage  111 , the second ink passage  112 , the third ink passage  113 , and the fourth ink passage  114 , respectively. 
     As for six groups of the ink passages  111  to  114  forming each of the six ink supply devices  14 , since the location relation of the ink supply needles  25 , the pump  43 , the sucking valves  41 , and the ejecting valves  45  is slightly different from each other in the ink supply device  14  in which the pumps  43  are located in the first row and the ink supply device  14  in which the pumps  43  are located in the second row, the passage path and the like are slightly different in each of the ink supply devices  14 . However, the groups of the ink passages  111  to  114  basically have the same configuration, except for the slightly different paths. Accordingly, in  FIG. 17 , the ink passages will be described focusing the two ink supply devices  14  located opposite the pipe connection section  63  (see  FIGS. 3 and 4 ). 
     In  FIG. 17 , the upper-side concave section  31  of the two concave sections  31  arranged in the upper and lower sides and the left concave sections  30  and  32  among the concave sections  30  and  32  arranged right and left correspond to one ink supply device  14 . The lower-side concave section  31  and the right concave sections  30  and  32  correspond to the other ink supply device  14 . 
     As shown in  FIG. 17 , the first ink passage  111  (the first groove  101 ) is a passage permitting the through-hole  90   a  corresponding to the ink supply needle  25  to communicate with the through-hole  30   b  of the sucking valve  41  (the concave section  30 ). Accordingly, upon the sucking drive of the pump  43 , the ink flowing from the ink supply needle  25  to the rear surface of the passage forming plate  90  via the through-hole  90   a  flows to the through-hole  30   b  via the first ink passage  111  and then flows from the through-hole  30   b  to the sucking valve  41 . 
     The second ink passage  112  is a passage permitting the through hole  90   b  in the vicinity of the sucking valve  41  (the concave section  30 ) to communicate with the through-hole  31   a  of the pump  43  (the concave section  31 ). Accordingly, upon the sucking drive of the pump  43 , the ink flowing from the through-hole  90   b  to the rear surface of the passage forming plate  90  via the sucking valve  41  which has been opened by the ink pressure (the negative pressure) caused by the sucking drive flows to the through-hole  31   a  via the second ink passage  112  and then flows from the through-hole  31   a  to the pump chamber  43   a.    
     The third ink passage  113  is a passage permitting the through-hole  31   b  of the pump  43  (the concave section  31 ) to communicate with the through-hole  32   b  of the ejecting valve  45  (the concave section  32 ). Accordingly, upon the ejecting drive of the pump  43 , the ink ejected from the pump chamber  43   a  and flowing from the through-hole  31   b  to the rear surface of the passage forming plate  90  flows to the through-hole  32   b  via the third ink passage  113  and then flows from the through-hole  32   b  to the ejecting valve  45 . 
     The fourth ink passage  114  serves as a passage which permits the through-hole  32   c  of the ejecting valve  45  (the concave section  32 ) to communicate with the through-hole  91   a  of the extension section  91 . Accordingly, upon the ejecting drive of the pump  43 , the ink flowing from the through-hole  32   c  to the rear surface of the passage forming plate  90  via the ejecting valve  45  which has been opened by the ink pressure pressurized by the ejecting drive flows to the through-hole  91   a  via the fourth ink passage  114  and then flows from the ink discharging port  64  of the pipe connection section  63  via the through-hole  91   a.    
     Next, the air passage to which the negative pressure is introduced will be described. As shown in  FIG. 18 , the negative pressure from the negative pressure introducing tube  106  is introduced to the air passage  115  on the rear surface via the groove  90   g  and the through-hole  90   f  of the passage forming plate  90 . The air passage  115  extends from the through-hole  90   f  to the negative pressure lead-out hole  91   b  sequentially through the positions corresponding to the rear surface of the pump chambers  43   a  (the concave sections  31 ) of the pumps  43  arranged in the first row. Moreover, the air passage  115  includes three air passages  115   a  diverged from the positions individually corresponding to the rear surface of the pump chambers  43   a  (the concave sections  31 ) to extend toward the lower side of  FIG. 18 . The air passage  115  communicates with the three through-holes  92  individually corresponding to the diverged three air passages  115   a . Accordingly, the negative pressure introduced into the air passage  115  via the tube  106  of the ink supply system  61  upon the sucking drive of the pumps  43  is led out from the through-holes  92  to the front surface of the passage forming plate  90  via the diverged air passages  115   a . In addition, the negative pressure led out from the through-holes  92  reaches the middle portion in the length direction of the grooves  77  of the rear surface of the cover  70  via the through-holes  81   b  of the diaphragm forming member  80  and then is introduced along the grooves  77  to the two negative pressure chambers  43   b  located on both the sides in the length direction. 
       FIG. 19  is an exploded perspective view illustrating the protective plate and the receiving plate. The protective plate  130  shown in  FIG. 19  is formed of a metal plate, for example, having almost the same outer circumferential shape as that of the film  120 . The protective plate  130  includes an extension section  131  corresponding to the pipe connection section  63  and plural screw holes  130   a  and  130   b  at the fastening positions of the screws  66  and  67 . In addition, a hole  132  for inserting the tube  106  is formed at the position corresponding to the tube  106  of the passage forming plate  90  on a side of the protective plate  130 . 
     The receiving plate  140  includes an extension section  141  which has almost the same outer circumferential shape of that of the protective plate  130  and corresponds to the pipe connection section  63 . An extension section  142  having a predetermined height from the bottom surface is formed in the nearly whole circumference of the receiving plate  140 . In the extension section  142  of the receiving plate  140 , a drain passage  143  (a drain unit) extending outward is provided at the position corresponding to the notch  88   a  of the diaphragm forming member  80 . The drain passage  143  includes a passage surface  143   a  which has a predetermined width and is formed as an inclined surface gradually lowered to the outside so as to discharge the waste ink accumulated in the receiving plate and a pair of guides  143   b  which extends by bending the extension section  142  outward along both the sides of the passage surface  143   a . A flowing direction of the discharged waste ink is guided by the guides  143   b  so that the waste ink flows on the passage surface  143   a . In the receiving plate  140 , a cylindrical portion  144  for inserting the negative pressure introducing tube  106  protrudes at the position corresponding to the hole  132  of the protective plate  130 . In the receiving plate  140 , plural circular concave portions  140   a  which can allow the front ends of the screws  66  threaded into the screw holes  130   a  protruding toward the rear surface of the protective plate  130  to avoid the interference with the receiving plate  140  are formed at the positions corresponding to the screw holes  130   a  of the protective plate  130 . In the receiving plate  140 , screw insertion holes  140   b  for inserting the screws  67  are formed at the positions corresponding to the screw holes  130   b  of the protective plate  130 . 
     The lamination structure constituted by the members  70 ,  80 ,  90 ,  120 , and  130  is assembled in a state where the sealing property of the members  70 ,  80 , and  90  is ensured, by laminating the members  70 ,  80 , and  90  after the film  120  is welded on the rear surface of the passage forming plate  90  in advance and by tightening the screws  66  inserted into the insertion holes by a predetermined fastening force. In addition, the ink supply system  61  can be assembled by laminating the receiving plate  140  on the bottom surface of the lamination structure in the state where the negative pressure introducing tube  106  is inserted into the cylindrical portion  144  and by inserting the two screws  67  into the screw insertion holes to fasten the receiving plate from the lower side. 
     In this embodiment, two sheets of the cover  70  and the passage forming plate  90  are used as a single passage forming member. When the members  70 ,  80 ,  90 ,  120 ,  130 , and  140  are fixed in the laminated state, the pumps  43 , the sucking valves  41 , and the ejecting valves  45  are disposed on the substantially same plane. In addition, the ink supply system  61  can be assembled in the state where the second passage  15   b  permitting the sucking valve  41  to communicate with the pump  43  and the third passage  15   c  permitting the pump  43  to communicate with the ejecting valve  45  are formed. Here, in the cover  70  and the passage forming plate  90 , the groove  33   a , the through-hole  90   b , the second groove  102  (the second ink passage  112 ), and the through-hole  31   a  for forming the second passage  15   b  connecting between the sucking valve  41  and the pump  43  are formed as a part of the liquid supply passage. In the passage forming plate  90 , the through-hole  31   b , the third groove  103  (the third ink passage  113 ), and the through-hole  32   b  for forming the third passage  15   c  connecting between the pump  43  and the ejecting valve  45  are formed as a part of the liquid supply passage. In this way, since the plural parts (the second passage  15   b  and the third passage  15   c ) of the liquid supply passage are formed in the cover  70  and the passage forming plate  90  as the single passage forming member, the second passage  15   b  and the third passage  15   c  are also integrally formed in the ink supply system  61 . Accordingly, a piping work for communicating the pump  43 , the sucking valve  41 , and the ejecting valve  45  by use of a tubing material such as a tube is not required. 
     At this time, by inserting the boss sections  94  and  95  and the pins  96  of the passage forming plate  90  into the screw insertion holes  89   a  and the pin holes  89   c  of the diaphragm forming member  80 , respectively, in the laminated state of the members  70 ,  80 ,  90 ,  120 , and  130  before the screw fastening, the diaphragm forming member  80  is positioned to the passage forming plate  90  in the state where the sucking valve bodies  36 , the diaphragms  37 , and the ejecting valve bodies  38  face the concave sections  30 ,  31 , and  32 , respectively. In addition, by inserting the pins  79  into the positioning holes  97 , the cover  70  is positioned to the passage forming plate  90  in the state where the sucking valve bodies  36 , the diaphragms  37 , and the ejecting valve bodies  38  face the concave sections  33 ,  34 , and  35 , respectively. 
     When the laminated members  70 ,  80 ,  90 ,  120 , and  130  are tightened by the screws  66 , the boss sections  94  and  95  of the passage forming plate  90  come in contact with the rear surface of the cover  70  and a predetermined gap is ensured between the cover  70  and the passage forming plate  90 . In this case, the height of the boss sections  94  and  95  is set such that the sealing portions  83   a  to  87   a  and the sealing portions  83   b  to  87   b  of the diaphragm forming member  80  interposed between the sealing portions  78   a ,  78   b ,  78   c ,  78   d , and  78   e  and the sealing portions  93   a ,  93   b ,  93   c ,  93   d , and  93   e  are pressed upon fastening the screws  66  by a sealing ensuring force so as not to be excessively pressed and deformed. Accordingly, even when the screws  66  are further tightened after the boss sections  94  and  95  come in contact with the rear surface of the cover  70  by fastening the screws  66 , the sealing portions  83   a  to  87   a  and the sealing portions  83   b  to  87   b  of the diaphragm forming member  80  are regulated so as not to be deformed. Therefore, the sealing portions  83   a  to  87   a  and the sealing portions  83   b  to  87   b  are pressed to an appropriate degree without the excessive press. 
     For example, in a configuration in which the sealing portions  84   a ,  84   b ,  85   a , and  85   b  surrounding the sucking valve bodies  36  and the ejecting valve bodies  38  in the diaphragm forming member  80  are excessively pressed and deformed when the screws  66  are too strongly tightened, the rubber pressed and deformed is extruded to the inside of the valve chamber and the sucking valve bodies  36  or the ejecting valve bodies  38  are deformed and become loose. As a consequence, non-uniformity in opening or closing time of the valve body caused by whether or not the valve body is loose may occur due to non-uniformity in the tightening force of the screws  66 . 
     In this case, for example, the opening or closing time of the sucking valve body may become different and the sucking valve  41  which has to be closed when the negative pressure chamber  43   b  is opened to the air may not be completely closed. Moreover, when the ink cartridge  13  is detached in such a situation, the ink pressurized in the ink supply system may flow backward and thus the ink may leak from the ink supply needle  25 . In the configuration according to this embodiment, however, since the sealing portions  84   a  and  84   b  of the diaphragm forming member  80  is not excessively pressed and deformed, the non-uniformity in the opening or closing time of the sucking valve body  36  rarely occurs. In addition, when the negative pressure chamber  43   b  is opened to the air, the sucking valve  41  is completely closed. As a consequence, when a user detaches the ink cartridge  13 , the ink can be prevented from leaking from the ink supply needle  25  because the ink pressurized in the ink supply system  61  flows backward and thus the sealing portions  84   a  and  84   b  are excessively pressed and deformed. 
     When the ejecting valve  45  is not fully closed and ink leakage occurs, non-uniformity in the amount of ink flowing between the ink passages of the ink colors occurs. In the configuration according this embodiment, however, since the sealing portions  85   a  and  85   b  of the diaphragm forming member  80  is not excessively pressed and deformed, the non-uniformity in the opening or closing time of the ejecting valve body  38  rarely occurs. In addition, the ejecting valve  45  is surely closed upon the sucking drive of the pump  43 . As a consequence, since the ejecting valve  45  is ensured to be fully closed and the ink leakage does not occur, the non-uniformity in the amount of ink flowing between the ink passages of ink colors rarely occurs. 
     In this way, the excessive pressing and deformation of the sealing portions can be prevented. However, when an urging force for closing the sucking valve body  36  and the ejecting valve body  38  is weak, the ink leakage in the sucking valve  41  and the ejecting valve  45  may occur, the ink leakage from the ink supply needle  25  upon detaching or mounting the above-described ink cartridge  13  may occur, and the non-uniformity in the amount of ink flowing between the ink passages may occur. In order to solve these problems, a check valve configuration having the coil springs  40  and  44  (the urging members) urging the sucking valve body  36  and the ejecting valve body  38  in the valve closing direction is intentionally used to ensure the closed state of the valve, even though the size of the sucking valve  41  and the ejecting valve  45  is increased. 
     Even though the size of the sucking valve  41  and the ejecting valve  45  is increased, the compact ink supply system  61  is configured by disposing the six pumps  43 , the six sucking valves  41 , and the six ejecting valves  45  constituting the six ink supply devices  14  on the same plane in the main body  62  of the ink supply system  61  in a relatively precise manner. In this case, the pumps  43  having the relatively large diameter are arranged in two rows, the six ink supply needles  25  are arranged in one row at the same interval in the spatial areas between the rows of the pumps, the six sucking valves  41  and the six ejecting valves  45  are arranged in one row in the direction parallel to the rows of the pumps in the areas adjacent to the rows of the pumps. 
     In this layout, the pumps  43  and the valves  41  and  45  are precisely arranged, but the positions of the ink supply needles  25 , the pumps  43 , and the valves  41  and  45  may be relatively distant from each other. Therefore, the passages  15   a ,  15   b ,  15   c , and  15   d  may be relatively lengthened. In this embodiment, however, the passages  15   a ,  15   b ,  15   c , and  15   d  surrounded by the grooves  101  to  104  and the film  120  are disposed on the rear surface opposite to the surface (the front surface) of the passage forming plate  90  provided with the pumps  43  and the valves  41  and  45 , by providing the plural grooves  101  to  104  on the rear surface of the passage forming plate  90  and welding the film  120  on the rear surface thereof. With such a configuration, the passages  15   a ,  15   b ,  15   c , and  15   d  can be assembled in one same component without sacrificing the relatively precise layout of the pumps  43  and the valves  41  and  45 . 
       FIG. 20  is a plan view illustrating the ink supply system  61  mounted with the six ink cartridges  13 . Assuming that a projection range obtained by projecting an area (a minimum rectangular area containing the six ink cartridges  13  in a plan view of  FIG. 20 ) for disposing the six ink cartridges  13  on the upper surface of the ink supply system  61  in the lamination direction is “a cartridge projection range”, as shown in  FIG. 20 , the six pumps  43  are laid out relative to the positions of the six ink supply needles  25  such that all the central points of the pumps fall within the cartridge projection range. The six sucking valves  41  arranged in one row are laid out relative to the positions of the six ink supply needles  25  such that all the central points of the sucking valves fall within the cartridge projection range. The six ejecting valves  45  arranged in one row are also laid out relative to the positions of the six ink supply needles  25  such that all the central points of the ejecting valves fall within the cartridge projection range. That is, in this embodiment, the six pumps  43 , the six sucking valves  41 , and the six ejecting valves  45  are laid out such that all the central points thereof fall within the cartridge projection range determined by the positions of the six ink supply needles  25 . 
     The main body  62  having a relatively compact size is configured to include screw fastening boss sections  75  and  76  and an extension section  71   a  in the outer circumference formed by laying out the six ink supply needles  25 , the six pumps  43 , the six sucking valves  41 , and the six ejecting valves  45  in the relatively precise manner. The cartridge projection range is within the upper surface of the compact main body  62 . With such a configuration, a space required to dispose the ink supply system  61  (the cartridge holder) and the six ink cartridges  13  in the printer  11  can be restrained so as to be relatively small. As a consequence, it is possible to make the printer  11  compact. 
     At this time, the first ink passage  111  to the fourth ink passage  114  formed on the rear surface of the passage forming plate  90  extend so as to be spaced from and adjacent to the partition wall  100  at the portions (the areas between the through-holes  90   a  in the vertical direction of  FIG. 17  and the vicinities of the middles of the concave sections  30 ) corresponding to the path of the first to fourth ink passages. For example, when the partition wall is in contact with the air (the atmosphere) of the outside, the air gas-permeates the partition wall to be dissolved in the ink flowing inside the partition wall and the dissolved air may become bubbles in the ink. Alternatively, the moisture of the ink may permeate the partition wall and evaporate. In this embodiment, however, since the ink of the other ink passages flows outside the partition wall  100 , it is possible to prevent the cause that the air permeates the partition wall and is dissolved in the ink to make the bubbles or the cause that the moisture of the ink permeates the partition wall and the concentration of the ink is increased. As a consequence, the bubbles rarely occur in the ink and it is easy to prevent a failure in the ejection of ink droplets caused due to the bubbles and a failure in the ejection of the ink droplets caused by clogging of the nozzles occurring because the concentration of the ink is increased due to the moisture evaporation and the ink is easily thickened. 
     Since the protective plate  130  formed of a metal plate is disposed on the lower side of the film  120 , the passage forming plate  90  made of a plastic material (PP) can be prevented from being deformed in a rippling shape due to the distribution of a force particularly strongly pushed in the tightened positions of the screws  66  upon tightening the screws  66 . Accordingly, even when the screws  66  is fastened, it is possible to prevent the sealing performance from deteriorating due to the guarantee of the flatness of the passage forming plate  90 , for example, or prevent the non-uniformity in the opening or closing time of the valve body from occurring. 
     The waste ink leaking in the peripheral of the ink supply needle  25  on the upper surface of the cover  70  upon mounting or detaching the ink cartridge  13  may flow onto the diaphragm forming member  80  located on the rear surface of the cover  70  via the through-hole  68 . In addition, the waste ink accumulated on the upper surface of the diaphragm forming member  80  flows to the outside via the notch  88   a , flows to the lower side along the notch  98  of the side wall of the passage forming plate  90  to drop to the drain passage  143  of the receiving plate  140 , and is discharged to the outside along the drain passage  143  to be collected in the waste liquid tank  21 . Even though the ink leaks from the sealing portions between the cover  70  and the diaphragm forming member  80  and the sealing portions between the diaphragm forming member  80  and the passage forming plate  90 , the leaking ink flows and drops from the notch  88   a  to the outside and is likewise collected in the waste liquid tank  21 , for example, via the drain passage  143 . Accordingly, it is possible to prevent the inside of the printer  11  from being smeared due to the waste ink leaking from the ink supply system  61 . 
     As described in detail above, the following advantages can be obtained according to this embodiment. 
     (1) Since the pumps  43 , the sucking valves  41 , and the ejecting valves  45  are disposed on the same plane, the ink supply system  61  can be formed so as to have the lamination structure. The lamination structure formed by laminating the plural members  70 ,  80 ,  90 ,  120 , and  130  including the cover  70  and the passage forming plate  90  as the single passage forming member is used. Accordingly, the ink supply system  61  can be provided as the relatively thin component incorporated with the plural ink supply devices  14  including the pumps  43 , the sucking valves  41 , the ejecting valves  45 , and the passages  15   a ,  15   b ,  15   c , and  15   d . Accordingly, the piping work is finished just by connecting the air passage tube  46   a  to the tube  106  and attaching the pipe connection tool  59  formed in the front end of the flexible pipe plate extending from the printing head unit  12  to the pipe connection section  63 . As a consequence, it is not necessary to carry out a troublesome piping work for connecting the pumps to the two unidirectional valves (the check valves) and connecting the ink supply devices  14  to each other to share a working fluid as a pump between the ink supply devices. 
     (2) Since the boss sections  94  and  95  are provided on the upper surface of the passage forming plate  90 , the sealing portions of the diaphragm forming member  80  are prevented from being further pressed and deformed even when the screws  66  are further tightened in the state where the boss sections  94  and  95  come in contact with the rear surface of the cover  70 . As a consequence, even when the screws  66  are too strongly fastened, the non-uniformity in the opening or closing time of the sucking valve body  36  and the ejecting valve body  38  caused by the excessive pressing and deformation of the sealing portions of the diaphragm forming member  80  rarely occurs, while ensuring the sealing property of the diaphragm forming member  80 . For example, even though the negative pressure chamber  43   b  becomes the air pressure, the sucking valve  41  can be prevented from not being completely closed. As a consequence, when a user detaches the ink cartridge  13 , the ink pressurized in the ink supply system  61  can be prevented from flowing backward and leaking from the ink supply needle  25 . Moreover, the ink leakage from the ejection valve  45  during the closed state thereof can be prevented and the non-uniformity in the amount of ink flowing between the ink passages of ink colors can be prevented. 
     (3) The passages permitting the pumps  43 , the sucking valves  41 , and the ejecting valves  45  to connect each other are disposed on the rear surface of the passage forming plate  90  by forming the passage grooves  101  to  105  on the rear surface of the passage forming plate  90  and welding the film  120  to the rear surface. Accordingly, since the pumps  43 , the sucking valves  41 , and the ejecting valves  45  provided on the front surface of the passage forming plate  90  and the passages  111  to  115  provided on the rear surface and permitting the pumps  43 , the sucking valves  41 , and the ejecting valves  45  to connect each other can be disposed so as to overlap with each other in the lamination direction (the Z direction). As a consequence, it is possible to compactly form the size of the ink supply system  61  in a plan view. Moreover, since the passages  111  to  115  on the rear surface of the passage forming plate  90  are disposed on the same plane, the ink supply system  61  is not thick and thus the thinness can be achieved. 
     (4) Since the pumps  43  are laid out relative to the ink supply needles  25  so that all the central points of the pumps  43  fall within the cartridge projection range, the space for disposing the ink supply system  61  mounted with the ink cartridges  13  can be relatively small. Moreover, since the valves  41  and  45  are also laid out relative to the ink supply needles  25  so that all the central points of the valves  41  and  45  fall within the cartridge projection range, the space for disposing the ink supply system  61  mounted with the ink cartridges  13  can be smaller. 
     (5) Since the protective plate  130  is disposed on the rear surface on which the film  120  of the passage forming plate  90  is welded, the rippling deformation of the passage forming plate  90  upon fastening the screws  66  can be prevented. Accordingly, it is possible to prevent the sealing performance from deteriorating because the sealing surface is deformed in the rippling shape and prevent the ink leakage. Moreover, the protective plate  130  can protect the film  120 . 
     (6) In the ink supply system  61 , the concave sections  30  and  33  individually forming parts of the valve chambers  41   a  and  45   a  of the sucking valves  41  (the sucking check valve) and the ejecting valve  45  (the ejecting check valve) are formed in the concave shape in the passage forming plate  90  which is the lower case provided with the concave sections  31  each forming a part of the pump chamber  43   a . With such a configuration, it is possible to make the whole pump mechanism thin and make the ink supply system  61  compact. 
     For example, when the pump  43   a , the valve chamber  41   a , and the valve chamber  45   a  are formed in the passage forming plate  90  (a lower case) without providing the concave section, it is necessary to form a relatively large concave section for forming the valve chamber in the cover  70  (an upper case) and the passage forming plate  90  is required to have the thickness corresponding to the concave section  31  of the pump chamber  43   a  of the passage forming plate  90 . In this way, the lower and upper cases are separated from each other and the concave sections are formed, the thickness is larger and the ink supply system  61  becomes thick. In this embodiment, however, since the concave sections  30  and  32  for the valve chamber  41   a  of the sucking valve  41  and the valve chamber  45   a  of the ejecting valve  45  are provided in the passage forming plate  90  in which the concave sections  31  of the pump chambers  43   a  are formed, the concave section for the valve chamber of the cover  70  can be made thin and it is easy to make at least the portion other than the pumps  43  thin. 
     (7) The check valve chamber according to this embodiment is configured such that the inflow port to the valve chamber  41   a  is formed by the through-hole  31   b  opened to the bottom surface of the concave section  30  formed in the passage forming plate  90 . In addition, the sucking valve body  36  is configured so as not to block the inflow port upon valve closeness of the sucking valve body  36 . Accordingly, as for the valve chamber  41   a  of the sucking valve  41 , the negative pressure (the ink pressure) from the pump chamber  43   a  upon the sucking drive of the pump is applied to the whole upper surface of the sucking valve body  36 , and the ink pressure of the ink cartridge  13  is also applied to the surface (the lower surface) opposite to the sucking valve body  36  and a broad pressure receiving area with a ring shape. Therefore, due to the differential pressure based on the broad pressure receiving surface in both the surfaces of the sucking valve body  36 , the sucking valve  41  can be opened or closed by a relatively small pressure variation and pressure loss can be reduced. Since the same is applied to the valve chamber  45   a  of the ejecting valve  45 , the ejecting valve  45  can be opened or closed even by the relatively small pressure variation. On the contrary, in a valve such as a flap valve having a configuration in which the inflow port to each valve chamber, the opening area of the inflow port blocked by the valve body is a pressure receiving area of the valve body. Therefore, when large negative pressure is not applied, it is difficult to surely open the valve. The same is applied to the valve chamber  45   a  of the ejecting valve  45 . As described above, in this embodiment, the check valves of the sucking valve  41  and the ejecting valve  45  have the configuration in which the opening or closing operation can be surely performed even by the small pressure variation, and the pump mechanism can be made thin. 
     (8) Since all the members  70 ,  80 ,  90 ,  120 ,  130 , and  140  are common to the six ink supply devices  14 , the number of constituent elements is reduced and it is easy to assembly the ink supply system  61 . 
     The invention is not limited to the above-described embodiment, but may be deformed in the following forms. 
     MODIFIED EXAMPLE 1 
     The layout of the pumps  43  and the valves  41  and  45  in the main body  62  can be appropriately modified. For example, the sucking valves  41  and the ejecting valves  45  may be arranged in one row, respectively, on both the sides interposing the plural rows(for example, two rows) of the pumps. The row of the valves may be arranged between the rows of the pumps. The pumps and the valves may be individually arranged in one row. For example, the pumps  43  and the valves  41  and  45  in  FIG. 1  may be arranged in the same number of rows as that of the ink colors in a vertical direction of the surface of  FIG. 1 . The respective valves may be arranged in plural rows. 
     MODIFIED EXAMPLE 2 
     At least one of the protective plate  130  and the receiving plate  140  as the constituent members of the ink supply system  61  may be removed. When the protective plate  130  is removed, a fastening force may be set so that the passage forming member is not deformed in the rippling shape upon fastening the fastening members or the passage forming member may be formed of a material having a high rigidity degree that the deformation does not occur upon fastening the fastening members. When the film is formed of a material having high solidity, the problem with damage can be prevented without the protective plate. In addition, when the sealing property is completely ensured, there is no problem with the removal of the receiving plate  140 . 
     A configuration which does not use the film may be employed. For example, a configuration may be used in which the passage grooves are formed on the surface on the side of the passage forming plate facing the diaphragm forming member  80  and passages are formed by the spatial areas surrounded by the grooves and the diaphragm forming member  80  or passages are formed by holes formed in the passage forming member and extending along the path parallel to the XY plane. A configuration may be used in which plural (for example, two) passage forming members laminated are formed instead of one passage forming plate of the above-described embodiment, grooves are formed on at least one surface of the facing surfaces thereof, and the passages are surrounded by the grooves upon laminating the plural passage forming plates. 
     MODIFIED EXAMPLE 3 
     It is preferable that the laminated location of the protective plate as the metal plate is close to at least one of the first passage forming member and the second passage forming member, but any layer may be used. For example, a configuration may be used in which a partial area other than the area where the ink supply needles  25  are formed on the front surface of the first passage forming member is formed as a flat surface and the metal plate is laminated on the area of the plate surface. In this case, metal plates may be laminated on both the sides of the surfaces opposite to the surfaces of the first and second passage forming members facing the flexible member. In this case, areas for disposing the metal plates may be different in the first and second passage forming members. 
     MODIFIED EXAMPLE 4 
     In the above-described embodiment, both the cover  70  (the second passage forming member) and the passage forming plate  90  (the first passage forming member) are formed by the single passage forming member, but only one of the cover  70  and the passage forming plate  90  may be formed by the single passage forming member. For example, the passage forming plate  90  is used as the single (one) passage forming member and the cover  70  may be formed by plural passage forming members. Conversely, the cover  70  may be formed by the single passage forming member and plural passage forming plates are assembled for the cover  70 . When both the cover and the passage forming plate are formed by the single member, only one of the cover and the passage forming plate may be formed as the passage forming member. 
     MODIFIED EXAMPLE 5 
     In the above-described embodiment, the parts of the liquid supply passages are formed in the plural single passage forming members and the liquid supply passages are formed in the laminated state of the plural constituent members. However, only one single passage forming member may be provided and all the liquid supply passages may be formed in the one passage forming member. For example, in  FIG. 1 , a configuration may be provided in which the upstream end of the first passage  15   a  is opened to the right end surface of the first passage forming member  27  (the passage forming plate  90 ) in  FIG. 1 , the upstream end of the second passage  15   b  is opened to the middle of the valve seat  30   a , and the downstream end of the fourth passage  15   d  is opened to the left end surface in  FIG. 1 . In this case, a connection tube for connecting a tube or the like to a portion serving as the upstream end and the downstream end of the liquid supply passage may be formed in the first passage forming member  27  and the ink supply needles may be provided in the upstream end. 
     MODIFIED EXAMPLE 6 
     The third passage  15   c  may be partially formed in the cover  70 , the diaphragm forming member  80 , and the passage forming plate  90 , like the second passage  15   b . 
     MODIFIED EXAMPLE 7 
     Only one of the second passage  15   b  serving as the partial passage permitting the first unidirectional valve to communicate with the supply pump and the third passage  15   c  serving as the partial passage permitting the supply pump to communicate with the second unidirectional valve may be formed in the single passage forming member. For example, a lamination plate having a hole for the pump chamber may be interposed between the passage forming plate  90  and the diaphragm forming member  80 , an ink sucking port opened to a space between the lamination plate and the diaphragm forming member  80  or the inner circumferential surface of the lamination plate may be provided, the second passage  15   b  communicating the ink sucking port may communicate with the first unidirectional valve in a path which does not pass through the passage forming plate  90  but pass through the cover  70 . 
     MODIFIED EXAMPLE 8 
     The invention is not limited to the configuration in which the boss sections also serve as the regulating unit. For example, a protrusion having a columnar shape, or a square columnar shape, or a frustum shape which has no screw insertion hole may be provided as the regulating unit. The regulating unit may not be provided on the passage forming plate  90 , but may be provided on the rear surface of the cover  70 . Alternatively, the regulating unit may be provided in at least one of the first and second passage forming members. 
     MODIFIED EXAMPLE 9 
     A passage may be formed on the front surface of the cover by forming grooves on the front surface of the cover provided with the ink supply needles  25  and by attaching a film on the surface in which the grooves are formed by a method such as welding. In addition, this kind of passage may be formed only on the front surface of the cover. 
     MODIFIED EXAMPLE 10 
     The liquid supply device is not limited to the ink supply system formed by making the plural ink supply devices  14  into one unit. Any configuration may be used as long as the pumps  43 , the sucking valves  41 , and the ejecting valves  45  forming one ink supply device  14  are disposed on the substantially same plane and the plural constituent members are laminated. 
     MODIFIED EXAMPLE 11 
     The cover  70  and the diaphragm forming member  80  may not be the single member in which all the ink supply devices  14  in the printer  11  are shared. For example, the cover may be formed by plural elements in one ink supply system  61 , the diaphragm forming member may be formed by plural elements, or both the cover and the diaphragm forming member may be formed by the same number of elements or the different number of elements. In this case, when one member (single member) in which the passage forming plate  90  is shared by the plural ink supply devices  14  is used, the ink supply system  61  can be made into one unit. 
     MODIFIED EXAMPLE 12 
     In the above-described embodiment, the ink supply system  61  is configured by making all the ink supply devices  14  for all the ink colors into one unit. However, plural ink supply systems  61  may be configured by making the ink supply devices  14  for plural ink colors of all the ink colors into one unit. Alternatively, a configuration may be used in which the same number of ink supply devices  14  as the ink colors is disposed in the printer, a lamination structure in which each one of the pumps  43 , the sucking valves  41 , and the ejecting valves  45  is disposed on the same plane is used, a piping work for connecting between the pumps  43 , the sucking valves  41 , and the ejecting valves  45  by use of a tube or the like is not required. In this case, even though a piping work for connecting between the ink supply devices  14  by use of an air passage tube is required, the piping work can be reduced in comparison to a known configuration. 
     MODIFIED EXAMPLE 13 
     The ink supply needles  25  (connection sections) may not be provided in the cover  70 , but may be provided in the passage forming plate  90  or divided into both the cover  70  and the passage forming plate  90 . In this case, it is preferable that all the central points of the pumps  43  fall within the cartridge projection range. 
     MODIFIED EXAMPLE 14 
     The ink supply system  61  may not be the cartridge holder. For example, a configuration may be used in which the ink supply system is replaced by the ink supply needles  25 , supply tubes for supplying ink are provided, and a tube extending from an ink supply source such as an ink tank or the cartridge holder mounted with the ink cartridges is connected to the supply tubes of the ink supply system. Alternatively, an ink supply device including pumps, first unidirectional valves (sucking unidirectional valves), and second unidirectional valves (ejecting unidirectional valves), as in JP-A-2006-272661, may be mounted in the printing head unit. That is, the ink supply system  61  according to the above-described embodiment is mounted on the carriage. With such a configuration, by using the ink supply system  61  having the lamination structure, it is possible to reduce the piping work and make the ink supply device thin. 
     MODIFIED EXAMPLE 15 
     In the above-described embodiment, the ink jet printer and the ink cartridge have been used. However, a liquid ejecting apparatus discharging or ejecting another liquid other than ink and a liquid storing unit storing the liquid may be used. The invention is useful for various liquid ejecting apparatuses including a liquid ejecting head for ejecting minute liquid droplets. The liquid droplet refers to a liquid ejected from the liquid ejecting apparatus and includes a liquid having a particle shape, a liquid having a droplet shape, and a liquid having a thread trailing shape. The liquid is a material which can be ejected by the liquid ejecting apparatus. For example, the liquid is a matter in a liquefied state and includes a liquid of a fluid state such as a liquid-like material having high or low viscosity, sol, gel water, other inorganic solvents, an organic solvent, liquid solution, liquid-like resin, and liquid-like metal (metallic melt), a liquid in one state of a matter, and a liquid in which particles of a functional material formed of a solid matter such as colorant or metal particle is dissolved, dispersed, or mixed. Representative examples of a liquid are ink or liquid crystal, as described in the embodiment. Here, the ink includes a liquid composition such as general water-based ink, general oil-based ink, gel ink, and hot-melt ink. Specific examples of the liquid ejecting apparatus include a liquid crystal display, an EL (electro-luminescence) display, a plane emission display, a liquid ejecting apparatus ejecting a liquid containing a material such as an electrode material or a color material used to manufacture a color filter is dispersed or dissolved, a liquid ejecting apparatus ejecting bio organism used to manufacture a bio chip, a liquid ejecting apparatus ejecting a liquid as a sample used by a precise pipette, a printing apparatus, and a micro dispenser. In addition, examples of the liquid ejecting apparatus include a liquid ejecting apparatus ejecting a lubricant to a precision instrument such as a clock or a camera by a pin point, a liquid ejecting apparatus ejecting a transparent resin liquid such as ultraviolet cured resin on a board to form a minute hemispheric lens (an optical lens) used in an optical communication element or the like, and a liquid ejecting apparatus ejecting an acid or alkali etching liquid to etch a board or the like. In addition, the invention is applicable to one liquid ejecting thereof and the liquid storing unit. 
     The technical sprints understood from the above-described embodiment and the modified examples will be described below. 
     (1) The first and second unidirectional valves form valve portions in a part of the flexible member and the liquid supply device may further comprise urging units ( 40  and  44 ) urging the valve portions in the valve closing direction. With such a configuration, the area (the pressure receiving area) of the valve portions has to be broad to open the valves against the urging force of the urging units. Accordingly, the size of the first and the second unidirectional valve is increased. However, by providing a part of the liquid supply passage on at least the surface of one of the first and second passage forming members opposite to the flexible member, the liquid supply device can be made thin, compared to the valve configuration in which the urging units are provided. 
     (2) In the liquid supply device, the connection sections, the supply pumps, and the first and second unidirectional valves are laid out so that all the central points of one of the first and second unidirectional valves fall within the cartridge projection range. 
     (3) In the liquid supply device, the connection sections, the supply pumps, and the first and second unidirectional valves are laid out so that all the central points of the first and second unidirectional valves fall within the cartridge projection range. 
     (4) In the liquid supply device, a connection section for connecting a supply port of the liquid storing member is provided on the outer surface of at least one of the first and second passage forming members. With such a configuration, since the connection port of the liquid supply source is directly connected to the liquid supply connection section, a tube or the like is not required to connect the liquid supply source and the liquid supply connection section to each other. 
     (5) In the liquid supply device, the liquid supply source is a liquid cartridge storing a liquid, the connection section is a liquid supply needle inserted into the supply port of the liquid storing source, and the liquid supply device is a cartridge holder mounted with the liquid cartridge in which the liquid supply needle is inserted into the supply port of the liquid cartridge. With such a configuration, since the liquid supply device is formed such that the pumps and the unidirectional valves are assembled in the cartridge holder on which the liquid supply source (the liquid cartridge) is directly mounted, it is not necessary to pipe a tube or the like for connecting the liquid supply source to the liquid supply device.