Patent Publication Number: US-7213913-B2

Title: Ink cartridge

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application is a continuation of application Ser. No. 10/150,479, filed on May 17, 2002 now U.S. Pat. No. 6,945,641. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to an ink cartridge for use with an ink-jet recording apparatus, which supplies ink to a recording head for ejecting ink droplets in response to a print signal. 
   An ink-jet recording apparatus is generally constituted such that an ink-jet recording head for ejecting ink droplets in response to a print signal is mounted on a carriage which travels back and forth in a widthwise direction of recording paper and such that ink is supplied to the recording head from an external ink tank. In the case of a compact recording apparatus, an ink reservoir like the ink tank is removably provided on a carriage. In the case of a large recording apparatus, an ink reservoir is set in a casing and connected to a recording head by an ink supply tube. 
   As an ink cartridge to be set on a carriage, such types are available, that a porous member, such as a sponge, impregnated with ink is accommodated within an ink cartridge, and that only ink is stored in an ink cartridge, and a differential pressure regulating valve is disposed in the vicinity of a supply port of an ink storage section. 
   These types of ink cartridges can maintain ink pressure exerted on nozzle openings of a recording head at a predetermined level using the porous material or the differential pressure regulating valve, thereby preventing leakage of ink from the nozzle openings. 
   The present invention relates to the ink cartridges as described above, and aims at providing an ink cartridge which enables easy formation of a comparatively-complicated flow path such as an ink flow path and an atmosphere communication path. 
   SUMMARY OF THE INVENTION 
   To achieve the object, the invention provides an ink cartridge for use with an ink-jet recording apparatus in which ink is stored in a container having an ink supply port, wherein 
   an ink flow recess defining an ink flow path is formed in a surface of the container, and an atmosphere communication recess defining an atmosphere communication path is formed in the surface of the container; and 
   an opening of the ink flow recess and an opening of the atmosphere communication recess in the surface of the container, are sealed by a film, thereby constituting the ink flow path by the ink recess and the atmosphere communication path by the atmosphere communication recess. 
   According to the ink cartridge of the invention, the ink flow recess and atmosphere communication recess are formed in the surface of the container, and openings of these recesses are sealed by the film, thus constituting flow paths. Hence, it is possible to readily form a container having comparatively complicated flow path, such as the ink flow path and the atmosphere communication path. Therefore, designing and machining of a molding die are facilitated, thereby enabling lower-cost manufacture of an ink cartridge. 
   When the opening of the ink flow recess and the opening of the atmosphere communication recess are sealed with a single film, the number of films is not increased unduly, and hence the ink cartridge of the invention is advantageous in terms of cost. 
   When the opening of the ink flow recess and the opening of the atmosphere communication recess are sealed by welding the film onto the surface of the container, the ink flow recess and the atmosphere communication recess are sealed by means of welding of the film. Hence, manufacture of an ink cartridge is facilitated. 
   When the surface of the container is roughly divided into a region where primarily the ink flow recess is formed and another region where primarily the atmosphere communication recess is formed, and/or when a welding region of the film is divided into a region in which primarily the atmosphere communication recess is formed and another region, a further advantage can be obtained. That is, since precision for welding height is required for the opening of the atmosphere communication recess defining the atmosphere communication path, the region where the atmosphere communication recess is formed can be welded separately from the other region, thereby facilitating management of height precision in welding. It is possible to control the welding status only for a relatively small area. Hence, setup of requirements for welding can also be performed comparatively readily. 
   When the welding region of the film is divided into a region which primarily requires management of precision for welding height and another region which primarily requires management of welding strength, a height for welding can be accurately managed in the region which requires precision for welding height. Further, welding strength can be managed so as to be enhanced in the region which requires management of welding strength. Thus, management of welding precision and management of welding strength can be performed simultaneously. 
   When the ink cartridge further comprises a negative pressure generation system for generating negative pressure in the cartridge, and/or when a welding region of the film is divided into a region which is formed with the ink flow recess defining an ink flow path located downstream of the negative pressure generation system, and another region, since the cartridge having the negative pressure generation system involves the ink flow path and atmosphere communication path having comparatively-complicated geometries, the invention&#39;s advantage of the ability to readily form complicated flow paths is noticeable and effective. 
   When a grove which does not constitute a flow path is formed in the surface of the container, and/or when the groove which does not constitute the flow path is provided in a boundary between the divided welding regions, surfaces to be used for welding and pressurization can overlap between the divided welding regions. Thus, design freedom for a welding machine can be increased. 
   When an over-sheet for covering the film is attached to the surface of the container, the film is protected by the over-sheet, thereby preventing leakage of ink, which would otherwise be caused by damage of the film, as well as evaporation of ink. 
   When the over-sheet has an extended region for covering a surface other than said surface of the container, and/or when the extended region covers an ink injection port, the area up to the ink injection port can be covered by one over-sheet. Thus, the ink cartridge of the invention is advantageous in simplifying manufacturing process and curtailing the number of components. 
   In case that the thickness of the film is set so as to become smaller than that of the over-sheet, the film is likely to follow the surface of the container when the ink flow recess and the atmosphere communication recess are sealed by welding the film. Hence, the ink cartridge of the invention is advantageous in improving welding strength and precision. Further, the film can be effectively protected by a comparatively-thick over-sheet. 
   In the invention, the term “welding region” means a region in which welding can be effected with use of a single welding and pressurizing surface. 
   The present disclosure relates to the subject matter contained in Japanese patent application Nos. 2001-148296 (filed on May 17, 2001), and 2001-149786 (filed on May 18, 2001), which are expressly incorporated herein by reference in their entireties. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view showing an ink-jet recording apparatus using a cartridge according to the invention; 
       FIG. 2  is an exploded perspective view showing an embodiment of the cartridge of the invention; 
       FIG. 3  is an exploded view showing the cartridge; 
       FIG. 4  is a view showing a configuration of an opening section of a container main body; 
       FIG. 5  is a view showing a configuration of a surface of the container main body; 
       FIG. 6  is an enlarged view showing a cross-sectional structure of a differential pressure regulating valve storage chamber; 
       FIG. 7  is an enlarged view showing a cross-sectional structure of a valve storage chamber; 
       FIG. 8  is a view showing an example cartridge holder; 
       FIG. 9  is a view showing a welded status of a first film; 
       FIG. 10  is a descriptive view showing the layout of flow paths of a cartridge according to the invention; and 
       FIG. 11  is a view showing a welded status of an over-sheet. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   An embodiment of the invention will now be described in detail. 
     FIG. 1  is a view showing an example of an ink-jet recording apparatus employing an ink cartridge according to the invention. Ink cartridges to which the present invention is applied (hereinafter referred to simply as “cartridges”) are mounted on a carriage  75  of the ink-jet recording apparatus. The carriage  75  has a recording head  73  attached thereto. 
   The carriage  75  is connected to a stepping motor  79  by way of a timing belt  77  and is guided by a guide bar  78 , to travel back and forth across the width of recording paper (i.e., a primary scanning direction). The carriage  75  has substantially a box-like shape having an open top. The recording head  73  is mounted on the carriage  75  such that a nozzle surface of the recording head  73  is exposed at the surface of the carriage  75  opposing recording paper  76  (i.e., a lower surface of the carriage  75  in this example). The cartridges  1  are mounted on the carriage  75 . 
   Ink is, supplied from the ink cartridges  1  to the recording head  73 . Ink droplets are ejected onto an upper surface of the recording paper  76  while the carriage  75  is being moved, thereby printing an image or characters on the recording paper  76  in the form of a matrix of dots. 
     FIGS. 2 and 3  are exploded perspective views showing an embodiment of the cartridge  1  of the invention.  FIG. 4  is a view of a container main body  2  when viewed from an opening side thereof.  FIG. 5  is a view of the container main body  2  when viewed from a front surface side thereof (the surface of the container main body  2  opposite the opening side thereof will be hereinafter called a “front surface of the container main body  2 ”). 
   The cartridge  1  has a flat, rectangular, box-shaped container main body  2  which is open at one surface (i.e., a left side surface as viewed in  FIG. 2 ); and a cover member  3  welded to the open surface to seal the opening. Both the container main body  2  and the closure  3  are made of synthetic resin. 
   Formed in the front surface of the container main body  2  are ink flow grooves  35 ,  18 A which are to act as ink flow paths; and an atmosphere communication groove  36  which is to act as an atmosphere communication path. A single first film  57  possessing a gas impermeability is welded to the front surface of the container main body  2  so that openings of the ink flow grooves  35 ,  18 A and atmosphere communication groove  36  are sealed, whereby the ink flow grooves  35 ,  18 A constitute ink flow paths, and the atmosphere communication groove  36  constitutes an atmosphere communication path. 
   In this manner, the cartridge  1  of the invention is formed with the flow paths by sealing the opening of the ink flow groove  35  and that of the atmosphere communication groove  36  formed in the surface of the container main body  2  using the first film  57 . Hence, a container having comparatively-complicated flow paths, such as an ink flow path and an atmosphere communication path, can be readily formed, thereby facilitating designing or processing of a molding die and enabling low-cost manufacture of an ink cartridge. 
   Structures of the flow paths in the container main body  2  will now be described in detail. 
   An ink supply port  4  is formed in the leading end surface of the container main body  2  in a direction in which the container main body  2  is to be inserted into the carriage  75  (i.e., in a bottom surface in the embodiment). Grip arms  5  and  6  to be gripped at the time of removal or attachment of the cartridge  1  are formed integrally with forward and backward surfaces (i.e., a right-side surface and a left-side surface in  FIG. 4 ) of the container main body  2 . A valve member (not shown) to be opened by insertion of an ink supply needle is housed in the ink supply port  4 . In  FIG. 3 , reference numeral  49  designates a memory device provided in a portion of the container main body  2  close to the ink supply port  4  and below the grip arm  6 . 
   Formed in the opening side interior of the container main body  2  is a frame section  14  including a wall  10  which extends in a substantially horizontal direction and is sloped slightly downward toward the ink supply port  4 . The frame section  14  is spaced at a substantially uniform clearance from a ceiling surface and both side surfaces of the container main body  2 . An area located beneath the frame section  14  forms a first ink chamber  11  for storing ink. 
   The clearance formed between the frame section  14 , and the outer-peripheral wall of the container main body  2  and a wall  12  provided along the side of the frame section  14  opposing a valve storage chamber  8  constitute atmosphere communication paths  13 ,  13 A which bring the first ink chamber  11  in communication with the atmosphere by way of a through hole  67 . 
   The cover  3  is attached to the wall  12  and the outer peripheral wall of the container main body  2  by means of fusing, thus constituting the atmosphere communication path  13 A. The upper end of the wall  12  constituting the atmosphere communication path  13 A extends up to the neighborhood of the ceiling of the container main body  2  so as to protrude upward from a fluid level of the ink stored in the first ink chamber  11  when the ink cartridge is in use. As a result, an opening of the atmosphere communication path  13 A is opened at a location upward from the fluid level of the ink stored in the first ink chamber  11 , thereby preventing, to the extent possible, reverse flow of ink into the through hole  67 . 
   The inside of the frame section  14  is divided into left and right sub-divisions by a wall  15 . A communication port  15 A through which ink flows is formed in a bottom of the wall  15 , and the wall  15  extends in a vertical direction. The sub-division that is divided by the wall  15  and is located on the right side of the drawing forms a second ink chamber  16  for temporarily storing the ink sucked up from the first ink chamber  11 . Formed in the sub-division located,on the left side of the drawing are a third ink chamber  17 , a fourth ink chamber  23 , and a fifth ink chamber  34 . Further, a differential pressure regulating valve constituted of a membrane valve  52 , a spring  50 , etc. is also housed in the left-side sub-division. 
   Formed in the area of the first ink chamber  11  located below the second ink chamber  16  is a suction flow path  18  which connects the second ink chamber  16  to surroundings of a bottom surface  2 A of the container main body  2  to suck-up ink in the first ink chamber  11  into the second ink chamber  16 . A rectangular region surrounded by a wall  19  is formed in an area located below the suction flow path  18 . A communication port  19 A is formed in a lower portion of the wall  19 , and another communication port  19 B is formed in an upper surface of the wall  19 . 
   The suction flow path  18  is defined by forming a channel-like ink flow groove  18 A in the front surface of the container main body  2 , and sealing the ink flow groove  18 A with the first film  57 . 
   An upper portion of the suction flow path  18  is in communication with the second ink chamber  16  by way of a communication port  47 . An opening section  48  is formed in a lower portion of the suction flow path  18  located within the rectangular region surrounded by the wall  19 . An opening  18 B (see  FIG. 9B ) formed in the lower end of the suction flow path  18  is in communication with the first ink chamber  11 . As a result, the first ink chamber  11  and the second ink chamber  16  are in communication with each other by way of the suction flow path  18 , and the ink stored in the first ink chamber  11  is introduced into the second ink chamber  16 . 
   An ink injection port  20  to be used in injecting ink into the first ink chamber  11  is formed in an area on the bottom surface of the container main body  2  corresponding to the suction flow path  18 . An air vent  21  which allows air to escape at the time of injection of ink is formed in the vicinity of the ink injection port  20 . 
   A wall  22  is formed in the third ink chamber  17  so as to extend horizontally while being spaced a given interval from an upper surface  14 A of the frame section  14 . The third ink chamber  17  is partitioned by a substantially-arc-shaped wall  24  continuous with the wall  22 . A differential pressure regulating valve storage chamber  33  and the fifth ink chamber  34  are formed in the area surrounded by the wall  24 . 
   The area surrounded by the arc-shaped wall  24  is divided into two sub-divisions in the thickness direction, by a wall  25 , such that a differential pressure regulating valve storage chamber  33  is formed in the area on the front surface side and opposite from the fifth ink chamber  34 . The wall  25  has ink-flow-path ports  25 A for guiding the ink having flowed into the fifth ink chamber  34  to the differential pressure regulating valve storage chamber  33 . 
   A partition wall  26  having a communication port  26   a  is provided between a lower portion of the wall  24  and the wall  10 . The area located downstream of the partition wall  26  (a left-side in  FIG. 4 ) is formed as the fourth ink chamber  23 . Interposed between the substantially arc-shaped wall  24  and the frame section  14  are a partition wall  27  and a partition wall  32 . A communication port  27 A is formed in a lower portion of the partition wall  27 , and the partition wall  27  extends vertically. Further, a communication ports  32 A and  32 B are respectively formed in upper and lower portions of the vertically extending partition wall  32 . 
   An arc-shaped wall  30  is formed in the container main body  2  so as to be continuous with an upper end section of the partition wall  27 , and is connected to the substantially-arc-shaped wall  24  and the wall  22 . An area surrounding by the substantially arc-shaped wall  30  is formed into a filter housing chamber  9  for housing a block-shaped filter (a cylindrical filter in the embodiment) therein. 
   A through hole  29  having a combined shape of a large circle portion and a small circle portion is formed so as to extend across the circular-arc-shaped wall  30  constituting the filter housing chamber  9 . The large circle portion of the through hole  29  is in communication with the upper portion of the ink flow path  28 A, and the small circle portion of the through hole  29  is in communication with an upper portion of the fifth ink chamber  34  by way of a communication port  24 A formed in a tip end portion of the substantially-arc-shaped wall  24 . As a result, the ink flow path  28 A and the fifth ink chamber  34  are in communication with each other by way of the through hole  29 . 
   The ink that has flowed from the second ink chamber  16  into the ink flow path  28 A by way of the communication ports  15 A,  26 A,  32 B,  27 A, etc. flows into the large circle portion of the through hole  29  after having been filtered by the filter  7  of the filter housing chamber  9 . The ink that has flowed into the through hole  29  flows from the small circle portion of the through hole  29  into the fifth ink chamber  34  by way of the communication port  24 A. An opening of the through hole  29  formed in the front surface side of the container main body  2  is also sealed by the first film  57 . 
   A gas impermeable second film  56  is attached to the opening side of the frame section  14  by means of welding. That is, the second film  56  is attached to the frame section  14 , the walls  10 ,  15 ,  22 ,  24 ,  30 , and  42 , and the partition walls  26 ,  27 , and  32  by means of welding, thus constituting ink chambers and flow paths. 
   A lower portion of the differential pressure regulation valve storage chamber  33  and the ink supply port  4  are in communication with each other via the flow path defined by the ink flow groove  35  formed in the front surface of the container main body  2  and the gas impermeable first film  57  covering the ink flow groove  35 . The upper and lower ends of the ink flow groove  35  are respectively in communication with the differential pressure regulation valve storage chamber  33 , and the ink supply port  4 . As a result, the ink that has flowed into the fifth ink chamber  34  passes through the ink-flow-path ports  25 A and the differential pressure regulating valve storage chamber  33 , and flows into the ink supply port  4  by way of the flow path defined by the ink groove  35 . 
   Formed in the front surface of the container main body  2  are the atmosphere communication groove  36  which meanders so as to increase flow resistance to the greatest possible extent; and a wide groove  37  which is in communication with the atmosphere communication groove  36  and surrounds the differential pressure regulating valve storage chamber  33  and the atmosphere communication groove  36 . Further, a rectangular recess  38  is formed in an area in the front surface of the container main body  2  and corresponding to the second ink chamber  16 . 
   A frame section  39  and ribs  40  are formed with in the rectangular recess  38  at a location lowered from an open edge of the recess  38 . A gas permeable sheet  55  possessing an ink repellent characteristic is stretched over and attached onto the frame section  39  and the ribs  40 . As a result, the inside of the rectangular recess  38  is formed into an atmosphere communication chamber which is in communication with the atmosphere by way of the atmosphere communication groove  36  and the groove  37 . 
   A through hole  41  is formed in a deep surface of the recess  38 , and is in communication with a narrow, elongated area  43  defined by an elongated oval wall  42  provided within the second ink chamber  16 . The area of the recess  38  closer to the front surface side than the gas permeable sheet  55  is located is in communication with the atmosphere communication groove  36 . Further, a through hole  44  is formed in the end of the narrow, elongated area  43  opposite from the through hole  41 . The through hole  44  is in communication with the valve storage chamber  8  serving as an atmosphere release valve chamber, by way of a communicating groove  45  formed in the front surface side of the container main body  2  and a through hole  46  formed in communication with the groove  45 . 
   A through hole  60  is formed in the valve storage chamber  8  so as to be in communication with the through hole  67  formed in the atmosphere communication path  13 A formed in the first ink chamber  11 . As a result, the air that has entered the recess  38  by way of the atmosphere communication groove  36  reaches the valve storage chamber  8 , by way of the through hole  41 , the narrow, elongated area  43 , and the through holes  44 ,  46 . The air further reaches the first ink chamber  11  from the valve storage chamber  8 , by way of the through hole  60 , the communication hole  67 , and the atmosphere communication paths  13 ,  13 A. 
   The cartridge insertion side of the valve storage chamber  8  (i.e., a bottom surface in the embodiment) is opened. As will be described later, identification pieces and an operation lever provided on a recording apparatus main unit can enter into the storage chamber  8  through the opening. Housed in an upper portion of the valve storage chamber  8  is an atmosphere release valve which opens upon entry of the operation lever, thereby maintaining a normally-open valve status. 
     FIG. 6  shows a cross-sectional view of the structure located in the vicinity of the fifth ink chamber  34  and the differential pressure regulating valve storage chamber  33 . The right-side portion of the drawing shows the front surface side of the container main body  2  where the differential pressure regulating valve storage chamber  33  is located. Stored in the differential pressure regulating valve storage chamber  33  are the spring  50  and the membrane valve  52  formed of an elastically-deformable material, such as elastomer. The membrane valve  52  has a through hole  51  formed in the center thereof. The membrane valve  52  has an annular thick-walled section  52 A in the periphery thereof, and is fastened to the container main body  2  by way of a frame section  54  formed integrally with the thick-walled section  52 A. One end of the spring  50  is contacted with and supported by a spring receiving section  52 B of the membrane valve  52 , and the other end of the same is contacted with and supported by a spring receiving section  53 A of a lid member  53  which closes the differential pressure regulating valve storage chamber  33 . 
   With this arrangement, the membrane  52  blocks flow of the ink that has flowed from the fifth ink chamber  34  and passed through the ink-flow-path ports  25 A. If the pressure of the ink-supply port  4  has dropped in this state, the membrane valve  52  is separated from a valve seat section  25 B against the urging force of the spring  50 , by the negative pressure. Hence, the ink passes through the through hole  51  and flows into the ink supply port  4  via the flow path defined by the ink flow groove  35 . 
   When an ink pressure of the ink supply port  4  has risen to a predetermined level, the membrane valve  52  is brought, by the urging force of the spring  50 , into elastic contact with the valve seat section  25 B, thus interrupting the ink flow. Through repetition of this operation, ink can be output to the ink supply port  4  while a constant negative pressure is maintained. 
     FIG. 7  shows a cross-sectional view of the structure of the valve storage chamber  8  for use in communication with the atmosphere. The right-side portion of the drawing shows the front surface side of the container main body  2 . A through hole  60  is formed in the partition wall defining the valve storage chamber  8 . A press member  61  constituted of an elastic member, such as rubber, is fitted into the through hole  60  in a movable manner while surroundings of the press member  61  are supported by the container main body  2 . A valve member  65  is disposed on the leading end of the press member  61  in the entry side so that the valve member  65  is supported by an elastic member  62 , and constantly urged onto the through hole  60 . In this example, a plate spring is used as the elastic member  62 , such that the lower end of the spring is fixed by a projection  63  and the central portion of the spring is regulated by projections  64 . 
   An arm  66  is disposed on the other side of the press member  61 . The cartridge insertion direction side of the arm  66  (i.e., a lower end in the embodiment) is fixed to the container main body  2  by way of a pivot point  66 A located at an inner side than an operation lever  70  to be described later. The pulling-out side of the arm  66  (i.e., an upper side in the embodiment) obliquely projects into an entry path of the operation lever  70 . A protuberance  66 B is formed at the leading end of the arm  66  for resiliently pressing the press member  61 . With this construction, at the time when the valve member  65  is opened, the through hole  67  formed in an upper portion of the first ink chamber  11  is connected to the atmosphere communicating recess  38  by way of the through hole  60 , the valve storage  8 , the through hole  46 , the groove  45 , the through hole  44 , the narrow, elongated region  43  and the through hole  41 . 
   A identification projection  68  is provided in the valve storage chamber  8  at a location closer to the insertion direction side (i.e., the lower side in the embodiment) than the arm  66  is located, for identifying whether or not the cartridges  1  are suitable for the recording apparatus. The identification projection  68  is disposed at such a location that a determination can be made through use of the identification piece (operating rod)  70  before the ink supply port  4  is connected to the ink supply needle  72  (see.  FIG. 8 ) and the valve member  65  is opened. 
   With this arrangement, when the cartridge  1  is loaded into a cartridge holder  71  having the operation rod  70  provided upward on a lower surface thereof, as shown in  FIG. 8 , the operating rod  70  is brought into contact with the inclined arm  66  to tilt the press member  61  toward the valve member  65  in association with pressing of the cartridge  1 . As a result, the valve member  65  is separated from the through hole  60 , and the atmosphere communication recess  38  is opened to the atmosphere by way of the through hole  46 , the groove  45 , the through hole  44 , the area  43 , and the through hole  41  as described above. 
   When the ink cartridge  1  is pulled out from the cartridge holder  71 , the arm  66  becomes free from the support by the operation rod  70 . As a result, the valve member  65  closes the through hole  60  under the urging force of the elastic member  62 , thereby interrupting communication between the ink storage region and the atmosphere. 
   Next, the gas impermeable first film  57  is attached to the front surface of the container main body  2  so as to cover at least the area having the recess formed therein, after all the components, such as valves, are incorporated into the container main body  2 . As a result, a capillary serving as an atmosphere communication path is formed in the front surface side of the container main body  2  by the recess and the first film  57 . 
   Here, the detailed description will be given of the layout and formation of the flow paths, including the capillary. 
   In case of the ink cartridge  1  as mentioned above, the single first film  57  is welded to the front surface of the container main body  2  of the cartridge  1  to seal the openings of the ink flow groove  35 , the through hole  29 , the ink flow groove  18 A, the groove  45 , the atmosphere communication groove  36 , and the recess  38  in the front surface of the container main body  2 , whereby the ink flow groove  35 , the through hole  29 , the ink flow groove  18 A, and the groove  45  define respective ink flow paths, and the atmosphere communication groove  36  and the recess  38  define respective atmosphere communication paths.  FIG. 9  shows a state of the cartridge  1  where the first film  57  has been welded thereto. 
   At this time, the first time  57  is welded to the front surface of the container main body  2 , by such a thermal welding method that the first film  57  is applied to cover the front surface of the container main body  2 , and pressed using a heating/pressurizing plate. 
   Here, the atmosphere communication groove  36  is formed as a shallow, narrow, complicatedly-bent groove in order to prevent evaporation of ink to the extent possible and to avoid an unduly increased flow resistance. Therefore, when the atmosphere communication groove  36  is sealed by the first film  57 , the atmosphere communication groove  36  may be collapsed or destroyed to hinder an air communication unless the height at which the first film  57  is to be welded is controlled with high precision. On the other hand, it is preferably that the welding, the importance of which is given to welding strength is carried out for the recess constituting an ink flow path, such as the ink groove  35 , in order to prevent leakage of ink. 
   For this reason, as shown in  FIG. 10 , the layout of flow paths in the front surface of the container main body  2  is such that the front surface can be roughly divided into a region (b) where recesses, such as the ink flow groove  35  and the through hole  29 , defining the ink flow paths are primarily disposed, and a region (a) where the atmosphere communication groove  36  is primarily disposed. Further, a groove  31  that does not form a flow path is disposed in a boundary between regions (a) and (b) in the front surface of the container main body  2 . 
   Moreover, a range where the first film  57  is pressurized at one time using one heating/pressurizing plate when the first film  57  is welded to the container main body  2  (hereinafter called a “welding region”) is set as each of divided regions (a) and (b) where the region (a) primarily requires management of precision for welding height, and the region (b) primarily requires management of welding strength. Welding requirements or conditions are controlled independently in the respective regions (a) and (b). As a result, welding precision and welding strength can be managed concurrently. Further, since the control of a welding status for a relatively small area is made possible, setup of welding requirements can be performed comparatively readily. 
   In other words, the region of the first film  57  to be welded is divided into the region (b), where the ink flow groove  35  is formed, which defines the ink flow path located downstream of the differential pressure valve generating negative pressure within the cartridge  1 , and the other region (a). That is, in case of the cartridge having the differential pressure regulating valve, the geometries of flow paths, such as the ink flow paths and atmosphere communication paths, become comparatively complicated, and therefore a noticeable effect can be obtained to readily form the complicated flow paths. 
   Since the groove  31  which does not constitute any flow path is situated in a boundary between the divided welding regions (a),(b), surfaces to be used for welding and pressurizing the first film  57  can overlap between the divided welding regions (a), (b), thereby increasing a design freedom of a welding machine. In  FIGS. 9A and 9B , reference numeral  57 A designates a notch provided in the area of the first film  57  corresponding to the groove  31 . 
   As shown in  FIG. 11 , in the case of the cartridge  1  mentioned above, an over-sheet  59  for covering the first film  57  is attached to the front surface side of the container main body  2 . With this arrangement, the over-sheet  59  protects the first film  57 , thereby preventing leakage of ink caused by damage of the first film  57 , and eliminating evaporation of ink. In the drawing, reference numeral  59 A designates a notch formed in the area of the over-sheet  59  corresponding to the groove  31 . 
   A sheet which is thicker than the first film  57  is used as the over-sheet  59 . That is, in the case of the cartridge  1  mentioned above, the thickness of the first film  57  is set smaller than that of the over-sheet  59 . As a result, when the ink grooves  35 ,  18 A, the atmosphere communication groove  36 , etc. are sealed by welding the first film  57 , the first film  57  is readily overlaid along the front surface of the container main body  2 , and hence it is advantageous in improving welding strength and precision. The first film  57  can be effectively protected by the relatively thick over-sheet  59 . 
   The over-sheet  59  is formed with an extended area  59 B for covering a portion of the lower surface of the container main body  2 , and the extended area  59 B covers the ink injection port  20  and the air outlet port  21 . Thus, the single over-sheet  59  can cover up to the ink injection port  20  and the air outlet port  21 , and hence it is advantageous in simplifying manufacturing processes and reducing the number of components. 
   As mentioned-above, the gas impermeable second film  56  is thermally-welded to the opening section of the container main body  2  to be hermetic with respect to the frame section  14 , the walls  10 ,  15 ,  22 ,  24 ,  30 , and  42 , and the partition walls  26 ,  27 , and  32 . The cover  3  is further placed over the second film  56  and fixed by welding. As a result, the areas partitioned by the walls are sealed so as to be in communication by way of only communication ports or openings. 
   Similarly, an opening of the valve storage chamber  8  is sealed with the gas impermeable third film  58  by thermal welding, thus completing the cartridge  1 . By adopting such a structure that the ink storage area is sealed using the gas impermeable first and second films  56 ,  57 , etc., the container main body  2  can be formed readily, and also ink pressure can be maintained as constant as possible because fluctuations in ink stemming from reciprocal movement of the carriage can be absorbed by deformation of the first and second films  56 ,  57 . 
   Next, an ink injection tube is inserted into the ink injection port  20 , and sufficiently degassed ink is injected while the air outlet port  21  is remained open. After completion of injection of ink, the ink injection port  20  and the air outlet port  21  are sealed with a film and the over-sheet  59 . 
   Since the ink cartridge  1  having such a construction is preserved while being isolated from the atmosphere by the valves, etc., the degassed rate of ink is sufficiently maintained. 
   In a case where the cartridge  1  is loaded into the cartridge holder  71 , if the cartridge  1  is suitable for the cartridge holder  71 , the ink supply port  4  enters up to a position where the ink supply needle  72  is inserted into the ink supply port  4 . As mentioned previously, the through hole  60  is released by the operation rod  70 , whereby the ink storage region is brought in communication with the atmosphere, and the valve of the ink supply port  4  is opened by the ink supply needle.  72 . 
   If the cartridge  1  is not suitable for the cartridge holder  71 , the identification protuberance  68  comes into contact with an identification piece  70 A of the holder  71  before the ink supply port  4  reaches the ink supply needle  72 , thus hindering advancement of the ink supply port  4 . In this state, the operation rod  70  is also unable to reach the arm  66 . Hence, the valve member  65  maintains a sealed status, and release of the ink storage region to the atmosphere is hindered, thereby preventing evaporation of ink. 
   When the cartridge  1  has been properly loaded into the cartridge holder  71  and ink has been consumed by the recording head  73  as a result of execution of printing operation, the pressure of the ink supply port  4  drops to a specified level or less, and the membrane valve  52  is opened. Further, if the pressure of the ink supply port  4  has increased, the membrane valve  52  is closed. Thus, the ink maintained at predetermined negative pressure flows into the recording head  73 . 
   When consumption of ink by the recording head  73  has proceeded, the ink stored in the first ink chamber  11  flows into the second ink chamber  16  by way of the suction flow path  18 . Air bubbles having flowed into the second ink chamber  16  are elevated by means of buoyancy, and only ink flows into the third ink chamber  17  by way of the communication port  15 A located in the low part of the second ink chamber  16 . 
   The ink stored in the third ink chamber  17  flows into the ink flow paths  28 A,  28 B by way of the fourth ink chamber  23  after having passed through the communication port  26 A of the partition wall  26  formed in the lower end of the substantially-circular wall  24 . 
   The ink having flowed through the ink flow path  28 A flows into the filter storage chamber  9 , where the ink is filtrated by the filter  7 . The ink having passed through the filter storage chamber  9  flows through the large and small circle portions of the through hole  29  and enters an upper portion of the fifth ink chamber  34  after having passed through the communication port  24 A. 
   Next, the ink having flowed into the fifth ink chamber  34  flows into the differential pressure regulating valve storage chamber  33  after having passed through the ink-flow-path port  25 A. As mentioned previously, the ink flows into the ink supply port  4  at predetermined negative pressure by opening and closing actions of the membrane valve  52 . 
   The first ink chamber  11  is in communication with the atmosphere by way of the atmosphere communication paths  13 ,  13 A, the through hole  67 , the valve storage chamber  8 , etc., and is maintained at the atmospheric pressure. Hence, there does not arise a hindrance to an ink flow, which would otherwise be caused by generation of negative pressure. Even if the ink stored in the first ink chamber  11  has reversely flowed into the recess  38 , the ink-repellent gas permeable sheet  55  provided on the recess  38  maintains communication with the atmosphere, while preventing the flow-out of ink. Thus, it is possible to prevent clogging in the atmosphere communication groove  36 , which would otherwise be caused when ink has flowed into the atmosphere communication groove  36  and solidified there. 
   As mentioned above, in the cartridge  1 , the ink flow groove  35  and the like, and the atmosphere communication groove  36  are formed in the front surface of the container main body  2 , and the openings of these grooves are sealed by the first film  75 , thus constituting flow paths. Hence, there can be readily formed a container having comparatively complicated flow paths, such as ink flow paths and atmosphere communication paths. Therefore, designing and machining of a molding die are facilitated, thereby enabling lower-cost manufacture of an ink cartridge. 
   The embodiment has illustrated, while taking an example in which a columnar filter is used as the filter  7 . However, the invention is not limited to that example. Filters of various sizes and shapes may be used, so long as the filters assume the shape of a block. 
   As has been described, according to an ink cartridge of the invention, a recess for ink and an atmosphere communication groove are formed in the front surface of a container, and an openings of the recess and the groove are sealed by a film, thereby constituting flow paths. Hence, there can be readily formed a container having comparatively complicated flow paths, such as an ink flow path and an atmosphere communication path. Therefore, designing and machining of a molding die are facilitated, thereby enabling lower-cost manufacture of an ink cartridge. 
   In addition, in  FIG. 5 , reference character A designates an example of an imaginary straight line that is substantially parallel to an insertion direction B of an ink cartridge to a recording apparatus and that defines first and second sides of the ink cartridge.