Abstract:
A method of refilling an ink bag that is used in an ink jet recorder, the ink bag is initially filled with ink through an opening in the bag, and is sealed after the ink bag is initially filled. The method comprises the steps of removing the ink bag from the ink jet recorder, positioning the ink bag, inserting an ink needle into a separate opening in the ink bag that is different than the first opening through which the ink bag is initially filled with ink, discharging ink from the ink bag through the second opening, and charging the ink bag through the second opening with a specified quantity of ink.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application is a continuation of pending U.S. application Ser. No. 09/306,651, filed May 6, 1999, which is a divisional of U.S. application Ser. No. 08/969,326, filed Nov. 13, 1997, the entire contents of which are hereby incorporated by reference.  
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates to an ink cartridge which is removably attached to an enclosure of an ink jet recorder and supplies ink to a recording head, and more particularly, to a method of manufacturing an ink cartridge comprising a flexible ink bag housed in a hard case.  
           [0003]    A conventional ink jet printer includes an ink container carried by a carriage equipped with an ink jet recording head. Ink droplets are produced by supplying to the recorder head ink that has been pressurized within a pressure generation chamber located within the ink container via a tube. However, when the carriage is pivoted, shaken or caused to travel during printing, the movement can cause the ink to become frothy or foamy. This, in turn, may result in a change in head pressure or cause print failures. Specifically, if ink contains gas bubbles, the pressure at which the ink is under drops, thereby decreasing the ability to eject ink droplets. For this reason, dissolved air must be eliminated from the ink.  
           [0004]    Accordingly, it is desirable to develop a method for manufacturing an ink jet cartridge for use in an ink jet recorder, that overcomes disadvantages and limitations of existing methods. The present invention has been contrived in view of drawbacks in the prior art, and an object of the present invention is to provide a manufacturing method that enables efficient and more simple manufacture of an ink cartridge for use in an ink jet recorder.  
         SUMMARY OF THE INVENTION  
         [0005]    Generally speaking, in accordance with the invention, a method of manufacturing an ink cartridge for use in an ink jet recorder, is provided. An ink bag, having a top end, and a bottom end below the top end, the top end being open and the bottom end having an ink feed port, can be hung from a first position near a top edge thereof and positioned in a vacuum chamber. The vacuum chamber can be depressurized, upon which a selected quantity of ink can be charged into the ink bag. The open end of the ink bag can be sealed at a second position below the first position, and the sealed portion of the ink bag pressed to a selected thickness with press plates. The ink bag can be sealed at a third position below the second position, and thereafter cut between the second and third positions.  
           [0006]    Accordingly, it is an object of the present invention to provide a method of manufacturing an ink cartridge which permits efficient filling of degassed ink into an ink bag of an ink cartridge used in an ink jet recorder that can withstand handling during distribution and use, as well as recycling.  
           [0007]    Another object of the present invention is to propose a method of recycling a comparatively expensive ink container.  
           [0008]    Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.  
           [0009]    A first embodiment of the invention is directed to a method of refilling an ink bag for use in an ink jet recorder in which the ink bag is initially filled with ink through a first opening in the bag that is sealed after the ink bag is initially filled. The method of this embodiment comprises the steps of removing the ink bag from the ink jet recorder, positioning the ink bag, inserting an ink needle into a separate opening in the ink bag that is different than the first opening through which the ink bag is initially filled with ink, discharging ink from the ink bag through the second opening, and charging the ink bag through the second opening with a specified quantity of ink.  
           [0010]    A second embodiment of the invention is directed to a method of refilling an ink bag for use in an ink jet recorder. The method of this second embodiment comprises the steps of removing the ink bag from the ink jet recorder, positioning the ink bag, inserting an ink needle into a port of the ink bag, discharging ink from the ink bag through the same port, and charging the ink bag through the same port with a specified quantity of ink.  
       
    
    
       [0011]    The invention accordingly comprises the features of construction, combination of elements, and arrangements of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.  
       BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    For a fuller understanding of the invention, reference is had to following description taken in connection with the accompanying drawings, in which:  
         [0013]    [0013]FIG. 1 is a perspective exploded view showing an ink cartridge according to one embodiment of the present invention;  
         [0014]    [0014]FIG. 1A is a cross-sectional view showing an ink bag of the ink cartridge depicted in FIG. 1;  
         [0015]    [0015]FIG. 2 is a schematic diagram showing one embodiment of an ink filling apparatus in accordance with the ink cartridge manufacturing method of the present invention;  
         [0016]    [0016]FIG. 3 is a schematic diagram showing a second embodiment of an ink filling apparatus in accordance with the ink cartridge manufacturing method of the present invention;  
         [0017]    [0017]FIG. 4 is a front elevational view showing one embodiment of an ink bag prior to being charged with ink;  
         [0018]    [0018]FIGS. 5A and 5B are schematic representations showing a step of hanging the ink bag in accordance with an ink cartridge manufacturing method of the present invention;  
         [0019]    [0019]FIGS. 6A and 6B are schematic representations showing preliminary steps of filling ink into the ink bag in accordance with an ink cartridge manufacturing method of the present invention;  
         [0020]    [0020]FIGS. 7A and 7B are schematic representations showing the initial steps of filling ink into the ink bag in accordance with an ink cartridge manufacturing method of the present invention;  
         [0021]    [0021]FIGS. 8A and 8B are schematic representations showing the final steps of filling ink into the ink bag in accordance with an ink cartridge manufacturing method of the present invention;  
         [0022]    [0022]FIG. 9 is a schematic representation showing the ink bag in its final sealed condition in accordance with an ink cartridge manufacturing method of the present invention;  
         [0023]    [0023]FIG. 10 is a schematic diagram showing a third embodiment of an ink filling apparatus in accordance with the ink cartridge manufacturing method of the present invention;  
         [0024]    [0024]FIGS. 11A and 11B are schematic representations showing a step of positioning an ink bag and of charging the ink bag in accordance with an ink cartridge manufacturing method of the present invention;  
         [0025]    [0025]FIGS. 12A and 12B are schematic representations showing a step of sealing the ink bag in accordance with an ink cartridge manufacturing method of the present invention;  
         [0026]    [0026]FIG. 13 is a block diagram showing a fourth embodiment of an ink filling apparatus in accordance with the ink cartridge manufacturing method of the present invention;  
         [0027]    [0027]FIG. 14 is a block diagram showing a refilling apparatus in accordance with one embodiment of the present invention;  
         [0028]    [0028]FIGS. 15A and 15B are schematic representations showing the initial steps of a process for refilling an ink bag in accordance with one embodiment of the present invention; and  
         [0029]    [0029]FIGS. 16A and 16B are schematic representations showing the final steps of a process for refilling the ink bag in accordance with one embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0030]    Reference is made to FIG. 1, which shows an ink cartridge  70  manufactured by a method in accordance with an embodiment of the present invention. Ink cartridge  70  includes a case body  2 , an elastic ink bag  1 , having ink sealed therein, designed to be accommodated within case body  2 , and a cover  3  for covering case body  2 . An ink detection plate  4  is provided preferably between ink bag  1  and cover  3 , and includes a detector (not shown) for detecting when ink bag  1  no longer contains a sufficient quantity of ink and for activating an indicator (not shown) that indicates that ink bag  1  is empty.  
         [0031]    As shown in FIG. 4, ink bag  1  is preferably formed in a rectangular shape, having a width W and an ink level length L when charged. As such, referring to FIG. 1, ink bag  1  includes two longitudinal sides  1   b , and an inlet side  1   c  and an outlet side  1   a  positioned between longitudinal sides  1   b . Longitudinal sides  1   b  are preferably the same length, and are preferably longer than inlet side  1   c  and outlet side  1   a.    
         [0032]    In a preferred embodiment, ink bag  1  is formed by overlaying superimposing two outer films  100 ,  101 , one on top of the other. Each outer film  100 ,  101  is formed of an aluminum laminate, and includes two layers, preferably, an outer nylon layer and an inner polyethylene layer. Inner films  102 , preferably formed of aluminum foil, are interposed adjacent to the inner surface of the outer films  100 ,  101 , and create an air-tight seal when heat-welded. Referring to FIG. 1A, films  100 ,  101 ,  102  are layered, for example, such that layer  100  is superimposed on inner films  102 , which are superimposed on outer layer  102 . Ink bag  1  is preferably formed by thermally welding films  100 ,  101  and  102  at longitudinal sides  1   b . Ink bag  1  includes a port  5 , preferably formed of a plastic, which is thermally welded to ink bag  1  at a base  6  of outlet side  1   a . Base  6  functions to impart rigidity to ink bag  1 . Port  5  is sealed at its free end with a septum  7 , which is formed from a resilient material, such as rubber, and is inserted into port  5 . Port  5  elastically engages an ink feed needle (not shown) during the printing process.  
         [0033]    A method of manufacturing ink cartridge  70  will now be described. Referring to FIG. 2, an ink filling apparatus  200  constructed in accordance with one embodiment of the present invention, is shown. Ink filling apparatus  200  includes a vacuum chamber  10  having one side that can be opened or closed by a door  11 . Vacuum chamber  10  is in fluid communication via a channel  12  to a vacuum pump  13 , which upon activation depressurizes vacuum chamber  10  to a predetermined vacuum pressure. Vacuum chamber  10  includes two support rods  14 , which extend horizontally from an inner surface  10   a  of vacuum chamber  10 . Ink filling apparatus  200  also includes heat welders  15 ,  15 ′ and press plates  16 ,  16 ′ positioned below support rods  14  within chamber  10 .  
         [0034]    A through hole  10   b  is formed in a top wall  10   c  of vacuum chamber  10 . A manifold  10   d  includes a channel  10   e  and a channel  10   f . A needle inserter  19  is disposed within channel  10   e  and is connected at one end to an ink feed needle  18 . Ink feed needle  18  is disposed within vacuum chamber  10 , and is vertically positioned by needle inserter  19  in a direction indicated by double arrow A. Needle inserter  19  is in fluid communication with a branch pipe  21  via a tube  20 .  
         [0035]    Ink filling apparatus  200  also includes a gas-liquid separation unit  22 . In one preferred embodiment of the invention, gas-liquid separation unit  22  includes a hollow yarn bundle  23 , which is preferably connected fluid-tight at both longitudinal ends to a cylinder  24  so as to permit fluid to flow therethrough. Cylinder  24  is connected to a vacuum pump  25  so as to produce negative pressure around the outer periphery of yarn bundle  23 . Cylinder  24  includes an inlet  24   a , which is connected to an ink tank  27  having ink  37  therein, via a tube  26 , and an outlet  24   b , which is connected to branch pipe  21  via a stop valve  28 . Ink  37  is pumped to gas-liquid separator unit  22  by a pump  35 .  
         [0036]    Branch pipe  21  is also connected to a measuring tube  30  via a tube  33 . Measuring tube  30  includes a cylinder  31  and a piston  32 , and is preferably connected to branch pipe  21  at the center of one end of cylinder  31 .  
         [0037]    Referring now to FIG. 3, a second embodiment of an ink filling apparatus  500  constructed in accordance with the invention, is shown where like elements are indicated by like reference numerals. Ink filling apparatus  500  includes a dispenser  36  for metering the quantity of ink  37  to be filled into ink bag  1 . Dispenser  36  is disposed between stop valve  34  of tube  20  and stop valve  28  provided downstream of outlet  24   b . A valve  137  is in fluid communication with dispenser  36  via a tube  37   a . Valve  137  is opened to ambient air when dispenser  36  has metered a specified quantity of ink. Ink is fed into ink bag  1  from dispenser  36  by means of the pressure differential between the ambient pressure and the pressure in vacuum chamber  10 .  
         [0038]    Referring to FIG. 2, a method of filling ink into ink bag  1  in accordance with a first embodiment of the invention will be described with reference to ink filling apparatus  200 . Referring now to FIG. 4, port  5  includes a free end  5   a  and a fixed end  5   b , and is attached to outlet side  1   a  of ink bag  1  by heat-welding base  6  of outlet side  1   a  about fixed end  5   b  of port  5 . At the same time, the remainder of outlet side  1   a  is heat-welded. Free end  5   a  is fitted with septum  7  to form a seal. Next, inlet side  1   c  of ink bag  1  is opened, and a plurality of through holes  1   f  are formed in the vicinity of opening  1   e.    
         [0039]    As shown in FIG. 5A, ink bag  1  is hung from support rods  14  by sliding through holes  1   f  over support rods  14  such that opening  1   e  of ink bag  1  is in a spread position. Subsequently, door  11  is closed to form a vacuum chamber  10 , stop valve  28  connected to gas-liquid separation unit  22  is closed, and stop valve  34  is opened as is shown in FIG. 5B. Vacuum pump  13 , which is connected via channel  12  to chamber  10 , is then activated to depressurize chamber  10 , tubes  20  and  33 , and measuring tube  30  to a predetermined pressure.  
         [0040]    Referring to FIG. 6A, when vacuum chamber  10  and tubes  20 ,  30  and  33  have been evacuated to a predetermined pressure, stop valve  34  is closed. Thereafter, measuring tube  30  is placed in fluid communication with gas-liquid separation unit  22  by opening stop valve  28 , and a predetermined quantity of ink  37  is filled into measuring tube  30 . Since gas-liquid separation unit  22  is connected close to measuring tube  30 , ink flows into measuring tube  30  immediately after having been degassed by gas-liquid separation unit  22 . In conjunction with this operation, as is shown in FIG. 6B, needle inserter  19  is lowered such that injection needle  18  is in part disposed within ink bag  1 .  
         [0041]    Next, as shown in FIG. 6B, stop valve  28  is closed to isolate gas-liquid separation unit  22 , stop valve  34  is opened, and piston  32  of measuring tube  30  is pressed to discharge the predetermined quantity of ink  37  into ink bag  1  via tube  33 , tube  20  and needle inserter  19 . After ink bag  1  has been filled with ink  37 , needle inserter  19  is activated to withdraw ink feed needle  18  from ink bag  1  to an upper position recessed within channel  10   e . Press plates  16 ,  16 ′ are then moved by a presser (not shown) to compress ink bag  1  from a thickness shown as X in FIG. 6B to a predetermined thickness X′ as shown in FIG. 7A. Accordingly, the level of ink  37  contained in ink bag  1  rises from a level Z as shown in FIG. 6B to a level Z′ as shown in FIG. 7A. At level Z′, the quantity of ink  37  contained within ink bag  1  is slightly more than that contained in a completed product.  
         [0042]    At this point, as shown in FIG. 7B, an upper portion of ink bag  1  is pinched at a first seal position  1   g  by heat welders  15 ,  15 ′ which are moved in a direction indicated by arrows B and C, respectively, thereby sealing ink bag  1  at first seal location  1   g . If, at this stage of the ink-filling process, ink bag  1  was permanently sealed, a small amount of air would be sealed together with ink  37 . Accordingly, further steps are taken to prevent air from being trapped in a sealed ink bag  1 .  
         [0043]    After the initial sealing operation, as is shown in FIG. 8A, press plates  16 ,  16 ′ and heat welders  15 ,  15 ′ are moved back to their original positions to permit air bubbles to aggregate just below first seal position  1   g  of ink bag  1 . When press plates  16 ,  16 ′ are retracted, ink bag  1  assumes a more rounded form, having a thickness X″. At this point, as is shown in FIG. 8B, ink bag  1  is again pressed to a predetermined thickness by moving press plates  16 ,  16 ′ in directions indicated by arrows F and G, respectively, by a presser (not shown) to compress ink bag  1  to a predetermined thickness X′″.  
         [0044]    Next, as is shown in FIG. 9, heat welders  15 ,  15 ′ pinch ink bag  1  at a second seal position  1   j , located below first seal position  1   g , and permanently seal ink bag  1  by heat welding at position  1   j  over a width V that is wider than the width of the seal at first seal position  1   g . In this manner, ink bag  1  remains sealed even after second seal position  1   j  has been cut.  
         [0045]    As a result of these additional steps, ink  37  is sealed within ink bag  1  having substantially eliminated air bubbles. Furthermore, ink bag  1  is sealed while it is shaped to a given thickness by means of press plates  16 ,  16 ′. As a result, ink  37  can be sealed at a given ink level, thereby making it possible to accurately charge ink bag  1  with a predetermined quantity of ink  37 .  
         [0046]    After ink bag  1  has been sealed, ink bag  1  is transported out of ink filling apparatus  200 , where upon second seal position  1   j  is cut along its center line  1   h . While section  1   j  is cut, a cup portion  1   k  is held in position such that, upon cutting section  1   j , ink  37  is not spilled, because ink  37  is captured in cup portion  1   k  and a small bag  1   m , formed between first seal position and second seal position  1   j.    
         [0047]    In the previously described embodiment, ink bag  1  is pressed to a width X′ by press plates  16 ,  16 ′ whereupon ink bag  1  is temporarily sealed below the ink level. Alternatively, ink bag  1  may also be temporarily welded at a position above ink level Z′ without shaping ink bag  1 .  
         [0048]    Where an ink jet recorder is used for commercial printing or the like, a large quantity of ink is consumed. Hence, the volume of ink bag  1  is at times increased to a volume greater than three times that of a typical ink bag  1 . In such a case, great water-head pressures act on a lower portion of ink bag  1  during the ink-filling step, thereby expanding the lower portion. As a result, great tensile forces act on the sealed area, thereby causing ink bag  1  to rupture under certain circumstances.  
         [0049]    Referring now to FIG. 10, a third embodiment of an ink filling apparatus  300  constructed in accordance with the invention is shown, where like elements are indicated by like reference numerals. Press plates  38  having a length L′, which is at least half of length L of an ink-filled ink bag  1 , are spaced apart from each other by an interval D which is less than one-third of width W of outlet side  1   a  of ink bag  1  shown in FIG. 4. Lower ends  38   a  of press plates  38  are positioned slightly lower than the outlet side  1   a  of ink bag  1 . Press plates  38  are movable in a horizontal direction, designated by double arrow K in FIG. 10.  
         [0050]    Referring to FIGS.  10 - 12 , a method of filling ink into ink bag  1 ′ in accordance with a third embodiment of the invention will be described with reference to ink filling apparatus  300 . As shown in FIG. 10, ink bag  1 ′ is hung from support rods  14  by sliding through holes  1   f  over support rods  14  such that opening  1   e  of ink bag  1 ′ is in a spread position. Subsequently, door  11  is closed forming chamber  10 , stop valve  28  connected to gas-liquid separation unit  22  is closed, and stop valve  34  is opened as is shown in FIG. 10. Vacuum pump  13 , which is connected via channel  12  to chamber  10 , is then activated to depressurize chamber  10 , tubes  20  and  33 , and measuring tube  30  to a predetermined pressure.  
         [0051]    Referring to FIG. 11A, when vacuum chamber  10  and tubes  20 ,  30  and  33  have been evacuated to a predetermined pressure, stop valve  34  is closed. Thereafter, measuring tube  30  is placed in fluid communication with gas-liquid separation unit  22  by opening stop valve  28 , and a predetermined quantity of ink  37  is filled into measuring tube  30 . Since gas-liquid separation unit  22  is connected close to measuring tube  30 , ink flows into measuring tube  30  immediately after having been degassed by gas-liquid separation unit  22 . In conjunction with this operation, as is shown in FIG. 11B, needle inserter  19  is lowered such that injection needle  18  is disposed within ink bag  1 ′.  
         [0052]    Next, as shown in FIG. 11B, stop valve  28  is closed to isolate gas-liquid separation unit  22 , stop valve  34  is opened, and piston  32  of measuring tube  30  is pressed to discharge the predetermined quantity of ink  37  into ink bag  1 ′ via tube  33  and  20 , and injection needle  18 .  
         [0053]    Press plates  38  are spaced apart by approximately one-third the width of outlet side  1   a  to restrict the amount of ink  37  that enters into a lower portion  99  of ink bag  1 ′. Accordingly, as ink bag  1 ′ is filled with ink, the area of ink bag  1 ′ just above restricted lower portion  99  bulges under the weight of ink  37 .  
         [0054]    As ink bag  1 ′ is filled with ink  37 , until the level of ink  37  is below heat welders  15 ,  15 ′ press plates  38  are continuously moved back and forth in the direction indicated by double arrows N in FIG. 12A at an amplitude that permits press plates  38  to remain in contact with ink bag  1 ′. As a result, the water head pressure exerted on each portion of ink bag  1 ′ is continuously changing, thereby preventing the formation of stress concentrations at particular points in ink bag  1 ′. Under the force provided by press plates  38 , air bubbles escape to an upper portion of ink bag  1 ′.  
         [0055]    Next, as shown in FIG. 12B, needle inserter  19  is activated to withdraw ink feed needle  18  from ink bag  1 ′ to an upper position, recessed within manifold  10   d . Press plates  38  are then positioned to limit the lower portion of ink bag  1 ′ to a width R, and ink bag  1 ′ is pinched at a position slightly lower than the ink level by heat welders  15 ,  15 ′ to seal ink bag  1 ′ by heat-welding.  
         [0056]    In accordance with this embodiment of the invention, ink bag  1 ′ is directly and permanently sealed at a position slightly lower than the ink level. However, as in the first embodiment, the same advantageous result may be accomplished when ink bag  1 ′ is permanently sealed at a position lower than the ink level after having been temporarily sealed at a position slightly above the ink level.  
         [0057]    In another embodiment, when ink  37  is filled into ink bag  1 ″, the thickness of ink bag  1 ″ is limited by ink press plates  38  whose spacing was previously set to a predetermined distance. As shown in FIG. 13, if a tensile force is imparted to the lower portion of ink bag  1 ″ through the use of a spring  39 , for example, ink bag  1 ″ can be prevented from bulging. Thus, where positioning ink press plates  38  hinders the heat welding of opening  1   e  of ink bag  1 , the welding operation will be facilitated by applying a tensile force to ink bag  1  to limit the thickness of ink bag  1 .  
         [0058]    Next, a method of recycling an ink cartridge  70  will be described. Referring now to FIG. 14, a refilling apparatus  400  constructed in accordance with a first embodiment of the invention, is shown. Ink refilling apparatus  400  includes a vacuum chamber  40  having one side that can be opened or closed by a door  41 . Vacuum chamber  40  is in fluid communication via a channel  42  to a vacuum pump  43 , which upon activation evacuates vacuum chamber  40  to a predetermined vacuum pressure.  
         [0059]    A press plate  46 , having a lower surface  46   a  to which an elastic member  45  is affixed, is disposed within vacuum chamber  40 . Press plate  46  is constructed so as to be capable of moving vertically in a direction indicated as double arrow S. A through hole  40   a  is formed in a side wall  40   b  of vacuum chamber  40 . Ink filling needle  44  projects from through hole  40   a , and is disposed within vacuum chamber  40 . Ink filling needle  44  is in fluid communication with a suction pump  49  via a tube  48  and a branch pipe  47 , and as well as with a branch pipe  51  via a tube  50 .  
         [0060]    Ink refilling apparatus  400  also includes a gas-liquid separation unit  52 . In one preferred embodiment of the invention, gas-liquid separation unit  52  includes a hollow yarn bundle  53 , which is preferably connected fluid-tight at both longitudinal ends to a cylinder  54  so as to permit fluid to flow therethrough. Cylinder  54  is connected to a vacuum pump  55  so as to produce negative pressure around the outer periphery of yarn bundle  53 . Cylinder  54  includes an inlet  54   a , which is connected to an ink tank  57  having ink  37  therein, via a tube  56 , and an outlet  54   b , which is connected to branch pipe  51  via a stop valve  58 . Ink  37  is pumped to gas-liquid separator unit  52  by a pump  66 .  
         [0061]    Branch pipe  51  is also connected to a measuring tube  60  via a tube  63 . Measuring tube  60  includes a cylinder  61  and a piston  62 , and is preferably connected to branch pipe  51  at the center of one end of cylinder  61 . Stop valves  64 ,  65  are positioned on either side of branch pipe  47 . A waste ink tank  67  is connected to suction pump  49 , which provides suction to tube  48 .  
         [0062]    Referring to FIG. 1, when used ink cartridges are depleted of ink and collected by a user, ink bag  1  may be removed from case body  2  and cleaned, as required. Because the amount of dissolved air remaining in recovered ink bag  1  is unknown, mixing degassed ink with recovered ink bag  1  may cause the degassed state of the ink to become unstable, thereby adversely affecting print quality. Furthermore, if an attempt is made to fill ink bag  1  that contains an unmeasured quantity of ink, the weight of the extra ink may cause ink bag  1  to rupture or an overflow condition may occur, thereby interrupting the ink filling process.  
         [0063]    To prevent such a problem, as shown in FIG. 15A, ink filling needle  44  is inserted into septum  7  of port  5  of ink bag  1 , while ink bag  1  is positioned on a surface  40   c . Subsequently, as is shown in FIG. 15B, stop valve  64  is closed, and stop valve  65  is opened. Press plate  45  is then lowered from an upper position in a direction indicated by arrow T so as to apply a predetermined pressure on ink bag  1 , and thereby bring ink bag  1  into a pressed state. In this state, the residual ink in ink bag  1  is discharged to wasted ink tank  67  through ink filling needle  44  either by operation of suction pump  49  or by compression of ink bag  1 .  
         [0064]    In one embodiment, the residual ink in ink bag  1  may immediately be reduced by applying suction to ink bag  1  while ink bag  1  is being pressed by press plate  45 . In this way, ink bag  1  can be prevented from being deformed, which would occur if the residual ink is discharged solely by applying suction by suction pump  67 .  
         [0065]    After the discharge of the residual ink from ink bag  1  is complete, stop valve  65  is closed, and valve  58  is opened, thereby dispensing a given amount of ink to measuring tube  60  from ink tank  57 . Because gas-liquid separation unit  52  is connected close to measuring tube  60 , ink  68  flows into gas-liquid separation unit  52  immediately after having been degassed, as shown in FIG. 16A.  
         [0066]    As shown in FIG. 16B, if ink  68  is pressed out of measuring tube  60  by piston  62  while press plate  45  is returned to its original position and ink bag  1  is in an open state, a measured quantity of ink  68  flows into ink bag  1 . After ink bag  1  is filled with ink  68 , vacuum chamber  40  is returned to ambient pressure, and ink filling needle  44  is removed from septum  7 . Ink bag  1  is then removed from vacuum chamber  40 .  
         [0067]    At this stage, septum  7 , which is preferably formed of an elastic member, remains seated in port  5 . Accordingly, when ink filling needle  44  is removed from port  5 , the hole formed in septum  7  as a result of the insertion of ink filling needle  44 , is closed thereby preventing leakage of ink  68 . Next, the refilled ink bag  1  is housed in its original body  2 , and ink-empty detection plate  4  is re-attached to ink bag  1 . Body  2  is then sealed with cover  3 , thereby completing the recycling of the ink cartridge.  
         [0068]    Although the residual ink is discharged by pressing ink bag  1  in the previous embodiment, the ink can be sufficiently discharged solely by pressing ink bag  1  to such that ink bag  1  is prevented from being deformed, which would occur if suction alone was used to discharge the ink.  
         [0069]    Although the discharge of ink from ink bag  1  and the refilling of ink  68  into ink bag  1  are performed in a vacuum in the previous embodiment, these steps may be carried out under ambient pressure if septum  7  maintains an air-tight seal of ink bag  1 .  
         [0070]    It will thus be seen that the objects set forth above, and those made apparent from the preceding description, are efficiently attained and, because certain changes may be made in the above construction without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.  
         [0071]    It is also to be understood that the following claims are intended to cover all the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.