Abstract:
An ink refilling method capable of refilling ink into at least two kinds of ink cartridges having different ink capacities and having substantially the same outer configurations, the method includes a step of discriminating the kind of the ink cartridge; a step of determining the capacity of the ink cartridge on the basis of a result of the discriminating step; and a step of filling, into the ink cartridge, an amount of the ink on the basis of the capacity determined in the determining step.

Description:
FIELD OF THE INVENTION AND RELATED ART 
     The present invention relates to a method for refilling an ink jet cartridge made up of an ink container portion having multiple ink storage chambers, and a recording head portion which records on recording medium by ejecting ink. More specifically, it relates to a method for efficiently refilling a substantial number of used opaque color ink jet cartridges (cartridges, whose interior are difficult to see), whose ink container portion and recording head portion are inseparable from each other, and which have multiple ink storage chambers and are the same in external appearance, but, are different in the ink capacity (absorbing member volume) of the ink storage chamber, in such a manner that each ink storage chamber is refilled with a proper amount of ink, that is, virtually the exact amount of ink necessary for filling up the ink storage chamber. 
     Incidentally, the present invention is also applicable to the method for refilling an ink jet cartridge for an ordinary printing apparatus, a copying machine, a facsimile machine, a wordprocessor with a printing portion, a multifunction recording apparatus capable of performing two or more of the functions of the preceding apparatuses, etc. 
     Regarding the method for supplying the recording head of an ink jet printer with ink, in the case of an ink jet recording apparatus which employs an ink jet cartridge, the main ink container and recording head of which are separable from each other, the main ink container is connected to the recording head with a piece of tube to supply the recording head with the ink from the main ink container. In the case of an ink jet recording apparatus, which employs an ink jet cartridge, the main ink container and recording head of which are inseparable from each other, the ink jet cartridge is removably mounted on the ink jet cartridge carriage, which is movable in a manner to scan the surface of recording medium. 
     If a main ink container, such as the one described above, or the ink container of an ink jet cartridge, which is inseparable from the recording head of the ink jet cartridge, becomes unusable because of ink consumption, for example, it is to be replaced with a new one. 
     In the past, some used ink jet cartridges were discarded. In recent years, however, people has become highly concerned with environmental preservation, fostering a social movement that demands ink jet cartridge makers to recover (collect) as many used ink jet head cartridges as possible and utilize the used ink jet head cartridge as a fresh supply of resource. 
     Further, in order to deal with this social concern, some ink jet cartridge makers have been studying the possibility of efficiently reusing the recovered ink jet cartridges. 
     For example, Japanese Laid-open Patent Application H07-309017 proposes a method for reusing recovered monochromatic ink jet recording head cartridges. According to this method, the amount of ink remainder in a used ink container is obtained by measuring the weight of the ink container, and then, the amount by which the used ink container is to be refilled with ink is determined by comparing the amount by which the used ink container was initially filled with ink, with the measured amount of ink remainder in the used ink container. International Patent Publication WO 01/092017 proposes to fill a used ink container with ink by an amount which can be calculated from the amount of ink consumption stored in a data storage means. 
     The ink jet cartridges removably mountable on an ink jet cartridge carriage can be roughly classified into two groups, that is, a group in which an ink jet cartridge is structured so that its recording head and ink container are separable from each other, and a group in which an ink jet cartridge is structured so that its recording head and ink container are integrated (not separable). If an ink jet cartridge belonging to the first group becomes unusable because of ink consumption, only the ink container is replaced. In the case of an ink jet cartridge belonging to the second group, however, if the ink jet cartridge becomes unusable because of ink consumption, the entirety of the ink jet cartridge is replaced. As examples of an ink jet cartridge belonging to the second group, there are multicolor ink jet cartridges, in particular, multicolor ink jet cartridges made up of an ink container having yellow, cyan, and magenta ink storage chambers, and a recording head inseparably attached to the ink container. 
     Japanese Laid-open Patent Application 2001-310480 discloses an ink jet cartridge which can be changed in ink capacity (absorbing member volume) according to its usage, without changing it in external appearance. 
     SUMMARY OF THE INVENTION 
     In the case of a used multicolor ink jet cartridge, that is, a used ink jet cartridge which stores two or more inks different in color, it is difficult to determine the amount by which each ink storage chamber is to be refilled with ink, simply by measuring the weight of the used ink jet cartridge as proposed in Japanese Laid-open Patent Application H07-309017. 
     Further, the inks (yellow, magenta, and cyan inks, for example) stored in a multicolor ink jet cartridge are different in the cumulative amount by which they are used (ejected). Therefore, simply measuring the weight of a multicolor ink jet cartridge is not enough to accurately determine the amount by which each of the ink storage chambers of the multicolor ink jet cartridge is to be refilled with ink. 
     On the other hand, in a case where the cumulative amount of ink consumption is stored in the data storage means of an ink jet cartridge as disclosed in International Patent Publication WO 01/092017, the information storage means must be capable of storing the cumulative amount of consumption for each of the multiple inks. In other words, an expensive data storage means is required. In addition, if a used ink jet cartridge (ink storage chamber or chambers) is refilled with ink by a user, the information in the data storage means becomes unreliable. 
     Further, in the case of an ink jet cartridge, such as the one disclosed in Japanese Laidopen Patent Application 2001-310480, which can be changed in ink capacity (absorbing member volume) without changing it in external appearance, it is impossible to accurately determine the volume of the absorbing member therein, based on its external appearance. Thus, the amount by which a used ink jet cartridge of this type was to be filled was kept substantially smaller than the exact amount of ink necessary to filling up the used ink jet cartridge, in order to prevent the problem that the ink jet cartridge is overfilled; while an ink storage chamber is refilled, ink begins to overflow from the refilled ink storage chamber. 
     Thus, the primary object of the present invention is to provide a method for refilling a substantial number of opaque color ink jet cartridges (cartridges, the interior of which are difficult to see), the ink container and recording head of which are inseparable from each other, and which have multiple ink storage chambers and are the same in external appearance, but, are different in the ink capacity (absorbing member volume) of the ink storage chamber, in such a manner that each ink storage chamber is refilled with a proper amount of ink, that is, virtually the exact amount of ink necessary for filling up the ink storage chamber. 
     According to an aspect of the present invention, there is provided an ink refilling method capable of refilling ink into at least two kinds of ink cartridges having different ink capacities and having substantially the same outer configurations, said method comprising a step of discriminating the kind of the ink cartridge a step of determining the capacity of the ink cartridge on the basis of a result of said discriminating step; and a step of filling, into the ink cartridge, an amount of the ink on the basis of the capacity determined in said determining step. 
     In the aspect of the present invention, the method may further comprises a step of determining the amounts of the ink to be filled into the respective ink accommodating portions, said filling amount determining step including a step of measuring remaining amounts of the ink in the respective accommodating portions, wherein said filling amount determining step determines the filling amounts on the basis of differences between the ink capacities determined by said ink capacity determining step and the remaining amounts of the ink measured by said measuring step, respectively. 
     The present invention makes it possible to efficiently refill a substantial number of color ink jet cartridges, the ink container and recording head of which are inseparable from each other, and which are the same in external appearance, but, are different in the ink capacity (absorbing member) of each ink storage chamber thereof, in such a manner that each ink storage chamber is refilled with a proper amount of ink, that is, virtually the exact amount of ink necessary for filling up the ink storage chamber. 
     These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1(   a ) is an exploded perspective view of the recording head portion of an ink jet cartridge (of typical shape and standard size) in accordance with the present invention, and  FIG. 1(   b ) is an exploded perspective view of the ink container portion of the ink jet cartridge (of typical shape and standard size). 
         FIG. 2(   a ) is an exploded perspective view of the recording head portion of an ink jet cartridge (of typical shape and mini size) in accordance with the present invention, and  FIG. 2(   b ) is an exploded perspective view of the ink container portion of the ink jet cartridge (of typical shape and mini size). 
         FIG. 3  is a schematic partial plan view of the recording head chip of an ink jet cartridge in accordance with the present invention. 
         FIG. 4  is a flowchart of the process for refilling a used ink jet cartridge, in the first embodiment of the present invention. 
         FIG. 5  is a schematic drawing for describing the “absorbing member capacity finding step” in the first embodiment of the present invention. 
         FIG. 6  is a schematic drawing for describing the “seal separating step” in the first embodiment of the present invention. 
         FIG. 7  is a schematic drawing for describing the “hole making step” in the first embodiment of the present invention,  7 ( a ) being a schematic perspective view of an ink jet cartridge in accordance with the present invention, and a pair of hole making means which are being used to drill a pair of holes through the top lid of the ink container portion of the ink jet cartridge,  FIG. 7(   b ) being a sectional view of the standard ink jet head cartridge, and the pair of hole making means having just finished drilling a pair of holes through the top lid of the ink container portion of the ink jet cartridge; and  FIG. 7(   c ) being a sectional view of the mini ink jet cartridge in accordance with the present invention, and the pair of hole making means having just finished drilling a pair of holes through the top lid of the ink container portion of the ink jet cartridge. 
         FIG. 8  is a schematic drawing for describing the “ink remainder amount measuring step” in the first embodiment of the present invention,  FIG. 5   a ) being a schematic drawing for describing the general structure of the ink remainder amount detecting device used in the “ink remainder amount measuring step”,  FIG. 8(   b ) being a combination of the schematic sectional view of the standard ink jet cartridge, and the schematic drawing of the ink remainder amount detecting device which is in the middle of the “ink remainder amount measuring step”, and  FIG. 8(   c ) being a combination of the schematic sectional view of the standard ink jet cartridge, and the schematic drawing of the ink remainder amount detecting device which is at the end of the “ink remainder amount measuring step”. 
         FIG. 9  is a graph showing the relationship between the distance by which a pair of electrodes are inserted into the absorbent member from the top surface of the absorbent member, and voltage between the pair of electrodes. 
         FIG. 10(   a ) is a sectional view of the ink jet cartridge, and a pair of ink injection tubes through which ink is being injected into one of the ink storage chambers of the ink container portion of the ink jet cartridge, in the first embodiment, and  FIG. 10(   b ) is a schematic sectional view of the ink jet cartridge in the first embodiment, one of the ink storage chambers of which has just been refilled to its full capacity. 
         FIG. 11  is a schematic drawing for describing the “seal pasting step” in the first embodiment of the present invention,  FIG. 11(   a ) being a schematic perspective view of the ink jet cartridge, the ink storage chambers of which have just been refilled with ink to their full capacity,  FIG. 11(   b ) being a schematic perspective view of the ink jet cartridge, to which a seal is ready to be pasted, and  FIG. 11(   c ) being a schematic perspective view of the ink jet cartridge to which the seal has just been pasted. 
         FIG. 12  is a flowchart of the ink jet cartridge refilling process in the second embodiment of the present invention. 
         FIG. 13  is a schematic drawing for describing the “ink remainder extracting step” in the second embodiment of the present invention,  FIG. 13(   a ) being a schematic sectional view of a combination of the ink jet cartridge, and a pair of ink extraction tubes of an ink extracting device, which are ready to be inserted into the ink jet cartridge,  FIG. 13(   b ) being a schematic sectional view of a combination of the ink jet cartridge, and the pair of ink extraction tubes of the ink extracting device, which have just been inserted into the ink jet cartridge, and  FIG. 13(   c ) being a schematic sectional view of the ink jet cartridge from which the entirety of the ink remainder therein has just been extracted. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, the preferred embodiments of the present invention will be described with reference to the appended drawing. 
       FIG. 1  is a schematic perspective view of one of the preferable ink jet cartridges to which the present invention is applicable, and shows the general structure of the cartridge. The ink jet cartridge shown in  FIG. 1  is made up of a recording head and an ink container, which are inseparable from each other. It is an ink jet cartridge of a large ink capacity.  FIG. 2  is a schematic perspective view of another preferable ink jet cartridge to which the present invention is applicable, and shows the general structure of the cartridge. The ink jet cartridge shown in  FIG. 2  is the same in external appearance, but, is smaller in ink capacity.  FIG. 3  is a schematic partial plan view of the recording head chip of the ink jet cartridge, and shows the general structure of the chip. Incidentally, ink jet cartridges to which the present invention is applicable ink container portions which are made of an opaque material, that is, the internal structure of which cannot be confirmed from outside. 
     Next, the structural components of this ink jet cartridge will be described with reference to the drawings. 
       FIG. 1(   a ) is an exploded perspective view of the recording head portion of the ink jet cartridge in accordance with the present invention, and  FIG. 1(   b ) is an exploded perspective view of the ink container portion of the ink jet cartridge. As will be evident from  FIG. 1 , this ink jet cartridge is made up of a recording head H 1002 , and an ink container H 1003 , which are inseparable from each other. The recording head H 1002  ejects color inks (cyan, magenta, and yellow inks) onto recording medium. It is made up of a recording element chip H 1101  and an electrical wiring tape H 1301 . The electrical wiring tape H 1301  transmits the signals from the main assembly of the printer to the recording element chip H 1101 . The ink container H 1003  has three ink storage chambers for storing three color inks, different in color, one for one. It also has three ink absorbing members H 1601 , H 1602 , and H 1603 , which are stored in the three ink storage chambers, one for one. The ink container H 1003  is also provided with three filters H 1701 , H 1702 , and H 1703 , which correspond to the three ink absorbing members H 1601 , H 1602 , and H 1603 , respectively. Each filter is located at the junction between each ink storage chamber and the ink path which leads to the recording head H 1002 . The top of the ink container is covered with a lid H 1901 . The top surface of the lid H 1901  is covered with a sheet H 1801 , which is pasted to the top surface of the lid H 1901  in a manner to cover the grooves cut, as air passages (vents), in the outward surface of the lid H 1901 . 
     Referring to  FIG. 3 , the recording element chip H 1101  is provided with electrical wiring, fuses H 1117 , resistors, electrodes, etc. It is also provided with ink passage walls, ink ejection nozzles, etc., which are formed of resinous material, on the substrate of the recording element chip H 1101 , with the use of electrophotographic technologies, in a manner to cover the abovementioned components. The electrodes for supplying the electrical wiring with electric power are provided with bumps, which are formed of Au, or the like. 
       FIG. 2  is a schematic perspective view of another preferable ink jet cartridge to which the present invention is applicable, and shows the general structure of the cartridge. The ink jet cartridge shown in  FIG. 2  is the same in external appearance as the ink jet cartridge shown in  FIG. 1 , but, is smaller in the volume of the absorbing member stored in each of the ink storage chamber, being therefore smaller in ink capacity, than the ink jet cartridge shown in  FIG. 1 . In comparison to the ink jet cartridge shown in  FIG. 1 , it may be reasonable for the ink jet cartridge shown in  FIG. 2  to be referred to as an ink jet cartridge of a mini-size (which hereafter will be referred as mini ink jet cartridge).  FIG. 2(   a ) is an exploded perspective view of the recording head portion of the mini ink jet cartridge, and  FIG. 2(   b ) is an exploded perspective view of the ink container portion of the mini ink jet cartridge. 
     Referring to  FIG. 2 , the mini ink jet cartridge is the same in external shape and size as the standard ink jet cartridge shown in  FIG. 1 . The mini ink jet cartridge is made up of the recording element chip H 1101 , electrical wiring tape H 1301 , main structure H 1501 , filters H 1701 , H 1702 , and H 1703 , ink absorbing member H 1611 , H 1612 , and H 1613 , top lid H 1901 , and seal H 1801 . The ink absorbing members H 1611 , H 1612 , and H 1613  of this ink jet cartridge are smaller in capacity than those of the standard ink jet cartridge shown in  FIG. 1 . Further, the top lid  1901  of this ink jet cartridge is provided with ribs H 1930 . 
     Hereafter, the preferred embodiments of the present invention will be described with reference to the standard and mini ink jet cartridges and the method for refilling the two ink jet cartridges. 
     However, the present invention is also applicable to ink jet cartridges other than the standard and mini ink jet cartridges. 
     Next, the preferred embodiments of the present invention will be described in detail. 
     [Embodiment 1] 
     Into the absorbing members H 1601 , H 1602 , and H 1603  of the standard ink jet cartridge shown in  FIG. 1 , yellow, cyan, and magenta inks are injected, respectively. In the absorbing members H 1611 , H 1612 , and H 1613  of the mini ink jet cartridge shown in  FIG. 2 , yellow, cyan, and magenta inks are injected, respectively. The absorbing members of the mini ink jet cartridge are roughly 15 mm in height, and capable of holding roughly 5 g of ink. The absorbing members of the standard ink jet cartridge are roughly 30 mm in height, and are capable of holding roughly 10 g of ink. 
     Hereafter, one of the proper methods for refilling the recovered standard and mini ink jet cartridges, which are different in ink capacity while being the same in external appearance, will be described with reference to  FIGS. 4-10 . 
       FIG. 4  is a flowchart of the process for refilling an ink jet cartridges with ink, in the first embodiment. 
     In the first embodiment, the process for refilling a recovered ink jet cartridge with ink has a “recovery (collecting) step: S 101 ”, which is for recovering a used ink jet cartridges, a “absorbing member capacity finding step: S 102 ”, which is for finding the capacity of one of the absorbing members in the recovered ink jet cartridge, a “seal separating step: S 103 ”, which is for separating the seal from the recovered ink jet cartridge, a “hole making step: S 104 ”, which is for making holes through the top lid of the recovered ink jet cartridge, an “ink remainder amount measuring step: S 105 ”, which is for measuring the amount of ink remainder in the recovered ink jet cartridge, an “ink injection amount deciding step: S 106 ”, which is for deciding the amount of ink to be injected into one of ink storage chambers of the recovered ink jet cartridge, an “ink injecting step: S 107 ”, which is for injecting ink into one of the ink storage chambers of the recovered ink jet cartridge, and a “seal pasting step: S 108 ”, which is for pasting a seal to the refilled ink jet cartridge after all the ink storage chambers are refilled. Obviously, a recovered ink jet cartridge can be refilled with ink using only a part, or parts, of the above described process for refilling a recovered ink jet cartridge. Further, the process may be changed in the order in which the abovementioned steps are carried out. These modifications of the above described used ink jet cartridge refilling process are within the technical gist of the present invention. 
     Used ink jet cartridges are recovered in the “recovery step: S 101 ”. Incidentally, some used ink jet cartridges are directly brought to an ink jet cartridge recycling plant, whereas the others are indirectly recovered, that is, by way of recovery stations located in local stores, or through recycling movement, etc. 
     The recovered used ink jet cartridges are sent to the “absorbing member capacity finding step: S 102 ”. 
     In a case where a used ink jet cartridge, the label of which has not been peeled away by a user or the like, is directly brought in, and it is sure that this ink jet cartridge has not been refilled, the absorbing member capacity of this used ink jet cartridge may be determined based on the information on the label on the ink jet cartridge. 
     However, if it is impossible to identify the recovery route of a recovered used ink jet cartridge, because the seal (label H 1801  shown in  FIGS. 1 and 2 ) pasted to the ink jet cartridge had been lost (peeled off) while the cartridge was used, while the cartridge was recovered, or in the like situations, it is impossible to find out the absorbing member capacity of the cartridge, based on the seal (label). In such a case, the absorbing member capacity may be found out by removing the top lid H 1901 , or by making hole(s) through the top lid H 1901  or the like to find out the type of the absorbing member in the cartridge. 
     Referring to  FIG. 3 , the recording element chip H 1101  of this ink jet cartridge is provided with the fuses H 1117 . The fuse H 1117  stores information, such as recording head type and ink storage chamber capacity (absorbing member capacity). In other words, it functions as a data storage means for identifying a recovered used ink jet cartridge. Referring to FIG.  5 , in this embodiment, the absorbing member capacity of a recovered used ink jet cartridge is found out by reading the information provided by the fuse H 1117 , with the use of a fuse reading device  100 . 
     Next, the “seal separating step: S 103 ” shown in  FIG. 6 , is carried out. However, it is possible that the seal (label) will have been lost (peeled off) through usage, recovery process, or the like, as described above. In such a case, this step (S 103 ) may be skipped. 
     Next, the “hole making step: S 104 ” is carried out, which will be described with reference to  FIG. 7  and the case in which one of the ink storage chambers of the ink jet cartridge is filled with cyan ink. 
     Referring to  FIG. 7(   a ), a pair of holes  210  are made through the portion of the top lid H 1901 , which corresponds to the ink storage chamber for cyan ink, with the use of a tool such as a drill. Incidentally,  FIG. 7(   a ) shows only the holes which correspond to the ink storage chamber for cyan ink. It is not intended to limit the present invention in terms of the size and number of the holes  210 . 
     In the “hole making step: S 104 ”, the depth to which the drills  200  are to be inserted into the ink storage chamber is adjusted according to the ink jet cartridge type identified in the above described “absorbing member capacity finding step: S 102 ”.  FIGS. 7(   b ) and  7 ( c ) are for showing the difference between the standard and mini ink jet cartridges, in terms of the depth to which the drills  200  are to be inserted into the ink storage chamber. In the case of the standard ink jet cartridge, the depth to which the drills  200  are to be inserted has only to be roughly 1 cm from the top surface of the top lid H 1901 . In the case of the mini ink jet cartridge, however, the top lid H 1901  is provided with multiple ribs H 1930 , which extend inward of each ink storage chamber. Therefore, it sometimes occur that holes have to be drilled through one or more of the ribs H 1930 , although whether or not the holes have to be drilled through the ribs depends on the size of the holes. Thus, when making the holes  210  through the top lid H 1901  of the mini ink jet cartridge, the drills  200  have to inserted further into the ink jet cartridge by roughly 2 cm than when making the holes  210  through the top lid H 1901  of the standard ink jet cartridge. Therefore, in consideration of the possibility that the holes  210  will have to be drilled through the rib H 1930  or ribs H 1930 , the depth to which the drills  200  are to be inserted into the mini ink jet cartridge is set to be just enough for the drills  200  to come into contact with the absorbing member. 
     Next, the “ink remainder amount deciding step: S 106 ” will be described. 
     The color inks in a color ink jet cartridge which stores two or more inks are different in the amount by which they are consumed. Further, the amount by which each of the color inks is used is affected by the condition and/or situation in which the color ink jet cartridge is used. Therefore, the ink storage chambers of a recovered color ink jet cartridge may be different in the amount of the ink remainder therein. Therefore, it is reasonable to think that simply refilling a recovered used color ink jet cartridge may result in the problem that the ink storage chambers of the ink jet cartridge are different in the amount of the ink therein after the refilling, and/or the problem that one or more inks overflow from the ink jet cartridge (ink storage chambers). This is why it is necessary to measure the amount of the ink remainder in each ink storage chamber, in order to determine the accurate amount by which each ink storage chamber is to be refilled with ink. 
       FIG. 8(   a ) shows an apparatus to be used for the “ink remainder amount measuring step”. Next, the apparatus used for measuring the amount of the ink remaining in each ink storage chamber will be described with reference to  FIG. 8(   a ). The ink remainder amount measuring apparatus is provided with a pair of electrodes  302  ( 302   a  and  302   b ) formed of a metallic material. One end of the electrode  302   a  is connected to one end of an electrical lead wire  301   a . One end electrode  302   b  is connected to one end of an electrical lead wire  301   b . The other ends of the electrical lead wires  301   a  and  301   b  are connected to a constant current circuit  300  for measuring the voltage between the electrodes  302   a  and  302   b . The constant current circuit  300  is designed so that 100 μm of DC voltage flows between the electrodes  302   a  and  302   b , with the maximum amount of voltage set to 5 V, for example. 
     Next, referring to  FIGS. 8(   b ) and  8 ( c ), the method for measuring the amount of the ink remainder in each ink storage chamber of the color ink jet cartridge will be described. As the ink in each ink storage chamber consumed, the interface  310  between the air and the body of ink in the absorbing member gradually falls. Thus, if the position of the interface  310  can be detected, the amount of the ink remainder in the ink storage chamber can be calculated. 
       FIG. 8(   b ) represents a case in which the electrodes  302  have not reached the interface  310  in the absorbing member, whereas  FIG. 8(   c ) represents a case in which the electrodes  302  have reached the interface  310  in the absorbing member. A referential letter A designates the distance from the top surface of the absorbing member to the interface  310  between the air and the body of ink in the absorbing member.  FIG. 9  is a graph showing the relationship between the distance by which the electrodes  302  were inserted into the absorbing member from the top surface of the absorbing member, and the voltage between the two electrodes  302 . 
     Referring to  FIG. 8(   b ), the electrodes  302  are gradually inserted into the absorbing member through the holes  210  created in “hole making step: S 104 ”, while the voltage between the two electrodes  302  is measured. Until the electrodes  302  come into contact with the interface  310 , there is no ink between the electrodes  302   a  and  302   b , and therefore, there is no electrical connection between the electrodes  302   a  and  302   b . Therefore, the voltage between the electrodes  302   a  and  302   b  remains at a high level as it is in a range a in  FIG. 9(   a ). 
     However, as the electrodes  302  reach the interface  310  as shown in  FIG. 8(   c ), electrical connection is established between the two electrodes  302   a  and  302   b  through ink, changing thereby the voltage between the electrodes  302   a  and  302   b . Where this voltage change occurs corresponds to a point b in  FIG. 9 . 
     The distance A from the top surface of the absorbing member to the interface  310  between the air and the body of ink in the absorbing member can be determined based on this change in the voltage. 
     
       
         
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Distance A 
                   
                   
               
               
                 from absorbing 
               
               
                 member top to 
                 Small 
                 Standard 
               
               
                 ink (mm) 
                 size 
                 size 
               
               
                   
               
             
             
               
                 0 ≦ A &lt; 2 
                 0.0 
                 0.0 
               
               
                 2 ≦ A &lt; 4 
                 0.7 
                 0.7 
               
               
                 4 ≦ A &lt; 6 
                 1.4 
                 1.4 
               
               
                 6 ≦ A &lt; 8 
                 2.1 
                 2.1 
               
               
                  8 ≦ A &lt; 10 
                 2.8 
                 2.8 
               
               
                 10 ≦ A &lt; 12 
                 3.5 
                 3.6 
               
               
                 12 ≦ A &lt; 14 
                 4.2 
                 4.3 
               
               
                 14 ≦ A &lt; 16 
                 5.0 
                 5.0 
               
               
                 16 ≦ A &lt; 18 
                 — 
                 5.7 
               
               
                 18 ≦ A &lt; 20 
                 — 
                 6.4 
               
               
                 20 ≦ A &lt; 22 
                 — 
                 7.1 
               
               
                 22 ≦ A &lt; 24 
                 — 
                 7.8 
               
               
                 24 ≦ A &lt; 26 
                 — 
                 8.5 
               
               
                 26 ≦ A &lt; 28 
                 — 
                 9.2 
               
               
                 28 ≦ A &lt; 30 
                 — 
                 10.0  
               
               
                 30 ≦ A &lt; 32 
                 — 
                 — 
               
               
                 32 ≦ A &lt; 34 
                 — 
                 — 
               
               
                   
               
             
          
         
       
     
     Next, the “ink remainder amount deciding step: S 106 ” will be described. Table 1 is for the “ink remainder amount deciding step: S 106 ”. As described above, each of the absorbing members of the mini ink jet cartridge is roughly 15 mm in height, and is capable of holding roughly 5 g of ink, whereas each of the absorbing members of the standard ink jet cartridge is roughly 30 mm in height, and is capable of holding roughly 10 g of ink. 
     First, whether a recovered used ink jet cartridge is mini or standard is decided based on the information obtained in the “absorbing member capacity finding step: S 102 ”. 
     Then, the amount by which ink is to be injected into the ink storage chamber is calculated based on the difference between the full ink capacity of the ink storage chamber, and the amount of ink remainder in the ink storage chamber (absorbing member), which is obtained in the “ink remainder amount deciding step: S 106 ”, with the use of Table 1, which shows the relationship between the distance A from the top surface of the absorbing member to the interface  30  in the absorbing member. In this embodiment, the distance from the top surface of the absorbing member to the interface  30  in the absorbing member was classified with a 2 mm interval. However, an interval other than 2 mm may be used. 
     Next, the “ink injecting step: S 107 ” is taken. 
       FIG. 10  is for describing “ink injecting step: S 107 ”. Referring to  FIG. 10(   a ), ink is injected into an ink storage chamber (absorbing member) by the amount decided in the “ink injection amount deciding step: S 106 ”, through the holes made in the “hole making step: S 104 ”, with the use of a pair of ink injection needles  401  (ink injecting devices) put though the holes, one for one. The amount by which ink is injected into the ink storage chamber (absorbing member) is decided through the steps, such as those described above, based on the absorbing member capacity and amount of ink remainder. Therefore, the ink storage chamber (absorbing member) is perfectly refilled with ink as shown in  FIG. 10(   b ); it does not occur that the ink storage chamber is overfilled, or insufficiently filled, with ink. 
     This concludes the process of refilling the cyan ink storage chamber of the recovered multicolor ink jet cartridge with cyan ink. Then, the same process as that carried out to refill the cyan ink storage chamber with cyan ink is carried out for the magenta ink storage chamber and yellow ink storage chamber to finish refilling the recovered multicolor ink jet cartridge. 
     In the above, the method for sequentially refilling the multiple (three) ink storage chambers was described. However, the three ink storage chambers may be refilled at the same time. Further, the color ink refilling process may be structured so that a random combination of two among the three ink storage chambers is refilled at the same time, whereas the other is refilled separately from the two. Whether the multiple ink storage chambers are to be sequentially refilled or at the same time, or whether two among the three ink storage chambers are to be refilled at the same time, whereas the other is refilled separately from the two, may be decided based on the type of the available ink injecting device, or the like factors. 
     Next, the “seal pasting step: S 108 ” will be described. 
       FIG. 11(   a ) is a perspective view of the color ink jet cartridge immediately after its three ink storage chambers have been satisfactorily refilled with three inks different in color, one for one. The holes  210   a  and  210   b  are the holes made for measuring the amount of cyan ink remainder, and also, for injecting cyan ink into the cyan ink storage chamber. The holes  210   c  and  210   d  are the holes made for measuring the amount of magenta ink remainder, and also, for injecting magenta ink. The holes  210   e  and  210   f  are the holes made for measuring the amount of yellow ink remainder, and also, for injecting yellow ink. If the holes are left as they are, the inks easily evaporate through the holes. Therefore, in order to prevent the inks from evaporating through the holes  210 , a new seal  600  (label), such as the one shown in  FIG. 11(   b ), is pasted to the top lid H 1901  to seal the holes  210  as shown in  FIG. 11(   c ). 
     Incidentally, information, such as the refill history of the ink jet cartridge, which is useful for ink jet cartridge management, may be recorded on the label  600 . Recording such information on the label  600  pasted on a refilled ink jet cartridge makes it easier to carry out the “absorbing member capacity finding step: S 102 ” when the refilled ink jet cartridge is brought back next time for refilling. 
     Through the steps, such as those described above, the process for refilling the recovered used ink jet cartridge is completed. 
     [Embodiment 2] 
     Next, referring to  FIG. 2 , the second embodiment of the present invention will be described. 
     This embodiment is different from the first embodiment only in that an “ink remainder extracting step: S 205 ” is carried out in place of the “ink remainder amount finding step: S 102 ”. Thus, only the difference of this embodiment from the first embodiment will be described. 
     Also in the second embodiments the “used cartridge recovery step: S 201 ”, “absorbing member capacity finding step: S 202 ”, “seal removing step: S 203 ”, and “hole making step: S 204 ” are carried out. 
     Thereafter, the “ink remainder extracting step: S 205 ” is carried out, which will be described next. 
     The multiple ink storage chambers in a recovered color ink jet cartridge are different in the amount of ink remainder therein, because of the different in the purpose for which each used ink jet cartridge was used, condition under which each used ink jet cartridge was used, and the like factors, as described before. This step for extracting the ink remainder is for erasing the difference among the multiple (three) ink storage chambers in the amount of ink remainder. In other words, this step is for equalizing all the ink storage chambers of a used ink jet cartridge in terms of the amount of ink therein. That is, as the ink remainder in each ink storage chamber is extracted, all ink storage chambers become empty, that is, practically free of ink, as they were before they were filled with ink for the first time. Thus, in the following step, that is, the “ink injection amount deciding step”, it can be simply decided that all ink storage chambers are to be filled with the same amount of ink as the amount by which they were initially filled. 
       FIG. 13  is a schematic drawing for describing an example of the “ink remainder extracting step: S 205 ”. Designated by alphanumeric symbols H 1603  and H 1602  are the absorbing members for magenta and cyan inks, respectively. The “ink remainder extracting step” will be described referring to the case of the used ink jet cartridge, shown in  FIG. 13(   a ), the magenta ink of which has been used up, but, the cyan ink of which has not been used up. First, a pair of ink extracting needles  501  are inserted, as ink extracting devices, through the pair of holes made in the hole making step, as shown in  FIG. 13(   a ). In order to ensure that the entirety of the ink remainder in the absorbing member H 1602  is extracted, it is desired that the pair of needles  500  are inserted close to the bottom surface of the absorbing member H 1602  as shown in  FIG. 13(   b ). Thereafter, the ink remainder is to be extracted so that the absorbing member H 1602  become practically free of ink as shown in  FIG. 13(   c ). The “ink remainder extracting step” is continued until ink stops coming out of the ink extraction needles  501 . 
     The “ink remainder extracting step” is ended as ink stops coming out of the ink extraction needles  501 . In a case where yellow and/or cyan ink remains in a recovered used ink jet cartridge, the same step as that carried out for cyan ink is carried out for yellow and/or cyan ink. 
     If it is sure that there is no ink remaining in a given ink storage chamber, the “ink remainder extracting step” does not need to be carried out for this ink storage chamber. 
     In the above, the case in which the three ink storage chambers are sequentially subjected to the “ink remainder extracting step” was described. However, it may be the same time that the “ink remainder extracting step” is carried out for the three ink storage chambers (cyan, magenta, and yellow ink storage chambers). Further, it may be any two among the three ink storage chambers that are subjected to the “ink remainder extracting” step at the same time, leaving the other to be subjected to the “ink remainder extracting step” separately from the two. Whether the multiple ink storage chambers are to be sequentially refilled or at the same time, or whether any two among the three ink storage chambers are to be refilled at the same time, whereas the other is refilled separately from the two, may be decided based on the type of the available ink injecting device, or the like factors. Further, the method used in the “ink remainder extracting step” to extract the ink remainder does not need to be the one described above. For example, the ink remainder may be extracted with the use of a suction pump, or the like, connected to a cap, while the ink ejection outlets remain covered with the cap. 
     Incidentally, the interior of each ink storage chamber may be washed clean by injecting cleaning liquid, or the like, into the ink storage chambers after the ink remainder extraction, and then, suctioning out the injected cleaning liquid or the like. Many of the recovered ink jet cartridges do not have information, such as their recovery routes, length of time having elapsed since they were discarded, or the like. Therefore, washing clean a recovered ink jet cartridge is one of the steps which are desired to be carried out before refilling the recovered ink jet cartridge. 
     Next, the “ink injection amount deciding step: S 206 ” is carried out. The standard recording head cartridge in this embodiment is capable of holding roughly 10 g of ink per ink storage chamber, and the mini recording head cartridge in this embodiment is capable of holding roughly 5 g of ink per ink storage chamber. Thus, it is decided in “ink injection amount deciding step: S 206 ” that in the case of a standard recording head cartridge, 10 g of ink is to be injected per ink storage chamber, whereas in the case of a mini recording head cartridge, 5 g of ink is to be injected per ink storage chamber, based on the information obtained in the “absorbing member capacity finding step: S 202 ”. 
     Next, an “ink injecting step: S 207 ” is taken, in which ink is injected into each ink storage chamber by the amount decided in the “ink injection amount deciding step”. The three ink storage chambers may be sequentially refilled, or at the same time, as they are in the first embodiment. Further, the “ink injecting step” may be designed so that any two among the three ink storage chambers are filled at the same time, and the other is refilled separately from the two. Further, in this embodiment, it is not by the amount decided based on the amount of ink remainder in each ink storage chamber, but, the amount decided based on the absorbing member capacity that each ink storage chamber is refilled. Therefore, each ink storage chamber of the ink jet cartridge is perfectly refilled; it is neither overfilled, nor insufficiently filled. 
     Thereafter, a “seal pasting step: S 208 ” is taken, in which a seal  600  (label) is pasted to the top lid H 1901  to prevent ink from evaporating (being wasted) through the holes  210 . Further, information, such as refill history, which is useful for ink jet cartridge management, may be recorded on the label. 
     In the above, the present invention was described with reference to the ink jet cartridges structured so that their ink container portion and recording head portion were inseparable from each other. Obviously, the present invention is also applicable to an ink container separable from a recording head, more specifically, an ink container, the internal structure of which cannot be confirmed from outside the container, and which has multiple ink storage chambers which are the same in external appearance, but, are different in ink capacity. When the present invention is applied to such an ink container, the information storage medium attached to the ink container and holding the information regarding the ink container can be used in the “ink container capacity finding step”. 
     While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims. 
     This application claims priority from Japanese Patent Application No. 160215/2007 filed Jun. 18, 2007 which is hereby incorporated by reference.