Abstract:
An ink cartridge includes a first case having a particular opening formed therethrough, and a second case enclosed within the first case, in which the second case includes a particular wall. The ink cartridge also includes a signal blocking portion provided at the particular wall and extending in a predetermined direction into the particular opening, and the signal blocking portion divides the particular opening into a first opening portion and a second opening portion.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   The present application claims priority from Japanese Patent Application No. JP-2005-284646, which was filed on Sep. 29, 2005, Japanese Patent Application No. JP-2005-342697, which was filed on Nov. 28, 2005, Japanese Patent Application No. JP-2005-377987, which was filed on Dec. 28, 2005, Japanese Patent Application No. JP-2006-081806, which was filed on Mar. 23, 2006, and U.S. Provisional Patent Application No. 60/826,254, which was filed on Sep. 20, 2006, the disclosures of which are incorporated by reference in their entirety. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to ink cartridges. In particular, the present invention is directed towards ink cartridges which may be used in combination with ink jet printers. 
   2. Description of Related Art 
   Ink cartridges which are configured to be used in combination with ink jet printers are known in the art. 
   SUMMARY OF THE INVENTION 
   According to an embodiment of the present invention, an ink cartridge comprises a first case, and a second case enclosed within the first case. The second case comprises a particular wall, and a translucent portion extending from the particular wall in a predetermined direction. Moreover, the translucent portion has an inner space formed therein. The ink cartridge also comprises a signal blocking portion disposed within the second case, wherein the signal blocking portion is disposed within the inner space of the translucent member. 
   According to another embodiment of the present invention, an ink cartridge comprises a first case, and a second case disposed within the first case. The second case comprises a particular wall, an ink chamber configured to store ink therein, and an air intake portion extending from the particular wall in a predetermined direction. Moreover, the air intake portion is configured to communicate air from an interior of the ink chamber to an exterior of the ink chamber. 
   According to yet another embodiment of the present invention, an ink cartridge comprises a first case having a particular opening formed therethrough, and a second case enclosed within the first case, in which the second case comprises a particular wall. The ink cartridge also comprises a signal blocking portion provided at the particular wall and extending in a predetermined direction into the particular opening, and the signal blocking portion divides the particular opening into a first opening portion and a second opening portion. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of the present invention, the needs satisfied thereby, and the features and technical advantages thereof, reference now is made to the following descriptions taken in connection with the accompanying drawings. 
       FIG. 1  is a perspective view of an ink cartridge, according to an embodiment of the present invention. 
       FIG. 2  is an expanded, perspective view showing an interior of the ink cartridge of  FIG. 1 , according to an embodiment of the present invention. 
       FIG. 3(   a ) is a side view of a signal blocking portion of a movable member, which is disposed within an inner space of a translucent portion;  FIG. 3(   b ) is a cross-sectional view of the signal blocking portion and the translucent portion of  FIG. 3(   a ) along the XVIIIb-XVIIIb line; and  FIG. 3(   c ) is a cross-sectional view of the signal blocking portion and the translucent portion of  FIG. 3(   a ) along the XVIIIc-XVIIIc line, according to an embodiment of the present invention. 
       FIG. 4(   a ) is a front view of a movable member having a float member and a signal blocking portion; and  FIG. 4(   b ) is a view of the movable member of  FIG. 4(   a ) along the arrow XIXb perspective, according to an embodiment of the present invention. 
       FIG. 5(   a ) is a side view of an ink reservoir element;  FIG. 5(   b ) is a side view of the front of the ink reservoir element of  FIG. 5(   a ); and  FIG. 5(   c ) is a cross-sectional view of the ink reservoir element of  FIG. 5(   a ) along the XXc-XXc line, according to an embodiment of the present invention. 
       FIG. 6  is a cross-sectional view of a communication path of an ink cartridge, in which the ink cartridge is installed in a printer, according to an embodiment of the present invention. 
       FIG. 7  is a perspective view of an ink cartridge showing a process for attaching a protective cap to the ink cartridge, according to an embodiment of the present invention. 
       FIG. 8(   a ) is a side view of an ink reservoir element showing the position of a movable member when there is ink within the ink reservoir element; and  FIG. 8(   b ) is a side view of the ink reservoir element of  FIG. 8(   a ) showing the position of the movable member when there is no ink within the ink reservoir element, according to an embodiment of the present invention. 
       FIG. 9(   a ) is a perspective view of an ink cartridge according to another embodiment of the present invention; and  FIG. 9(   b ) is a perspective view of an ink cartridge according to yet another embodiment of the present invention 
       FIG. 10  is a side view of an ink reservoir element, according to another embodiment of the present invention. 
       FIG. 11  is a side view showing a process for replacing an ink reservoir element, according to an embodiment of the present invention 
   

   DETAILED DESCRIPTION OF EMBODIMENTS 
   Embodiments of the present invention and their features and technical advantages may be understood by referring to  FIGS. 1-11 , like numerals being used for like corresponding portions in the various drawings. 
   Referring to  FIGS. 1 ,  2 , and  7 , an ink cartridge  14  may comprise an ink reservoir element/case  100  which is configured to store ink, a case  200  which may substantially cover the entire body of ink reservoir element  100 , and a protector  300  which may be attached to case  200  and protects ink reservoir element  100  when ink cartridge  14  is in transit. Case  200  may have a substantially rectangular, parallelepiped shape. In an embodiment of the present invention, ink reservoir element  100 , case  200 , protector  300 , and all of the members contained in ink cartridge  14  may comprise non-metal materials, e.g., may comprise resin materials, such that they may be burned at the time of disposal. For example, nylon, polyester, or polypropylene may be used as resin materials. 
   Ink reservoir element  100  may comprise a frame portion  110  which forms an ink chamber  111  which is configured to store ink, an ink supply portion  120  which is configured to supply ink stored in ink chamber  111  to a multifunction device (not shown), such as a printer, and an ambient air intake portion  130  which is configured to introduce ambient air into frame portion  110 . Ink reservoir element  100  also may comprise a translucent portion  140  which may allow for the detection of the amount of ink stored in ink chamber  111 , and a film  160  which may be welded to the top surface and the bottom surface of frame portion  110  to form an ink reservoir chamber on frame portion  110 . In an embodiment of the present invention, ink supply portion  120  and ambient air intake portion  130  each extend further from ink reservoir element  100  than translucent portion  140 . 
   Case  200  may comprise a first case member  210  and a second case member  220  which are configured to sandwich ink reservoir element  100 . Alternatively, case  200  may be an integral case. When case  200  comprises first case member  200  and second case member  220 , first case member  210  may be a member which covers the bottom side surface of ink reservoir element  100 , and second case element  220  may be a member which covers the top side surface of ink reservoir element  100 . First and second case members  210  and  220  may comprise at least one resin material, and may be manufactured using injection molding. 
   A pair of case cutout portions  211  and  212  may be provided through first case member  210  for exposing ink supply portion  120  and ambient air intake portion  130 , respectively, to the outside of case  200 . Case cutout portions  211  and  212  may be substantially semicircular. A case cutout portion  213  also may be provided through first case member  210  between case cutout portion  211  and case cutout portion  212 , and case cutout portion  213  may be for receiving a sensor (not shown) of the multifunction device at a position where the sensor sandwiches translucent portion  140 . For example, case cutout portion  213  may have a substantially square or rectangular shape. Similarly, second case member  220  may comprise case cutout portions  221 ,  222 ,  223 , which may correspond to case cutout portions  211 ,  212 , and  213 , respectively. When first case member  210  is connected to second case member  220  to form case  200 , case cutout portions  211  and  221  may form a first opening, case cutout portions  212  and  222  may form a second opening, and case cutout portions  213  and  223  may form a third opening. Moreover, when ink reservoir element  100  is positioned within case  200 , ink supply portion  120  may protrude from the first opening, ambient air intake portion  130  may protrude from the second opening, and a portion of translucent portion  140  may be aligned substantially flush with the third opening. In an embodiment of the present invention, translucent portion  140  divides the third opening into a first opening portion  140   a  and a second opening portion  140   b , which are configured to receive a light emitting portion and a light receiving portion, respectively, of the sensor. 
   Referring to  FIG. 3(   a ), translucent portion  140  may protrude outward from frame portion  110 . Translucent portion  140  may comprise an enclosure portion  141  which encloses the end of a movable member  470 , e.g., a signal blocking portion  473   c  of movable member  470 , by sandwiching the end of movable member  470  with a pair of wall surfaces and forms a passage through which movable member  470  may be displaced. Translucent portion  140  also may comprise a translucent arm supporting portion  142  which may supports movable member  470  from below. Translucent arm supporting portion  142  may be positioned in the center of the width direction of the passage within translucent portion  140 , and it may be arranged, such that the end of movable member  470  also is positioned in the center of the passage within translucent portion  140 . 
   Movable member  470  may rotate based on the amount of ink within ink chamber  111 , and it may be a member which may be used in combination with the sensor to detect whether the amount of ink within ink chamber  111  is sufficient by detecting the position of signal blocking portion  473   c . The sensor may comprise a light emitting portion and a light receiving portion, and translucent portion  140  may be positioned therebetween. Therefore, when signal blocking portion  473   c  is positioned in the light path between the light emitting portion and the light receiving portion, it blocks the light transmitted by the light emitting portion. Consequently, by rotating based on the amount of ink within ink chamber  111 , movable member  470  may change the amount of light received by the light receiving portion and may be used to detect the presence or absence of ink. 
   Referring to  FIG. 3(   b ), the thickness of translucent arm supporting portion  142  may be selected, such that a gap t 4  between the inside walls of enclosure portion  141  and the outside wall of translucent arm supporting portion  142  may be less than a gap t 3  between the inside walls of enclosure  141  and the outside of movable member  470 . When liquid surface I of the ink falls below translucent portion  140 , the ink within translucent portion  140  may be depleted, however, because gap t 3  between movable member  470  and enclosure  141  may be relatively small, ink may remain within translucent portion  140  due to the surface tension of the ink, and movable member  470  may not rotate normally due to the surface tension of the ink. Nevertheless, by forming arm supporting portion  142 , such that gap t 3  is greater than gap t 4 , capillary force generated between translucent arm supporting portion  142  and enclosure portion  141  may be greater than the capillary force generated between movable member  470  and enclosure portion  141 . Consequently, the ink which remains within enclosure portion  141  may be drawn between arm supporting portion  142  and enclosure portion  141 , such that it may be possible to substantially prevent ink from remaining between movable member  470  and enclosure portion  141 . As such, the amount of ink may be accurately detected. 
   Referring to  FIGS. 4(   a ) and  4 ( b ), movable member  470  may be a member for detecting the amount of ink within ink chamber  111 . Movable member  470  may be manufactured by injection molding using a resin material, e.g., polypropylene, and it has light-blocking properties, e.g., it may be opaque. Movable member  470  may be a rotating member which rotates based on the amount of ink within ink chamber  111 , and a portion of movable member  470  may be detected by the sensor which detects the amount of ink stored within ink chamber  111 . Movable member  470  may comprise a float portion  471  which may comprise a material with a specific gravity which is less than the specific gravity of ink, a pivot portion  472  which may be attached to frame portion  110 , such that it may pivot, and an arm portion  473 , which extends from pivot portion  472  in a direction which may be substantially orthogonal to float portion  471 . Pivot portion  472  may be a linking portion which connects float portion  471  and arm portion  473 . In operation, when movable member  470  rotates upward, movable member  470  contacts a ceiling surface of translucent portion  140 , and the rotation of movable member  470  may be restricted. Therefore, it may be possible to prevent movable member  470  from moving out of translucent portion  140 . 
   Arm portion  473  may comprise a vertical arm portion  473   a  which extends in a direction which is substantially perpendicular to float portion  471 , a sloping arm portion  473   b  which slopes upward from vertical arm portion  473   a , and a signal blocking portion  473   c , which may be used as a light-blocking portion which blocks the light transmitted by the light emitting portion of the sensor. 
   Referring to  FIG. 4(   b ), arm portion  473  may be substantially thinner than float portion  471  and pivot portion  472 . Specifically, if arm portion  473  has a thick profile, the scale of translucent portion  140  may be increased, and consequently, the size of ink cartridge  14  and the resistance when movable member  470  rotates also may increase, which makes it difficult to accurately detect the amount of ink. Further, when the thickness of translucent portion  140  increases, the gap between the light emitting portion and the light receiving portion of the sensor widens accordingly, and the detection sensitivity deteriorates, which increases the costs associated with the sensor. Therefore, arm portion  473  may have a relatively thin profile. A plurality of ribs  473   d  may be provided on vertical arm portion  473   a  and sloping arm portion  473   b , which may increase the strength of arm portion  473 . 
   A pair of substantially semispherical arm protruding portions  473   e   1  and  473   e   2  may be provided on signal blocking portion  473   c  on the top and the bottom of the portion housed within translucent portion  140 , respectively. Arm protruding portions  473   e   1  and  473   e   2  may reduce the likelihood of signal blocking portion  473   c  adhering to the inside wall of translucent portion  140  due to the surface tension of the ink. For example, because arm protruding portions  473   e   1  and  473   e   2  may have a substantially semispherical shape, the only portion which contacts the inside wall of translucent portion  140  may be the end of arm protruding portions  473   e   1  and  473   e   2 , such that the effects of the surface tension of the ink may be reduced. 
   Float portion  471  may comprise a resin material with a specific gravity which is less than the specific gravity of ink, such that when liquid surface I of the ink is lowered, float portion  471  moves in the direction of the bottom portion of frame portion  110 , i.e., float portion  471  and liquid surface I of the ink move in the same direction as ink is dispensed. When float portion  471  moves in the direction of the bottom portion, and arm portion  473  moves in the direction of the top portion using pivot portion  472  as a rotational axis, the signal blocking portion  473   c  may move out of between the light emitting portion and the light receiving portion and therefore, the state in which ink is depleted may be detected. Moreover, when the specific gravity of the materials comprising float portion  471  are less than the specific gravity of ink, it may be unnecessary to manufacture complex dies, such that the manufacturing cost of movable member  470  may be reduced. 
   Referring to  FIGS. 5(   a ), and  5 ( b ), ink supply portion  120 , ambient air intake portion  130 , and translucent portion  140  may be provided on one of the side surfaces of frame portion  110 . When ink cartridge  14  is installed within the multifunction device, ambient air intake portion  130 , translucent portion  140 , and ink supply portion  120  may be sequentially aligned from top to bottom. 
   Referring to  FIG. 5(   a ), a width t 5  of translucent portion  140  may be less than a diameter t 6  of the opening of ink supply portion  120 , and a length t 7  of translucent portion  140  may be greater than width t 5  of translucent portion  140 . Referring to  FIG. 5(   b ), translucent portion  140  may be receded in the direction of frame portion with respect to ink supply portion  120  and ambient air intake portion  130 . A width t 8  of translucent portion  140  may be greater than width t 5  of translucent portion  140 . 
   Arm portion  473  of movable member  470  may be positioned within the inner space of translucent portion  140 , and the light path of the sensor may be opened from the light-blocking state due to the rotation of arm portion  473 , and the amount of ink may be detected. The light receiving portion and the light emitting portion may be positioned on both sides of translucent portion  140 , such that both side surfaces of translucent portion  140  form detection surfaces  140   a  and  140   b . Referring again to  FIG. 5(   a ), detection surfaces  140   a  and  140   b  may be parallel to the height direction, e.g., Y-direction, of ink cartridge  14  when ink cartridge  14  is installed in the multifunction device. 
   When ink adheres to detection surfaces  140   a  and  140   b , it may be difficult to accurately detect the amount of ink. Referring to  FIG. 5(   b ), translucent portion  140  may be provided in a position withdrawn to the side of ink chamber  111  with respect to ink supply portion  120 , such that it may be difficult for ink to adhere to translucent portion  140  even when ink drips from ink supply portion  120 . Specifically, the ink which drops from ink supply portion  120  generally may not head towards translucent portion  140 , such that it does not adhere to translucent portion  140 . 
   Because detection surfaces  140   a  and  140   b  are vertical when ink cartridge  14  is installed in the multifunction device, the ink may be most susceptible to the effects of gravity when ink cartridge  14  is installed in the multifunction device. Therefore, even if the ink has adhered to detection surfaces  140   a  and  140   b , it drops relatively quickly. It therefore may be possible to substantially avoid the transfer of ink to the light receiving portion and the light emitting portion of the sensor. Moreover, the ink which drops from detection surfaces  140   a  and  140   b  may not adhere to the end surface of ink supply portion  120 . 
   Referring to  FIG. 5(   c ), side walls which form detection walls  140   a  and  140   b  extending from the side surface of frame portion  110  may be provided on translucent portion  140 . Therefore, an edge portion  140   c  where the side surface of frame portion  110  and detection surfaces  140   a  and  140   b  intersect may be provided at a substantially perpendicular angle. When ink adheres to the vicinity of edge  140   c , the capillary force of edge  140   c  acts upon the ink because edge  140   c  may be provided at a substantially perpendicular angle, and the ink may flow towards ink supply portion  120  along edge  140   c . It therefore may be possible to reduce the adherence of ink to detection surfaces  140   a  and  140   b.    
   When ink cartridge  14  is installed in the multifunction device, ink cartridge  14  may be installed, such that ink supply portion  120  is located below ambient air intake portion  130 . This state may be the installation position of ink cartridge  14 . Moreover, when ink cartridge  14  is installed in the multifunction device, ink supply portion  120 , translucent portion  140 , and ambient air intake portion  130  may be sequentially positioned from bottom to top, and ink supply portion  120 , translucent portion  140 , and ambient air intake portion  130  may be provided on a single end surface. Therefore, because ink supply portion  120 , translucent portion  140 , and ambient air intake portion  130  are provided, such that they are focused, e.g., positioned adjacent to each other, on a single end surface, the sensor, a needle configured to be connected with the ink supply portion (not shown), and a passage configured to be connected with air intake portion  130  (not shown) associated with the multifunction device may be consolidated on a single surface, such that the size of the multifunction device may be reduced. 
   Ink supply portion  120  and translucent portion  140  may be sequentially provided on the single end surface from top to bottom, and by using movable member  470  for detecting ink, the ink may be used to the fullest extent. For example, when the amount of ink is detected by irradiating a portion of the ink cartridge using a photo-detector, if a method in which the presence of ink may be detected directly were used, the ink could not be fully used with a configuration in which the ink supply opening and the irradiated portion which may be irradiated by photo-detector are both provided on a single end surface, as in this embodiment. Specifically, if the irradiated portion is positioned below the ink supply opening, the position of the ink supply opening becomes relatively high, such that ink which is stored below the ink supply opening may not be used. Conversely, if the irradiated portion is positioned above the ink supply opening, the position of the irradiated portion becomes relatively high, such that a significant quantity of ink may be inside the ink cartridge when the photo-detector detects the absence of ink. Nevertheless, in this embodiment, movable member  470  may be used, such that even when the irradiated portion is provided in a relatively high position, the absence of ink may be detected in step with the timing in which the actual amount of ink becomes low, and the ink supply opening may be provided in a low position, such that there may be an insignificant amount of ink inside the ink cartridge when the absence of ink is detected. 
   Referring to  FIGS. 3(   a ),  8 ( a ), and  8 ( b ), when ink cartridge  14  is installed in the multifunction device, the light emitting portion and the light receiving portion of the sensor may be positioned at positions sandwiching translucent portion  140 . Because signal blocking portion  473   c  of movable member  470  may be positioned in enclosure portion  141  of translucent portion  140 , the ink quantity may be detected by the operation of movable member  470 . 
   The direction of rotation of movable member  470  may be determined based on the combined force of the buoyancies and gravities acting on the right side portion and the left side portion. Nevertheless, in order to simply the description of sensor  470 , it is assumed that all of the forces which act on movable member  470  also act on float portion  471 . Based on this assumption, the rotation of movable member  470  is determined by the buoyancy and the gravity acting on float portion  471 . When there is a large amount of ink stored in ink chamber  111 , because float portion  471  of movable member  470  may comprise resin material with a lower specific gravity than the specific gravity of ink, the buoyancy generated on float portion  471  increases, and float portion  471  floats in the ink. The combined force of gravity and buoyancy generated on float portion  471  causes a rotating force to be received in the clockwise direction in  FIGS. 3(   a ),  8 ( a ), and  8 ( b ). Nevertheless, signal blocking portion  473   c  contacts arm supporting portion  142 , and thus, signal blocking portion  473   c  may be positioned in a position blocking the optical path between the light emitting portion and the light receiving portion of the sensor. 
   As the ink within ink chamber  111  decreases in quantity, the surface level I of the ink drops. As the surface level I of the ink drops, signal blocking portion  473   c  emerges on the surface level I of the ink, and subsequently, float portion  471  also emerges on the surface level I of the ink. When float portion  471  emerges on the surface level I of the ink, the buoyancy generated on float portion  471 , which causes movable member  470  to rotate in the clockwise direction in  FIGS. 3(   a ),  8 ( a ), and  8 ( b ), and the gravity generated on float portion  471 , which causes movable member  470  to rotate in the counterclockwise direction in  FIGS. 3(   a ),  8 ( a ), and  8 ( b ), balance each other out, such that the overall combined force may be balanced. Subsequently, as the surface level I of the ink drops further, float portion  471  moves downward following the surface level I, such that movable member  470  rotates counterclockwise. The rotating operation causes signal blocking portion  473   c  to move upward away from arm supporting portion  142 , and an optical path may be created between the light emitting portion and the light receiving portion of the sensor. In this state, a controller (not shown) of the multifunction device determines that ink cartridge  14  is out of ink. 
   As the quantity of ink transitions from a substantial amount of ink to substantially no ink, float portion  471  may transition from an upper position to a lower position within ink chamber  111 . Thus, when the quantity of ink in ink chamber  111  is low, an out-of-ink discrimination accurately may be detected. 
   Referring to  FIG. 6 , a communication path  116  may be formed within ink cartridge  14 , and ink may flow through communication path  116  as indicated by arrow K. Communication path  116  may be in fluid communication with ink chamber  111  and ink supply portion  120 , and may be configured to dispense ink from an interior of ink chamber  111  to an exterior of ink chamber  111  via an opening formed in ink supply portion  120 . Communication path  116  may be substantially perpendicular to the wall on which ink supply portion  120 , ambient air intake portion  130 , and translucent portion  140  are formed. 
   Referring to  FIG. 9(   a ), an ink cartridge  4014  according to yet another embodiment of the present invention is depicted. Ink cartridge  4014  may have a through-hole  4130  for admitting ambient air into ink cartridge  4014  provided in a portion of its top surface. The air admitted through through-hole  4130  may pass through a labyrinth shaped air intake passage  4131  and may be admitted within ink cartridge  4014 . A seal member  4132  may be glued to ink cartridge  4014  to prevent deaeration and outflow of ink within ink cartridge  4014  before use. To use ink cartridge  4014 , seal member  4132  may be peeled off, and then the cartridge is installed the multifunction device. 
   A portion  4140  may be a protrusion provided outward from one end surface extending substantially in the vertical direction of ink cartridge  4014 , and below which may be provided ink supply portion  4120 . Portion  4140  may be translucent. An ink supply opening  4121  into which a needle of the multifunction device may be inserted may be provided on the protrusion tip of ink supply portion  4120 . Ink cartridge  4014  may not have a structure corresponding to ink reservoir element  100 , and stores the ink directly within the case. A movable member like movable member  470  may be provided within ink cartridge  4014  and a signal blocking portion of the movable member may be positioned within portion  4140 . Alternatively, portion  4140  may not be translucent, e.g. opaque, and the movable member may not be within the ink cartridge. In this case, an ink amount in ink cartridge  4014  may not be detected by the sensor. However, at least presence and absence of ink cartridge  4014  can be detected by the sensor because portion  4140  blocks the light emitted from the light emitting portion of the sensor when ink cartridge  4014  is installed in the multifunction device. 
   Referring to  FIG. 9(   b ), an ink cartridge  5014  according to still yet another embodiment of the present invention is depicted. Ink cartridge  5014  may be substantially the same as ink cartridge  4014 , except that ink supply portion  4120  has been replaced by ink supply portion  5120 . 
   Referring to  FIG. 10 , an ink reservoir element  9300  according to another embodiment of the present invention is depicted. Ink reservoir element  9300  may be substantially similar to ink reservoir element  100 . Therefore, only the differences between ink reservoir element  9300  and ink reservoir element  100  are discussed with respect to ink reservoir element  9300 . Ink reservoir element  9300  may be fixed within the first and second case members. Ink reservoir element  9300  may comprise a hard portion  9301  which may be provided through injection molding using a resin material, and a bag element  9302  connected to hard portion  9301 , which may be a flexible element which forms a reservoir space for storing ink therein. Hard portion  9301  may comprise a detection portion  9303 . Detection portion  9303  may divide the third opening into a first opening portion and a second opening portion, which are configured to receive a light emitting portion and a light receiving portion, respectively, of the sensor as translucent portion  140  divides the third opening into first opening portion  140   a  and second opening portion  140   b . Detection portion  9303  may be configured to be positioned between the light emitting portion and the light receiving portion of the sensor. In operation, when the ink within bag portion  9302  is reduced, bag portion  9302  may shrink in response to the reduction in ink, and the ink is substantially depleted, the reservoir space also may be substantially depleted. Therefore, it may be difficult to position a movable member within bag portion  9302  to detect the amount of ink remaining within bag portion  9302 . 
   Moreover, hard portion  9301  may have light barrier properties, and because it may be positioned between the light emitting portion and the light receiving portion, it may block the emitted light which is emitted from the light emitting portion. Therefore, it may be possible to detect whether there is an ink reservoir element  9300  contained within the first and second case members, and as such, it may be possible to prevent printing processes from being performed by the multifunction device when no ink reservoir element  9300  is present 
   Referring to  FIG. 11 , in each of the above-described embodiments of the present invention, at least one wall of first case member  210  may be secured to at least one corresponding wall of second case member  220  via an adhesive member  9100 , such that it is possible to open and to close first case member  210  and second case  220  with adhesive member  9100  functioning as a hinge member for first case member  210  and second case member  220 . Therefore, ink reservoir element  100  or  9300  may be replaced by separating a portion of first case member  210  from a corresponding portion of second case member  220  without separating first case member  210  entirely from second case member  220 . 
   While the invention has been described in connection with exemplary embodiments, it will be understood by those skilled in the art that other variations and modifications of the exemplary embodiments described above may be made without departing from the scope of the invention. Other embodiments will be apparent to those skilled in the art from a consideration of the specification or practice of the invention disclosed herein. It is intended that the specification and the described examples are considered merely as exemplary of the invention, with the true scope of the invention being indicated by the flowing claims.