Abstract:
There is provided an ink sheet cartridge that includes a cartridge case having a case body disposed opposite to an upper surface of an ink sheet unit, driving sidewall portions rotatably supporting driving shafts of respective sheet supply and winding bobbins, and a supporting sidewall portion to rotatably support supporting shafts of respective sheet supply and winding bobbins. The ink sheet unit is detachably insertable in the case body, receives an ink sheet wound around the sheet supply bobbin, and includes a supply sheet case capable of drawing out the ink sheet therefrom at the time of receiving the ink sheet. The ink sheet cartridge enables replacement of the ink sheet unit such that the cartridge case is reusable and protects the replacement ink sheet from foreign objects and substances.

Description:
[0001]    This application claims the benefit of priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2006-078750 filed on Mar. 22, 2006, which is hereby incorporated by reference in its entirety. 
       BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The present disclosure relates to an ink sheet cartridge, and more particularly, to an ink sheet cartridge used in a line thermal printer for printing a print image. 
         [0004]    2. Description of the Related Art 
         [0005]    In general, a line thermal printer having a longitudinal thermal head, and heater elements of which are arranged in a width direction of a printing paper, is used as a printer which promptly performs a printing operation line-by-line or page-by-page on a printing paper. 
         [0006]    An ink sheet cartridge which receives an ink sheet unit in a cartridge case is fitted into the line thermal printer as an ink sheet cartridge for the line thermal printer. 
         [0007]    The ink sheet cartridge includes a longitudinal ink sheet of which a coloring region is continuously applied with ink of colors yellow, magenta, cyan, or the like. One end of the ink sheet is wound around a sheet supply bobbin of a cylindrical shape while the other end of the ink sheet is wound around a winding bobbin of a cylindrical shape. In addition, the cartridge case includes upper and lower halves made of a synthetic resin, which are bonded or engaged with each other by an ultrasonic welding or a snap-in method. 
         [0008]    A known ink sheet cartridge allows the ink sheet unit to receive the sheet supply and winding bobbins to be rotatable in the cartridge case. 
         [0009]    However, in an ink sheet cartridge formed by bonding the upper and lower halves with each other so as to form the cartridge case, it is difficult to reuse the cartridge case as the cartridge case needs, inevitably, to be broken to replace a used ink sheet unit with an unused ink sheet unit. Likewise, in an ink sheet cartridge formed by engaging the upper and lower halves with each other in terms of the snap-in method, it is difficult for a common user to reuse the cartridge case as a tool for detaching the engaged halves by the snap-in method, or a certain degree of skill, is necessary to replace the ink sheet unit. 
         [0010]    Additionally, in the ink sheet unit of the known ink sheet cartridge, the coloring region applied with the ink of yellow, magenta, cyan, or the like color is exposed. Because of this, even when it is possible to detach the upper and lower halves to replace the ink sheet unit, there is a concern of touching a wound part of the ink sheet in the sheet supply bobbin or the sheet winding bobbin with a hand or finger, etc., so that a foreign substance such as dust can be attached to, or a flaw created on, the coloring region of the ink sheet. Therefore, when an image is printed by using the above-mentioned ink sheet, a failure or glitch in the transfer of the ink results in an unsatisfactory image print. 
         [0011]    Examples of such an ink sheet cartridge are disclosed in Japanese Patent No. 3496267 and Japanese Unexamined Patent Application Publication No. 5-155122. 
       SUMMARY 
       [0012]    The present disclosure is contrived in consideration of the above-mentioned problems. Various objects of the disclosure include, but are not limited to, providing an ink sheet cartridge of which: an ink sheet unit can be easily replaced, an effective utilization of resources can be achieved because the reuse of a cartridge case is possible, and printing a satisfactory, if not higher quality, image can be obtained by preventing foreign substances from attaching on an ink sheet and preventing flaws from being made on the ink sheet when replacing the ink sheet unit. 
         [0013]    To achieve at least some of the above objects, there is provided an ink sheet cartridge having an ink sheet unit including a sheet supply bobbin on which a longitudinal ink sheet is wound from one end thereof and a sheet winding bobbin on which the longitudinal ink sheet is wound from the other end. A cartridge case detachably receives the ink sheet unit, wherein the cartridge case includes a case body having a central opening portion disposed opposite to a main surface of the ink sheet unit so as to expose the ink sheet from the center thereof; first and second driving sidewall portions disposed on one side of the case body so as to rotatably support corresponding first and second driving shafts disposed on one end of the sheet supply and winding bobbins, respectively; and first and second supporting sidewall portions disposed on the other side of the case body so as to rotatably support corresponding supporting shafts disposed on the other end of the sheet supply and winding bobbins, respectively. The ink sheet unit includes a sheet case that receives the ink sheet wound around the sheet supply bobbin, such that the ink sheet is drawn from the sheet supply bobbin through a central slit opening of the sheet case to be wound around the sheet winding bobbin. 
         [0014]    An ink sheet cartridge according to one embodiment includes a case body disposed on the main surface of an ink sheet unit, a driving sidewall portion, and a supporting sidewall portion disposed in a semi-open type structure so as to receive and hold the ink sheet unit when the cartridge case is inserted into a printer. Because the ink sheet cartridge has the semi-open type structure, it does not require labor or skill to disassemble the cartridge case, thereby making it easy to replace and recover the ink sheet unit. 
         [0015]    According to an ink sheet cartridge of the disclosure, because a part of the ink sheet (wound around at least the sheet supply bobbin) is coated with a sheet case, it is possible to prevent a hand or the like from directly touching a part that is wound around the sheet supply bobbin. The part is an unused part in a coloring region of the ink sheet unit when replaced and recovered. 
         [0016]    According to an ink sheet cartridge of the disclosure, an end opening portion to expose the sheet case is disposed on a part opposite to the sheet case in the case body. This arrangement of the end opening portion and the sheet case reduces the amount of material used in manufacturing the case body as well as the amount of waste from scraping the cartridge case. 
         [0017]    According to an ink sheet cartridge of the disclosure, a locking protrusion is disposed on a supporting sidewall and in opposition to the supporting sidewall portion of the sheet case. A holding member is to hold the sheet case is disposed on, and moveable in parallel with, an inner surface of the supporting sidewall portion. The holding member includes a locking claw having a locking portion locked to the locking protrusion, a guiding slope being formed on an edge of the locking claw so as to guide the locking protrusion to the locking portion while moving the holding member to abut against the locking protrusion when the cartridge case receives the ink sheet unit. 
         [0018]    An ink sheet cartridge according to another embodiment includes a sheet case having a first driving sidewall portion coupled to a first end of the sheet case and a first supporting sidewall portion coupled to a second end of the sheet case to rotatably support, respectively, corresponding driving and supporting shafts of a sheet supply bobbin within the sheet case. A case body has supply and winding dome portions at respective first and second ends thereof, the supply dome portion for detachable insertion therein of the sheet case through an end opening portion of the case body, and the winding dome portion for detachable insertion therein of a sheet winding bobbin. A second driving sidewall portion is coupled to a first side of the winding dome portion, and a second supporting sidewall portion is coupled to a second side of the winding dome portion to rotatably support, respectively, corresponding driving and supporting shafts of the winding supply bobbin. An ink sheet has a first end wound around the sheet supply bobbin and threaded through a central slit opening defined along the side of the sheet case, and having a second end wound around the sheet winding bobbin. 
         [0019]    In this embodiment, an ink sheet unit includes the sheet case having therein the sheet supply bobbin, the sheet winding bobbin, and the ink sheet, wherein the ink sheet unit is detachable from the case body. 
         [0020]    In addition, it is possible to prevent a foreign substance, such as a dust, from being attached on an unused part of the coloring region of the ink sheet. Accordingly, the various embodiments help to prevent a transfer failure of the ink from the ink sheet caused by the attachment of foreign substances thereon, thereby enabling the printing of higher quality images. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a perspective view illustrating an ink sheet cartridge according to the present disclosure. 
           [0022]      FIG. 2  is an exploded perspective view illustrating an ink sheet unit and a cartridge case of the ink sheet cartridge as shown in  FIG. 1 . 
           [0023]      FIG. 3  is a side view illustrating an unlocked state of a holding member and a sheet case of the ink sheet cartridge as viewed from a supporting sidewall portion as shown in  FIG. 1 . 
           [0024]      FIG. 4  is a schematic side view illustrating a locked state of the holding member as shown in  FIG. 3 , and the sheet case as viewed from the supporting sidewall portion. 
           [0025]      FIG. 5  is a top plan view illustrating a main part of the supporting sidewall portion in the ink sheet cartridge as shown in  FIG. 1 . 
           [0026]      FIG. 6  is a sectional view illustrating the main part of the supporting sidewall portion in the ink sheet cartridge as shown in  FIG. 1 . 
           [0027]      FIG. 7  is a side view illustrating the holding member as shown in  FIG. 3  moved toward a winding side as viewed from an inside of the cartridge case. 
           [0028]      FIG. 8  is a side view illustrating the holding member as shown in  FIG. 3  moved toward a supply side as viewed from the inside of the cartridge case. 
           [0029]      FIG. 9  is a top plan view illustrating a main part of the holding member as viewed from the supporting sidewall portion in the cartridge case as shown in  FIG. 2 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0030]    Hereinafter, an ink sheet cartridge according to an embodiment of the invention will be described with reference to  FIGS. 1 through 9 . 
         [0031]      FIG. 1  is a perspective view illustrating the ink sheet cartridge according to one embodiment.  FIG. 2  is an exploded perspective view illustrating the ink sheet cartridge as shown in  FIG. 1 . 
         [0032]    As shown in  FIGS. 1 and 2 , an ink sheet cartridge  1  according to the disclosure includes an ink sheet unit  2  and a cartridge case  3  to receive the ink sheet unit  2 . 
         [0033]    The ink sheet unit  2  includes a longitudinal ink sheet  23  of which a coloring region is sequentially and continuously applied with ink of yellow (Y), magenta (M), and cyan (C) colors. The ink sheet unit  2  also includes a sheet supply bobbin  21  on which the ink sheet  23  is wound from one end thereof, and a winding bobbin  22  on which the ink sheet  23  is wound from the other end thereof. 
         [0034]    Additionally, the sheet supply and winding bobbins  21  and  22  of the ink sheet unit  2  are made of a resin cylindrical member, and include cylindrical-shaped base portions  21   a  and  22   a  disposed at the center thereof a supporting shaft having a smaller outer diameter than that of the base portions  21   a  and  22   a  disposed on one end of the base portions  21   a  and  22   a , and driving shafts  21   c  and  22   c  having a larger outer diameter than that of the base portions  21   a  and  22   a  disposed on an outer end of the base portions  21   a  and  22   a.    
         [0035]    One end of the unused ink sheet  23  is wound around the base portion  21   a  of the sheet supply bobbin  21  and the other end of the ink sheet  23  is wound around the base portion  22   a  of the sheet winding bobbin  22 . 
         [0036]    The supporting and driving shafts  21   c  and  22   c  include a lower guard-shaped flange abutting against the base portions  21   a  and  22   a , respectively (e.g., flanges  21   d  and  22   d  of the supporting shafts, and flanges  21   e  and  22   e  of the driving shafts  21   c  and  22   c ). Rectangular-shaped grooves  21   f  and  22   f  of a plurality teeth used as a fitting portions are radially arranged around the shaft on the outer wall surface of the flanges  21   e  and  22   e , which are disposed on the driving shafts  21   c  and  22   c . Theses fitting grooves  21   f  and  22   f  receive corresponding gripping protrusions (not shown) on the inner wall of driving sidewall portions ( 11   b  and  36  discussed further below). 
         [0037]    On an inner surface of the driving shafts  21   c  and  22   c , locking protrusions  21   g  and  22   g  are formed to lock to a driving system of a printer (not shown) that transmits rotary power for rotating the sheet supply and winding bobbins  21  and  22 . The driving system of the printer is locked to the locking protrusions  21   g  and  22   g  so as to transmit rotary power to the sheet supply and winding bobbins  21  and  22 . 
         [0038]    Additionally, the ink sheet unit  2  includes the supply-side sheet case  6  that receives a part of the ink sheet  23  wound around the sheet supply bobbin  21 . 
         [0039]    The sheet case  6  is formed of a resin material (or the like), and is cylindrical in shape. The supply-side sheet case  6  includes upper and lower cases  10  and  11 . 
         [0040]    The upper case  10  includes a semi-cylindrical shaped upper wall  10   a  which is disposed opposite to an upper surface side of the ink sheet  23  (wound around the sheet supply bobbin  21 ) and a cylindrical-shaped supporting-side wall  10   b , which is disposed opposite to a supporting shaft side of the sheet supply bobbin  21 . In the supporting-side wall  10   b  side with reference to the upper wall  10   a , an upper side bearing  10   c  is disposed in parallel with the supporting-side wall  10   b  and locked to the flange  21   d  of the sheet supply bobbin  21  so as to rotatably support the supporting shaft. In addition, at the outer surface of the supporting-side wall  10   b , a plurality of locking protrusions  10   d , e.g., two locking protrusions  10   d  are disposed longitudinally along the width direction of the supporting-side wall  10   b  as shown in  FIGS. 3 and 4  according to one embodiment. 
         [0041]    In addition, the lower case  11  includes a semi-cylindrical shaped lower wall  11   a  which is disposed opposite to a lower part of the ink sheet  23  (wound around the sheet supply bobbin  21 ) and a cylindrical-shaped driving-side sidewall  11   b  which is disposed opposite to the driving shaft  21   c  side of the sheet supply bobbin  21 . In the supporting-side wall  10   b  with respect to the lower wall  10   a , a lower side bearing (not shown) is formed and locked to the flange  21   d  of the sheet supply bobbin  21  so as to rotatably support the supporting shaft. In addition, at the center part of the driving-side sidewall  11   b , a cylindrical-shaped donut bearing  11   d  is formed so as to rotatably support the driving shaft  21   c  of the sheet supply bobbin  21 . 
         [0042]    The upper and lower cases  10  and  11  form a single body by locking a locking portion  10   e  formed on an end of the upper case  10  into a locking portion (not shown) formed on an end of the lower case  11  corresponding to the one end of the upper case  10 . 
         [0043]    Additionally, in the supply-side sheet case  6 , an opening portion  8  is formed at the gap between edges of the upper and lower cases  10  and  11 , extending longitudinally of the sheet case  6  so as to draw the ink sheet  23  out of the sheet winding bobbin  22 . 
         [0044]    Meanwhile, a cartridge case  3  includes a case body  31  disposed in opposition to an upper surface of the ink sheet unit  2  and made of a plate-shaped member. A window frame-shaped central opening portion  32  is formed at the center part of the case body  31  so as to allow a printing portion (not shown) of the printer to abut against the ink sheet  23 , which is thereby tensely stretched between the sheet supply and winding bobbins  21  and  22 . 
         [0045]    On one end of the case body  31  (in opposition to the sheet supply bobbin  21 ), a supply dome portion  33  is formed in a bent semi-cylindrical shape so as to receive the supply-side sheet case  6 . At the part of the supply dome portion  33  opposed to the supply-side sheet case  6 , a window frame-shaped supply-side  33   a  is formed so as to expose the upper surface of the supply-side sheet case  6 . Meanwhile, on the other end of the case body  31  (opposite from the sheet winding bobbin  22 ), a winding dome portion  34  is formed in a bent semi-cylindrical shape so as to receive the sheet winding bobbin  22  around which the ink sheet  23  is wound. 
         [0046]    On one end of the case body  31 , a cylindrical-shaped driving-side sidewall portion  35  is formed that rotatably supports the driving shaft  21   c  of the sheet supply bobbin  21  and corresponds to the supply dome portion  33 . On the other end of the case body  31 , a cylindrical-shaped driving-side sidewall portion  36  is formed that rotatably supports the driving shaft  22   c  of the sheet winding bobbin  22 , and corresponds to the winding dome portion  34 . 
         [0047]    On the center part of the wall surface of the driving sidewall portions  35  and  36 , donut-shaped bearings  35   a  and  36   a  are formed so as to rotatably support the driving shafts  21   c  and  22   c  of the sheet supply or winding bobbins  21  or  22 . 
         [0048]    In addition, on the other side of the case body  31 , a supporting-side sidewall portion  37  is formed so as to support the supporting-side wall  10   b  of the supply-side sheet case  6  and to rotatably support the supporting shaft  22   b  disposed on the other end of the sheet winding bobbin  22 . 
         [0049]    As shown  FIGS. 5 and 6 , the part of the supporting-side sidewall portion  37  that supports the supporting shaft  22   b  includes: an outer wall portion  38  forming the outer wall of the cartridge case  3 ; an inner wall portion  40  having a predetermined gap in parallel with the outer wall portion  38  inside the winding dome portion  34  of the cartridge case  3 ; and a central wall portion  42  disposed in parallel with the outer wall portion  38  at the gap between the outer wall portion  38  and the inner wall portion  40 . 
         [0050]    On the inner wall portion  40  of the supporting-side sidewall portion  37 , a U-shaped bearing  40   a  is opened on an end of the inner wall portion  40  so as to slide within it the supporting shaft  22   b  of the sheet winding bobbin  22 . 
         [0051]    Additionally, a convex-shaped locking portion  38   a  is formed on the inner wall surface of the outer wall portion  38  so as to lock in one end of a spring member  44 . A convex-shaped locking portion  42   a  is formed on the outer wall surface of the central wall portion  42  so as to lock in the other end of the spring member  44 . That is, the spring member  44  is disposed between the outer and central wall portions  38  and  42  by allowing both ends thereof to lock in the locking portions  38   a  and  42   a.    
         [0052]    Here, the central wall portion  42  is a plate-shaped member of which its base is fixed in the case body  31 , and formed in a bar-shape having a cantilever which enables the end to be flexible in a direction of the end perpendicular to the outer wall  38 . As the flexibility is released, the supporting shaft  22   b  of the sheet winding bobbin  22  abuts against the inner wall surface of the central wall portion  42 , and therefore, the sheet winding bobbin  22  is able to be biased to the driving-side sidewall portion  36 . 
         [0053]    In addition, a guiding wall surface (not shown) is formed on the inner wall surface of the central wall portion  42  in a slope rising from an end of the central wall portion  42  to a base portion thereof. A guiding protrusion  42   b , also formed in the inner wall surface of the central wall portion  42 , has a locking surface extending perpendicular to the inner wall surface of the central wall portion  42  and in parallel with the inner wall surface of the case body  31 . Also, an end of the central wall portion  42  is made as a gripper portion for a user to manipulate the central wall portion  42 . 
         [0054]    Also, on the supporting-side sidewall portion  37 , a flat L-shaped protrusion  49  includes an end connected to the inner wall surface of the outer wall portion  38 . The other end of the L-shaped protrusion  49  extends in parallel with the case body  31  in the space above the spring member  44  (between where the central wall portion  42  approaches near the outer wall portion  38 ) and against the pressing force of the outer wall portion  38  and the spring member  44 . 
         [0055]    On an inner surface of the supporting-side sidewall portion  37 , a holding member  12  is attached so as to support the supply-side sheet case  6 . 
         [0056]    The holding member  12  includes a base portion  12   a  disposed on the center part of the supporting-side sidewall portion  37  and an arm portion  12   b  extended so as to be disposed on the part in opposition to the supporting-side wall  10   b  of the supply-side sheet case  6 . A first locking aperture  12   j  is formed on a winding-side end of the base portion  12   a  on which the sheet winding bobbin  22  is disposed, longitudinally in a direction corresponding to the movement of the holding member  12  between the supply and winding sides as shown in  FIGS. 7 and 8 . 
         [0057]    Additionally, a second locking base portion  12   k  is longitudinally formed as was the first locking aperture  12   j , but on a supply-side end of the arm portion  12   b.    
         [0058]    Locking clamps  37   c  and  37   d  that protrude from the supporting-side sidewall portion  37  are formed in correspondence with, and for insertion into, locking apertures  12   j  and  12   k  on the inner surface of the supporting-side sidewall portion  37 . In this way, the holding member  12  is attached to the inner surface of the supporting-side sidewall portion  37  by allowing the locking clamps  37   c  and  37   d  to lock in the respective locking apertures  12   j  and  12   k.    
         [0059]    As shown in  FIGS. 7 and 8 , the holding member  12  is able to move within the locking range of which the locking clamps  37   c  and  37   d  are locked to the longitudinal locking apertures  12   j  and  12   k  formed in the above direction by using the locking clamps  37   c  and  37   d  as a guide. Thus, the holding member  12  is attached so as to be able to move between the supply side and the winding side along the inner surface of the supporting-side sidewall portion  37 . 
         [0060]    On an end of the base portion  12   a , as shown in  FIG. 9 , a convex portion  12   f  is formed so as to protrude toward the supporting-side sidewall portion  37 . The convex portion  12   f  formed in a ⊃ shape causes a ⊃-shaped opening  12   g  to be formed toward the winding side. Additionally, a spring supporting member  12   i  is disposed inside the opening  12   g  of the convex portion  12   f  and an end of the spring member  12   h  is attached to the spring supporting member  12   i.    
         [0061]    A concave portion  37   a  movably fits within the convex portion  12   f , and is formed on the inner surface of the supporting-side sidewall portion  37  opposite to the convex portion  12   f , and the convex portion  12   f  is moveable between the supply side and the winding side in the concave portion  37   a . In addition, a concave portion  37   b  supporting the other end of the spring member  12   h  is formed on the concave portion  37   a  opposite to the opening  12   g  of the convex portion  12   f  when the convex portion  12   f  of the holding member  12  is movably inserted into the concave portion  37   a.    
         [0062]    When the holding member  12  moves to the winding side, the convex portion  12   f  of the holding member  12  in the concave portion  37   a  of the supporting-side sidewall portion  37  moves to the winding side, and the spring member  12   h  shrinks correspondingly. When the holding member  12  does not move to the winding side, the convex portion  12   f  moves to the supply side in the concave portion  37   a  with the restoring force of the spring member  12   h  such that the holding member  12  is biased to the supply side. 
         [0063]    Each locking claw  12   d  has a locking portion  12   c  and protrudes from a lower end of the arm portion  12   b  on the position corresponding to each locking protrusion  10   d  that is formed on the supporting-side wall  10   b  of the arm portion  12   b . On an edge of the locking claw  12   d , a guiding slope  12   e  is formed by a slope angle intersecting at an acute angle in a direction of movement to the winding side of the holding member  12 . The guiding slope  12   e  thus guides the locking protrusion  10   d  to the locking portion  10   c  while moving the holding member  12  to the sheet winding bobbin  22  at the time the supply side sheet case  6  abuts against the locking protrusion  10   d  when the sheet supply dome portion  33  receives the supply-side sheet case  6 . 
         [0064]    An example of a method of inserting the ink sheet unit  2  into the cartridge case  3  will now be described. 
         [0065]    First, an example of a method of inserting the supply-side sheet case  6  into the supply dome portion  33  will be described. 
         [0066]    As shown in  FIG. 3 , when the supply-side sheet case  6  is disposed in the supply dome portion  33 , each locking protrusion  10   d  of the supply-side sheet case  6  abuts against each guiding slope  12   e . When the supply-side sheet case  6  is inserted in the sheet supply dome portion  33 , each locking protrusion  10   d  is guided to the locking portion  12   c  of the locking claw  12   d  along the guiding slope  12   e , and the holding member  12   a  moves to the winding side of the cartridge case  3  against the bias force of the spring member  12   h . As shown in  FIG. 4 , when each locking protrusion is locked to the locking portion of each locking claw (with the restoring force of the spring member  12   h ), the holding member  12   a  moves to the supply side on which the sheet supply bobbin  21  of the cartridge case  3  is disposed so as to return to an original position. 
         [0067]    The supply-side sheet case  6  is accordingly locked as each locking protrusion  10   d  thereof is locked to each locking claw  12   d  on the supporting-side wall  10   b  side, and each locking claw  12   d  presses each locking protrusion  10   d  with the bias force of the holding member  12 , thereby fixing the final position of each locking protrusion  10   d  after locking. In addition, in the driving-side sidewall  11   b , the driving shaft  21   c  is held in the bearing  35   a  of the driving-side sidewall portion  35 , thereby holding the driving shaft  21   c  inside the supply dome portion  33  of the cartridge case  3 . 
         [0068]    According to the above description, when the sheet supply bobbin  21  is inserted in the reception portion of the sheet supply bobbin  21 , an unused ink sheet wound around the sheet supply bobbin  21  is drawn out and extends to the opening portion  32  of the case body  31  which is opened as a transport path. 
         [0069]    An example of a method of inserting the sheet winding bobbin  22  into the winding dome portion  34  will now be described. 
         [0070]    The driving shaft  22   c  of the sheet winding bobbin  22  is introduced into the bearing  36   a  of a hole shape formed on the driving-side sidewall portion  36  so as to rotatably slide by disposing the sheet winding bobbin  22  of the ink sheet unit  2  in the sheet winding dome portion  34  of the cartridge case  3  ( FIGS. 5 and 6 ). 
         [0071]    By sliding an end of the supporting shaft  22   b  that abuts against the guiding wall surface of the guiding protrusion  42   b , the central wall portion  42  is enabled to flex toward the outer wall portion  38  and engage the U-shaped bearing  40   a  formed on the inner wall portion  40 . At this time, a user can enable the central wall portion  42  to be flexible toward the outer wall portion  38  against the pressing force of the spring member  44  by gripping the gripper portion formed on an end thereof. 
         [0072]    When an end of the supporting shaft  22   b  is out of the guiding wall surface of the guiding protrusion  42   b  and is in the bearing  40   a , the central wall portion  42  is pressed back to the inner wall portion  40  with the flexible restoring force thereof. With the restoring force of the spring member  44 , the sheet winding bobbin  22  in the inner surface of the central wall portion  42  is biased against the driving-side sidewall portion  36 , and the sheet winding bobbin  22  is held in the winding dome portion  34 . Likewise, as the sheet winding bobbin  22  is biased in a direction of the driving-side sidewall portion  36  the flange  22   e  is placed in contact with the driving sidewall  36  of the cartridge case  3 , and the rectangular grooves  22   f  formed on the outer wall surface of the flange  22   e  receive at least one gripping protrusion (not shown) formed on the driving-side sidewall portion  36 . An idle rotation of the sheet winding bobbin  22  is thereby prevented when the cartridge case is not inserted into the printer, as is the looseness of the ink sheet  23 . 
         [0073]    Accordingly, when the ink sheet cartridge  1  receives the ink sheet unit  2  within the cartridge case  3 , the ink sheet unit  2  is inserted into a predetermined position of the printer, making it ready to print. 
         [0074]    Next, an example of a method of detaching the ink sheet unit  2  from the cartridge case  3  is described. Advantageously, the method provides for recovery of a used up sheet winding bobbin  22  from the winding dome portion  34 . The user: enables the central wall portion  42  to flex toward the outer wall  38  against the pressing force of the spring member  44  by gripping the gripper portion formed on the end thereof; takes out the supporting shaft  22   b  from the U-shaped bearing  40   a  of the inner wall portion  40  while the guiding protrusion  42   b  and the supporting shaft  22   b  are disengaged; and continuously releases the slide of the driving shaft  22   c  with respect to the bearing  36   a  formed on the driving-side sidewall portion  36 . 
         [0075]    Next, the supply-side sheet case  6  of the ink sheet unit  2  is detached from the supply dome portion  33  of the cartridge case  3 . 
         [0076]    As shown in  FIG. 7 , while moving the base portion  12   a  of the holding member  12  to the winding side against the bias force of the spring member  12   h , and while moving the supply-side sheet case  6  in a direction separate from the supply dome portion  33 , the user unlocks each locking protrusion  10   d  of the supply-side sheet case  6  from the locking portion  12   c  of each locking claw  12   d  in the cartridge case  3 , and detaches the driving shaft  21   c  from the bearing  35   a  of the driving-side sidewall portion  35 . Accordingly, the supply-side sheet case  6  of the ink sheet unit  2  is detached from the supply dome portion  33  of the cartridge case  3 . 
         [0077]    Additionally, when the force of the base portion  12   a  toward the winding side is off, the holding member  12  moves toward the supply side so as to return to an original position by way of a restoring force of the spring member  12   h  ( FIG. 8 ). 
         [0078]    In the ink sheet cartridge  1  of one embodiment, the outer wall surface of the case body  31  faces upside down at the time of insertion into the printer. That is, the ink sheet cartridge  1  is formed in a semi-open type structure so as to receive and hold the ink sheet unit  2  in the upper half of the above-mentioned known ink sheet cartridge. 
         [0079]    In addition, as the part wound around the sheet supply bobbin  21  of the ink sheet  23  is coated with the supply-side sheet case  6 , direct touching of the unused part of the coloring region of the ink sheet  23  with a hand or foreign object can be prevented at the time of replacing and recovering the ink sheet unit  2 . 
         [0080]    Accordingly, labor and skill is not required to disassemble the cartridge case  3  of the ink sheet cartridge  1  having a semi-open type structure, thereby making it easier to replace and recover the ink sheet unit  2 . Additionally, the cartridge case  3  can be reused, and thus running costs are reduced as well. 
         [0081]    Additionally, it is possible to prevent foreign substances such as dust or the like from attaching on the unused part of the coloring region of the ink sheet  23 , thus preventing a transfer failure of the ink from the ink sheet  23  caused by such attachment. The result is a higher quality print. It is also possible to prevent a hand or other foreign object from polluting the coloring region at the time of replacing and recovering the ink sheet unit  2 . 
         [0082]    Also, at the time of using the ink sheet cartridge, the locking surface of the guiding protrusion  42   b  formed on the central wall portion  42  is locked to an end of the supporting shaft  22   b  of the sheet winding bobbin  22 , and the supporting shaft  22   b  is controlled in the bearing  40   a , thereby preventing the supporting shaft  22   b  of the sheet winding bobbin  22  from separating from the bearing  40   a . Each locking protrusion  10   d  of the supply-side sheet case  6  is locked to each locking claw  12   d  of the holding member  12   a . Each locking protrusion  10   d  is pushed by each locking claw  12   d  because of the bias force of the holding member  12 , thereby fixing the position of each locking protrusion  10   d  after locking. Accordingly, the supply-side sheet case  6  is firmly held in the supply dome portion  33  of the cartridge case  3 . Because two locking protrusions  10   d  are locked to the corresponding two locking claws  12   d , it is possible to prevent the supply-side sheet case  6  from moving in the supply dome portion  33  of the cartridge case  3 , thereby more securely holding the supply-side sheet case  6  in the supply dome portion  33  of the cartridge case  3 . 
         [0083]    Furthermore, when unlocking the spring member  44  with a certain shock at the time of detaching the sheet winding bobbin  22  from the cartridge case  3  (for the purpose of replacing the ink sheet unit  2 , for instance), it is possible to prevent the spring member  44  from protruding from the ink sheet cartridge  1  by using the protrusion  49  that causes the spring member  44  to protrude toward the space directly above the spring member  44 . Additionally, loss of the spring member  44  can be prevented. 
         [0084]    When the cartridge case  3  needs to be scraped because of prolonged usage of the ink sheet cartridge  1 , the user can scrape the cartridge case  3  by sorting the metal spring member  44  and the resin cartridge case  3  after bending a connection part between the protrusion  49  disposed in the space above the spring member  44  and the outer wall portion  38 . 
         [0085]    Because the supply-side end opening portion  33   a  is formed on the part of the case body  31  of the cartridge case  3  opposed to the supply-side sheet case  6 , the material needed to manufacture the case body  31  is reduced, as is the amount of waste when required to scrape the cartridge case  3 . 
         [0086]    Additionally, the invention is not limited to the above-described embodiment, and may be modified to various forms of the embodiment, if necessary. 
         [0087]    For example, the part of the ink sheet  23  wound around the sheet supply bobbin  21  is received in the supply-side sheet case  6  in one embodiment, but the scope of the disclosure is not limited thereto. The portion wound around the sheet winding bobbin  22  may be received in a winding-side sheet case (not shown). In this case, a winding-side end opening portion may be formed on the part of the case body  31  of the cartridge case  3  opposed to the winding-side sheet case, thereby further reducing the manufacturing material and the time required to scrape the cartridge case  3 . 
         [0088]    Additionally, a holding mechanism which holds the ink sheet unit  2  in the cartridge case  3  is not limited to the above-described embodiment, and may be modified in various ways as recognized by one of skill in the art. 
         [0089]    Additionally, the case body  31  of the cartridge case  3  is disposed to face the upper surface of the ink sheet unit  2  in the embodiment, but may by modified to be disposed to face the lower surface of the ink sheet unit  2 . 
         [0090]    The terms and descriptions used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations can be made to the details of the above-described embodiments without departing from the underlying principles of the disclosure. The scope of the disclosure should therefore be determined only by the following claims (and their equivalents) in which all terms are to be understood in their broadest reasonable sense unless otherwise indicated.