JP2018058268A - Ink ribbon cassette and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink ribbon cassette which can apply the proper back tension to an ink ribbon with a simple configuration without complicating the configuration of a printer body.SOLUTION: An ink ribbon cassette stores: an ink ribbon 204; a supply bobbin 205 around which the ink ribbon is wound; and a take-up bobbin which takes up the ink ribbon supplied from the supply bobbin. A storage part 207 for storing the supply bobbin is provided with sliding parts 221, 222 which can slide with the ink ribbon. The sliding parts are formed so that the sliding area between the sliding parts and the ink ribbon becomes small when the diameter of the ink ribbon wound to the supply bobbin becomes small.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an ink ribbon cassette in which an ink ribbon is accommodated and a printing apparatus to which the ink ribbon cassette can be attached and detached.

  A sublimation printer presses a recording medium such as paper and an ink ribbon with a thermal head and a platen roller, and energizes the thermal head to generate heat on the thermal head and sublimate the dye applied to the ink ribbon. Printing is performed by transferring to paper.

  The ink ribbon is configured so that a cylindrical supply bobbin and a take-up bobbin around which the ink ribbon is wound are accommodated in the ink ribbon cassette so that the ink ribbon can be easily detached from the printer body. The take-up bobbin is held rotatably.

  When the ink ribbon cassette is mounted on the printer main body, the thermal head is positioned between the supply bobbin and the take-up bobbin, and the thermal ribbon is pressed against the platen roller in a state where the ink ribbon and the paper are stacked, and printing is performed.

  In Patent Document 1, when an ink ribbon cassette containing a supply bobbin and a take-up bobbin is loaded into a printer main body, a supply bobbin and a take-up bobbin are opposite to the mounting direction of the ink ribbon cassette by a compression spring provided in the printer main body. Pressed. Then, a sliding frictional force is generated by sliding of the supply bobbin tip and the sliding surface provided on the ink ribbon cassette, and a constant torque can be applied to the supply bobbin. The torque generated in the supply bobbin serves as a brake so that the ink ribbon is not pulled out more than necessary when the ink ribbon is taken up by the take-up bobbin. Further, the tension generated in the ink ribbon at this time is called back tension.

JP 2012-187802 A

  However, since the ink ribbon cassette described in Patent Document 1 applies a certain torque to the supply bobbin, the back tension changes according to the winding diameter of the ink ribbon in the supply bobbin. FIG. 13 In the case where the beginning of the ink ribbon cassette is just started and the number of printed sheets is small, the winding diameter of the ink ribbon wound around the supply bobbin is large, so that the back tension is small as shown in FIG. On the other hand, when the number of printed sheets increases, the winding diameter of the ink ribbon wound around the supply bobbin becomes smaller, so that the back tension increases.

  Therefore, when the number of printed sheets is small and the winding diameter of the ink ribbon is large, since the back tension is small, the ink ribbon is not sufficiently stretched and wrinkles are likely to occur. In addition, at the end of the roll where the number of printed sheets is large and the winding diameter of the ink ribbon is small, the back tension is increased more than necessary, so that a problem that the ink ribbon cannot be wound by the winding bobbin is likely to occur.

  It is also possible to provide a back tension adjustment mechanism that adjusts the back tension according to the winding diameter of the ink ribbon wound around the supply bobbin. In this case, however, the structure of the printer main body becomes complicated, and the number of parts increases. And the cost will increase.

  Accordingly, the present invention has been made in view of the above problems, and provides an ink ribbon cassette that can apply an appropriate back tension to the ink ribbon with a simple configuration without changing the configuration of the printer body. It is.

In order to achieve the above object, the ink ribbon cassette of the present invention comprises:
An ink ribbon cassette that stores an ink ribbon, a supply bobbin around which the ink ribbon is wound, and a take-up bobbin that winds up the ink ribbon supplied from the supply bobbin, and stores the supply bobbin The storage portion includes a sliding portion that is slidable with the ink ribbon, and the sliding portion and the sliding portion, when the diameter of the ink ribbon wound around the supply bobbin decreases, It is characterized in that the sliding area with the ink ribbon is reduced.

  According to the present invention, the sliding area of the ink ribbon cassette and the sliding area of the ink ribbon cassette and the sliding area of the ink ribbon change according to the winding diameter of the ink ribbon wound around the supply bobbin. An appropriate back tension can be applied to the ink ribbon.

A perspective view showing the entire printer and ink ribbon cassette Cross section of ink ribbon cassette Bobbin perspective view Bush side view Sectional drawing explaining operation | movement when loading an ink ribbon cassette in a printer main body Sectional view when the ink ribbon cassette is loaded in the printer body Expanded cross section near the supply bobbin A graph explaining the back tension value generated on the ink ribbon Enlarged sectional view of the vicinity of the supply bobbin in the second embodiment A graph for explaining the value of the back tension generated in the ink ribbon in the second embodiment Enlarged sectional view of the vicinity of the supply bobbin in the third embodiment A graph for explaining the value of the back tension generated in the ink ribbon in the third embodiment A graph for explaining the value of the back tension generated in the ink ribbon in the conventional example

[Example 1]
The first embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 is a perspective view showing the entire printer body and ink ribbon cassette according to an embodiment of the present invention.

  Reference numeral 100 denotes a printer main body, 200 denotes an ink ribbon cassette, and 300 denotes a paper tray. An ink ribbon cassette insertion port 101 is provided on the side surface of the printer main body 100 so that the ink ribbon cassette 200 can be mounted. The ink ribbon cassette 200 is detachable in the direction of arrow A. A front side of the printer main body 100 has a paper tray insertion slot 102 for allowing the paper tray 300 to be mounted. The paper tray 300 is detachable in the direction of arrow B.

  Reference numeral 103 denotes a display unit, and 104 denotes an operation unit, which are arranged on the top surface of the printer main body 100. The display unit 103 includes a display unit such as an LCD, displays an image to be printed, image processing information, and the like on the display unit 103, selects an image by operating the operation unit 104, and appropriately processes and prints the image. be able to.

  FIG. 2 is a cross-sectional view of the ink ribbon cassette 200.

  As shown in FIG. 2, the ink ribbon cassette 200 includes an upper case 201, a first lower case 202, and a second lower case 203. The upper case 201 and the first lower case 202 form a supply bobbin storage portion 207 that stores a supply bobbin 205 that supplies the ink ribbon 204. In addition, the upper case 201 and the second lower case 203 form a winding bobbin storage portion 208 that stores a winding bobbin 206 that winds up the ink ribbon 204. The supply bobbin storage portion 207 and the take-up bobbin storage portion 208 are connected by a connecting portion 209 and are arranged at a predetermined interval.

  Reference numeral 221 denotes a first sliding surface, and 222 denotes a second sliding surface, which has a shape protruding on the inner wall of the upper case 201 on the supply bobbin storage portion 207 side so as to slide with the ink ribbon 204. The second sliding surface 222 is provided in the supply-side opening 214 and has a shape with a smaller radius of curvature than that of the first sliding surface 221 and a smaller area for sliding with the ink ribbon 204. . The second sliding surface 222 also serves to curve the transport path of the ink ribbon 204 and guide the ink ribbon 204 to the thermal head 124.

  The supply bobbin 205 stored in the supply bobbin storage unit 207 is rotatably held, and the ink ribbon 204 is guided by the first sliding surface 221 and the second sliding surface 222 and pulled out from the supply side opening 214. The ink ribbon 204 drawn out from the supply bobbin storage unit 207 is guided by the winding side support wall 215 and the guide shaft 210 and the drawing direction is changed by approximately 90 °, and is rotatably held in the winding bobbin storage unit 208. The winding bobbin 206 is configured to be wound. In this embodiment, the guide shaft 210 is used to reduce the sliding resistance when the ink ribbon 204 is wound, but the guide shaft 210 that slides with the ink ribbon 204 is omitted, and the second lower case 203 is omitted. And the ink ribbon 204 may be guided.

  FIG. 3 is a perspective view of the supply bobbin 205 (winding bobbin 206).

  As shown in FIG. 3A, the supply bobbin 205 and the take-up bobbin 206 are both made of a substantially cylindrical resin member having the same shape, and are provided integrally with a cylindrical base portion 205a (206a) provided in the center. The small-diameter portion 205b (206b) and the large-diameter portion 205c (206c) provided at the other end.

  A first flange portion 205d (206d) is provided at the boundary between the small diameter portion 205b (206b) and the base portion 205a (206a), and a second flange portion is formed at the boundary between the large diameter portion 205c (206c) and the base portion 205a (206a). The flange portion 205e (206e) is provided. As shown, the ink ribbon 204 is wound between the first flange portion 205d (206d) and the second flange portion 205e (206e).

  A convex portion 205f (206f) is provided on the inner wall surface of the large-diameter portion 205c (206c), and engages with a bush provided on the printer main body 100, which will be described later, and engages with a supply bobbin 205 and a take-up bobbin 206.

  FIG. 4 is a side view of a bush provided in the printer main body 100.

  Reference numeral 111 denotes a bush, which is fitted to a shaft 113 attached to the frame 110 of the printer main body 100 and supported so as to be movable from the position shown in FIG. 4A to the position shown in FIG. Reference numeral 112 denotes a compression spring that always urges the bush 111 in the direction of arrow D in the figure. Reference numeral 114 denotes an E-ring that restricts the bush 111 from falling off the shaft 113, and the bush 111 is held at the position shown in FIG.

  The bush 110 is fitted with the large diameter portion 205c of the supply bobbin 205 and the large diameter portion 206c of the take-up bobbin 206, and can hold the supply bobbin 205 and the take-up bobbin 206 rotatably. Further, the bush 110 has a plurality of protrusions 111 a and can engage with the supply bobbin 205 and the take-up bobbin 206 by engaging with the convex part 205 f of the supply bobbin 205 and the convex part 206 f of the take-up bobbin 206. . Further, the take-up bobbin 206 can rotate the take-up bobbin 206 by rotating the shaft 113 by a drive source (not shown), and can wind the ink ribbon 204 around the take-up bobbin 206.

  FIG. 5 is a sectional view for explaining the operation when the ink ribbon cassette 200 is loaded in the printer main body 100. 5A is a cross-sectional view in the middle of loading the ink ribbon cassette 200 in the printer main body 100, and FIG. 5B is a cross-sectional view when the ink ribbon cassette 200 is completely loaded in the printer main body 100.

  A bobbin sliding surface 201a is provided integrally with the upper case 201. As shown in FIG. 5A, when the ink ribbon cassette 200 is not completely loaded in the printer main body 100, the supply bobbin 205 is urged by an elastic member (not shown) in the direction of arrow E in the figure, so that the supply bobbin The small diameter portion 205 b of 205 is located at a position away from the bobbin sliding surface 201 a provided on the upper case 201.

  When the ink ribbon cassette 200 is pushed in from the position shown in FIG. 5A in the direction of arrow E in the figure, the bush 111 enters the large diameter portion 205c of the supply bobbin 205 and holds the supply bobbin 205 rotatably. At this time, since the bush 111 is urged by the compression spring 112 in the direction of arrow F in the figure, the supply bobbin 205 moves in the direction of arrow F in the figure, and the tip of the small diameter portion 205b is applied to the bobbin sliding surface 201a with a constant force. It is pressed. In this state, when the ink ribbon 204 is pulled out and the supply bobbin 205 rotates, a constant rotational frictional force is generated between the tip of the small diameter portion 205b and the bobbin sliding surface 201a. Since this rotational frictional force is a force opposite to the force with which the ink ribbon 204 is pulled out, it becomes the back tension of the ink ribbon 204.

  FIG. 6 is a cross-sectional view of the printer main body 100 when the ink ribbon cassette 200 is loaded. FIG. 6A is a cross-sectional view in a printing standby state, and FIG. 6B is a cross-sectional view during a printing operation.

  120 is a thermal head, 121 is a thermal head support arm, 122 is a heat sink, and 130 is a platen roller. The thermal head 120 is held by a thermal head support arm 121 and supported so as to be rotatable about a rotation shaft 123, and is rotated from a standby position shown in FIG. 6A to a printing position shown in FIG. 6B. It is possible to generate a pressure contact force with the platen roller 130. The heat radiating plate 122 is attached to the thermal head 120, and is configured so that heat generated by the thermal head 120 can be transferred to the heat radiating plate 122. The platen roller 130 is rotatably disposed on the printer main body 100 and is configured to rotate in accordance with the conveyance of the paper.

  Reference numeral 131 denotes a conveying roller, and 132 denotes a driven roller. The transport roller 131 can be driven to rotate by a paper transport motor (not shown). The driven roller 132 is a driven roller facing the conveying roller 131 and is configured to rotate following the rotation of the conveying roller 131.

  Reference numeral 133 denotes a paper discharge driving roller, and 134 denotes a paper discharge driven roller. The paper discharge driving roller 133 can be driven to rotate by a paper conveyance motor (not shown). The paper discharge driven roller 134 is a driven roller facing the paper discharge driving roller 133 and is configured to rotate following the rotation of the paper discharge driving roller 133.

  When a print instruction is given to the printer main body 100 as shown in FIG. 6B and the print state is entered, the paper 301 is fed to the print start position shown in FIG. Then, the thermal head 120 rotates from the standby position in FIG. 6A to the printing position in FIG. 6B, and the ink ribbon 204 and the paper 301 are pressed against each other by the thermal head 120 and the platen roller 130.

  Then, the take-up bobbin 206 is rotationally driven in the direction of arrow G in the figure by a bobbin rotational drive unit (not shown), and the ink ribbon 204 is taken up. At the same time, the transport roller 132 is driven to rotate by a paper transport motor (not shown) and the paper 301 is transported in the direction of arrow H in the figure, while the heating element of the thermal head 120 generates heat by a print signal supplied from a control device (not shown). Then, the dye on the ink ribbon 204 is thermally transferred to the paper 301 to print a desired image.

  FIG. 7 is an enlarged cross-sectional view in the vicinity of the supply bobbin 205. 7A is a cross-sectional view when the ink ribbon cassette 200 is first used, FIG. 7B is a cross-sectional view when the ink ribbon cassette 200 is being used, and FIG. 7C is a state when the ink ribbon cassette 200 is completely used. FIG.

  As shown in FIG. 7A, the ink ribbon 204 wound around the supply bobbin 205 is pulled out from the supply bobbin storage portion 207 while sliding on the first sliding surface 221 and the second sliding surface 222.

  At this time, the range in which the first sliding surface 221 and the ink ribbon 204 slide is a1.

  Next, when the ink ribbon 204 is consumed and the winding diameter of the ink ribbon 204 wound around the supply bobbin 205 becomes small, the area range in which the first sliding surface 221 and the ink ribbon 204 slide as shown in FIG. Becomes smaller than a1 and becomes a2. Further, when the ink ribbon 204 is consumed and the winding diameter of the ink ribbon 204 wound around the supply bobbin 205 becomes smaller, as shown in FIG. 7C, the range in which the first sliding surface 221 and the ink ribbon 204 slide is a2. It becomes smaller and becomes a3.

  That is, when the number of printed ink ribbon cassettes 200 is increased and the ink ribbon 204 is consumed and the winding diameter of the ink ribbon 204 wound around the supply bobbin 205 is reduced, the first sliding surface 221 and the ink ribbon 204 slide. The range becomes smaller. Therefore, the frictional force generated when the first sliding surface and the ink ribbon 204 slide is reduced. Further, since the frictional force at this time is a force opposite to the force with which the ink ribbon 204 is pulled out, it becomes the back tension of the ink ribbon 204.

  Further, since the ink ribbon 204 is supported by the second sliding surface 222 when pulled out from the supply-side storage unit 207, the sliding range of the first sliding surface 221 and the ink ribbon 204 changes. However, the ink ribbon 204 in the supply side opening 214 always takes the same transport path. Therefore, the ink ribbon 204 drawn out from the supply side storage unit 207 is not likely to be poorly conveyed.

  Next, the operation of the present embodiment having the above-described configuration will be described.

  FIG. 8 is a graph for explaining the value of the back tension generated in the ink ribbon 204. Also, the values shown in FIG. 8 are simplified for easy understanding. The horizontal axis represents the number N of printed ink ribbon cassettes 200, and the vertical axis represents the tension T generated in the ink ribbon 204. Since the ink ribbon cassette 200 of this embodiment stores ink ribbons for printing 50 sheets, the maximum value of N is 50.

  As described above, the rotational friction force generated between the tip of the small diameter portion 205b of the supply bobbin 205 and the bobbin sliding surface 201a is constant. Therefore, when the number of printed sheets N of the ink ribbon cassette 200 is increased, the winding diameter of the ink ribbon 204 wound around the supply bobbin 205 is decreased and the tension T generated on the ink ribbon 204 is increased. It becomes a curve.

  On the other hand, the tension T generated in the ink ribbon 204 due to the frictional force between the first sliding surface 221 and the ink ribbon 204 is the ink wound around the supply bobbin 205 as the number N of printed ink ribbon cassettes 200 increases as described above. Since the winding diameter of the ribbon 204 is reduced and the tension T generated in the ink ribbon 204 is reduced, a dotted curve shown in FIG. 8 is obtained.

  Therefore, the total back tension generated in the ink ribbon 204 is a tension obtained by adding the above two tensions, and therefore the solid back tension shown in FIG. 8 is obtained, and can be controlled within a certain range regardless of the number N of printed ink ribbon cassettes 200. Therefore, good print quality can be realized.

[Example 2]
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.

  FIG. 9 is an enlarged sectional view of the vicinity of the supply bobbin 205 in the second embodiment. 9A is a cross-sectional view when the ink ribbon cassette 200 is first used, and FIG. 9B is a cross-sectional view when the ink ribbon cassette 200 is used.

  In order to simplify the explanation, the same reference numerals as those in the first embodiment are assigned to the same portions.

  As shown in FIG. 9A, the ink ribbon 204 wound around the supply bobbin 205 is pulled out while sliding at two locations of the first sliding surface 221 and the second sliding surface 222.

  Next, when the ink ribbon 204 is consumed and the winding diameter of the ink ribbon 204 wound around the supply bobbin 205 becomes small, the ink ribbon 204 moves away from the first sliding surface 221 as shown in FIG. The sliding surface 222 is pulled out while sliding only.

  Next, the operation of the second embodiment having the above-described configuration will be described.

  FIG. 10 is a graph for explaining the value of the back tension generated in the ink ribbon 204 in the second embodiment. Further, the values shown in FIG. 10 are simplified for easy understanding. The horizontal axis represents the number N of printed ink ribbon cassettes 200, and the vertical axis represents the tension T generated in the ink ribbon 204.

  As in the first embodiment, the rotational friction force generated between the tip of the small diameter portion 205b of the supply bobbin 205 and the bobbin sliding surface 201a is constant. Therefore, when the number of printed sheets N of the ink ribbon cassette 200 increases, the winding diameter of the ink ribbon 204 wound around the supply bobbin 205 decreases, and the tension T generated on the ink ribbon 204 increases. Therefore, the dotted line shown in FIG. It becomes a curve.

  On the other hand, the tension T generated between the first sliding surface 221 and the second sliding surface 222 and the ink ribbon 204 is wound around the supply bobbin 205 as the number of printed sheets N of the ink ribbon cassette 200 increases as described above. The winding diameter of the ink ribbon 204 becomes smaller and is separated from the first sliding surface 221. At that time, the tension T generated in the ink ribbon 204 is rapidly reduced, so that the dotted curve shown in FIG. 10 is obtained.

  For this reason, the back tension generated in the ink ribbon 204 is a tension obtained by adding the above two tensions, and is therefore a solid line shown in FIG.

  That is, when the number N of printed sheets increases, the back tension can be suppressed to the same level as in the conventional case, and the back tension can be increased even when the number N of printed sheets is small. As a result, it is possible to suppress wrinkles that have been easily generated when the number of printed sheets N is small, and the ink ribbon 204 can be taken up by the take-up bobbin 206 even if the number of printed sheets N increases.

[Example 3]
Hereinafter, a third embodiment of the present invention will be described with reference to FIGS.

  FIG. 11 is an enlarged sectional view of the vicinity of the supply bobbin 205 in the third embodiment. 11A is a cross-sectional view when the ink ribbon cassette 200 is first used, FIG. 11B is a cross-sectional view when the ink ribbon cassette 200 is being used, and FIG. 11C is a state when the ink ribbon cassette 200 is used up. FIG.

  Reference numeral 223 denotes a third sliding surface which is located on the supply bobbin 205 side from the first sliding surface 221 and slides with the ink ribbon 204 on the inner wall of the upper case 201 in the same manner as the first sliding surface 221. It has a protruding shape. In order to simplify the explanation, the same reference numerals as those in the first embodiment are assigned to the same portions.

  As shown in FIG. 11A, the ink ribbon 204 wound around the supply bobbin 205 slides at three places, that is, the third sliding surface 223, the first sliding surface 221 and the second sliding surface 222. It is pulled out while.

  Next, when the ink ribbon 204 is consumed and the winding diameter of the ink ribbon 204 wound around the supply bobbin 205 becomes small, the ink ribbon 204 moves away from the third sliding surface 223 as shown in FIG. The sliding surface 221 and the second sliding surface 222 are pulled out while sliding.

  When the ink ribbon 204 is further consumed and the winding diameter of the ink ribbon 204 wound around the supply bobbin 205 is reduced, the ink ribbon 204 is separated from the third sliding surface 223 and the first sliding surface 221 as shown in FIG. And is pulled out while sliding only with the second sliding surface 222.

  Next, the operation of the third embodiment having the above-described configuration will be described.

  FIG. 12 is a graph for explaining the value of the back tension generated in the ink ribbon 204 in the third embodiment. FIG. 12 is simplified for easy understanding. The horizontal axis represents the number N of printed ink ribbon cassettes 200, and the vertical axis represents the tension T generated in the ink ribbon 204.

  As in the first embodiment, the rotational friction force generated between the tip of the small diameter portion 205b of the supply bobbin 205 and the bobbin sliding surface 201a is constant. Therefore, when the number of printed sheets N of the ink ribbon cassette 200 increases, the winding diameter of the ink ribbon 204 wound around the supply bobbin 205 decreases and the tension T generated on the ink ribbon 204 increases. Therefore, the dotted line shown in FIG. It becomes a curve.

  On the other hand, the tension T generated between the first sliding surface 221, the second sliding surface 222, the third sliding surface 223, and the ink ribbon 204 increases the number of printed sheets N of the ink ribbon cassette 200 as described above. Then, the winding diameter of the ink ribbon 204 wound around the supply bobbin 205 is reduced and separated from the third sliding surface 223. At that time, the tension T generated in the ink ribbon 204 decreases rapidly.

  Further, when the number of printed sheets N of the ink ribbon cassette 200 is increased, the winding diameter of the ink ribbon 204 wound around the supply bobbin 205 is further reduced and separated from the first sliding surface 221. At that time, the tension T generated in the ink ribbon 204 is rapidly reduced to a dotted curve shown in FIG.

  For this reason, the back tension generated in the ink ribbon 204 is a tension obtained by adding the above two tensions, and therefore, the solid line shown in FIG. 12 is obtained, and the back tension generated in the ink ribbon 204 can be controlled step by step. That is, an appropriate back tension can be applied to the ink ribbon 204 regardless of the number N of printed ink ribbon cassettes.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

Claims (7)

An ink ribbon cassette that contains an ink ribbon, a supply bobbin around which the ink ribbon is wound, and a take-up bobbin that winds up the ink ribbon supplied from the supply bobbin,
The storage portion for storing the supply bobbin includes a sliding portion that can slide with the ink ribbon,
The sliding portion is formed so that a sliding area between the sliding portion and the ink ribbon becomes small when the diameter of the ink ribbon wound around the supply bobbin becomes small. Characteristic ink ribbon cassette.   The sliding portion is formed such that a sliding area between the sliding portion and the ink ribbon decreases as the diameter of the ink ribbon wound around the supply bobbin decreases. The ink ribbon cassette according to claim 1.   The sliding portion is formed so that the sliding portion and the ink ribbon do not slide apart when the diameter of the ink ribbon wound around the supply bobbin becomes smaller than a predetermined value. The ink ribbon cassette according to claim 1, wherein the ink ribbon cassette is provided. A plurality of sliding portions as the sliding portion;
When the diameter of the ink ribbon wound around the supply bobbin is reduced, the plurality of sliding portions are formed so that the number of sliding portions sliding with the ink ribbon is reduced. The ink ribbon cassette according to claim 1 or 2, characterized in that   At least one sliding portion among the plurality of sliding portions slides with the ink ribbon regardless of the diameter of the ink ribbon wound around the supply bobbin so as to curve the transport path of the ink ribbon. The ink ribbon cassette according to claim 4, wherein the ink ribbon cassette is formed as described above.   6. The ink ribbon cassette according to claim 4, wherein sliding surfaces of the plurality of sliding portions are curved surfaces, and a sliding portion closer to the take-up bobbin has a larger curvature.   The printing apparatus which can attach or detach the ink ribbon cassette of any one of Claim 1 thru | or 6.

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