Patent Publication Number: US-7594770-B2

Title: Ink ribbon cassette

Description:
This application claims the benefit of the Japanese Patent Application No. 2005-208726 filed on Jul. 19, 2005, which is hereby incorporated by reference 
     BACKGROUND 
     1. Field 
     An ink ribbon cassette is provided. 
     2. Related Art 
     A conventional ink ribbon cassette  34  will be described with reference to a thermal transfer printer disclosed in JP-A-2002-144616. As shown in  FIG. 4 , the ink ribbon cassette  34  includes a first ribbon-receiving part  34   a  for receiving a feeding reel  32  on which an unused ink ribbon  31  is wound, and a second ribbon-receiving part  34   b  for receiving a take-up reel  33  on which a used ink ribbon  31  is wound. 
     The first and the second ribbon-receiving parts  14   a  and  14   b  are connected to each other by means of connecting walls  34   c  that face each other. In addition, an outlet  34   d , through which the ink ribbon  31  wound on the feeding reel  32  can be withdrawn, is provided on the lower side of the first ribbon-receiving part  34   a.    
     A head insertion portion  35 , in which a thermal head (not shown) of a printer body is positioned and can move up and down, is provided between the connecting walls  34   c  that face each other, and between the first ribbon-receiving part  34   a  and the second ribbon-receiving part  34   b  in the ribbon cassette  34 . 
     An escape groove  36 , in which a paper feeding mechanism (not shown) can be positioned, is formed between the head insertion portion  35  and the second ribbon-receiving part  34   b  so as to have a predetermined depth. 
     A winding opening  34   e  is provided on the upper side of the escape groove  36  in  FIG. 4 , and a guide roller  34   f  formed of a metal rod is rotatably supported in the vicinity of a wall  37  (to be described below) of the winding opening  34   e.    
     The ribbon cassette  34  is provided with a wall  37  between the head insertion portion  35  and the escape groove  36  and the winding opening  34   e , through which the ink ribbon  31  drawn through the outlet  34   d  can be drawn, is provided on the lower side (upper side in  FIG. 3 ) of the escape groove  36 . 
     As shown in  FIG. 3 , in the escape groove  36 , a ribbon-sliding portion  37   a  is formed at the lower end of the wall  37 , and the ink ribbon  31  is drawn through the outlet  34   d  and exposed at the ribbon-sliding portion  37   a . The ink ribbon  31  slides on the ribbon-sliding portion  37   a  of the wall  37 , and is wound on the take-up reel  33 . 
     When the ink ribbon cassette is inserted in a cassette-mounting portion formed in the printer body (not shown) in a direction perpendicular to the plane of the drawing, it is possible to mount the conventional ribbon cassette  34  in the printer body. 
     When the conventional ribbon cassette  34  is inserted and mounted in the cassette-mounting portion of the printer body, if the ink ribbon  31  exposed at the ribbon-sliding portion  37   a  of the wall  37  is loose, the ink ribbon is caught by the printer body. For this reason, there has been an undesirable possibility that the ink ribbon cassette  34  cannot be normally mounted. 
     SUMMARY 
     An ink ribbon cassette includes a ribbon guide capable of guiding an ink ribbon exposed at the ribbon-sliding portion formed at the end of the wall and can be normally mounted in a printer body even when the ink ribbon exposed at the ribbon-sliding portion is loose. 
     According to a preferred embodiment, an ink ribbon cassette includes a first ribbon-receiving part that recieves a feeding reel on which an unused ink ribbon is wound, and a second ribbon-receiving part that receives a take-up reel on which a used ink ribbon is wound. In this embodiment, the first and the second ribbon-receiving parts include walls, which face each other with a predetermined distance therebetween. The ink ribbon slides on a first ribbon-sliding portion formed at the wall of the first ribbon-receiving part and a second ribbon-sliding portion formed at the wall of the second ribbon-receiving part, and is wound on the take-up reel from the feeding reel. A ribbon guide, which prevents the ink ribbon exposed at the second ribbon-sliding portion from coming in contact with a printer body when the ink ribbon cassette is mounted in the printer body, is provided outside the second ribbon-sliding portion. 
     According to another preferred embodiment, in the above-mentioned structure, the ink ribbon, which slides on the second ribbon-sliding portion and is wound on the take-up reel, is guided by a guide roller provided to the printer body and is wound on the take-up reel. The second ribbon-receiving part is provided with an escape portion for the guide roller, and the ink ribbon, which is guided by the guide roller positioned at the escape portion, is wound on the take-up reel. 
     According to another preferred embodiment, in the above-mentioned structure, a head insertion opening in which a thermal head of the printer is inserted is formed between the walls, which face each other with the predetermined distance therebetween, so as to have a predetermined size. The second ribbon-receiving part is provided with the escape portion for the guide roller of the printer body. When the ink ribbon cassette is inserted in the printer body and the guide roller is positioned at the escape portion, the ink ribbon is guided by the guide roller. 
     According to another preferred embodiment, in the above-mentioned structure, the printer body is provided with a scooper that prevents the ink ribbon to be inserted from being caught by the guide roller. While the ink ribbon scooped by the scooper slides on the outer periphery of the guide roller in an axial direction, the ink ribbon cassette is mounted in the printer body. 
     According to another preferred embodiment, in the above-mentioned structure, the ribbon guide is provided with a slope that is inclined in a direction in which the ink ribbon is wound on the take-up reel. 
     According to another aspect of the invention, an ink ribbon cassette includes a first ribbon-receiving part that recieves a feeding reel on which an unused ink ribbon is wound, a second ribbon-receiving part that recieves a take-up reel on which a used ink ribbon is wound, and a guiding unit that allows the ink ribbon to pass between the first ribbon-receiving part and the second ribbon-receiving part. The guiding unit is provided between a first wall of the first ribbon-receiving part and a first wall of the second ribbon-receiving part, and is provided with a head insertion opening into which a thermal head of a printer body is inserted. The feeding reel, the take-up reel, and the guiding unit are disposed such that an acute angle is formed between a ribbon-passing direction from one end of the guiding unit toward the feeding reel and the first wall of the first ribbon-receiving part and an acute angle is formed between a ribbon-passing direction from the other end of the guiding unit toward the take-up reel and the second wall of the second ribbon-receiving part. 
    
    
     
       DRAWINGS 
         FIG. 1  is a perspective view of an ink ribbon cassette according to a preferred embodiment; 
         FIG. 2  is a cross-sectional view taken along line  2 - 2  of  FIG. 1 ; 
         FIG. 3  is a perspective view of a printer body in which the ink ribbon cassette  1  according to a preferred embodiment is mounted; and 
         FIG. 4  is a cross-sectional view of main parts of a conventional ribbon cassette. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, an ink ribbon cassette  1  will be described with reference to the drawings.  FIG. 1  is a perspective view of an ink ribbon cassette according to a preferred embodiment,  FIG. 2  is a cross-sectional view taken along line  2 - 2  of  FIG. 1 , and  FIG. 3  is a perspective view of a printer body in which the ink ribbon cassette  1  according to the preferred embodiment is mounted. 
     The ink ribbon cassette  1  is made of a resin material, and is provided with a first ribbon-receiving part  4  that recieves a feeding reel  3  therein as shown in  FIGS. 1 and 2 . An unused ink ribbon  2  having a width of A is wound on the feeding reel  3 . 
     The first ribbon-receiving part  4  includes a first wall  4   a  and a second wall  4   b , which are formed in the shape of a substantially circular arc, so as to have a cavity therein. A first ribbon-sliding portion  4   c , with which the ink ribbon  2  to be wound on a take-up reel  6  to be described below can come in sliding contact, is formed at the lower end of the first wall  4   a.    
     A ribbon outlet  4   e , through which the ink ribbon wound on the feeding reel  3  is withdrawn, is formed between the first ribbon-sliding portion  4   c  and the lower end  4   d  of the second wall  4   b.    
     The front side of the hollow first ribbon-receiving part  4  shown in  FIG. 1  is covered with a first sidewall  4   f.    
     The ink ribbon cassette is provided with a second ribbon-receiving part  7  that recieves the take-up reel  6  therein so that the first ribbon-receiving part  4  and the second ribbon-receiving part  7  face each other with a head insertion opening  5  interposed therebetween. The second ribbon-receiving part  7  includes a first wall  7   a  and a second wall  7   b , which are formed in the shape of a substantially circular arc, so as to have a cavity therein. 
     A second ribbon-sliding portion  7   c , with which the ink ribbon  2  wound on the take-up reel  6  can come in sliding contact, is formed at the lower end of the first wall  7   a . A guiding unit  20  of the ink ribbon  2  is provided between the first walls  4   a  and  7   a , which face each other, of the first and the second ribbon-receiving parts  4  and  7 . When printing is performed by a thermal head, the guiding unit prevents the wrinkles of the ink ribbon. The guiding unit  20  includes the first ribbon-sliding portion  4   c  and the second ribbon-sliding portion  7   c  at both ends thereof. The guiding unit is provided with a head insertion opening into which the thermal head is inserted, and also includes a ribbon guide  10  to be described below. 
     As shown in  FIG. 2 , since the ink ribbon  2  withdrawn from the feeding reel  3  comes in sliding contact with the first ribbon-sliding portion  4   c , the ink ribbon is inclined upward with respect to the first wall  4   a  to form an acute angle. Since the ink ribbon wound on the take-up reel  6  comes in sliding contact with the second ribbon-sliding portion  7   c , the ink ribbon is inclined upward with respect to the first wall  7   a  to form an acute angle. Since the ink ribbon  2  is inclined to form an acute angle at the both ends of the guiding unit  20 , tension is always generated in the ink ribbon. For this reason, a pressed portion, which is pressed by the thermal head, of the ink ribbon  2  is flat. Accordingly, it is possible to achieve clean printing. 
     The front side of the hollow second ribbon-receiving part  7  shown in  FIG. 1  is covered with a second sidewall  7   d.    
     The first sidewall  4   f  and the second sidewall  7   d  shown in  FIG. 1  are connected to each other by a crosspiece  8  on the front side of the ink ribbon cassette, and the rear sides of the first and the second ribbon-receiving parts  4  and  7  are connected to each other by a connecting member  9 . The first and the second ribbon-receiving parts  4  and  7 , which face each other with the head insertion opening  5  interposed therebetween, are unified. 
     A ribbon guide  10  is provided outside the second ribbon-sliding portion  7   c , which is formed at the lower end of the first wall  7   a  of the second ribbon-receiving part  7 , with a predetermined gap  7   e  (through which the ink ribbon to be fed can pass) between the second ribbon-sliding portion  7   c  and the ribbon guide  10 . 
     When the ink ribbon cassette  1  is mounted in a printer body (not shown), the ribbon guide  10  can prevent the ink ribbon  2  exposed at the second ribbon-sliding portion  7   c  from coming in contact with the printer body. 
     The ink ribbon  2 , which slides on the second ribbon-sliding portion  7   c  and is wound on the take-up reel  6 , is guided by a guide roller  11  provided to the printer body  13  and can be wound on the take-up reel  6 . 
     The second ribbon-receiving part  7  is provided with an escape portion  12  for the guide roller  11 , and the ink ribbon  2 , which is guided by the rotatable guide roller  11  positioned at the escape portion  12 , can be wound on the take-up reel  6 . 
     The printer body  13  in which the ink ribbon cassette  1  of the invention is inserted and mounted is provided with a scooper  14  that can prevent the ink ribbon  2  to be inserted from being caught by the end of the guide roller  11 . When the ink ribbon  2  scooped by the scooper  14  of the printer body  13  (supported in a direction of separating from the end of the guide roller  11 ) passes by the end of the guide roller  11 , the ink ribbon slides on the outer periphery of the guide roller  11  in an axial direction (a direction perpendicular to the plane of the drawing). The ink ribbon cassette  1  can be mounted in the printer body  13 . 
     When the ink ribbon cassette  1  is mounted in the printer body  13 , the guide roller  11  is positioned at the escape portion  12 . The ink ribbon  2  scooped by the scooper  14  of the printer body  13  is guided by the guide roller  11  and is wound on the take-up reel  6 . 
     The ribbon guide  10  is provided with a slope  10   a . The slope  10   a  is inclined in a direction in which the ink ribbon  2  is wound on the take-up reel  6 . For this reason, the ink ribbon  2  can be smoothly wound on the take-up reel  6  via the second ribbon-sliding portion  7   c  and the slope  10   a.    
     The ribbon guide  10  is provided only outside the second ribbon-sliding portion  7   c  of the second ribbon-receiving part  7 , which is shown on the left side of  FIG. 2 . However, a ribbon guide may be also provided outside the first ribbon-sliding portion  4   c  of the first ribbon-receiving part  4 , which is shown on the right side of  FIG. 2 . 
     An ink ribbon of an ink ribbon cassette slides on a first ribbon-sliding portion formed at a wall of a first ribbon-receiving part and a second ribbon-sliding portion formed at a wall of a second ribbon-receiving part, and can be wound on a take-up reel from the feeding reel. A ribbon guide, which prevents the ink ribbon exposed at the second ribbon-sliding portion from coming in contact with a printer body when the ink ribbon cassette is mounted in the printer body, is provided outside the second ribbon-sliding portion. When the ink ribbon cassette according to the invention is inserted in the printer body, it is possible to prevent the ink ribbon at the second ribbon-sliding portion from being caught by the printer body and to normally mount the ink ribbon cassette in the printer body. For this reason, it is possible to print images with high efficiency. 
     The ink ribbon, which slides on the second ribbon-sliding portion and is wound on the take-up reel, is guided by a guide roller provided to the printer body and can be wound on the take-up reel. The second ribbon-receiving part is provided with an escape portion for the guide roller, and the ink ribbon, which is guided by the guide roller positioned at the escape portion, can be wound on the take-up reel. Accordingly, it is possible to reliably wind the ink ribbon of the ink ribbon cassette mounted in the printer body during printing. 
     A head insertion opening in which a thermal head of the printer is inserted is formed between the walls, which face each other with the predetermined distance therebetween, so as to have a predetermined size. The second ribbon-receiving part is provided with the escape portion for the guide roller of the printer body. When the ink ribbon cassette is inserted in the printer body and the guide roller is positioned at the escape portion, the ink ribbon is guided by the guide roller. Accordingly, it is possible to reliably wind the ink ribbon on the take-up reel. 
     The printer body is provided with a scooper that prevents the ink ribbon to be inserted from being caught by the guide roller. While the ink ribbon scooped by the scooper slides on the outer periphery of the guide roller in an axial direction, the ink ribbon cassette can be mounted in the printer body. When the ink ribbon cassette is mounted in the printer body, it is possible to reliably mount the ink ribbon cassette in the printer body without wrinkles of the ink ribbon. 
     The ribbon guide is provided with a slope that is inclined in a direction in which the ink ribbon is wound on the take-up reel. Accordingly, the ink ribbon can be wound on the take-up reel along the slope, whereby it is possible to smoothly wind the ink ribbon. 
     An acute angle is formed between a ribbon-passing direction from one end of the guiding unit toward the feeding reel and the first wall of the first ribbon-receiving part and an acute angle is formed between a ribbon-passing direction from the other end of the guiding unit toward the take-up reel and the second wall of the second ribbon-receiving part. Therefore, it is possible to always generate tension in the ink ribbon with simple structure.