Patent Publication Number: US-2011072995-A1

Title: Printer having detachably mounted platen roller

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present invention contains subject matter related to and claims the benefit of Japanese Patent Application JP 2009-227300 filed in the Japanese Patent Office on Sep. 30, 2009, the entire contents of which is incorporated herein by reference. 
     BACKGROUND OF THE DISCLOSURE 
     1. Technical Field 
     The present invention relates a printer that detachably mounts a platen roller when a paper for printing is set or the like. 
     2. Related Art 
     A compact printer is used in the receipt issuing section or the like of a cash register or various other like apparatus. As described in Japanese Unexamined Patent Application Publication No. 2007-118247 and Japanese Unexamined Patent Application Publication No. 2008-179079, this kind of compact printer is a line printer that includes a thermal head and has a head unit and a platen roller that pushes the head unit. Since the platen roller is detachably mounted, the platen roller is detached and thus the paper for printing is set in the front of the head unit. Then, the platen roller is mounted so that the paper for printing is interposed between the head unit and the platen roller. 
     In the printer that is described in Japanese Unexamined Patent Application Publication No. 2007-118247, a shaft of the platen roller is mounted in a groove section that is formed in a frame. Hook elements that are arranged at opposite sides in an axial direction of the platen roller are connected to each other and thus rotatably supported in the frame. Two hook elements are rotated together and then the shaft is regulated so as not to deviate from the groove section after the shaft of the platen roller is mounted in the groove section. 
     In the printer that is described in Japanese Unexamined Patent Application Publication No. 2008-179079, when a shaft of the platen roller is mounted in a groove section that is formed in the frame, the shaft is pressed against a upper edge of the groove section by a release arm that is pressed by a coil spring so that the platen roller is regulated so as not to deviate from the frame. 
     The printer described in Japanese Unexamined Patent Application Publication No. 2007-118247 is unstable in the regulation of the shaft because rotated hook elements face an opening of the groove section after the shaft of the platen roller is mounted in the groove section of the frame so as to regulate the deviation of the shaft from the groove section of the shaft. 
     In the printer that is described in Japanese Unexamined Patent Application Publication No. 2008-179079, a release arm is biased by a coil spring and a head unit is pressed against the platen roller by another coil spring. Because there is a limit of shortening the length of the coil spring being installed, large space is needed to arrange two coil springs and thus a problem in downsizing the printer remains to be solved. 
     Also, in the printer that is described in Japanese Unexamined Patent Application Publication No. 2008-179079, the groove section formed in the frame is opened toward the head unit and thus there is a need to insert the shaft of the platen roller from the side in which the head unit is provided toward the groove section. Furthermore, because the shaft needs to forcibly ride over the release arm that is biased by the coil spring and thus the shaft is inserted to the groove section, the mounting operation of the platen roller is difficult. 
     These and other drawbacks exist. 
     SUMMARY OF THE DISCLOSURE 
     Embodiments of the disclosure solve the known problems described above and have a goal of providing a printer that can arrange two kinds of springs in a minimum space and can realize a compact size thereof. 
     Also, it is desirable to provide a printer from which the platen roller can easily be attached/detached. 
     According to various embodiments, a printer includes: a platen roller that is detachably supported on a support section that is formed in a frame, and a head unit that is supported on the frame and can be moved in a direction in which the head unit is brought into pressure-contact with the platen roller, wherein a regulating member is movably supported on the frame, and the regulating member has a regulating section that regulates a shaft of the platen roller to deviate from the support section and a pressing section that is arranged on the opposite side to the regulating section, with the head unit interposed therebetween, and wherein, a first plate spring that presses the head unit against the platen roller and a second plate spring that presses the pressing section so as to bias the regulating member in a direction in which the regulating section can regulate the shaft are provided in an area on the opposite to the platen roller, with the head unit interposed therebetween. 
     A printer according to various embodiments is provided such that the head unit and the regulating member are biased together with the plate spring. Because the first plate spring and the second plate spring are housed in the same area, the printer can be downsized. 
     For example, a printer according to the various embodiment may be a printer wherein the first plate spring and the second plate spring are independently formed and the first plate spring and the second plate spring are overlapped and arranged in the area. 
     The first plate spring and the second plate spring are arranged in the same area respectively, however because two plate springs are overlapped on each other, the plate springs are easily provided within a narrow space. 
     Also, various embodiments may have a printer wherein both the first plate spring and the second plate spring have a curved section, a engaging piece that extends to one direction from the curved section and a biased piece that extends in the other direction therefrom, wherein the curved section of the first plate spring and the curved section of the second plate spring are overlapped, each of the curved sections is arranged so as to surround a support shaft that rotatably supports the regulating member, the engaging piece engages with the frame, the biased piece of the first plate spring press the head unit, and the biased piece of the second plate spring presses the pressing section. 
     Two plate springs are overlapped with each other and are arranged so as to surround the support shaft of the regulating member, so that the lengths of the deformation sections of two plate springs can be secured sufficiently and furthermore the plate springs can be arranged within a narrow area. 
     Otherwise, embodiments may include a printer wherein the first plate spring and the second plate spring are branched from one main plate spring and are integrally formed. 
     Because the plate spring that presses the head unit and the plate spring that presses the regulating member are formed from one plate spring, the number of parts thereof can be reduced. 
     In this case, embodiments may include a printer wherein each of the first plate spring and the second plate spring of the main plate spring has a curved section, an engaging piece that extends in one direction from the curved section and a biased piece that extends in the other direction therefrom, and wherein the curved section is arranged so as to surround the support shaft that rotatably supports the regulating member, the engaging piece engages with the frame, the biased piece of the first plate spring presses the head unit, and the biased piece of the second plate spring presses the pressing section. 
     In above described invention, the deformation section of the plate spring can secure a sufficient length and the plate spring can be arranged within a narrow area. 
     Also, various embodiments may include a printer wherein the head unit and the pressing section are biased in opposite directions from each other in the area. 
     The various embodiments have the effect that the plate spring is arranged in a narrow space, furthermore the length for deformation can be secured sufficiently so that the head unit can be biased and the regulating member can be biased. Also, deviation of the shaft of the platen roller from the frame can be easily prevented by a regulation section that is urged. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an exploded perspective view illustrating a printer of an embodiment of the disclosure. 
         FIG. 2  shows a cross sectional view illustrating the printer of  FIG. 1 . 
         FIG. 3  shows an exploded perspective view illustrating a printer of an embodiment of the disclosure. 
         FIG. 4  is shows a cross sectional view illustrating the printer of  FIG. 2 . 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The following description is intended to convey a thorough understanding of the embodiments described by providing a number of specific embodiments and details involving printers having detachably mounted platen rollers. It should be appreciated, however, that the present invention is not limited to these specific embodiments and details, which are exemplary only. It is further understood that one possessing ordinary skill in the art, in light of known systems and methods, would appreciate the use of the invention for its intended purposes and benefits in any number of alternative embodiments, depending on specific design and other needs. 
     A printer  1  an exemplary embodiment shown in  FIG. 1  and  FIG. 2  may be used in the receipt issuing section or the like of a cash register or other apparatus. 
     The printer  1  may have a frame  2 . The frame  2  may be formed by bending a sheet metal material, for example. The frame  2  may have a bottom plate section  2   a  and a rear plate section  2   b  that may be formed by bending the same metal plate to a right angle. Also, a right side plate section  2   c  and a left side plate section  2   d  may be formed together by bending from both side sections of the rear plate section  2   b  to a right angle. Accordingly, the right side plate section  2   c  and the left side plate section  2   d  may be parallel to each other. 
     A concave support section  3   a  may be formed in the right side plate section  2   c  of the frame  2 , and a concave support section  3   b  may be formed in the left side plate section  2   d . The concave support sections  3   a  and  3   b  may be support sections that support both end sections of the platen roller  5 . The concave support section  3   a  that is formed in the right side plate section  2   c  and the concave support section  3   b  that is formed in the left side plate section  2   d  may be located at the same distance from the rear plate section  2   b , and the openings thereof may have the same shape. The concave support sections  3   a  and  3   b  may be recessed parallel to the rear plate section  2   b  may be are upwardly opened together. 
     The platen roller  5  may have a platen main body  6  that may have a round rod shape formed of a synthetic rubber material or the like, a shaft  7   a  that is provided at the right side end section and a shaft  7   b  that is provided at the left side end section of the platen main body  6 . A sleeve  9   a  may be rotatably mounted in the outer periphery of a shaft  8   a  that is fixed to the platen main body  6  at the right side shaft  7   a . Thus, a driven gear  11  may be fixed to a leading section of the shaft  8   a  that is projected from the sleeve  9   a . A shaft  8   b  may be fixed to the platen main body  6  at the left side shaft  7   b  and a sleeve  9   b  may be rotatably provided on the outer periphery of the shaft  8   b.    
     A motor bracket  4  may be fixed at the outside of the right side plate section  2   c  of the frame  2 . The motor bracket  4  may be formed from a metal plate and may be fixed by welding to the outside surface of the right side plate section  2   c  and at the same time a portion thereof further extends towards the downside than the right side plate section  2   c . A motor M for transferring papers may be provided on the downside of the bottom plate section  2   a  of the frame  2  and the motor M may be fixed at the motor bracket  4 . 
     A pinion gear  12  may be fixed to an output shaft of the motor M. A reduction gear train  13  that may reduce and transfer a rotation force of the pinion gear  12  and a driving gear  14  that may be driven by the power reduced in the reduction gear train  13  may be provided at the motor bracket  4 . When the shaft  7   a  of the platen roller  5  is mounted at the concave support section  3   a  and the shaft  7   b  is mounted at the concave support section  3   b , a driven gear  11  fixed to the shaft  8   a  may mesh with the driving gear  14 . 
     Both end sections of a metal support shaft  15  may be fixed between the right side plate section  2   c  and the left side plate section  2   d  of the frame  2  respectively. A regulating member  16  may be provided on inside of the frame  2 . The regulating member  16  may be formed by bending a metal plate and integrally forms a right side moving section  16   a , the left side moving section  16   b  and a pressing section  16   c  that may connect both moving sections  16   a  and  16   b  are integrally formed. An insertion hole may be opened at the right side moving section  16   a  and the left side moving section  16   b , the insertion hole may be inserted in the support shaft  15  and the right side moving section  16   a  and the left side moving section  16   b  may be rotatably supported by the support shaft  15  as a fulcrum. 
     The right side moving section  16   a  of the regulating member  16  may rotate at a position that is nearly in close contact with the inside of the right side plate section  2   c  and the left side moving section  16   b  may rotate at a position that that is nearly in close contact with the inside of the left side plate section  2   d  of the frame  2 . As shown in  FIG. 2 , the pressing section  16   c  of the regulating member  16  may rotate at a position interval to inside of the rear plate section  2   b  of the frame  2 . 
     A groove section  17   a  may be formed at the right side moving section  16   a  of the regulating member  16  and a regulating section  18   a  may be formed at the leading section thereof. Also, a groove section  17   b  may be formed at the left side moving section  16   b  and a regulating section  18   b  may be formed at the leading section thereof. 
     When the regulating member  16  rotates toward a al direction, the groove section  17   a  formed in the right side moving section  16   a  may substantially conform to the concave support section  3   a  formed at the right side plate section  2   c  of the frame  2  and thus the groove section  17   a  may be opened to upward together with the concave support section  3   a . Similar to the above description, the left side groove section  17   b  may conform to the concave support section  3   b  and thus the groove section  17   b  may be opened to upward together with the concave support section  3   b . When the regulating member  16  rotates toward a α2 direction, at least a portion of the opening section of the concave support section  3   a  may be closed by the regulating section  18   a  formed in the right side moving section  16   a  and at least a portion of the opening section of the concave support section  3   b  may be closed by the regulating section  18   b  formed in the left side moving section  16   b.    
     A folded piece  16   d  may be bent to a right angle to the front direction of the right side moving section  16   a  at the regulating member  16  and an upper end of the folded piece  16   d  may be further bent to a right angle to the front direction so that a handle section  19  may be formed. When the handle section  19  is pressed, the regulating member  16  can be rotated toward the al direction. 
     A head unit  20  may be attached to inside of the frame  2 . A head support member  21  may be provided at the head unit  20 . The head support member  21  may be formed by folding a metal plate. A right side support plate section  21   a  and a left side support plate section may be formed by folding at the head support member  21 . A support hole  22   a  may be opened to the right side support plate section  21   a  and a support hole also may be similarly opened to the left side support plate. As shown in  FIG. 2 , each of the support holes may pass through the support shaft  15  and the head support member  21  may be rotatably supported about the support shaft  15  as a fulcrum toward the β1-β2 direction. 
     As shown in  FIG. 1 , a right side stopper  23   a  may be integrally formed on the right side upper section and a left side stopper  23   b  may be integrally formed on the left side upper section at the head support member  21 . A regulating groove section  2   e  may be formed on the upper section of the right side plate section  2   c  and a regulating groove section  2   f  may be formed on the upper section of the left side plate section  2   d  of the frame  2 . As shown in  FIG. 2 , when the head support member  21  is rotatably supported about the support shaft  15 , the right side stopper  23   a  may be entered into inside of the regulating groove section  2   e  and the left side stopper  23   b  may be entered into inside of the regulating groove section  2   f . The head support member  21  can rotate within a range in which the right side stopper  23   a  and the left side stopper  23   b  can be moved inside of the movement range of the regulating groove section  2   e  and the regulating groove section  2   f.    
     As shown in  FIG. 1  and  FIG. 2 , the head main body  25  may be fixed to the front surface of the head support member  21 . The head main body  25  may be formed of a thermal resistant ceramic material or a synthetic resin material and a heat generation section  26  may be provided on the upper side of the front surface thereof. The heat generation section  26  may have a plurality of heat generation points and the heat generation points may be arranged in a line with a predetermined pitch toward the longitudinal direction of the head main body  25 . 
     As shown in  FIG. 2 , a space between the head unit  20  and the rear plate section  2   b  of the frame  2  may be a pressed area  30  and the pressing section  16   c  of the regulating member  16  may be positioned within the biased area  30 . In other words, the pressing section  16   c  of the regulating member  16  may be arranged on a side opposite to the side in which the regulating sections  18   a  and  18   b  may be formed while interposing the head unit  20 . Also, the pressing section  16   c  may be arranged on a side opposite to the side in which the regulating sections  18   a  and  18   b  are formed while interposing the support shaft  15 , and the pressing section  16   c  is arranged on a side opposite to the head unit  20  while interposing the support shaft  15 . 
     A first plate spring  31  and a second plate spring  35  may be provided at the biased area  30 . The first plate spring  31  and the second plate spring  35  may be formed from a spring nature stainless steel plate or a phosphor bronze plate. 
     The first plate spring  31  may be integrally formed with the curved section  32 , a hanging piece  33  that may continuously extend from the curved section  32  to the rear direction and a biased piece  34  that may continuously extend from the curved section  32  to the front direction. A pair of positioning holes  33   a  may be opened at the hanging piece  33 . As shown in  FIG. 2 , a positioning protrusion  2   g  that is projected to the front direction at the rear plate section  2   b  of the frame  2  may be formed at two places, respective positioning hole  33   a  may be fitted to the positioning protrusion  2   g  and the hanging piece  33  may be positioned and arranged at the front surface of the rear plate section  2   b . A ridge section  34   a  that may be bent toward the front direction at the upper edge of the biased piece  34  may be integrally formed. 
     In the state that the first plate spring  31  exerts a forced contraction deformation force so as to approach the hanging piece  33  and the biased piece  34  to each other, the curved section  32  may be mounted so as to surround the support shaft  15  in the biased area  30 . When the contraction deformation force is released, the ridge section  34   a  presses the rear surface of the head support member  21  of the head unit  20  by the resilience restoring force, so that the head unit  20  may rotate toward the pi direction about the support shaft  15  as a fulcrum and the heat generation section  26  of the head main body  25  may be pressed to the platen main body  6 . 
     A second plate spring  35  may be integrally formed with a curved section  36 , a hanging piece  37  that may continuously extend from the curved section  36  to the rear direction and a biased piece  38  that may continuously extend from the curved section  36  to the front direction. The hanging piece  37  may be interposed between a pair of positioning protrusion  2   g  that may be provided at the rear plate section  2   b  of the frame  2  and may be positioned and arranged in the front surface of the rear plate section  2   b . As shown in  FIG. 2 , an upper edge  37   a  of a hanging piece  37  may lock with a lock section  2   h  formed at the rear plate section  2   b  from the rear surface side. Also, a ridge section  38   a  that is bent to the rearward may be formed at the upper edge of the biased piece  38 . 
     As shown in  FIG. 2 , the second plate spring  35  may be arranged inside of the first plate spring  31  in an overlapped state and the curved section  36  of the second plate spring  35  may be overlapped inside of the curved section  32  of the first plate spring  31 . Accordingly, the hanging piece  37  and the biased piece  38  of the second plate spring  35  may be positioned inside of the hanging piece  33  and biased piece  34  of the first plate spring  31 . 
     In the state that the hanging piece  37  and the biased piece  38  are forcedly widely deformed so as to separate to each other, the second plate spring  35  may be mounted so that the curved section  36  surrounds the support shaft  15 . When the wide deformation force is released, the ridge section  38   a  of the biased piece  38  presses the pressing section  16   c  to the rear plate section  2   b  and the regulating member  16  may be biased toward the α2 direction by the resilient return force. 
     As shown in— FIG. 2 , in the state that the printer  1  is assembled, one side shaft  7   a  of the platen roller  5  may be inserted inside of the concave support section  3   a  that is formed on the right side plate section  2   c  of the frame  2  and the other side shaft  7   b  may be inserted inside of the concave support section  3   b  that may be formed in the left side plate section  2   d . Because the biasing force is given toward the rear direction from the biased piece  38  of the second plate spring  35  to the pressing section  16   c , the regulating member  16  may be biased toward the α2 direction about the support shaft  15  as a fulcrum. The regulating section  18   a  that is provided in the regulating member  16  presses the shaft  7   a  of the platen roller  5  and the sleeve  9   a  of the shaft  7   a  may be maintained at the concave support section  3   a  and the regulating section  18   a  by the biasing force. Similar to above description, the sleeve  9   b  of the other side shaft  7   b  may be maintained at the left side concave support section  3   b  and regulating section  18   b.    
     The shaft  7   a  and the shaft  7   b  of the platen roller  5  may be maintained so as not to move within the concave support section  3   a  and the concave support section  3   b  of the frame  2 ; and the driven gear  11  that is provided in the shaft  7   a  may be meshed with the driving gear  14  that is provided in the frame  2 . 
     The head unit  20  can rotate about the support shaft  15  as a fulcrum within a range in which the right side stopper  23   a  and the left side stopper  23   b  may be moved inside the movement range of the regulating groove section  2   e  and the regulating groove section  2   f , and the head unit  20  may receive the pressing force of the biased piece  34  of the first plate spring  31  so that the head unit  20  may rotate toward the β1 direction and the heat generation section  26  of the head main body  25  is pressed to the platen main body  6 . 
     As shown in  FIG. 2 , in the state where the paper P for printing is inserted between the platen main body  6  and the head main body  25 , when the motor M for transferring paper rotates, the platen roller  5  may rotate and the paper P for printing may be transferred; and the heat generation point of the heat generation section  26  of the head main body  25  may be selected so that printing is performed on the heat sensitive paper P for printing. At this time, letter row may be printed per a row on the printing paper. 
     When the paper P for printing is changed or new paper P for printing is charged, the handle section  19  that is integrally formed in the regulating member  16  is pressed and the regulating member  16  may be rotated to the al direction against the pressed force of the second plate spring  35 . Because the regulating section  18   a  and the regulating section  18   b  that are formed on the regulating member  16  are simultaneously deviated from the shaft  7   a  and the shaft  7   b , the platen roller  5  can be removed from the frame  2 . 
     At this time, the platen roller  5  may be simply vertically lifted directly upward in a direction parallel with the rear plate section  2   b , and then the platen roller  5  can be removed from the frame  2 . When the platen roller  5  is removed, the head unit  20  that is biased by the first plate spring  31  may rotate further toward the al direction than the posture of  FIG. 2 , however the right side stopper  23   a  and the left side stopper  23   b  may be regulated at the regulating groove section  2   e  and the regulating groove section  2   f . Accordingly, the head unit  20  may be stable in the posture that is rotated slightly more toward the β1 direction than the posture shown in  FIG. 2 . Accordingly, after that, the platen roller  5  can be easily mounted from upward to the downward. 
     The printer  1  may be provided such that the head unit  20  and the regulating member  16  may be rotatably supported by the common support shaft  15 , the second plate spring  35  are overlapped inside of the first plate spring  31 ; and the curved section  32  and the curved section  36  may be arranged in the biased area  30  so as to surround the support shaft  15 . Thus, the first plate spring  31  and the second plate spring  35  can arrange and secure the resilient deformation section sufficiently long within a narrow area. Accordingly, the printer  1  can be of a compact size and the resilient force of the first plate spring  31  and the second plate spring  35  can easily be set to an appropriate size. 
     A printer  101  according to various embodiments shown in  FIG. 3  and  FIG. 4  uses one main body plate spring  130  instead of the first plate spring  31  and the second plate spring  35  of the printer  1  shown in  FIG. 1  and  FIG. 2 . Because other configurations except the plate spring of the printer  101  are the same as those of the printer  1  as described above, the constituent elements described above are given similar numbers in  FIG. 1  and  FIG. 2 , thus are not specifically described here. 
     The main body plate spring  130  shown in  FIG. 3  and  FIG. 4  may be integrally formed from a stainless steel plate spring material or a phosphor bronze plate. The main body plate spring  130  may form each of first plate springs  131  on both the left and right sides and a second plate spring  135  at center section. 
     The first plate spring  131  may be integrally formed with a curved section  132 , a hanging piece  133  and a biased piece  134 . A positioning hole  133   a  may be formed in the hanging piece  133  that may be respectively formed on the left and right side first plate spring  131 . The second plate spring  135  may be integrally formed with a curved section  136 , a hanging piece  137  and a biased piece  138 . 
     As shown in  FIG. 4 , the main body plate spring  130  may be mounted within the biased area  30  between the head unit  20  and the rear plate section  2   b . At this time, the curved section  132  and the curved section  136  may be mounted so as to surround the support shaft  15  from the lower side. Also, the positioning hole  133   a  that is formed in the hanging piece  133  of the first plate spring  131  may be fitted to the positioning protrusion  2   g  that is formed in the rear plate section  2   b  so that the main body plate spring  130  is positioned. 
     The head unit  20  may be pressed to the platen roller  5  by a ridge section  134   a  that may be formed in two first plate spring  131 . Also, a upper edge  137   a  of the hanging piece  137  of the second plate spring  135  may be hung at the rear surface of the lock section  2   h  that is formed in the rear plate section  2   b  and the ridge section  138   a  of the biased piece  138  may be resiliently pressed to the pressing section  16   c  of the regulating member  16  so that the regulating member  16  may be biased to the α2 direction. 
     In printer  101 , because the plate spring is formed as one, the number of parts can be reduced, and the plate spring can be arranged within a narrow biased area  30 , furthermore each of the resilient deformation sections of the first plate spring  131  and the second plate spring  135  can be secured sufficiently long. 
     Also, in respective embodiments, the head main body  25  may be the thermal head, however the various embodiments may also have a printing means besides the thermal head. 
     It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims of the equivalents thereof. 
     Accordingly, the embodiments of the present inventions are not to be limited in scope by the specific embodiments described herein. Further, although some of the embodiments of the present invention have been described herein in the context of a particular implementation in a particular environment for a particular purpose, those of ordinary skill in the art should recognize that its usefulness is not limited thereto and that the embodiments of the present inventions can be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in view of the full breadth and spirit of the embodiments of the present inventions as disclosed herein. While the foregoing description includes many details and specificities, it is to be understood that these have been included for purposes of explanation only, and are not to be interpreted as limitations of the invention. Many modifications to the embodiments described above can be made without departing from the spirit and scope of the invention.