Patent Publication Number: US-11046090-B2

Title: Printer

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2017-185767 filed on Sep. 27, 2017, the entire disclosure of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a printer. 
     BACKGROUND ART 
     In a printer that prints letters, characters and the like by transferring ink on a paper using an ink ribbon, the ink ribbon is wound in a roll around a feeding shaft. The printer feeds the ink ribbon at the same speed as the paper by winding the ink ribbon around a winding shaft. The ink ribbon is easily slackened since the ink ribbon is very thin and soft. Therefore, the ink ribbon is constantly tensioned to be kept flat during printing. 
     The printer includes a motor for feeding the papers and a gear train connected to the winding shaft via a clutch mechanism. The rotation of the gear train via the motor winds the ink ribbon around the winding shaft. The clutch mechanism includes a torsion spring. The feeding shaft includes a clutch mechanism which also includes a torsion spring. The ink ribbon between the feeding shaft and the winding shaft is biased by the respective torsion springs in directions toward the feeding and winding shafts. Consequently, the ink ribbon is constantly tensioned to be kept flat. 
     A casing of the printer includes a casing body that houses papers and a lid or cover that is opened and closed relative to the casing body. In the printer configured to include the motor in the casing body and the ink ribbon in the cover, the gear train in the cover disengages from the motor in the casing body when the cover is opened for changing papers or the like. Accordingly, the winding shaft does not receive the braking force generated by stopping the motor. On the other hand, the feeding shaft receives the torque from the torsion spring to pull the ink ribbon in a direction toward the feeding shaft from the winding shaft. Consequently, the ink ribbon is unwound from the winding shaft and slackened. 
     When the cover is closed while the ink ribbon is slackened, the tension may not be appropriately applied to the ink ribbon in the next printing and accordingly, the ink ribbon or paper may be jammed. To avoid the above issue, a printer is proposed, which prevents the winding shaft from being rotated in the direction opposite to the winding direction when the cover is open (see Patent Literature I: U.S. Pat. No. 8,882,371 B2, for example). 
     The printer disclosed in Patent Literature I includes a plurality of gears which forms the gear train in the cover to drive the winding shaft and a restriction gear with teeth for preventing the reverse rotation. The restriction gear is arranged in the axial direction with a gear branched from one or more of the plurality of gears. The teeth of the restriction gear engage with a rotatable lever. When the user manually rotates the ink ribbon in the winding direction to eliminate the slack of the ink ribbon that is generated upon mounting the ink ribbon, the lever engages the teeth of the restriction gear in response to the opening of the cover. In this state, the rotation of the restriction gear in the winding direction is allowed since the lever is pushed by the rotating teeth away from the teeth. On the other hand, the rotation of the restriction gear in the opposite direction is prevented since the lever engages the teeth of the restriction gear to restrict the rotation of the restriction gear. 
     SUMMARY 
     Generally, the ink ribbon and the ink ribbon flange are provided inside the casing body on the inner side in the width direction of the casing body. Accordingly, the gear train is provided inside the casing body on the outer side in the width direction thereof to avoid the ink ribbon, the ink ribbon flange and the like. Therefore, in the printer disclosed in Patent Literature I, the restriction gear is arranged with the gears of the gear train or the gears branched from the gear train in the axial direction at the outer side in the width direction of the casing body. Consequently, the size of the printer in the width direction increases. Moreover, the printer requires extra space for the rotation of the lever. 
     The present disclosure is made considering the above issue, and an object of the present disclosure is to provide a printer capable of suppressing an increase in the size in the width direction and preventing a winding shaft from rotating in a direction opposite to the winding direction without providing extra space. 
     A printer of the present disclosure includes a body, a cover configured to open and close relative to the body, a winding shaft provided in the cover for winding an ink ribbon, a regulation member provided in the cover and configured to change a position in accordance with an open and closed state of the cover, a passive member connected to an end of the winding shaft and configured to receive driving force, and a ribbon flange provided axially inside the passive member and configured to rotate with the winding shaft. The ribbon flange includes a cam face with a contour whose radial distance from an axis center of the winding shaft varies in accordance with a rotation angle position of the ribbon flange. The regulation member is configured to contact the cam face to restrict a rotation of the ribbon flange to one direction when the cover is open. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view illustrating a thermal printer (with a cover closed) which is an embodiment of a printer according to the present disclosure. 
         FIG. 2  is a perspective view illustrating the printer of  FIG. 1  when the cover is open. 
         FIG. 3  is a perspective view illustrating the thermal printer shown in  FIG. 1  when a top cover is open. 
         FIG. 4  is a perspective view illustrating a part of a printing portion. 
         FIG. 5  is a side view illustrating one side of the printing portion. 
         FIG. 6  is a schematic view illustrating an arrangement of an ink ribbon in the printing portion. 
         FIG. 7  is a cross-sectional view along a line A-A shown in  FIG. 5 . 
         FIG. 8  is a perspective view illustrating a ribbon flange. 
         FIG. 9  is a perspective view illustrating a lock member moved to a bottom end of a movable range. 
         FIG. 10  is a perspective view illustrating the lock member moved upward from the bottom end of the movable range. 
         FIG. 11  is a side view illustrating a positional relation between a cam face and an upper end portion shown in  FIG. 10 . 
         FIG. 12  is a side view illustrating the positional relation between the cam face and the upper end portion shown in  FIG. 9 . 
         FIG. 13  is an enlarged view illustrating the positional relation between the cam face and the upper end portion shown in  FIG. 12  and the movement of a first cam face. 
         FIG. 14  is a schematic view illustrating the transition of the positional relation among the first cam face, a second cam face and the upper end portion when the ribbon flange rotates in a counterclockwise direction R 1 . 
         FIG. 15  is a schematic view corresponding to  FIG. 12  and illustrating a ribbon flange and an upper end portion of a movable portion in a modified embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments of a printer according to the present disclosure will be described with reference to the drawings. 
     (Configuration of Thermal Printer)  FIG. 1  is a perspective view illustrating a thermal printer  100  (referred to as the printer  100  hereinafter) in an embodiment of a printer according to the present disclosure.  FIG. 2  is a perspective view illustrating the printer  100  when a lid or a cover  20  is open.  FIG. 3  is a perspective view illustrating the printer  100  when a top cover  30  is open. 
     As shown in  FIG. 1 , the printer  100  includes a body  10  and a cover  20 . The cover  20  is rotatably supported by the body  10 . Specifically, a rear portion of the cover  20  in the vicinity of the bottom end of the cover  20  is supported by a rear portion of the body  10  in the vicinity of the upper end of the body  10 . Therefore, the cover  20  rotates upward and rearward relative to the body  10  at a supported portion  21  as shown in  FIG. 2 . 
     The body  10  includes a paper storage portion  11 . The paper storage portion  11  is exposed when the cover  20  is open. The paper storage portion  11  houses a label paper  1  in a roll, for example. In addition to the paper storage portion  11 , the body  10  includes a motor  12 , a gear train  13 , a paper sensor  14 , a control portion  15 , a platen roller  16  and the like. 
     The motor  12  is driven under the control of the control portion  15  to rotate the gear train  13 . The gear train  13  rotates the platen roller  16  to move the label paper  1  contacting the platen roller  16  forward F. When the cover  20  is closed, the gear train  13  engages with a gear train  90  in the cover  20  to rotate a winding shaft  60  of an ink ribbon  2  connected to the gear train  90 . 
     The paper sensor  14  is configured to detect labels  1   b  on a paper mount  1   a  of the label paper  1 . The control portion  15  is configured to control the motor  12  and a thermal print head  42  based on the detection result from the paper sensor  14  such that the printing to the labels  1   b  can be properly performed on the platen roller  16 . 
     As shown in  FIG. 3 , an ink ribbon storage portion  31  of the cover  20  houses a printing portion  40 .  FIG. 4  is a perspective view illustrating a part of the printing portion  40 .  FIG. 5  is a side view illustrating one side of the printing portion  40 .  FIG. 6  is a schematic view illustrating the arrangement of the ink ribbon  2  in the printing portion  40 .  FIG. 7  is a cross-sectional view along a line A-A shown in  FIG. 5 . 
     As shown in  FIGS. 4 to 7 , the printing portion  40  includes the ink ribbon  2 , the thermal print head  42 , a feeding shaft  50  for the ink ribbon  2 , the winding shaft  60  for the ink ribbon  2 , a ribbon flange  70 , the gear train  90 , a ribbon guide member  48  and a guide shaft  49  for guiding the ink ribbon  2 , and a regulation member or lock member  80 . These elements such as the thermal print head  42  are supported by a support member  41  which has a box shape. 
     As shown in  FIG. 6 , the thermal print head  42  is located above the platen roller  16  when the cover  20  is closed and controlled by the control portion  15 . The unused portion of the ink ribbon  2  is wound in a roll around the feeding shaft  50  and the used portion of the ink ribbon  2  is wound in a roll around the winding shaft  60 . In other words, the ink ribbon  2  is wound around the winding shaft  60  from the feeding shaft  50  in use. The ribbon guide member  48  and the guide shaft  49  are arranged on the path of the ink ribbon  2  between the feeding shaft  50  and the winding shaft  60  so that the thermal print head  42  and the platen roller  16  are located between the ribbon guide member  48  and the guide shaft  49  when the cover  20  is closed. 
     As shown in  FIG. 6 , the ink ribbon  2  is wound around the winding shaft  60  from the feeding shaft  50  via the ribbon guide member  48  and the guide shaft  49 . In addition, the ink ribbon  2  overlaps the label paper  1  between the thermal print head  42  and the platen roller  16  and is moved forward F on the path between the ribbon guide member  48  and the guide shaft  49  at the same speed as the label paper  1  or a speed slightly faster than the label paper  1 . 
     The feeding shaft  50  and the winding shaft  60  are disposed in the width direction between side walls  41   a ,  41   b  of the support member  41 . The gear train  90  is disposed outside the side wall  41   a . The winding shaft  60  extends through the side wall  41   a  and includes a winding gear  61  (passive member) at an end thereof. The gear train  90  engages with the winding gear  61  and rotates with the winding shaft  60 . The gear train  90  also engages with the gear train  13  provided in the body  10  when the cover  20  is closed. 
     Accordingly, the winding shaft  60  is connected to the motor  12  when the cover  20  is closed but is disconnected from the motor  12  when the cover  20  is open. When the cover  20  is closed, the motor  12  rotates the winding shaft  60  in a direction for winding the ink ribbon  2  (i.e. the counterclockwise direction in  FIG. 5 ; also referred to as the winding direction R 1 ) via the gear train  13  in the body  10  and the gear train  90  in the cover  20  so that the ink ribbon  2  is wound around the winding shaft  60 . When the motor  12  is stopped and the cover  20  is closed, the braking force of the motor  12  holds the winding shaft  60  unmoved. 
     On the other hand, when the cover  20  is open, the braking force of the motor  12  does not act on the winding shaft  60  since the winding shaft  60  is disconnected from the motor  12 , but the rotation of the winding shaft  60  is restricted by the ribbon flange  70  and the lock member  80 , which will be described below. 
     The feeding shaft  50  includes a torsion spring (not shown) that applies torque in a direction R 2  opposite to the winding direction R 1  (i.e. the clockwise direction R 1 ) of the winding shaft  60  that winds up the ink ribbon  2 . Accordingly, when the cover  20  is closed, the ink ribbon  2  receives a force that pulls the ribbon rearward, i.e. in a direction −F (minus F) by the torque of the torsion spring and a force that pulls the ribbon forward, i.e. in a direction F by the driving force of the motor  12 . Therefore, the ink ribbon  2  is not slackened but tensioned to be kept flat. 
     Also, when the motor  12  is stopped, the ink ribbon  2  receives the force that pulls the ribbon rearward (i.e. in the direction −F) by the torque of the torsion spring and a force that keeps the ribbon in place by the braking force of the motor  12 . Therefore, the ink ribbon  2  is not slackened but tensioned to be kept flat. 
     Accordingly, the portion of the ink ribbon  2  between the thermal print head  42  and the platen roller  16  is not slackened but pressed onto the label paper  1  when the cover  20  is closed and the printer is in use. Therefore, the ink of the ink ribbon  2  is appropriately transferred to the label paper  1  so that the printing is properly performed. Also, the ink ribbon  2  is not slackened when the cover  20  is closed and the printer is not in use. Accordingly, the printing can be resumed with the ink ribbon  2  which is not slackened at the next use. 
     As shown in  FIG. 7 , the winding shaft  60  includes a ribbon flange  70  which has a disc shape. The ribbon flange  70  is located at an inner side of the side wall  41   a  of the support member  41 . The ribbon flange  70  is configured to prevent the ink ribbon  2  wound around the shaft  60  from moving in one of the axial directions along the shaft  60 . Also, the ribbon flange  70  is configured to allow the winding shaft  60  to be manually rotated, which will be described below. The ribbon flange  70  may also be provided to prevent the ink ribbon  2  wound around the shaft  60  from moving in the axial direction along the shaft  60  by the side edge of the ink ribbon  2  contacting the ribbon flange  70 . 
       FIG. 8  is a perspective view illustrating the ribbon flange  70 . As shown in  FIG. 8 , the ribbon flange  70  includes a through-hole  79  in the center thereof. The through-hole  79  has a substantially D-shaped cross-section. Corresponding to the through-hole  79 , the winding shaft  60  also has a substantially D-shaped cross-section. The winding shaft  60  is fitted into the through-hole  79  so that the ribbon flange  70  rotates integrally with the shaft  60 . The substantially D-shaped cross-sections of the through-hole  79  and the winding shaft  60  prevent the winding shaft  60  to freely rotate in the through-hole  79 . The ribbon flange  70  includes teeth  71  on an outer circumference. The teeth  71  provide an anti-slip function when the user manually rotates the ribbon flange  70  about the axis of the shaft  60  by putting her or his fingers on the teeth  71 . 
     The ribbon flange  70  includes a surface  72  facing the side wall  41   a  and a surface facing the ink ribbon  2 . A recess  73  is provided on the surface  72  at an area radially inward from the outer circumference of the ribbon flange  70 . The recess  73  is concaved in the thickness direction of the ribbon flange  70 . The recess  73  includes a plurality of cam faces  74  on the circumference thereof. The cam faces  74  may consist of twelve faces continuously formed on the entire circumference of the recess  73 , for example. The cam faces  74  have radial distances from the center of the shaft  60  that vary in accordance with the rotation angle about the shaft  60  fitted in the through-hole  79 . The cam faces  74  are configured to regulate or restrict the rotation of the ribbon flange  70  by contacting the lock member  80 , which will be described below. 
     As shown in  FIG. 8 , each of the cam faces  74  includes a first cam face  74   a , a second cam face  74   b , and a third cam face  74   c . The first cam face  74   a  is a flat surface. The second cam face  74   b  is a curved surface that protrudes radially outwardly. The third cam face  74   c  connects the first cam face  74   a  and the second cam face  74   b . The third cam face  74   c  is a short arc surface or a flat surface where the radius or radial distance from the center axis C is the largest and is substantially constant. The first cam face  74   a , the third cam face  74   c , and the second cam face  74   b  are arranged in a clockwise direction R 2  in this order as shown in the figures. 
       FIG. 9  is a perspective view illustrating the lock member  80  moved to the bottom end of the movable range.  FIG. 10  is a perspective view illustrating the lock member  80  moved upward from the bottom end of the movable range. As shown in  FIG. 7 , the lock member  80  is provided outside the side wall  41   a  of the support member  41 . As shown in  FIG. 9 , the lock member  80  includes a movable portion  81  and a coil spring  89 . The movable portion  81  is a main body of the lock member  80  and configured to regulate the rotation of the ribbon flange  70 . 
     As shown in  FIG. 7 , the side wall  41   a  includes a guide portion  41   e  integrally formed therewith. The guide portion  41   e  is disposed so that the movable portion  81  is located between the guide portion  41   e  and the side wall  41   a . The guide portion  41   e  is configured to guide the movable portion  81  so that the movable portion  81  only moves within a predetermined range. Specifically, the guide portion  41   e  restricts the moving direction of the movable portion  81  to the vertical direction in the figure (the opening and closing direction of the cover  20  (tangent direction of the opening and closing direction when opening)) and the moving range of the movable portion  81  to the predetermined range. Alternatively, the side wall  41   a  may include an elongate hole extending in the vertical direction instead of the guide portion  41   e  and the movable portion  81  may include a convex portion. In this case, the convex portion may be inserted into the elongate hole and moved upward and downward to guide the movable portion  81 . Such configuration does not require the guide portion  41   e.    
     The movable portion  81  extends in the vertical direction and includes an upper end portion  83 , an intermediate portion, and a bottom end portion  82 . The upper end portion  83  is bent inward in the width direction of the support member  41  and extends through an opening  41   d  on the side wall  41   a  into the recess  73  of the ribbon flange  70 . The bottom end portion  82  is bent outward in the width direction of the support member  41  and contacts the upper surface  19   a  of the side wall  19  of the body  10  (see  FIG. 2 ) from above when the cover  20  is closed. Further, the movable portion  81  includes a spring seat  84  at the intermediate portion. The spring seat  84  receives the coil spring  89  and contacts a bottom end  89   b  of the coil spring  89 . 
     Thought the bottom end portion  82  is an outermost portion projecting in the width direction of the printing portion  40  among the movable portion  81  and the coil spring  89 , the bottom end portion  82  is located inside the gear train  90  and the winding gear  61  in the width direction as shown in  FIG. 7 . 
     A spring receiving portion  41   c  (see  FIG. 5 ) is disposed outside the side wall  41   a  of the support member  41  which is provided in the cover  20 . The spring receiving portion  41   c  (see  FIG. 5 ) receives the coil spring  89  and contacts the upper end  89   a  of the coil spring  89 . The coil spring  89  is arranged between the spring seat  84  and the spring receiving portion  41   c  with contracted from its natural length. As a result, an elastic force acts between the movable portion  81  and the side wall  41   a  for restoring the coil spring  89  from the contracted state to the natural length. The elastic force pushes down the movable portion  81  to the bottom end of a movable range in the vertical direction. 
     The bottom end portion  82  of the movable portion  81  extends below the bottom surface  29   a  of the side wall  29  in the cover  20  at the bottom end of the movable range. However, the bottom surface  29   a  of the cover  20  contacts the upper surface  19   a  of the side wall  19  of the body  10  when the cover  20  is closed. Accordingly, when the cover  20  is closed, a bottom surface of the bottom end portion  82  contacts the upper surface  19   a  of the side wall  19  of the body  10  as shown in  FIG. 10  so that the movable portion  81  is pushed up to the upper end of the movable range against the elastic force of the coil spring  89 . The movable portion  81  is an example of the regulation member whose position changes in accordance with the open and closed state of the cover  20 . 
       FIG. 11  is a side view illustrating a positional relation between the cam face  74  and the upper end portion  83  shown in  FIG. 10 .  FIG. 12  is a side view illustrating the positional relation between the cam face  74  and the upper end portion  83  shown in  FIG. 9 . When the cover  20  is closed, the movable portion  81  is moved to the upper end of the movable range and the upper end portion  83  extending into the recess  73  of the ribbon flange  70  escapes to a position where the upper end portion  83  does not contact the cam face  74  which is the circumferential surface of the recess  73 . 
     Specifically, as shown in  FIG. 11 , the upper end portion  83  of the movable portion  81  that has been moved upward is located radially inward of the cam faces  74  of the ribbon flange  70  so that the upper end portion  83  does not contact the cam faces  74  when the ribbon flange  70  rotates. Therefore, the movable portion  81  does not prevent the rotation of the winding shaft  60  when the cover  20  is closed. 
     On the other hand, the movable portion  81  is moved to the bottom end of the movable range when the cover  20  is open, and the upper end portion  83  extending into the recess  73  of the ribbon flange  70  contacts the cam face  74  of the ribbon flange  70  as shown in  FIG. 12 . As shown in  FIGS. 11 and 12 , the upper end portion  83  extending into the recess  73  is substantially rectangular in a cross-section and a lower right corner in the figure is chamfered. The upper end portion  83  is positioned lower than the center axis C of the ribbon flange  70  in the state where the movable portion  81  has been moved to the bottom end of the movable range. In this state, a right side surface  83   a  of the upper end portion  83  contacts the first cam face  74   a , which is in a vertically extending state. 
       FIG. 13  shows an enlarged view illustrating the positional relation between the cam face  74  and the upper end portion  83  shown in  FIG. 12  and the movement of the first cam face  74   a . Now, the movement from the state where the right side surface  83   a  of the upper end portion  83  contacts the first cam face  74   a  of the ribbon flange  70  is described. When the ribbon flange  70  rotates in the clockwise direction R 2  (i.e. the unwinding direction) opposite to the winding direction R 1  relative to the ink ribbon  2 , the first cam face  74   a  located lower than the center axis C moves downward and leftward in the figure to a position shown with a two-dot chain line in  FIG. 13 . 
     The bottom portion of the first cam face  74   a  has a radius from the center axis C larger than that of the upper portion of the first cam face  74   a . Accordingly, when the first cam face  74   a  reaches a position where the first cam face  74   a  is aligned horizontally with the center axis C by the rotation in the winding direction R 1 , the first cam face  74   a  is inclined to extend diagonally up left so that the bottom portion is horizontally further away from the center axis C than the upper portion. 
     Specifically, when the ribbon flange  70  rotates in the clockwise direction R 2 , the first cam face  74   a  moves into a space occupied by the upper end portion  83  the first cam face  74   a  contacts before the rotation. Therefore, in a condition to rotate the ribbon flange  70  in the clockwise direction R 2 , the first cam face  74   a  contacting the flat right side surface  83   a  of the upper end portion  83  must push the upper end portion  83  to move the upper end portion  83  upward or leftward. 
     However, the movable portion  81  including the upper end portion  83  does not move in the horizontal direction but only in the vertical direction. Moreover, the movable portion  81  including the upper end portion  83  is in a state that the right side surface  83   a  contacts the first cam face  74   a . Accordingly, the upper end portion  83  cannot be moved upward even if the first cam face  74   a  intended to rotate in the clockwise direction R 2  pushes the right side surface  83   a . Consequently, the lock member  80  restricts the movement of the ribbon flange  70  and prevents the ribbon flange  70  from moving in the clockwise direction R 2 . Therefore, the rotation of the winding shaft  60  in the direction to unwind the ink ribbon  2  (i.e. the clockwise direction R 2 ) and accordingly the slack of the ink ribbon  2  can be prevented even if the braking force of the motor  12  is not applied to the winding shaft  60  while the cover  20  is opened. 
     On the other hand, when the ribbon flange  70  rotates in the counterclockwise direction R 1  (i.e. the direction for winding the ink ribbon  2 ), the first cam face  74   a  located lower than the center axis C moves upward and rightward to a position shown with a dashed line as shown in  FIG. 13 . 
     Specifically, when the ribbon flange  70  rotates in the counterclockwise direction R 1 , the first cam face  74   a  moves away from the upper end portion  83  which the first cam face  74   a  contacts before the rotation, and the upper end portion  83  of the movable portion  81  does not restrict the rotation of the ribbon flange  70  in relation to the first cam face  74   a.    
       FIG. 14  is a schematic view illustrating the transition of the positional relation among the first the cam face  74   a , the second the cam face  74   b  and the upper end portion  83  when the ribbon flange  70  rotates in the counterclockwise direction R 1 . As shown in the top and middle views of  FIG. 14 , when the ribbon flange  70  rotates in the counterclockwise direction R 1 , the first cam face  74   a  moves away from the right side surface  83   a  of the upper end portion  83  while the third cam face  74   c  next to the first cam face  74   a  and the second cam face  74   b  next to the third cam face  74   c  approach the upper end portion  83  from the lower and left sides of the upper end portion  83 . 
     As the rotation of the ribbon flange  70  in the counterclockwise direction R 1  progresses, the third cam face  74   c  does not contact the upper end portion  83  while the second cam face  74   b  approaches to contact a chamfered surface or C surface  83   b  of the upper end portion  83  from the lower and left sides as shown in the middle view of  FIG. 14 . The C surface  83   b  is formed at an end of the right side surface  83   a  of the upper end portion  83  in the clockwise direction R 2  (i.e. the rotational direction restricted by the lock member  80 ). 
     Then, the rotation of the ribbon flange  70  progresses with the second cam face  74   b  contacting the C surface  83   b . At this time, the second cam face  74   b  applies upward and rightward loads to the C surface  83   b . The rightward load does not move the upper end portion  83  rightward since the second cam face  74   b  and the C surface  83   b  slide relative to each other. The lower right corner of the upper end portion  83  is not a sharp corner but has the chamfered C surface  83   b , and the second cam face  74   b  is formed of a curved surface that protrudes outward with respect to the upper end portion  83 . Accordingly, the relative contact angle between the C surface  83   b  and the second cam face  74   b  becomes shallow, so that the slide between the C surface  83   b  and the second cam face  74   b  occurs easily. 
     It should be noted that changing the contour shape of the second cam face  74   b  makes it easier for the rightward load to be released by sliding without forming the C surface  83   b  on the upper end portion  83 . Also, forming the upper end portion  83  to have a shape that easily causes rightward sliding makes it easier for the rightward load to be released by sliding even if the upper end portion  83  is not formed substantially rectangular as described above. 
     The upward load on the upper end portion  83  is released by moving the movable portion  81  (the upper end portion  83 ) upward against the elastic force for compressing the coil spring  89  as shown in the bottom view of  FIG. 14 . Before the movable portion  81  reaches the upper end of the movable range, the second cam face  74   b  moves away from the upper end portion  83 , the movable portion  81  moves to the bottom end of the movable range by the elastic force of the coil spring  89 , and the upper end portion  83  returns to a position where the right side surface  83   a  contacts the first cam face  74   a  as shown in the top view of  FIG. 14 . 
     It should be noted that the two-dot chain lines in the bottom view of  FIG. 14  show a position of the upper end portion  83  when the movable portion  81  (the upper end portion  83 ) does not move upward. 
     As described above, the lock member  80  allows the rotation of the ribbon flange  70  in the counterclockwise direction R 1 . Accordingly, a user can manually rotate the ribbon flange  70  in the counterclockwise direction R 1  with his or her fingers on the teeth  71  of the ribbon flange  70  when cover  20  is open and the braking force of the motor  12  does not act on to the winding shaft  60 . Consequently, in the printer  100  of the present embodiment, the slack of the ink ribbon  2  can be manually removed when the ink ribbon  2  is slackened or the ink ribbon  2  gets slackened upon replacing the ink ribbon  2 . 
     According to the present embodiment, the printer  100  can suppress an increase in the size of the printer  100  in the width direction of the ink ribbon  2  and prevent the winding shaft from rotating in the direction R 2  opposite to the winding direction without providing extra space for the lock member  80  since the printer  100  is configured such that the lock member  80  extends into the recess  73  of the ribbon flange  70  but is not arranged with the gear train  90  or the winding gear  61  in the axial direction thereof. 
     Further, a part of the upper end portion  83  in the lock member  80  extends into the recess  73  of the ribbon flange  70  and remains within the recess  73 . Accordingly, the position of the lock member  80  can be moved toward the ribbon flange  70  by the substantially same distance as the depth of the recess  73 , which makes it easier to suppress the printer  100  from increasing in size in the width direction of the ink ribbon  2 . 
     The ribbon may reach close to the tips of the teeth  71  of the ribbon flange  70  when the diameter of the used ink ribbon  2  wound around the winding shaft  60  becomes as thick as the diameter of the ribbon flange  70 . Consequently, it may be difficult for the user to put his or her fingers on the teeth  71  of the ribbon flange  70  when the user manually rotates the ribbon flange  70 . However, in the printer  100  of the present embodiment, the inner surface of the ribbon flange  70  includes a separating portion  70   a  at the radially outer area as shown in  FIG. 7 . The separating portion  70   a  is concaved to be further away from the ink ribbon  2  compared to a radially inner area so that space is formed between the ink ribbon  2  and the teeth  71 . The separating portion  70   a  makes it easier for the user to put his or her fingers on the teeth  71  of the ribbon flange  70 . 
     Moreover, the separating portion  70   a  is formed at the radially outer area than the recess  73  as shown in the figures such as  FIG. 8 . Accordingly, the recess  73  can be formed to have a depth where the cam faces  74  are formed regardless of the thickness of the separating portion  70   a  in the ribbon flange  70 . 
     The separating portion  70   a  is continuously formed in the radially outer area over the entire circumference of the ribbon flange  70  as shown in  FIG. 7 . However, the separating portion  70   a  may be partially formed in the radially outer area. For example, a plurality of separating portions  70   a  may be formed in the radially outer area to be spaced apart from each other. 
     In the printer  100  according to the present embodiment, the position of the cam face  74  the lock member  80  contacts is located lower than the center axis C of the ribbon flange  70  as shown in  FIGS. 11 and 12 . However, in the printer according to the present disclosure, the location where the regulation member and the cam face contact each other to restrict the rotation of the ribbon flange is not limited to the location in the printer  100  of the present embodiment. 
     (Modification)  FIG. 15  is a schematic view corresponding to  FIG. 12  and illustrating a modification of the ribbon flange  70  and the upper end portion  83  of the movable portion  81 . In the printer  100  of the above embodiment, the recess  73  is formed on the surface  72  of the ribbon flange  70  and the cam faces  74  are formed on the inner circumference of the recess  73 . However, as shown in  FIG. 15 , a convex portion  173  may be provided to extend from the surface of the ribbon flange  70  and cam faces  174  may be formed on the outer circumference of the convex portion  173 . 
     In this case, it is necessary to modify the cross-section profile of the upper end portion  83  of the movable portion  81  in accordance with the cam faces  174 . The cam face  174  and the upper end portion  83  contact each other at a position higher than the center axis C of the ribbon flange  70  as shown in the figure. The cam face  174  includes a first cam face  174   a , a second cam face  174   b , and a third cam face  174   c . Preferably, the first cam face  174   a  is a flat surface and the second cam face  174   b  is a curved surface that is concave radially inwardly. Preferably, the third cam face  174   c  which connects the first cam face  174   a  and the second cam face  174   b  is a flat surface or a curved surface that is concave radially inwardly. 
     In the printer  100  of the present embodiment and the modification, the cam faces  74  or  174  which restrict the rotation of the ribbon flange  70  in the clockwise direction R 2  by the lock member  80  are provided in the ribbon flange  70  between the side walls  41   a ,  41   b  of the printing portion  40 . Accordingly, the amount of the protrusion of the lock member  80  in the width direction can be suppressed or eliminated. 
     In other words, the ribbon flange  70  is an element provided inside the side walls of the casing that is the exterior of the printer  100  and inwardly retracted in the width direction from the outer surface of the casing as described above. A certain amount of space can be formed between the outer surface of the casing and the ribbon flange  70 , and the lock member  80  is provided within the space. Therefore, the size of the printer in the width direction can be suppressed compared to one in which the lock member is arranged with the winding gear  61  and the gear train  90  in the axial direction thereof. 
     In the printer  100  according to the above embodiment and the modification, the cam faces  74  are formed on the inner side than the outer circumferential surface (outer contour) of the ribbon flange  70 . However, in the printer according to the present disclosure, the cam faces  74  may be formed on the outer circumferential surface (outer contour) of the ribbon flange  70 . In other words, the outer circumferential surface (outer contour) of the ribbon flange  70  itself may be the cam faces  74 .