JP2007268878A - Thermal printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal printer which facilitates exchange of a thermal head unit, and position adjustment of the same. <P>SOLUTION: The thermal printer has: adjusters 40a (40b) which are arranged so as to be movable frontward/rearward, and each have first and second shafts 42, 43; screws 46 and washers 45 for fixing the adjusters 40a (40b) and disengaging the fixture; and engaging side plates 32a (32b) which are arranged on both sides of the thermal head unit 20, and each have first and second engaging recesses 35, 36 formed therein. According to the structure of the thermal printer, the first and second engaging recesses 35, 36 engage with the first and second shafts 42, 43, respectively, and thereby frontward/rearward movement of the engaging side plates 32a (32b) is inhibited. Rotation of the engaging side plates 32a (32b) about the first shaft 42 of the adjuster 40a (40b) toward a platen roller 50 is not hindered by the second shaft 43. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thermal printer having a thermal head unit arranged so as to extend in a width direction of a housing and a platen roller arranged so as to be applied to a heat generating portion formed in the thermal head unit.

  In thermal printers, the heat generated from the heat generating part (resistor array) of the thermal head unit changes the color of the thermal paper into a pattern such as a letter or pattern, or the color ink of the ink ribbon is applied to the sheet as a pattern such as a letter or pattern. Printing is performed by transferring it. In this type of thermal printer, when the number of prints increases, it is necessary to replace the thermal head unit due to thermal deterioration of the heat generating part.

Conventionally, there has been proposed a head attaching / detaching mechanism capable of easily exchanging a thermal head unit in a thermal printer (see Patent Document 1). In this head attaching / detaching mechanism, an attaching / detaching lever is disposed on the thermal head unit (head substrate), and the joining of the thermal head unit and the supporting plate is released by rotating the attaching / detaching lever.
JP 2003-48335 A

  By the way, when exchanging the thermal head unit, it is necessary to adjust the relative positions of the thermal head unit and the platen roller disposed so as to be applied thereto. However, although the conventional thermal printer has a structure that makes it easy to replace the thermal head unit as described above, no consideration is given to the position adjustment of the thermal head unit after replacement. It was.

  The present invention has been made in view of such circumstances, and provides a thermal printer in which a thermal head unit can be easily replaced and its position adjustment work can be easily performed.

  A thermal printer according to the present invention is a thermal printer having a thermal head unit arranged so as to extend in a width direction of a housing and a platen roller arranged so as to be applied to a heat generating part formed in the thermal head unit. A movable support member having a first shaft and a second shaft disposed in front of the first shaft, the movable support member being provided so as to be movable back and forth along both sides of the housing; A fixing / releasing mechanism for fixing and releasing, a first engaging recess provided at each of both side ends of the thermal head unit, and rotatably engaged with the first shaft of the movable support member; And an engagement member formed with a second engagement recess that engages with the second shaft, wherein the first engagement recess and the second engagement recess are relative to the first shaft and the second shaft. Can be engaged and disengaged The engagement of the engagement member with the first shaft and the second shaft restricts the movement of the engagement member in the front-rear direction, and the engagement member that stops the first shaft of the movable support member moves toward the platen roller. Is configured so as not to be hindered by the second shaft.

  With such a configuration, when the platen roller is separated from the thermal head unit while the movable support member is fixed, the second engaging recess engages with the second shaft of the movable support member without being obstructed. The engaging member can be rotated to the side away from the platen roller around the first axis of the movable support member with which the one engaging recess engages. As a result, the thermal head unit integrated with the engaging member can be rotated about the first axis. And if the 2nd engagement recessed part of an engagement member remove | deviates from the 2nd axis | shaft of a movable support member in the process of the rotation, it will become possible to remove a thermal head unit.

  Further, the first engaging recess and the second engaging recess of the engaging member are regulated so that the movement of the engaging member in the front-rear direction is restricted by the engagement of the movable support member with the first shaft and the second shaft. Since it is formed, the thermal head unit can move back and forth together with the movable support member by releasing the fixation of the movable support member and making it movable.

  In the thermal printer according to the present invention, the first engagement recess is a recess formed at the rear end of the engagement member so as to open rearward, and the second engagement recess is the platen. It can be set as the structure which is a recessed part formed so that it might open to the opposite side to the side by which a roller is arrange | positioned.

  With such a configuration, in the state where the first engagement recess and the second engagement recess are engaged with the first shaft and the second shaft, the movement of the engagement member in the front-rear direction is restricted, and the first Rotation of the engaging member about the shaft toward the platen roller can be prevented from being hindered by the second shaft.

  In the thermal printer according to the present invention, the second engagement recess has a shape corresponding to a movement locus of the second axis relative to the engagement member that rotates about the first axis. It can be.

  With such a configuration, with the first engagement recess and the second engagement recess engaged with the first shaft and the second shaft, the engagement member centering on the first shaft moves toward the platen roller. Is not hindered by the second shaft.

  Furthermore, in the thermal printer according to the present invention, guide holes extending in the front-rear direction are formed in predetermined member walls on both sides in the housing, and the movable support member is a protrusion that is slidably fitted into the guide hole. It can be set as the structure which has these.

  With such a configuration, the protrusion of the movable support member slides while being guided by the guide hole extending in the front-rear direction of the member wall, so that the movable support member can move back and forth.

  The member wall may be a wall of any member provided in the housing, for example, a side wall of the housing itself.

  According to the thermal printer of the present invention, when the platen roller is separated from the thermal head unit, the thermal head unit integrated with the engaging member can rotate about the first axis of the movable support member. When the second engaging recess of the engaging member is disengaged from the second shaft of the movable support member during the turning process, the thermal head unit can be removed, so that the thermal head unit can be easily replaced. Become so.

  Further, the thermal head unit integrated with the engaging member formed with the first engaging recess and the second engaging recess engaging the first shaft and the second shaft of the movable support member is moved forward and backward together with the movable support member. Therefore, the position of the thermal head unit with respect to the platen roller can be easily adjusted by moving the fixed support released from the front and back.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  A schematic structure of a thermal printer according to an embodiment of the present invention is as shown in FIG.

  1, in this thermal printer, an upper casing 100a and a lower casing 100b are hinge-coupled at the rear end (not shown), and they can be opened and closed with the hinge as an axis. A print unit 200 is provided in a front portion of the upper housing 100a. The print unit 200 includes a head assembly 10 (including a thermal head unit as will be described later), an ink ribbon feed roller 60a, and a take-up roller 60b arranged to extend in the width direction. A platen roller 50 disposed to face the print unit 200 is provided at a front portion of the lower casing 100b. When the upper casing 100a and the lower casing 100b are closed, the platen roller 50 is placed in the print unit 200. It is applied to the heat generating part of the thermal head unit (included in the head assembly 10). The ink ribbon delivered from the delivery roller 60a passes between the head assembly 10 and the platen roller 50 and is taken up by the take-up roller 60b. Printing is performed by transferring the color ink of the ink ribbon into a pattern such as a character or a picture on the paper conveyed between the ink ribbon and the platen roller 50 by heat from the heat generating portion of the thermal head unit. Is made.

  The head assembly 10 is configured as shown in FIG.

  In FIG. 2, the head assembly 10 has a structure in which a plate-like thermal head unit 20 is fixed to a bracket 30. The bracket 30 includes a fixed plate portion 31 that covers the back surface of the thermal head unit 20, and engagement side plate portions 32a that are formed to be perpendicular to the fixed plate portion 31 at both side edges in the width direction of the fixed plate portion 31, respectively. 32b (engagement member). The thermal head unit 20 is set so that the back surface is in close contact with the fixed plate portion 31 between the both engagement side plate portions 32a and 32b, and the thermal head unit 20 is fixed to the fixed plate portion 31 with screws 37a and 37b. Since screw holes (not shown) larger than the outer diameters of the screws 37a and 37b are formed in the fixed plate portion 31, the relative positions of the thermal head unit 20 and the bracket 30 can be reduced by loosening the screws 37a and 37b. The thermal head unit 20 can be removed from the bracket 30 by removing the screws 37a and 37b.

  In this state where the thermal head unit 20 is fixed to the bracket 30, the engagement side plate portions 32 a and 32 b of the bracket 30 are arranged at both side ends in the width direction of the thermal head unit 20. An arcuate first engagement recess 35 that opens rearward is formed at the rear end of each engagement side plate 32a, 32b, and a second engagement recess 36 that opens upward is formed at an intermediate portion thereof. Has been. The second engaging recess 36 is opened to the opposite side of the platen roller 50 in a state where the head assembly 10 is mounted on the print unit 200 (see FIG. 1).

  Two engaging projections 33 a and 33 b are provided upright at a substantially central portion of the front end edge of the fixed plate portion 31 in the bracket 30.

  As shown in FIG. 3, both the engaging side plate portions 32a and 32b of the bracket 30 are engaged with adjusters 40a and 40b (movable support members), so that the head assembly 10 is supported by both adjusters 40a and 40b. The engagement state of the engagement side plate portions 32a and 32b with the adjusters 40a and 40b will be described later. As shown in FIG. 1, the adjusters 40a and 40b are provided so as to be able to move back and forth along both sides in the width direction of the upper casing 100a. More specifically, as shown in FIG. 4, the adjusters 40a and 40b are slidable in the front-rear direction on the side wall 200a of the print unit 200 (see FIG. 1) provided in the upper housing 100a. .

  In FIG. 4, the adjuster 40 a (40 b) has an elongated plate-like base portion 41, and a protruding portion 44 is formed on one surface of the plate-like base portion 41 so as to extend in the longitudinal direction. The adjuster 40a (40b) is attached to the side wall 200a so that the projection 44 is slidably fitted into a guide hole 201 formed to extend in a front-rear direction at a predetermined portion of the side wall 200a of the print unit 200. A screw hole 44a is formed in the protrusion 44, and the adjuster 40a (40b) is fixed to the side wall 200a by applying a washer 45 from the outside of the side wall 200a and turning the screw 46 into the screw hole 44a and tightening. Further, by loosening the screw 46, the adjustment of the adjuster 40a (40b) to the side wall 200a is released, and the protrusion 44 slides while being guided by the guide hole 201 so that the adjuster 40a (40b) can move in the front-rear direction. Become.

  A first shaft 42 and a second shaft 43 are formed side by side in the longitudinal direction on the surface of the adjuster 40a (40b) opposite to the surface on which the protrusions 44 are formed. With the adjuster 40a (40b) mounted on the side wall 200a of the print unit 200 as described above, the second shaft 43 is disposed in front of the first shaft.

  FIGS. 5 to 7 show a more detailed structure of the print unit 200 as seen from the side, partly cut away. A mounting state of the head assembly 10 to the print unit 200 will be described with reference to FIGS. 5 to 7, the engagement side plate portion 32a of the bracket 30 is partially cut away, and the opposite engagement side plate portion 32b that engages with the adjuster 40b is partially shown. Since the relative relationship between the combined side plate portion 32a and the adjuster 40a and the relative relationship between the engagement side plate portion 32b and the adjuster 40b are the same, hereinafter, the reference numeral of the engaging side plate portion is 32a (32b). In the following description, the reference numeral of the adjuster is 40a (40b).

  In FIG. 5, the adjuster 40a (40b) has a protruding portion in the guide hole 201 formed in the side wall 200a of the print unit 200 extending in the front-rear direction (slightly inclined forward and downward) as described above (see FIG. 4). 44 is mounted on the side wall 200a so as to be slidably fitted, and is fixed by a screw 46 screwed into the screw hole 44a. A first engagement recess 35 formed at the rear end of the engagement side plate portion 32a (32b) of the bracket 30 in the head assembly 10 is rotatably engaged with the first shaft 42 of the adjuster 40a (40b). The head assembly 10 is mounted on the adjusters 40a and 40b so that the second engaging recess 36 formed in the intermediate portion of the mating plate portion 32a (32b) engages with the second shaft 43 of the adjuster 40a (40b). . The second engagement recess 36 is a second axis relative to the head assembly 10 (the engagement side plate portion 32a (32b)) that rotates about the first shaft 42 with which the first engagement recess 35 is engaged. The shape corresponds to 43 movement trajectories.

  The thermal head unit 20 of the head assembly 10 includes an aluminum substrate 21 and a heat generating portion 22 (resistor array) arranged on the surface of the aluminum substrate 21, and the head assembly 10 is attached to the adjuster 40a (40b) as described above. In this state, the platen roller 50 is applied to the heat generating part 22 of the thermal head unit 20. A spring 212 provided at a predetermined front portion of the print unit 200 presses the back surface of the head assembly 10 (thermal head unit 20), and the thermal head unit 20 is pressed against the platen roller 50. Further, a hook 213 that is rotatably supported by the support shaft 214 is provided in the vicinity of the spring 212. The hook 213 is close to the engagement protrusion 33a (33b) protruding from the fixed plate portion 31 of the bracket 30 in the head assembly 10 attached to the adjuster 40a (40b).

  Above the head assembly 10 of the print unit 200, there is provided a feed roller holder 211a to which a feed roller 60a (see FIG. 1) for feeding the ink ribbon is to be rotatably mounted, and is aligned with the feed roller holder 211a. A take-up roller holder 211b to which a take-up roller 60b (see FIG. 1) for taking up the ink ribbon is to be rotatably mounted is provided.

  As described above, when the head assembly 10 is mounted on the print unit 200, the first engagement recess 35 and the second engagement recess 36 of the engagement side plate portion 32a (32b) are the first shaft 42 of the adjuster 40a (40b). Since the engagement side plate portion 32a (32b) is restricted from moving in the front-rear direction because of the engagement with the second shaft, as a result, the head assembly 10 (thermal head unit 20) is moved in the front-rear direction. Be regulated. In this state, by loosening the screw 46 (see FIG. 4) and moving the adjuster 40a (40b) along the guide hole 201, the head assembly 10 attached to the adjuster 40a (40b) is moved to the position shown in FIGS. As shown in (b), it can be moved in the front-rear direction. That is, the position of the heat generating portion 22 in the thermal head unit 20 can be adjusted with respect to the platen roller 50.

  Since the adjuster 40a (40b) is moved in the front-rear direction with the head assembly 10 mounted on the print unit 200 in this way, the position of the heat generating portion 22 of the thermal head unit 20 relative to the platen roller 50 can be adjusted. The heat generating portion 22 of the thermal head unit 20 can be easily adjusted to an appropriate position. Further, the position of the thermal head unit 20 can be adjusted while printing. Therefore, it is possible to adjust the position of the thermal head unit 20 while confirming the printing state, and it is possible to adjust the position more accurately in a shorter time.

  The head assembly 10 can be replaced as follows.

  The upper housing 100a and the lower housing 100b (see FIG. 1) are opened. Thereby, the platen roller 50 is separated from the thermal head unit 20 (head assembly 10). Then, as shown in FIG. 6A, the head assembly 10 is rotated toward the platen roller 50 around the first shaft 42 of the adjuster 40a (40b) by the pressing force of the spring 212. Then, the engaging projection 33a (33b) stops in a state where it is caught by the hook 213. Further, when the hook 213 is rotated rearward about the support shaft 214 to release the hook with the engaging protrusion 33a (33b), the head assembly 10 is adjusted to the adjuster 40a (40b) as shown in FIG. 6B. The second engagement recess 36 formed in the engagement side plate portion 32a (32b) of the bracket 30 is disengaged from the second shaft 43 of the adjuster 40a (40b). As a result, the first engagement recess 35 of the engagement side plate portion 32a (32b) is disengaged from the first shaft 42 of the adjuster 40a (40b), and as a result, the head assembly 10 (thermal head unit 20) is removed.

  When a new head assembly 10 is mounted, the first engagement recess 35 of the engagement side plate portion 32a (32b) in the head assembly 10 is engaged with the first shaft 42 of the adjuster 40a (40b) in reverse to the above-described procedure. Then, the head assembly 10 is rotated about the first shaft 42 until the engaging projection 33a (33b) is hooked on the hook 213 (see FIGS. 6B and 6A). When the upper casing 100a and the lower casing 100b are closed, the platen roller 50 pushes up the thermal head unit 20, and the head assembly 10 (thermal head unit 20) is set at a predetermined position (FIG. 5 ( a) and (b)).

  In the thermal printer having the above-described structure, the head assembly 10 can be easily removed from the adjuster 40a (40b) by opening the upper casing 100a and the lower casing 100b and separating the platen roller 50 from the thermal head unit 20. It will be removed. When a new head assembly 10 is mounted, the first engagement recess 35 of the engagement side plate portion 32a (32b) in the head assembly 10 is engaged with the first shaft 42 of the adjuster 40a (40b), and the first assembly 42 is engaged. By turning the head assembly 10 to a predetermined position with the single shaft 42 in the middle and then closing the upper casing 100a and the lower casing 100b, the new head assembly 10 is easily set at the predetermined position. Will be able to.

  Further, since the entire head assembly 10 in which the thermal head unit 20 and the bracket 30 (including the engagement side plate portion 32a (32b)) are integrated can be replaced, the alignment operation of the thermal head unit 20 can be performed more. It can be done easily. That is, first, the relative positional relationship between the first engagement concave portion 35 of the engagement side plate portion 32a (32b) of the removed head assembly 10 and the heat generating portion 22 of the thermal head unit 20 was measured in advance with a jig. Thereafter, the screws 37 a and 37 b are removed, the thermal head unit 20 is taken out from the head assembly 10, and is replaced with a new thermal head unit 20. Next, with the screws 37a and 37b loosened, the first engagement recess 35 of the engagement side plate portion 32a (32b) of the head assembly 10 to which the new thermal head unit 20 is attached, and the new thermal head unit 20 The relative positional relationship with the heat generating portion 22 is adjusted by a jig so as to coincide with the measured value before replacement. The head assembly 10 adjusted in this way is fixed between the first engagement recess 35 of the engagement side plate portion 32a (32b) and the heat generating portion 22 of the thermal head unit 20 by fixing the screws 37a and 37b. The distance can be kept substantially constant before and after the exchange. As described above, the distance between the first engagement recess 35 of the engagement side plate portion 32a (32b) and the heat generating portion 22 of the thermal head unit 20 is kept substantially constant, and therefore the engagement side plate portion 32a (32b). The head assembly 10 mounted on the print unit 200 with the first engaging recess 35 of the adjuster 40 a (40 b) engaged with the first shaft 42 of the adjuster 40 a (40 b) is connected to the heating unit 22 of the thermal head unit 20 and the platen roller 50. The relative positional relationship can always be kept substantially constant. For this reason, the position adjustment by the adjuster 40a (40b) is only slight (fine adjustment).

  As described above, the thermal printer according to the present invention has an effect that the thermal head unit can be easily replaced and the position adjustment work can be easily performed. This is useful as a thermal printer that performs printing by sandwiching an ink ribbon and paper between a thermal head unit and a platen roller.

1 is a diagram illustrating a schematic structure of a thermal printer according to an embodiment of the present invention. It is a perspective view which shows the thermal head assembly in the thermal printer shown in FIG. It is a figure which shows the state which the thermal head assembly shown in FIG. 2 engaged with the adjuster (movable support member). It is a figure which shows the detailed structure of an adjuster. It is a figure which shows the attachment state of a head assembly. It is a figure which shows the removal process of a head assembly. It is a figure which shows the state from which the head assembly was removed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Head assembly 20 Thermal head unit 21 Aluminum substrate 22 Heat generating part 30 Bracket 31 Fixed plate part 32a, 32b Engagement measuring plate part (engaging member)
33a, 33b engagement protrusion 35 first engagement recess 36 second engagement recess 37a, 37b screw 40a, 40b adjuster (movable support member)
41 Plate Base 42 First Axis 43 Second Axis 44 Projection 44a Screw Hole 45 Washer 46 Screw 50 Platen Roller 60a Feeding Roller 60b Winding Roller 100a Upper Housing 100b Lower Housing 200 Print Unit 200a Side Wall 201 Guide Hole 211a Sending Out Roller holder 211b Take-up roller holder 212 Spring 213 Hook 214 Support shaft

Claims (4)

A thermal printer having a thermal head unit disposed so as to extend in a width direction of the housing, and a platen roller disposed so as to be applied to a heat generating portion formed in the thermal head unit,
A movable support member provided so as to be movable back and forth along each of both sides in the width direction of the housing, and having a first shaft and a second shaft disposed in front of the first shaft;
A fixing / releasing mechanism for fixing and releasing the movable support portion;
A first engagement recess provided at each of both end portions in the width direction of the thermal head unit and rotatably engaged with the first shaft of the movable support member, and a second engaged with the second shaft. An engagement member formed with an engagement recess,
The first engagement recess and the second engagement recess can be engaged / disengaged with respect to the first shaft and the second shaft, and the engagement member is engaged with the first shaft and the second shaft. The movement in the front-rear direction is restricted, and the rotation of the engagement member around the first axis of the movable support member toward the platen roller is not hindered by the second axis. A thermal printer characterized by that. The first engagement recess is a recess formed to open rearward at the rear end of the engagement member,
The thermal printer according to claim 1, wherein the second engagement recess is a recess formed so as to open to a side opposite to a side where the platen roller is disposed.   The said 2nd engagement recessed part becomes a shape corresponding to the movement locus | trajectory of the said 2nd axis | shaft relative to the said engagement member rotated centering | focusing on the said 1st axis | shaft. Thermal printer. Guide holes extending in the front-rear direction are formed in predetermined member walls on both sides in the housing,
The thermal printer according to any one of claims 1 to 3, wherein the movable support member has a protrusion that is slidably fitted into the guide hole.

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