CN111070904A

CN111070904A - Thermal printer

Info

Publication number: CN111070904A
Application number: CN201911005598.2A
Authority: CN
Inventors: 川口幸治
Original assignee: Seiko Instruments Inc
Current assignee: Seiko Instruments Inc
Priority date: 2018-10-22
Filing date: 2019-10-22
Publication date: 2020-04-28
Anticipated expiration: 2039-10-22
Also published as: JP2020066143A; CN111070904B; CN212073377U

Abstract

The thermal printer includes a head unit and a platen unit detachably combined with the head unit. The head unit has a movable blade and a thermal head for printing on recording paper. The platen unit has a fixed blade and a platen roller that sandwiches and conveys a recording sheet with the thermal head. The movable blade is slidable relative to the fixed blade at the cutting position. The movable blade is provided with a guide portion which is bent so as to guide the movable blade to be pressed against the fixed blade when sliding. The distance between the tip of the guide part and the fixed blade is 0.4mm to 0.8 mm.

Description

Thermal printer

Technical Field

The present invention relates to a thermal printer.

Background

A thermal printer is known as a printer for printing on recording paper (thermal paper). A thermal printer includes: a thermal head having a heat generating element; a platen roller that sandwiches a recording sheet with a thermal head to feed the recording sheet; and a frame having a shaft support portion that supports the platen roller so as to be rotatable about an axis. In a thermal printer, various types of information can be printed on a recording sheet by appropriately generating heat from a heat generating element of a thermal head during the feeding of the recording sheet by the rotation of a platen roller.

In a thermal printer, a platen roller and a thermal head are detachably configured so as to facilitate roller replacement. The cutter is also separated from the fixed blade side and the movable blade side in accordance with this, and fixed to the platen roller side or the thermal head side (printer main body side), respectively (see, for example, japanese patent application laid-open No. 2006-.

However, when the fixed blade is provided on the detachable side (platen roller side), the movable blade may stop in the middle of the paper jam if the paper jam occurs. Hereinafter, the case where the movable blade is stopped halfway is also referred to as "tool lock". If the cutter lock occurs and the movable blade is blocked by the fixed blade, there is a possibility that the cover on the detachable side cannot be opened.

Specifically, if a paper jam occurs, the motor driving force corresponding to the increased load is transmitted to the platen driving wheel, and a large reaction force acts between the platen driving wheel and the final-stage gear. As a result, the embossing unit having the embossing roller and the fixed blade sometimes floats to a greater extent than usual, and the position of the fixed blade becomes higher than usual. Therefore, the distal end of the movable blade may collide with the end surface of the fixed blade, and the like, and the tool lock may occur.

Accordingly, in such a technical field, a thermal printer capable of suppressing the occurrence of the cutter lock is required.

Disclosure of Invention

A thermal printer according to one aspect of the present invention includes a head unit having a movable blade and a thermal head for printing on recording paper, and a platen unit having a fixed blade and a platen roller for sandwiching the recording paper between the platen roller and the thermal head and conveying the recording paper, the platen unit being detachably combined with the head unit, the movable blade being slidable relative to the fixed blade at a cutting position, the movable blade having a guide portion bent so as to guide the movable blade to be pressed against the fixed blade during sliding, and a distance between a tip end of the guide portion and the fixed blade being 0.4mm or more and 0.8mm or less.

In the thermal printer according to one aspect of the present invention, the guide portion has a bending angle of 25 ° or more and 35 ° or less.

Drawings

Fig. 1 is a sectional view showing a state in which a printer cover is in an open position in a thermal printer according to an embodiment.

Fig. 2 is a sectional view showing a state in which a printer cover is located at a closed position in the thermal printer of the embodiment.

Fig. 3 is a side view of the printing unit of the embodiment.

Fig. 4 is an exploded perspective view of the printing unit of the embodiment.

Fig. 5 is a perspective view of the head unit of the embodiment.

Fig. 6 is a top view of the head unit of the embodiment.

Fig. 7 is a perspective view of the wheel of the embodiment.

Fig. 8 is a perspective view of an exhaust hole of the embodiment.

Fig. 9 is a diagram for explaining the distance between the tip of the guide portion and the fixed blade in the embodiment.

Fig. 10 is an explanatory view of a bending angle of the guide portion of the embodiment.

Detailed Description

Embodiments according to the present invention will be described below with reference to the drawings. In the following embodiments, a thermal printer that is used in cash registers, portable terminal devices, and the like and can print various labels, receipts, tickets, and the like will be described as an example. In the drawings used in the following description, the scale of each member is appropriately changed so that each member can be recognized.

Fig. 1 is a sectional view showing a state in which a printer cover 6 is located at an open position in a thermal printer 1 of the embodiment. Fig. 2 is a sectional view showing a state in which the printer cover 6 is located at the closed position in the thermal printer 1 of the embodiment. In the drawing, FR denotes the front, LH denotes the left, and UP denotes the upper, respectively. As shown in fig. 1, the thermal printer 1 includes a housing 4 and a printing unit 9 incorporated in the housing 4.

The housing 4 includes a housing main body 5 and a printer cover 6. The case body 5 has a roll paper accommodating portion 5a that accommodates roll paper R. For example, the roll paper R is formed by winding the recording paper P. The printer cover 6 is provided so as to be able to open and close the roll paper storage 5 a. For example, the printer cover 6 is rotatably coupled to the housing main body 5 via a hinge portion 7.

As shown in fig. 2, at the closed position of the printer cover 6, between the opening edge of the roll paper accommodating portion 5a and the tip end portion of the printer cover 6, a discharge port 8 is formed, and the discharge port 8 can discharge the recording paper P drawn out from the roll paper R to the outside (upward).

The printing unit 9 includes the platen unit 2 and the head unit 3 which are detachably combined with each other. The platen unit 2 is assembled to the front end portion of the inner surface of the printer cover 6. The embossing unit 2 is a unit in which an embossing roller 10 and a fixed blade 13 are incorporated.

The head unit 3 is assembled to the housing main body 5. Therefore, the platen unit 2 is detachably combined with the head unit 3 in association with the opening and closing operation of the printer cover 6. The head unit 3 is a unit in which a thermal head 12 and a movable blade 11 are incorporated. In the example of fig. 1, the head unit 3 is fixed to the inner plate 5b disposed adjacent to the roll paper storage 5a in a state where the thermal head 12 faces the roll paper storage 5 a.

As shown in fig. 2, when the printer cover 6 is closed and the platen unit 2 is combined with the head unit 3, the thermal head 12 is pressed against the platen roller 10. At this time, the movable blade 11 and the fixed blade 13 are positioned at predetermined positions (cutting positions).

As shown in fig. 3, the platen unit 2 includes a platen roller 10, a fixed blade 13, a platen frame 21, and a sub-frame 22.

The platen roller 10 is configured as follows: at the closed position of the printer cover 6, when the platen unit 2 is combined with the head unit 3, the outer peripheral surface comes into contact with the thermal head 12 in a state of sandwiching the recording paper P therebetween (refer to fig. 2). The platen roller 10 includes a platen shaft 27 extending in the left-right direction. A roller body (not shown) made of rubber or the like is attached to the platen shaft 27.

Bearings 29 are externally fitted to both ends of the platen shaft 27, respectively. Each bearing 29 is held by the shaft support portion 24 of the platen frame 21. The platen roller 10 is rotatably supported by the platen frame 21 via a bearing 29. As shown in fig. 4, a platen gear 31 is attached to the right end of the platen shaft 27.

The fixed blade 13 is formed in a plate shape extending in the left-right direction. The fixed blade 13 is disposed on the upper surface of the platen frame 21. The fixed blade 13 is fixed to the coupling portion 25 of the platen frame 21 in a state where the blade edge thereof faces rearward.

The platen frame 21 supports the platen roller 10 and the fixed blade 13. The platen frame 21 has a U-shape opened downward in a front view seen from the front-rear direction. The platen frame 21 includes: a pair of shaft support portions 24 (see fig. 3) positioned at both ends in the left-right direction; and coupling portions 25 extending in the left-right direction and bridged between the shaft supporting portions 24.

As shown in fig. 3, a bearing 29 of the platen roller 10 is held at the rear end of each shaft support portion 24. A projecting piece 26 projecting to the left outside is formed at the lower end of the left-side shaft support 24 of the shaft supports 24.

As shown in fig. 4, the sub-frame 22 supports the platen frame 21. The sub-frame 22 is larger than the imprint frame 21. The sub-frame 22 surrounds the platen frame 21 from above and from both sides in the left-right direction. The sub-frame 22 includes: a pair of side wall portions 33 located on both sides in the left-right direction; and a base portion 34 extending in the left-right direction and bridging between the respective side wall portions 33. The bearings 29 of the platen roller 10 are loosely inserted into the rear end portions of the side wall portions 33, respectively. The platen unit 2 is attached to the printer cover 6 (see fig. 1) via a sub-frame 22.

The pressing mechanism 37 is interposed between the platen frame 21 and the sub-frame 22, and applies force (presses) to the platen frame 21 in a direction away from (downward of) the sub-frame 22 around the platen shaft 27. For example, the pressing mechanism 37 is constituted by a coil spring or the like extending in the up-down direction. The pressing mechanism 37 is provided at the left end of the imprint unit 2. The upper end of the pressing mechanism 37 is coupled to the coupling portion 25 of the platen frame 21. The lower end portion of the pressing mechanism 37 is coupled to the sub-frame 22. The pressing mechanism 37 may be provided at least one of the left and right ends of the platen unit 2.

As shown in fig. 4, the head unit 3 includes a head block 38, a movable blade 11, a head frame 41, and a guide member 43.

The head block 38 is provided with a head support 56 and the thermal head 12. The head support 56 is rotatably supported by a rotation shaft 55 provided in the head frame 41. The rotation shaft 55 extends in the left-right direction. Both ends of the rotating shaft 55 are supported by the

side walls

41a and 41b, respectively. As shown in fig. 3, a release lever 61 for releasing the combination of the platen unit 2 and the head unit 3 is provided on a portion of the pivot shaft 55 located outside the left side wall portion 41 b.

The release lever 61 has a V-shape in a side view seen from the left-right direction. The top of the release lever 61 is supported to be rotatable about the rotation shaft 55. A part of the release lever 61 located on one end side with respect to the top is locked to a member (not shown) provided in the housing main body 5. A portion of the release lever 61 on the other end side with respect to the top portion can abut against the projecting piece 26 of the platen frame 21 from below. The biasing member 60 is interposed between the release lever 61 and the side wall portion 41b, and biases the release lever 61 in a direction away from the protruding piece 26.

For example, the release lever 61 rotates in conjunction with the operation of the lever member. By rotating the release lever 61 against the biasing force of the biasing member 60, the release lever 61 is brought into contact with the projecting piece 26 from below. The release lever 61 pushes up the platen unit 2 via the protruding piece 26 toward the upper side, thereby separating the platen unit 2 from the head unit 3.

As shown in fig. 4, the head support 56 is disposed inside the head frame 41. The head support 56 has a head support wall 62 to which the thermal head 12 is fixed. The head support wall 62 extends in the left-right direction with the front-rear direction as the thickness direction. A pair of stays (not shown) for allowing the head support 56 to rotate about the rotation shaft 55 are provided at both left and right end portions of the head support wall 62.

The head support wall 62 is provided with a stopper engagement portion 66 (see fig. 3) that is locked to the restriction portion 67 of the head frame 41. The stopper engagement portion 66 (see fig. 3) is locked to the restriction portion 67, and restricts the rotation range of the head block 38. The head urging member 65 (see fig. 3) is interposed between the head support wall 62 and the support member 47 in the front-rear direction. The head biasing member 65 (see fig. 3) biases the head block 38 (thermal head 12) toward the platen roller 10 (front).

As shown in fig. 4, the thermal head 12 is fixed to the head support 56. The thermal head 12 is fixed to the front surface of the head support wall 62 in the head support 56. The thermal head 12 is formed in a plate shape extending in the left-right direction (the paper width direction of the recording paper P). A plurality of heating elements 12a are linearly arranged on the surface of the thermal head 12.

The movable blade 11 is attached to the head frame 41 (each of the

side walls

41a and 41b) via a support member 47. The movable blade 11 includes: a movable blade frame 81; a movable blade body 82 slidably supported by the movable blade frame 81; and a drive mechanism 83 for driving the movable blade body 82.

The movable blade frame 81 is detachably attached to the support member 47. The cutting edge of the movable blade body 82 has a V-shape in a plan view viewed from the top-bottom direction. The movable blade body 82 is formed such that the length from the root to the cutting edge gradually decreases from both ends in the left-right direction toward the center.

The drive mechanism 83 includes a tool motor that can rotate in the forward and reverse directions and is mounted on the movable blade frame 81, a gear train mechanism connected between the tool motor and the movable blade body 82, and the like. The drive mechanism 83 includes a worm wheel 100 (see fig. 7) and the like. The driving force of the cutter motor is transmitted via the gear train mechanism, and the movable blade body 82 slides. The cutting edge of the movable blade body 82 can slide relative to the fixed blade 13 at the cutting position.

As shown in fig. 4, the head frame 41 supports the head block 38 and the movable blade 11. The head frame 41 has a U shape opened upward in a front view seen from the front-rear direction.

A pair of

side wall portions

41a, 41b located on both sides in the left-right direction in the head frame 41 are formed with accommodating recessed portions 44. The accommodation recess 44 is opened upward, and the width in the front-rear direction gradually decreases downward. The bearings 29 of the platen roller 10 are respectively engaged with the accommodating recesses 44 (see fig. 3). A stopper 45 is provided on the inner peripheral edge of the accommodation recess 44 so as to protrude rearward. The stopper 45 engages with the bearing 29 of the platen roller 10 from above at the closed position. Positioning recesses 46 recessed rearward are formed at the front end edges of the

side walls

41a and 41b, respectively.

A support member 47 is provided at the rear (rearward of the head block 38) of the

side walls

41a and 41 b. The support member 47 extends in the left-right direction with the vertical direction as the thickness direction. The support member 47 is erected between the

side wall portions

41a, 41 b. The support member 47 supports the head block 38 from behind and connects the movable blade 11 to the head frame 41.

The platen train mechanism 53 is provided on the right side wall portion 41a of the

side wall portions

41a and 41 b. When the platen unit 2 and the head unit 3 are combined with each other, the train mechanism for platen 53 meshes with the gear for platen 31 of the platen unit 2. The platen train mechanism 53 is connected to a platen motor 54 (see fig. 3) mounted on the head frame 41. The rotational force of the platen motor 54 (see fig. 3) is transmitted to the platen gear 31 via the platen train mechanism 53, and the platen roller 10 rotates.

The guide member 43 guides the recording sheet P to the thermal head 12. As shown in fig. 4, the guide member 43 is provided between the

side wall portions

41a, 41b in the front portion of the head frame 41. The guide member 43 includes a pair of side blocks 85 positioned on both right and left sides, and a guide block 86 bridging between the side blocks 85.

The side block 85 is disposed inside the

side walls

41a and 41b of the head frame 41 in the left-right direction. A positioning projection 87 is provided at the front end of each side block 85 so as to project outward in the left-right direction. Each positioning protrusion 87 is accommodated in the positioning recess 46 of the head frame 41 from the front.

The upper surface of the guide block 86 is recessed downward relative to the side block 85. The front surface of the guide block 86 is recessed rearward relative to the side block 85. The guide passage 91 is formed by the upper surface and the front surface of the guide block 86 in the guide member 43 and the surface located on the inner side in the left-right direction in the side block 85. The recording paper P passes through the guide path 91 toward the thermal head 12. In the closed position, the platen roller 10 is accommodated in the guide passage 91 from above. In the guide passage 91, the heat generating element 12a of the thermal head 12 is exposed from the rear.

A recess 92 recessed downward is formed in the front portion of the guide block 86. The recesses 92 are formed at both ends in the left-right direction in the guide block 86. A through hole 93 penetrating in the vertical direction is formed in the bottom wall portion of the recess 92. The through hole 93 vertically overlaps with a through hole (not shown) formed in the bottom wall portion 41c of the head frame 41. Fastening members (not shown) such as screws are inserted through these through holes. The fastening member is fastened to the housing main body 5 (see fig. 1). For example, the guide member 43 is screwed to the housing main body 5 together with the head frame 41 (see fig. 1).

The guide block 86 is provided with a paper detection sensor 97 for detecting the presence or absence of the recording paper P passing through the guide path 91. For example, the paper detection sensor 97 is a reflection-type photosensor or the like. The paper detection sensor 97 is exposed in the guide passage 91 through a detection window 98 formed in the guide block 86.

As shown in fig. 5, the movable blade frame 81 includes a worm gear housing 70 that houses a worm gear (not shown). The worm gear housing 70 includes a worm housing 71 that houses a worm (not shown) and a wheel housing 72 that houses a worm wheel 100 (see fig. 7).

The worm gear housing 70 of the movable blade frame 81 is provided with

ribs

73 and 74. In fig. 5, reference numeral 73 denotes a first rib provided in the worm gear housing 71 in the worm gear housing 70, and reference numeral 74 denotes a second rib provided in the gear housing 72, respectively.

The first rib 73 is provided so as to straddle the worm accommodating portion 71. The first rib 73 linearly extends rearward from the outer peripheral edge of the wheel accommodating portion 72. A plurality of (three in the example of fig. 5) first ribs 73 are arranged at intervals in the left-right direction. The second rib 74 is provided on the upper surface of the wheel accommodating portion 72. The second ribs 74 are formed radially with the axial center of the worm wheel 100 (see fig. 7) as the center.

A dial knob 69 (see fig. 4) for adjusting the amount of movement (stroke) of the movable blade 11 is coupled to the right end of the worm (not shown). The movable blade frame 81 includes a dial knob housing 76 that houses the dial knob 69 (see fig. 4). Reference numeral 77 in the figure denotes a clearance groove which avoids the dial knob 69 (see fig. 4). The clearance groove 77 is recessed toward the rear from the knob accommodating part 76.

An engagement claw 78 for attaching the movable blade frame 81 to the support member 47 (see fig. 4) is provided at the rear end of the movable blade frame 81. The engagement claw 78 is disposed on the right side of the knob accommodating portion 76. For example, the engagement claw 78 is fixed to the support member 47 by snap-fit (snap-fit) (see fig. 4).

The wheel housing portion 72 of the movable blade frame 81 is provided with a window portion 79 for confirming the initial position (home position) of the movable blade body 82 (movable blade). The window 79 is a through hole that penetrates the wheel housing 72 (upper wall) of the movable blade frame 81 in the vertical direction. The window 79 has a circular shape in plan view (see fig. 6). An annular rib 75 is provided around the window 79. In the example of fig. 6, the hole portion 101 of the worm wheel 100 is located at the window portion 79.

As shown in fig. 7, the worm wheel 100 is provided with a hole 101 for confirming the initial position of the movable blade body 82. Hole 101 is disposed at a position adjacent to shaft 102 in worm wheel 100. The hole 101 is disposed at a position overlapping the window 79 (see fig. 6) in the rotation direction of the worm wheel 100. Hole 101 is recessed downward from the upper surface of worm wheel 100. Reference numeral 103 in the figure denotes an annular rib having an annular shape surrounding the shaft portion 102 of the worm wheel 100. The hole portion 101 is connected to a part of the annular rib 103. In a plan view, the hole 101 has a circular shape smaller than the window 79 (see fig. 6).

As shown in fig. 8, a hole 104 for air discharge (hereinafter, also referred to as "air discharge hole 104") is provided in the worm wheel 100. The exhaust hole 104 is disposed on the opposite side of the worm wheel 100 from the hole 101 (see fig. 7) with respect to the shaft 102. A part of the exhaust hole 104 is disposed below the annular rib 103 of the worm wheel 100. A part of the exhaust hole 104 is disposed at a position overlapping the annular rib 103 when viewed in the vertical direction (axial direction) of the worm wheel 100. The annular rib 103 is not provided with the exhaust hole 104.

As shown in fig. 9, the movable blade body 82 (movable blade 11) is slidable relative to the fixed blade 13 at the cutting position. The movable blade 11 is provided with a guide portion 110, and the guide portion 110 is bent so as to be guided to be pressed against the fixed blade 13 when sliding. The guide portion 110 is linearly inclined such that the tip end of the guide portion 110 is positioned above and the base end of the guide portion 110 is positioned below. The distance G between the tip of the guide 110 and the fixed blade 13 is 0.4mm to 0.8 mm. The gap G between the tip of the guide 110 and the fixed blade 13 means the vertical gap between the cutting edge of the movable blade body 82 and the cutting edge of the fixed blade 13. For example, the gap G between the tip of the guide 110 and the fixed blade 13 is set to 0.6 mm.

Reference numeral 111 in the figure denotes a tolerance-allowable portion (play-generating portion) of the movable blade frame 81. For example, the distance G between the tip of the guide 110 and the fixed blade 13 is set in consideration of the tolerance of the movable blade frame 81.

As shown in fig. 10, the bending angle a of the guide portion 110 of the movable blade 11 is set to an acute angle. The bending angle a of the guide portion 110 means an angle formed by an imaginary straight line along the lower surface of the movable blade body 82 (an imaginary horizontal line passing through the lower surface of the movable blade body 82) and the lower surface (lower inclined surface) of the guide portion 110. The bending angle a of the guide portion 110 is 25 ° or more and 35 ° or less. For example, the bending angle a of the guide portion 110 is set to 30 °.

Next, an operation method of the thermal printer 1 will be described. For example, as shown in fig. 2, in a state where the printer cover 6 is in the closed position and the two

units

2 and 3 are combined, the movable blade 11 and the fixed blade 13 are disposed at the cutting position. At the cutting position, the recording paper P is sandwiched between the platen roller 10 and the thermal head 12. The recording paper P passes between the movable blade 11 and the fixed blade 13, and is then drawn out of the discharge port 8 to the outside of the housing 4. The platen gear 31 on the platen unit 2 side meshes with the platen train mechanism 53 on the head unit 3 side.

If the rotational force of the platen motor 54 is transmitted to the platen gear 31 of the platen unit 2, the platen roller 10 rotates. This makes it possible to feed the recording paper P while sandwiching the recording paper P between the platen roller 10 and the thermal head 12. While the recording paper P is being fed out by the rotation of the platen roller 23, the heating elements 12a of the thermal head 12 are appropriately heated, whereby various information is printed on the recording paper P.

The printed recording paper P passes between the fixed blade 13 and the movable blade 11. After the recording paper P has passed a predetermined length, the drive mechanism 83 is driven to slide the movable blade body 82 toward the fixed blade 13. This enables the recording paper P to be cut between the fixed blade 13 and the movable blade 11. The cut recording paper P can be used as a receipt, ticket, or the like.

As described above, the thermal printer 1 of the present embodiment includes the head unit 3 and the platen unit 2, the head unit 3 includes the movable blade 11 and the thermal head 12 that prints on the recording paper, the platen unit 2 includes the fixed blade 13 and the platen roller 10 that sandwiches the recording paper with the thermal head 12 and conveys the recording paper, and is detachably combined with the head unit 3, the movable blade 11 is slidable with respect to the fixed blade 13 at the cutting position, the movable blade 11 includes the guide portion 110, the guide portion 110 is bent so as to guide the pressing against the fixed blade 13 at the time of the sliding, and the gap G between the tip of the guide portion 110 and the fixed blade 13 is 0.4mm or more and 0.8mm or less.

According to the present embodiment, the movable blade 11 includes the guide portion 110, the guide portion 110 is bent so as to be pressed against the fixed blade 13 during sliding, and the distance G between the tip of the guide portion 110 and the fixed blade 13 is 0.4mm or more, thereby achieving the following effects. As compared with the case where the distance G between the tip of the guide 110 and the fixed blade 13 is less than 0.4mm, it is difficult to cause a poor pressing of the movable blade 11 against the fixed blade 13. Therefore, the tip of the movable blade 11 can be prevented from hitting the end surface of the fixed blade 13. Therefore, the occurrence of tool lock can be suppressed. The distance G between the tip of the guide 110 and the fixed blade 13 is 0.8mm or less, and the following effects are obtained. The recording paper is easier to cut than in the case where the distance G between the tip of the guide 110 and the fixed blade 13 exceeds 0.8 mm.

In the present embodiment, the bending angle a of the guide portion 110 is 25 ° or more and 35 ° or less.

According to the present embodiment, the distance G between the tip of the guide 110 and the fixed blade 13 can be easily adjusted, as compared with the case where the bending angle a of the guide 110 is less than 25 ° or exceeds 35 °. For example, the distance G between the tip of the guide portion 110 and the fixed blade 13 can be easily adjusted by shifting the bending position of the guide portion 110.

In the present embodiment, the

ribs

73 and 74 are provided in the worm gear housing 70 of the movable blade frame 81.

According to the present embodiment, since the worm gear housing portion 70 is reinforced by the

ribs

73, 74, deformation of the drive train can be suppressed when a load is applied to the drive train (for example, the drive mechanism 83) at the time of occurrence of a jam.

In the present embodiment, the movable blade frame 81 includes a knob accommodating portion 76 that accommodates the dial knob 69, and a clearance groove 77 that avoids the dial knob 69.

According to the present embodiment, interference between the dial knob 69 and the movable blade frame 81 at the time of tool locking can be suppressed by the function of the clearance groove 77.

In the present embodiment, the wheel housing portion 72 of the movable blade frame 81 is provided with a window portion 79 for confirming the initial position of the movable blade 11, and a hole portion 101 is provided at a position overlapping with the window portion 79 in the rotation direction of the worm wheel 100.

According to the present embodiment, the initial position of the movable blade 11 can be confirmed by confirming the hole 101 of the worm wheel 100 through the window 79 of the movable blade frame 81. For example, the initial position of the movable blade 11 can be confirmed when the release lever 61 is operated to release the combination of the platen unit 2 and the head unit 3.

In the present embodiment, the worm wheel 100 includes an annular rib 103 having an annular shape surrounding the shaft portion 102, and the exhaust hole 104 is provided at a position overlapping the annular rib 103 when viewed from the axial direction of the worm wheel 100, and the exhaust hole 104 is not provided in the annular rib 103.

According to the present embodiment, the exhaust holes 104 are less noticeable than in the case where the exhaust holes 104 are provided in the annular rib 103.

The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be added within a scope not departing from the gist of the present invention.

In the above-described embodiment, the case where the thermal printer 1 is used in a cash register, a portable terminal device, or the like has been described as an example, but the present invention is not limited thereto. For example, the thermal printer 1 can be applied to various thermal printers other than cash registers and portable terminal devices.

In addition, the components in the above-described embodiments can be replaced with well-known components as appropriate without departing from the scope of the present invention.

Claims

1. A thermal printer includes:

a head unit having a movable blade and a thermal head for printing on recording paper; and

a platen unit having a fixed blade and a platen roller for conveying the recording sheet by sandwiching the recording sheet with the thermal head, the platen unit being detachably combined with the head unit,

the movable blade is slidable relative to the fixed blade at the cutting position,

the movable blade is provided with a guide portion bent so as to be guided to be pressed against the fixed blade when sliding,

the interval between the top end of the guide part and the fixed blade is more than 0.4mm and less than 0.8 mm.

2. The thermal printer according to claim 1, wherein a bending angle of the guide portion is 25 ° or more and 35 ° or less.