JP2019025888A - Printing unit and thermal printer - Google Patents

Abstract

To provide a printing unit that allows pape jamming to be easily released and a thermal printer.SOLUTION: A printing unit 8 comprises a fixed blade 34, a movable blade 22, a movable blade driving mechanism, a lock releasing lever 25, and a returning mechanism 26. The fixed blade is provided in a platen unit. The movable blade is provided in a head unit. The movable blade driving mechanism moves the movable blade to a cutting position P1 and to a stand-by position P2. The cutting position is a position where the movable blade runs on the fixed blade. The stand-by position is a position where the movable blade is separated from the fixed blade. The returning mechanism moves the movable blade to the stand-by position before releasing lock of a printer cover in interlock with the lock releasing lever 25.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a printing unit and a thermal printer.

For example, a thermal printer is provided with a printing unit. The printing unit cuts the paper with the movable blade and the fixed blade by moving the movable blade from the standby position to the cutting position. By moving the movable blade to the cutting position, a paper jam (that is, a paper jam) occurs between the movable blade and the fixed blade, and the movable blade may stop at the position where the movable blade rides on the fixed blade. .
In this case, a configuration is known in which a clearance is opened between the movable blade and the fixed blade by operating an operation lever in order to release the paper jam. The paper jam load is removed by providing a gap between the movable blade and the fixed blade. By removing the paper jam load, the movable blade can be returned to the home position (hereinafter referred to as a standby position) by the restoring force of the spring (see, for example, Patent Document 1).

JP 2014-40077 A

By the way, in the configuration in which a gap is provided between the fixed blade and the movable blade, it is difficult to completely remove the load of the paper jam when a paper jam larger than the gap occurs. For this reason, even if a clearance is provided between the fixed blade and the movable blade by a single operation of the operation lever, the movable blade may not return. In this case, it is necessary to release the paper jam by operating the operation lever many times, and it can be said that the paper jam release property is low.
Further, if the paper jam cannot be released, the state where the movable blade stops at the position where the movable blade rides on the fixed blade cannot be resolved. Therefore, the cover of the printer to which the fixed blade is attached cannot be opened. That is, the fixed blade and the movable blade cannot be exposed to the outside. For this reason, when a paper jam larger than the gap occurs, it is difficult to eliminate the paper jam, and there remains room for improvement from this viewpoint.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a printing unit and a thermal printer that can easily release a paper jam.

  In order to solve the above problems, a printing unit according to one aspect of the present invention includes a head unit having a thermal head for printing on recording paper and a platen roller for conveying the recording paper, and is separable into the head unit. , A fixed blade provided on one of the head unit and the platen unit, and provided on one of the other of the head unit and the platen unit, and slide-moves with respect to the fixed blade. A movable blade, a drive mechanism for sliding the movable blade between a standby position away from the fixed blade and a cutting position on the fixed blade, and unlocking the platen unit with respect to the head unit In a state where the unlocking lever and the movable blade are stopped at the cutting position In conjunction with the unlocking lever, characterized in that and a return mechanism for moving the movable blade to the standby position before unlocking of the platen unit.

According to this configuration, the lock release lever is interlocked with the return mechanism before the platen unit is unlocked. By operating the return mechanism with the lock release lever, the movable blade can be reliably returned to the standby position by the return mechanism. Thus, by reliably returning the movable blade to the standby position, the paper jam generated between the fixed blade and the movable blade can be easily released.
Further, by interlocking the lock release lever for releasing the lock of the platen unit with the return mechanism, the lock release lever can also be used as a paper jam removing lever. Thereby, the increase in the number of parts can be suppressed, and the configuration can be simplified.

  In the above aspect, the return mechanism may include a return rack formed in a drive rack of the drive mechanism, and a return pinion that meshes with a rack tooth of the return rack and can be interlocked with the lock release lever. .

According to this configuration, the return pinion is engaged with the rack teeth of the return rack. In addition, the unlocking lever can be linked to the return pinion. Therefore, by operating the lock release lever, the return rack can be reliably returned to the standby position by the return pinion.
Here, the return rack is formed in the drive rack. A movable blade is attached to the drive rack. Thus, by operating the lock release lever, the movable blade can be reliably returned to the standby position by the return pinion and the return rack.

  A return rack was formed on the drive rack of the drive mechanism. Therefore, the drive rack and the return rack can be integrally formed, and the return rack can be provided without increasing the number of parts. Thereby, the configuration of the printing unit and the thermal printer can be simplified, and the cost can be reduced.

  In the above aspect, the return mechanism is rotatably supported so as to mesh with the sun gear and the first gear and the sun gear that are coaxially and rotatably supported at the rotation center of the lock release lever, and the lock release. A planetary gear that revolves following the movement of the lever and an internal gear that meshes with the planetary gear may be provided, and the first gear may be formed so as to be able to mesh with the return pinion.

According to this configuration, when the lock release lever rotates, the planetary gear revolves following the movement of the lock release lever. When the planetary gear revolves, the planetary gear rotates (rotates) while meshing with the internal gear. The sun gear rotates as the planetary gear rotates. The first gear rotates together with the sun gear.
As described above, the first gear individually rotates with respect to the lock release lever, so that a large rotation amount of the first gear can be ensured with respect to the stroke amount of the lock release lever. Therefore, it is possible to secure the amount of rotation of the first gear necessary for returning the movable blade to the standby position while keeping the stroke amount of the lock release lever small. Thereby, the operativity of a lock release lever is securable favorably.

  In the above aspect, the return rack meshes with the return pinion with the return rack disposed at the cutting position, and releases the mesh with the return pinion with the return rack disposed at the standby position. Thus, you may have the rack tooth formed in the other side of the blade edge | tip of the said movable blade.

  According to this configuration, rack teeth are formed on the opposite side of the cutting edge of the movable blade. Therefore, in a state where the return rack is returned to the standby position, the engagement between the rack teeth of the return rack and the return pinion can be released. Therefore, after the movable blade is returned to the standby position, the lock release lever can be operated without moving the return rack when unlocking the platen unit. As a result, the platen unit can be unlocked while the movable blade is held at the standby position.

  In the above aspect, the return pinion may be rotatably provided on a support shaft of the drive pinion of the drive mechanism that meshes with the drive rack.

  According to this configuration, the return pinion is provided rotatably on the support shaft of the drive pinion. Therefore, when the movable blade is in the standby position, even if the lock release lever is operated, the power generated by the lever operation is not transmitted to the drive mechanism and the movable blade. Thereby, when the lock release lever is operated in a state where an error such as a paper jam has not occurred, the platen unit can be unlocked while the movable blade is held at the standby position.

  In the above aspect, one of the pinion teeth may be removed from the return pinion.

  According to this configuration, by removing one of the pinion teeth of the return pinion, a large interval between two adjacent pinion teeth can be secured. Therefore, when the pinion teeth are meshed with the rack teeth, it is possible to suppress the tip of the pinion teeth from being abutted with the tip of the rack teeth. Accordingly, the pinion teeth can be smoothly meshed with the rack teeth.

  In the above aspect, the first gear may have a first tooth portion that can first mesh with the return pinion and can be retracted radially inward.

Here, the return pinion is rotatably supported. Therefore, when the 1st tooth part of the 1st gear meshes with the return pinion, it is possible that the blade edge of a return pinion is arranged in the position which contacts the blade edge of the 1st tooth part. When the cutting edge of the first tooth portion contacts the cutting edge of the return pinion, the rotation of the first gear may be blocked by the returning pinion.
Therefore, in this configuration, the first tooth portion of the first gear is configured to be retractable radially inward. Therefore, when the cutting edge of the first tooth portion contacts the cutting edge of the return pinion, the first tooth portion can be retracted radially inward. Thereby, a 1st tooth part can get over the blade edge | tip of a return pinion. The first tooth portion that has passed over the cutting edge of the return pinion comes into contact with the side surface of the next tooth portion of the return pinion. Therefore, the return pinion can be rotated by the first tooth portion (that is, the first gear).

  In order to solve the above problems, a thermal printer according to an aspect of the present invention is a thermal printer having a printing unit according to any one of claims 1 to 5, wherein the recording paper accommodates the recording paper. The movable blade is provided in a printer main body having a storage portion, and the fixed blade is provided in a printer cover that is rotatably connected to the printer main body and opens and closes the recording paper storage portion. To do.

According to this configuration, the thermal printer includes the printing unit according to the above aspect. Therefore, it is possible to provide a thermal printer that can easily release the paper jam generated between the fixed blade and the movable blade by surely returning the movable blade to the standby position.
In the thermal printer according to one aspect of the present invention, the lock release lever that unlocks the platen unit is linked to the return mechanism, so that the lock release lever can also be used as a paper jam removal lever. Thereby, the increase in the number of parts can be suppressed, and the configuration can be simplified.
Furthermore, a fixed blade was provided on the printer cover, and a movable blade was provided on the printer body. Therefore, it is not necessary to provide a drive mechanism for driving the movable blade in the printer cover. As a result, the weight of the printer cover can be reduced, and the operability when opening and closing the printer cover can be secured satisfactorily.

  According to the printing unit and the thermal printer of one aspect of the present invention, the return mechanism can be operated with the lock release lever, and the movable blade can be reliably returned to the standby position with the return mechanism. Thereby, the paper jam which generate | occur | produced between the fixed blade and the movable blade can be canceled easily.

It is a perspective view which shows the state which closed the printer cover of the thermal printer which concerns on 1st Embodiment of this invention in the closed position. It is a perspective view showing the state where the printer cover of the thermal printer concerning a 1st embodiment of the present invention was opened to the open position. It is the perspective view which looked at the printing unit of the thermal printer which concerns on 1st Embodiment of this invention from the downward direction. FIG. 3 is a perspective view illustrating a state in which the recording paper is cut between the movable blade and the fixed blade of the printing unit according to the first embodiment of the present invention. It is a side view which shows the state which looked at the printing unit which concerns on 1st Embodiment of this invention from the V arrow direction of FIG. It is sectional drawing which follows the VI-VI line of FIG. 3 which shows the printing unit which concerns on 1st Embodiment of this invention. It is explanatory drawing explaining the operation | movement which a paper jam generate | occur | produces between the movable blade and fixed blade of the printing unit which concerns on 1st Embodiment of this invention. It is explanatory drawing explaining the operation | movement which returns the movable blade of the printing unit which concerns on 1st Embodiment of this invention to a standby position. It is explanatory drawing explaining the operation | movement which cancels | releases the lock | rock of the platen unit and head unit of the thermal printer which concerns on 1st Embodiment of this invention. It is the perspective view which looked at the printing unit of the thermal printer which concerns on 2nd Embodiment of this invention from the downward direction. It is sectional drawing which follows the XI-XI line of FIG. 10 which shows the printing unit which concerns on 2nd Embodiment of this invention. It is explanatory drawing explaining the operation | movement which a paper jam generate | occur | produces between the movable blade and fixed blade of the printing unit which concerns on 2nd Embodiment of this invention. It is explanatory drawing explaining the operation | movement which meshes | engages the 1st tooth part of the 1st gearwheel which concerns on 2nd Embodiment of this invention with a return pinion. It is explanatory drawing explaining operation | movement which the 1st tooth part of the 1st gearwheel concerning 2nd Embodiment of this invention gets over the blade edge | tip of a return pinion. It is explanatory drawing explaining the operation | movement with which the 1st tooth part which got over the blade edge | tip of the pinion tooth of the return pinion which concerns on 2nd Embodiment of this invention contact | abuts the side surface of the next pinion tooth. It is explanatory drawing explaining the operation | movement which returns the movable blade of the printing unit which concerns on 2nd Embodiment of this invention to a standby position. It is explanatory drawing explaining the operation | movement which cancels | releases the lock | rock of the platen unit and head unit of the thermal printer which concerns on 2nd Embodiment of this invention.

Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
<Configuration of thermal printer>
FIG. 1 is a perspective view showing the thermal printer 1 in a closed position of the printer cover 3. FIG. 2 is a perspective view showing the thermal printer 1 in the open position of the printer cover 3.
As shown in FIGS. 1 and 2, the thermal printer 1 prints on a recording paper P (thermal paper, paper) drawn from the roll paper R, and uses the recording paper P as a ticket, a receipt, or the like. It is a printer that can. The thermal printer 1 includes a casing (printer body) 2, a printer cover 3, a platen unit 4 provided on the printer cover 3 side, and a head unit 5 provided on the casing 2 side.
The platen unit 4 and the head unit 5 constitute a printing unit 8.

  In the embodiment, in the closed position of the printer cover 3 shown in FIG. 1, the lower left side (printer cover 3 side) is the front (arrow FW direction) and the upper right side (casing 2 side) is the rear (arrow) with respect to the paper surface. BA direction), the upper side is the upper side, and the lower side is the lower side. The recording paper P is discharged to the front FW. Furthermore, let the direction orthogonal to the front-back direction L1 and the up-down direction L2 be the left-right direction L3. Therefore, depending on each figure, each direction may be reversed.

(casing)
The casing 2 is formed in a cube shape that opens to the front FW by appropriately combining a resin material, a metal material, or a combination thereof. The casing 2 includes a frame body serving as a basic skeleton and an exterior cover that covers the frame body.
Inside the casing 2, a recording paper storage unit 10 that stores the roll paper R is formed, and when the printer cover 3 is opened, the recording paper storage unit 10 is opened.
The recording paper storage unit 10 has a box shape that opens toward the front FW formed by a part of the frame body described above, and the roll paper R is stored in a state in which the width direction coincides with the left-right direction L3. Is done.

A first rotating shaft 11 extending along the left-right direction L3 is disposed at the lower portion of the opening edge of the casing 2. A printer cover 3 is connected to the first rotation shaft 11 so as to be rotatable with respect to the casing 2. The printer cover 3 has an angular range of about 90 degrees between a closed position (the position shown in FIG. 1) that closes the opening of the casing 2 and an open position (the position shown in FIG. 2) that opens the opening of the casing 2. Rotate. As a result, the opening of the casing 2 (that is, the recording paper storage unit 10) is opened and closed by the printer cover 3.
When the printer cover 3 is in the open position, the recording paper storage unit 10 is opened, and for example, roll paper R can be loaded into the recording paper storage unit 10 (so-called drop-in method).

Further, the thermal printer 1 is configured such that a slight gap is left between the front end portion of the printer cover 3 and the casing 2 in the closed position of the printer cover 3. The recording paper P is drawn out from the inside of the casing 2 to the front FW using this gap. Therefore, the slight gap functions as the discharge port 12 for the recording paper P.
The casing 2 and the printer cover 3 are locked in a state where the platen unit 4 and the head unit 5 are combined in the closed position.
Furthermore, the combination of the platen unit 4 and the head unit 5 is released at the corner located on one side of the left-right direction L3 among the corners located on the upper front side of the casing 2, and the printer cover 3 is opened. An operation lever 13 for performing the above is provided.

(Printing unit)
FIG. 3 is a perspective view of the printing unit 8 as viewed from below.
As shown in FIGS. 2 and 3, the head unit 5 is a unit in which a thermal head (not shown) and the movable blade 22 are mainly incorporated, and is disposed on the upper front side in the casing 2. The head unit 5 is fixed on an internal plate extending downward from the upper surface of the casing 2, and is held at the front FW from the recording paper storage unit 10.

The head unit 5 includes a head frame 23, a thermal head, a movable blade 22, a movable blade drive mechanism (drive mechanism) 24, a lock release lever 25, a return mechanism 26, and a lock release mechanism 27. Yes.
The head frame 23 is, for example, a metal frame. The thermal head has a plurality of heating elements arranged in a line along the left-right direction L3.

The platen unit 4 is attached to the upper portion of the inner surface of the printer cover 3 at a position overlapping the reinforcing member 31 in the front-rear direction L1 and is detachably combined with the head unit 5 as the printer cover 3 is opened and closed. Specifically, the platen unit 4 includes a platen roller 33, a fixed blade 34, and a platen frame 35.
The platen roller 33 is a roller that conveys the recording paper P to the outside of the printer cover 3. The fixed blade 34 is provided inside the printer cover 3 and is disposed on the front FW with respect to the platen roller 33. The platen frame 35 is a frame that supports the platen roller 33 and the fixed blade 34.
Thus, the fixed blade 34 is provided on the printer cover 3. Therefore, it is not necessary to provide the movable cover driving mechanism 24 for driving the movable blade 22 in the printer cover 3. As a result, the weight of the printer cover 3 can be reduced, and the operability when opening and closing the printer cover 3 can be secured satisfactorily.

As shown in FIGS. 1 and 2, according to the printing unit 8 of the thermal printer, the thermal head of the head unit 5 is formed in a plate shape extending in the left-right direction L3 (width direction of the recording paper P). ing. The thermal head has a plurality of heating elements arranged in a line along the left-right direction L3. Printing is performed on the recording paper P by the thermal head.
The thermal head faces the platen roller 33 when the printer cover 3 is closed, and the recording paper P is disposed between the thermal head and the platen roller 33 so that the recording paper P can pass therethrough.

  Further, a coil spring is disposed between the thermal head and the platen roller 33 to urge the thermal head downward (on the platen roller 33 side). As a result, the thermal head can be reliably pressed against the recording paper P delivered by the platen roller 33, and good printing by the printing unit 8 is possible.

FIG. 4 is a diagram showing a state in which the recording blade P is cut between the fixed blade 34 and the movable blade 22 by sliding the movable blade 22.
As shown in FIGS. 3 and 4, the movable blade 22 is provided on the casing 2 (see FIG. 2) via a movable blade drive mechanism 24. The movable blade 22 is disposed so as to face the fixed blade 34 in the front-rear direction L1 when the head unit 5 and the platen unit 4 are combined in the closed position of the printer cover 3 (see FIG. 1). . The movable blade 22 is a V-shaped blade formed so that the length from the root 22a to the blade tip 22b gradually decreases from both ends toward the center.
The movable blade 22 is attached to a drive rack 46 of the movable blade drive mechanism 24 via a movable blade holder 29. The movable blade 22 is configured to be slidable in the vertical direction L2 with respect to the head frame 23 by the operation of the movable blade drive mechanism 24.
That is, the movable blade 22 is supported so as to be slidable with respect to the fixed blade 34.

FIG. 5 is a view taken in the direction of arrow V in FIG.
As shown in FIGS. 3 and 5, the movable blade drive mechanism 24 is a mechanism that moves the movable blade 22 between the cutting position P1 and the standby position P2. The cutting position P <b> 1 is a cutting in which the movable blade 22 rides on the fixed blade 34 and the movable blade 22 cuts the recording paper P together with the fixed blade 34. The standby position P <b> 2 is a position where the movable blade 22 is separated from the fixed blade 34.
Specifically, the movable blade drive mechanism 24 includes a drive motor M1, first to fourth drive teeth 41 to 44, a drive pinion 45, and a drive rack 46.

The drive motor M1 is a motor that can rotate forward and backward. The first drive teeth 41 are connected to the drive shaft of the drive motor M1. The first drive teeth 41 are connected to the drive pinion 45 via the second to fourth drive teeth 42 to 44.
The drive pinion 45 is coaxially attached to a pinion support shaft (support shaft) 48. The pinion support shaft 48 rotates together with the drive pinion 45. A pair of drive pinions 45 are provided in the left-right direction L3. The pair of drive pinions 45 are meshed with the drive rack 46 in the left-right direction L3. The pair of drive pinions 45 are connected by a pinion support shaft 48.

The drive rack 46 is formed with a plurality of drive rack teeth 47 from an end (upper end) 46a on the standby position P2 side to an end (lower end) 46b on the cutting position P1 side. In other words, the drive rack 46 has drive rack teeth 47 formed in the entire area of the drive rack 46.
The drive rack 46 is attached to both end portions along the left-right direction L3 of the movable blade holder 29, and extends along the up-down direction L2. That is, the movable blade 22 is attached to the drive rack 46 via the movable blade holder 29.
Hereinafter, in order to facilitate understanding of the configuration, the drive pinion 45 and the drive rack 46 on the drive motor M1 side will be described in detail, and the detailed description of the drive pinion 45 and the drive rack 46 on the opposite side of the drive motor M1 will be omitted. .

When the drive motor M1 rotates forward, the rotation of the drive motor M1 is transmitted to the drive pinion 45 through the first to fourth drive teeth 41 to 44. The drive pinion 45 rotates in the direction of arrow A, and the drive rack 46 moves in the direction of arrow B together with a return rack 58 (described later) of the return mechanism 26.
As the drive rack 46 moves, the movable blade 22 moves linearly in the direction of arrow B together with the drive rack 46. That is, the movable blade 22 moves to the cutting position P1.

  On the other hand, when the driving motor M1 is reversely rotated, the rotation of the driving motor M1 is transmitted to the driving pinion 45 through the first to fourth driving teeth 41 to 44. The drive pinion 45 rotates in the direction of arrow C, and the drive rack 46 moves in the direction of arrow D. As the drive rack 46 moves, the movable blade 22 moves linearly in the direction of arrow D together with the drive rack 46. That is, the movable blade 22 moves to the standby position P2.

  The lock release lever 25 is rotatably supported on the side wall portion 23a of the head frame 23 via a lever support shaft 51. Specifically, the lock release lever 25 can be pushed backward. Yes. The distal end portion 25 a of the lock release lever 25 is fitted inside the coupling body 16 (see FIG. 2) in the operation lever 13. The lock release lever 25 is operated in conjunction with the turning operation of the operation lever 13 (see FIG. 2).

That is, the lock release lever 25 is rotated in the direction of arrow E by rotating the operation lever 13 from the lock position to the release position. A first gear 54 and a second gear 55 are formed at the base end portion 25 b of the lock release lever 25.
The first gear 54 is a member that constitutes a part of the return mechanism 26. The second gear 55 is a member that constitutes a part of the lock release mechanism 27.

6 is a cross-sectional view taken along line VI-VI in FIG.
As shown in FIGS. 3 and 6, the return mechanism 26 is a mechanism that returns the movable blade 22 from the cutting position P1 to the standby position P2. Specifically, the return mechanism 26 includes a first gear 54, a return pinion 57, and a return rack 58.
The first gear 54 is formed at the upper end of the base end portion 25 b of the lock release lever 25. A return pinion 57 is disposed on the front upper side of the first gear 54. The return pinion 57 is rotatably supported by the pinion support shaft 48 and is disposed coaxially adjacent to the drive pinion 45. Specifically, the return pinion 57 is arranged along the side surface of the drive pinion 45 on the center side of the casing 2 (see FIG. 2) of the drive pinion 45 in the left-right direction L3.
The return pinion 57 is formed so as to be able to mesh with the first gear 54.

A return rack 58 is disposed in front of the return pinion 57 and engageable with the return pinion 57. The return rack 58 is integrally formed along the side surface of the drive rack 46 on the center side of the casing 2 (see FIG. 2) of the drive rack 46 in the left-right direction L3.
By forming the return rack 58 integrally with the drive rack 46, the return rack 58 can be provided without increasing the number of parts. Thereby, the structure of the printing unit 8 (that is, the thermal printer 1) can be simplified, and the cost can be reduced.

The return rack 58 is formed in the same manner as the drive rack 46, and the number of teeth of the drive rack teeth 47 is different from that of the drive rack 46. In other words, the drive rack 46 has drive rack teeth 47 formed in the entire area of the drive rack 46. On the other hand, the return rack 58 is formed with return rack teeth (rack teeth) 59 from an end (upper end) 58a of the movable blade 22 on the side opposite to the cutting edge 22b to a substantially central portion 58b of the return rack 58.
That is, the return rack 58 is formed with return rack teeth 59 only on the side opposite to the cutting edge 22 b of the movable blade 22. The return rack teeth 59 have the same tooth profile as the drive rack teeth 47 of the drive rack 46, and are formed on the same extension line as the drive rack teeth 47.

By forming the return rack teeth 59 of the return rack 58 only on the opposite side of the cutting edge 22b of the movable blade 22, the return rack 58 with respect to the return rack teeth 59 in the state where the return rack 58 is disposed at the standby position P2. The engagement of the return pinion 57 is released (see FIG. 8).
On the other hand, in a state where the return rack 58 is disposed at the cutting position P <b> 1, the return rack teeth 59 of the return rack 58 are kept engaged with the return pinion 57.

According to the return mechanism 26, the first gear 54 meshes with the return pinion 57 by rotating the lock release lever 25 in the direction of arrow E. In this state, the return pinion 57 rotates in the direction of arrow F by continuously rotating the lock release lever 25. As the return pinion 57 rotates, the return rack 58 moves in the direction of arrow G together with the drive rack 46. The movable blade 22 moves in the arrow G direction together with the return rack 58.
In this manner, the movable blade 22 can be moved in the direction of the arrow G (that is, the standby position P2) in conjunction with the turning operation of the lock release lever 25 in the direction of the arrow E.

Here, in the return pinion 57, one tooth (pinion tooth 57a) between the adjacent pinion teeth 57a is removed from among the plurality of pinion teeth 57a. Thus, by removing one tooth between the adjacent pinion teeth 57a, a large interval between the adjacent pinion teeth 57a is secured.
Therefore, when the pinion teeth 57 a are engaged with the return rack teeth 59, it is possible to suppress the tip of the pinion teeth 57 a from being abutted with the tip of the return rack teeth 59. Accordingly, the pinion teeth 57a can be smoothly meshed with the return rack teeth 59.
As another example, for example, a return pinion 57 having a shape in which one tooth between adjacent pinion teeth 57a is not removed can be used.

  The return pinion 57 is rotatably supported by the pinion support shaft 48. Therefore, when the movable blade 22 is in the standby position P2, even if the lock release lever 25 is operated, the power generated by the lever operation of the lock release lever 25 is not transmitted to the movable blade drive mechanism 24 and the movable blade 22. Thus, for example, when the lock release lever 25 is operated in a state where an error such as a paper jam (that is, paper jam) has not occurred, only unlocking of the platen unit 4 (see FIG. 2) can be realized. it can.

Further, a second gear 55 of the lock release mechanism 27 is formed at the base end portion 25 b of the lock release lever 25. The unlock mechanism 27 is a mechanism that unlocks the printer cover 3 (see FIG. 1) in conjunction with the rotation of the unlock lever 25. In other words, the lock of the platen unit 4 with respect to the head unit 5 is released by the lock release lever 25.
Specifically, the lock release mechanism 27 includes a second gear 55 and a release plate 62.
On the side wall 23 a side of the head frame 23, a release plate 62 is rotatably supported via a plate support shaft 66 behind the second gear 55. The release plate 62 includes a release gear 63 and a release cam 64.

  The release gear 63 is formed so as to be able to mesh with the second gear 55 of the lock release lever 25. The release cam 64 is a cam that is formed integrally with the release gear 63 and releases the combination of the head unit 5 and the platen unit 4 (see FIG. 2). The release cam 64 protrudes downward from the rotation center of the release plate 62 (that is, the plate support shaft 66).

According to the lock release mechanism 27, the lock release lever 25 is rotated in the direction of arrow E, and the second gear 55 meshes with the release gear 63. In this state, when the lock release lever 25 is continuously rotated, the release gear 63 rotates in the arrow H direction. As the release gear 63 rotates, the release cam 64 swings in the arrow H direction together with the release gear 63.
As the release cam 64 swings, the release cam 64 engages with the cam follower 71 on the platen unit 4 (see FIG. 2) side. When the release cam 64 is engaged with the cam follower 71, the cam follower 71 is pushed out in a direction in which the lock pin 72 is detached from the recess 73. When the lock pin 72 is detached from the recess 73, the combination of the platen unit 4 and the head unit 5 (see FIG. 2) is released.

  Here, when the lock release lever 25 is operated to unlock the printer cover 3, the drive pinion 45 can be kept in a non-rotating state (stopped state). As a result, the printer cover 3 can be unlocked while the movable blade 22 is held at the standby position P2.

Next, an example of returning the movable blade 22 to the standby position P2 by the return mechanism 26 when a paper jam 81 occurs between the movable blade 22 and the fixed blade 34 of the thermal printer 1 will be described with reference to FIGS. To do.
Here, the lock release lever 25 that operates the return mechanism 26 is interlocked with the operation lever 13 (see FIG. 2). However, in FIGS. 7 and 8, the operation of the return mechanism 26 will be described from the operation of the lock release lever 25 in order to facilitate understanding of the operation of the return mechanism 26.

FIG. 7 is an explanatory diagram for explaining an operation of generating a paper jam (paper jam) 81 between the movable blade 22 and the fixed blade 34.
As shown in FIG. 7, the movable blade 22 is slid to the cutting position P <b> 1 to cut the recording paper P between the fixed blade 34 and the movable blade 22. In this state, it is conceivable that a paper jam 81 occurs between the movable blade 22 and the fixed blade 34. It is conceivable that when the paper jam 81 occurs, the movable blade 22 stops at the position where the movable blade 22 rides on the fixed blade 34.

When the movable blade 22 stops, the lock release lever 25 is rotated in the direction of arrow I. The first gear 54 moves in the direction of arrow J toward the return pinion 57 and meshes with the return pinion 57. In this state, when the lock release lever 25 is continuously rotated, the return pinion 57 is rotated in the direction of the arrow K by the first gear 54. As the return pinion 57 rotates, the return rack 58 moves in the arrow L direction.
When the return rack 58 moves, the movable blade 22 moves in the arrow L direction together with the return rack 58.

FIG. 8 is an explanatory diagram for explaining the operation of returning the movable blade 22 to the standby position.
As shown in FIG. 8, the movable blade 22 is moved in the direction of arrow L by the rotation of the return pinion 57 to return to the standby position P2.
Thus, the return pinion 57 was engaged with the return rack teeth 59 of the return rack 58. Further, the lock release lever 25 can be interlocked with the return pinion 57. Therefore, by operating the lock release lever 25, the return rack 58 can be reliably returned to the standby position P2 by the return pinion 57.
Here, the return rack 58 is formed integrally with the drive rack 46 (see FIG. 5). The movable blade 22 is attached to the drive rack 46. Thus, by operating the lock release lever 25, the movable blade 22 can be reliably returned to the standby position P2 by the return pinion 57 and the return rack 58.

Incidentally, the return rack 58 has return rack teeth 59 formed only on the side opposite to the cutting edge 22b of the movable blade 22. Therefore, in a state where the movable blade 22 has returned to the standby position P2, the return pinion 57 is detached from the return rack teeth 59 of the return rack 58. That is, the engagement of the return pinion 57 with the return rack tooth 59 of the return rack 58 is released.
Therefore, after the movable blade 22 is returned to the standby position P2, the lock release lever 25 can be operated without moving the return rack 58 when unlocking the printer cover 3 (see FIG. 1). As a result, the printer cover 3 can be unlocked while the movable blade 22 is held at the standby position P2.

Next, an example in which the lock of the printer cover 3 of the thermal printer 1 is released by the lock release mechanism 27 will be described with reference to FIGS.
Also in FIG. 9, the operation of the return mechanism 26 will be described from the operation of the lock release lever 25 in order to facilitate understanding of the operation of the lock release mechanism 27.
FIG. 9 is an explanatory diagram for explaining the operation of releasing the lock between the platen unit and the head unit.

As shown in FIG. 9, in a state where the movable blade 22 is returned to the standby position P2, the lock release lever 25 is continuously rotated in the arrow I direction. By rotating the lock release lever 25, the second gear 55 moves in the direction of arrow M and meshes with the release gear 63.
In this state, when the lock release lever 25 is further rotated, the release gear 63 rotates in the arrow N direction. As the release gear 63 rotates, the release cam 64 swings in the arrow N direction together with the release gear 63.

  As the release cam 64 swings, the release cam 64 engages with the cam follower 71 on the platen unit 4 (see FIG. 2) side. When the release cam 64 is engaged with the cam follower 71, the cam follower 71 is pushed out in a direction in which the lock pin 72 is detached from the recess 73. When the lock pin 72 is detached from the recess 73, the lock of the combined state of the platen unit 4 and the head unit 5 (see FIG. 2) is released.

  As shown in FIG. 2, the printer cover 3 is opened with the first rotation shaft 11 as an axis in a state where the lock between the platen unit 4 and the head unit 5 is released. As a result, the recording paper storage unit 10 is opened, and the paper jam 81 (see FIG. 8) can be removed.

As described in FIGS. 2 and 7 to 9, the lock release lever 25 is interlocked with the return mechanism 26 before unlocking the printer cover 3 (specifically, the platen unit 4). By operating the return mechanism 26 with the unlock lever 25, the return mechanism 26 can reliably return the movable blade 22 to the standby position P2. Thus, the thermal printer 1 that can easily release the paper jam 81 generated between the fixed blade 34 and the movable blade 22 is obtained by surely returning the movable blade 22 to the standby position P2.
Further, by interlocking the lock release lever 25 for releasing the lock of the printer cover 3 with the return mechanism 26, the lock release lever 25 for releasing the lock of the printer cover 3 can also be used as a lever for removing the paper jam 81. Thereby, the increase in the number of parts of the printing unit 8 (that is, the thermal printer 1) can be suppressed, and the configuration can be simplified.

Here, the distal end portion 25 a of the lock release lever 25 is fitted inside the coupling body 16 in the operation lever 13. Therefore, the lock release lever 25 is operated in conjunction with the turning operation of the operation lever 13.
By rotating the operation lever 13 from the lock position to the release position, the lock release lever 25 is rotated backward in conjunction with the operation lever 13. Therefore, the return mechanism 26 and the lock release mechanism 27 can be operated as described with reference to FIGS. Thus, by turning the operation lever 13 from the lock position to the release position, the return mechanism 26 and the lock release mechanism 27 can be operated to remove the paper jam 81.

  Next, the printing unit 100 according to the second embodiment will be described with reference to FIGS. In the printing unit 100 of the second embodiment, the same reference numerals are given to the same or similar members as those of the printing unit 8 of the first embodiment, and detailed description thereof is omitted.

[Second Embodiment]
FIG. 10 is a perspective view of the printing unit 100 according to the second embodiment as viewed from below. 11 is a cross-sectional view taken along line XI-XI in FIG.
As shown in FIGS. 10 and 11, the printing unit 100 is obtained by replacing the lock release lever 25 of the first embodiment with the lock release lever 102 and replacing the return mechanism 26 of the first embodiment with the return mechanism 103. Other configurations are the same as those of the printing unit 8 of the first embodiment.

The lock release lever 102 has a lever support shaft 104 supported coaxially at the rotation center of the lock release lever 102. The first gear 105 and the sun gear 107 are rotatably supported on the same axis via the lever support shaft 104. The first gear 105 and the sun gear 107 are integrally formed.
The first gear 105 and the sun gear 107 are members that constitute a part of the return mechanism 103.

  The return mechanism 103 is a mechanism that returns the movable blade 22 from the cutting position P1 to the standby position P2, similarly to the return mechanism 26 of the first embodiment. Specifically, the return mechanism 103 includes a first gear 105, a return pinion 57, a return rack 58, and an acceleration mechanism 106.

The first gear 105 is rotatably supported via the lever support shaft 104 of the lock release lever 102. The lever support shaft 104 is coaxially supported at the rotation center of the lock release lever 102. The first gear 105 includes a first tooth portion 112. The first tooth portion 112 is disposed on the arc of the first gear 105 on the end portion 105a side in the clockwise direction (arrow O).
In other words, the first tooth portion 112 forms the earliest tooth portion of the first gear 105 in the clockwise direction. That is, when the first gear 105 rotates counterclockwise, the first tooth portion 112 of the first gear 105 is returned first and meshed with the pinion 57.
After the first tooth portion 112 meshes with the return pinion 57, the first gear 105 continues to rotate counterclockwise, so that the first gear 105 behind the first tooth portion 112 continues to the return pinion 57. And mesh.

Here, the first tooth portion 112 of the first gear 105 is formed at the distal end portion 113 a of the arm portion 113. The base end portion 113 b of the arm portion 113 is connected to the base portion 105 b of the first gear 105. The base portion 105 b is formed in a circular arc shape that is coaxial with the lever support shaft 104. The arm portion 113 is formed in a curved shape at a predetermined interval on the radially outer side with respect to the base portion 105b. The arm portion 113 is formed to be elastically deformable in the radial direction of the first gear 105 with the base end portion 113b as a fulcrum.
Therefore, the first tooth portion 112 can be retracted radially inward of the first gear 105 by elastically deforming the arm portion 113 toward the base portion 105b.
The reason why the first tooth portion 112 is formed so as to be retractable radially inward of the first gear 105 will be described in detail later.

The first gear 105 is formed integrally with the sun gear 107 of the acceleration mechanism 106. The acceleration mechanism 106 includes a sun gear 107, a planetary gear 108, and an internal gear (internal gear) 109.
The sun gear 107 is provided coaxially with the first gear 105. The sun gear 107 is integrally formed on the inner surface of the first gear 105. A planetary gear 108 is disposed so as to mesh with the sun gear 107.
The planetary gear 108 is rotatably supported by the lock release lever 102 via the planetary shaft 115. The planetary shaft 115 is provided at a position offset with respect to the lever support shaft 104.
Therefore, when the lock release lever 102 rotates about the lever support shaft 104, the planetary shaft 115 (that is, the planetary gear 108) revolves around the lever support shaft 104 following the movement of the lock release lever 102. To do.

  The planetary gear 108 is meshed with the internal gear 109. The internal gear 109 is formed in an arc shape on the inner periphery of the cover bending portion 117. The cover bending portion 117 is formed integrally with the side cover 118 that covers the side portion of the printing unit 100.

According to the return mechanism 103, the unlocking lever 102 rotates in the operation direction around the lever support shaft 104, so that the planetary shaft 115 (that is, the planetary gear 108) follows the movement of the unlocking lever 102. Revolve around the support shaft 104.
As the planetary gear 108 revolves, the planetary gear 108 rotates (rotates) clockwise while meshing with the internal gear 109. Therefore, the sun gear 107 rotates in the counterclockwise direction. Along with the sun gear 107, the first gear 105 rotates counterclockwise.

By rotating the sun gear 107 in the counterclockwise direction by the planetary gear 108, the first gear 105 rotates in the counterclockwise direction (arrow O) together with the sun gear 107. Therefore, the rotation amount of the first gear 105 can be ensured with respect to the stroke amount of the lock release lever 102.
In this manner, the first gear 105 is supported so as to be individually rotatable with respect to the lock release lever 102. Further, since the sun gear 107 of the acceleration mechanism 106 is formed integrally with the first gear 105, a large amount of rotation of the first gear 105 can be ensured while the stroke amount of the lock release lever 102 is kept small. Thereby, when returning the movable blade 22 to the standby position P2, the operability of the lock release lever 102 can be ensured satisfactorily.

Next, an example in which the movable blade 22 is returned to the standby position P2 by the return mechanism 103 when the paper jam 81 occurs between the movable blade 22 and the fixed blade 34 of the printing unit 100 will be described with reference to FIGS. To do.
Here, the lock release lever 102 for operating the return mechanism 103 is interlocked with the operation lever 13 (see FIG. 2). However, in FIGS. 12 to 16, the operation of the return mechanism 103 will be described from the operation of the lock release lever 102 in order to facilitate understanding of the operation of the return mechanism 103.

FIG. 12 is an explanatory diagram for explaining an operation in which a paper jam (paper jam) 81 occurs between the movable blade 22 and the fixed blade 34.
As shown in FIG. 12, the movable blade 22 is slid to the cutting position P <b> 1 to cut the recording paper P between the fixed blade 34 and the movable blade 22. In this state, it is conceivable that a paper jam 81 occurs between the movable blade 22 and the fixed blade 34. It is conceivable that when the paper jam 81 occurs, the movable blade 22 stops at the position where the movable blade 22 rides on the fixed blade 34.

When the movable blade 22 stops, the lock release lever 102 is rotated in the arrow P direction. The planetary gear 108 revolves around the lever support shaft 104 in the arrow Q direction, and rotates around the planetary shaft 115 in the arrow R direction.
Therefore, the sun gear 107 rotates in the arrow S direction. As the sun gear 107 rotates, the first gear 105 rotates in the arrow S direction together with the sun gear 107.

FIG. 13 is an explanatory view for explaining the operation of engaging the first tooth portion 112 of the first gear 105 with the return pinion 57.
As shown in FIG. 13, the first gear 105 moves in the direction of arrow S toward the return pinion 57 and meshes with the return pinion 57. When the first gear 105 meshes with the return pinion 57, first, the first tooth portion 112 of the first gear 105 meshes with the return pinion 57.
Here, the return pinion 57 is rotatably supported by the pinion support shaft 48. Therefore, when the first tooth portion 112 of the first gear 105 meshes with the return pinion 57, the blade edge 57b of the pinion tooth 57a of the return pinion 57 is disposed at a position where it contacts the blade edge 112a of the first tooth portion 112. It can be considered.

FIG. 14 is an explanatory view for explaining the operation of the first tooth portion 112 of the first gear 105 getting over the cutting edge 57b of the return pinion 57.
As shown in FIG. 14, when the cutting edge 112 a of the first tooth portion 112 abuts on the cutting edge 57 b of the return pinion 57, the rotation of the first gear 105 may be blocked by the return pinion 57. Therefore, the first tooth portion 112 of the first gear 105 is formed at the distal end portion 113a of the arm portion 113. Therefore, by elastically deforming the arm portion 113, the first tooth portion 112 can be retracted in the arrow T direction toward the radially inner side of the first gear 105.
In this state, the first gear 105 rotates counterclockwise as indicated by the arrow S, and the first tooth portion 112 gets over the cutting edge 57b of the pinion tooth 57a of the return pinion 57.

FIG. 15 is an explanatory view for explaining the operation in which the first tooth portion 112 that has passed over the blade edge 57b of the pinion tooth 57a of the return pinion 57 contacts the side surface 57c of the next pinion tooth 57a.
As shown in FIG. 15, after the first tooth portion 112 has passed over the cutting edge 57 b of the pinion tooth 57 a of the return pinion 57, the first tooth portion 112 returns to the original position from the retracted position by the restoring force of the arm portion 113. . The restored first tooth portion 112 contacts the side surface (tooth surface) 57c of the next pinion tooth 57a.

The “next pinion tooth 57a” refers to the pinion tooth 57a adjacent to the rotation direction of the first tooth portion 112 (that is, the arrow S direction) with respect to the pinion tooth 57a over which the first tooth portion 112 has overcome. In other words, it refers to the pinion tooth 57a with which the first tooth portion 112 that rotates in the direction of the arrow S first contacts after the first tooth portion 112 gets over the pinion tooth 57a.
When the restored first tooth portion 112 abuts on the side surface 57c of the next pinion tooth 57a, the return pinion 57 can be rotated in the arrow U direction by the first tooth portion 112 (that is, the first gear 105). .

FIG. 16 is an explanatory diagram for explaining the operation of returning the movable blade 22 to the standby position P2.
As shown in FIG. 16, by continuously rotating the lock release lever 102 in the arrow P direction, the first pinion 105 continuously rotates the return pinion 57 in the arrow U direction. As the return pinion 57 rotates, the rack 58 moves in the direction of arrow V as in the first embodiment. As the return rack 58 moves, the movable blade 22 moves in the arrow V direction together with the return rack 58 and returns to the standby position P2.

  Here, the sun gear 107 of the acceleration mechanism 106 is integrally formed with the first gear 105. Therefore, the rotation amount of the first gear 105 necessary for returning the movable blade 22 to the standby position P2 can be ensured in a state where the stroke amount of the lock release lever 102 is kept small. Thereby, the operativity of the lock release lever 102 can be ensured satisfactorily.

Incidentally, the return rack 58 has return rack teeth 59 formed only on the side opposite to the cutting edge 22b of the movable blade 22. Therefore, in a state where the movable blade 22 has returned to the standby position P2, the return pinion 57 is detached from the return rack teeth 59 of the return rack 58. That is, as in the first embodiment, the engagement of the return pinion 57 with the return rack teeth 59 of the return rack 58 is released.
Therefore, after the movable blade 22 is returned to the standby position P2, the lock release lever 25 can be operated without moving the return rack 58 when unlocking the printer cover 3 (see FIG. 1). As a result, the printer cover 3 can be unlocked while the movable blade 22 is held at the standby position P2.

Next, an example in which the lock of the printer cover 3 of the thermal printer 1 is released by the lock release mechanism 27 will be described with reference to FIGS.
Also in FIG. 17, the operation of the return mechanism 103 will be described from the operation of the lock release lever 102 in order to facilitate understanding of the operation of the lock release mechanism 27.
FIG. 17 is an explanatory diagram for explaining the operation of releasing the lock between the platen unit and the head unit.

As shown in FIG. 17, in a state where the movable blade 22 is returned to the standby position P2, the lock release lever 102 is continuously rotated in the arrow P direction. By rotating the lock release lever 102, the second gear 55 moves in the direction of arrow S and meshes with the release gear 63.
In this state, the release gear 63 rotates in the arrow W direction by further rotating the lock release lever 102 in the arrow P direction. As the release gear 63 rotates, the release cam 64 swings in the arrow W direction together with the release gear 63.

  As the release cam 64 swings, the release cam 64 engages with the cam follower 71 on the platen unit 4 (see FIG. 2) side. When the release cam 64 is engaged with the cam follower 71, the cam follower 71 is pushed out in a direction in which the lock pin 72 is detached from the recess 73. When the lock pin 72 is detached from the recess 73, the lock of the combined state of the platen unit 4 and the head unit 5 (see FIG. 2) is released.

  As shown in FIG. 2, the printer cover 3 is opened with the first rotation shaft 11 as an axis in a state where the lock between the platen unit 4 and the head unit 5 is released. As a result, the recording paper container 10 is opened, and the paper jam 81 (see FIG. 16) can be removed.

As described with reference to FIGS. 2 and 12 to 17, the lock release lever 102 is interlocked with the return mechanism 103 before the printer cover 3 (specifically, the platen unit 4) is unlocked. By operating the return mechanism 103 with the unlock lever 102, the return mechanism 103 can reliably return the movable blade 22 to the standby position P2. Thus, the thermal printer 1 that can easily release the paper jam 81 generated between the fixed blade 34 and the movable blade 22 is obtained by surely returning the movable blade 22 to the standby position P2.
Further, by interlocking the lock release lever 102 for releasing the lock of the printer cover 3 with the return mechanism 103, the lock release lever 102 for releasing the lock of the printer cover 3 can also be used as a lever for removing the paper jam 81. Thereby, the increase in the number of parts of the printing unit 8 (that is, the thermal printer 1) can be suppressed, and the configuration can be simplified.

Here, the distal end portion 102 a of the lock release lever 102 is fitted inside the coupling body 16 in the operation lever 13. Therefore, the lock release lever 102 is operated in conjunction with the turning operation of the operation lever 13.
By rotating the operation lever 13 from the lock position to the release position, the lock release lever 102 is rotated backward in conjunction with the operation lever 13. Therefore, the return mechanism 103 and the lock release mechanism 27 can be operated as described with reference to FIGS. Thus, by turning the operation lever 13 from the lock position to the release position, the return mechanism 103 and the lock release mechanism 27 can be operated to remove the paper jam 81.

The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, in the first and second embodiments, the fixed blade 34 is provided on the printer cover 3 (specifically, the platen unit 4), and the movable blade 22 is provided on the casing 2 (specifically, the head unit 5). Although the example provided in is described, it is not limited to this. As another example, for example, the fixed blade 34 may be provided in the casing 2 and the movable blade 22 may be provided in the printer cover 3.

  In the first embodiment and the second embodiment, the fixed blade 34 is held in a fixed state, and the paper jam 81 is removed by returning the movable blade 22 to the standby position P1 with the lock release levers 25 and 102. However, the present invention is not limited to this. As another example, for example, when the movable blade 22 is returned to the standby position P <b> 1 by the lock release levers 25 and 102, the fixed blade 34 can be lowered in a direction away from the movable blade 22. In this case, the operation of separating the fixed blade 34 from the movable blade 22 can be operated by the lock release levers 25 and 102.

  Furthermore, although the first embodiment and the second embodiment have described the examples in which the lock release levers 25 and 102 are interlocked with the rotation operation of the operation lever 13, the present invention is not limited to this. As another example, for example, the end portions 25a and 102a of the lock release levers 25 and 102 are exposed to the outside of the casing 2, and the user directly operates the lock release levers 25 and 102 from the outside of the casing 2. It is also possible to do.

  In the first embodiment and the second embodiment, the example in which the return rack 58 is formed integrally with the drive rack 46 has been described. However, the present invention is not limited to this. As another example, for example, the return rack 58 can be provided separately from the drive rack 46. In this case, it is necessary to attach the return rack 58 to the movable blade 22.

  Furthermore, in the first and second embodiments, the example in which the return rack 58 is disposed inside the drive rack 46 has been described, but the present invention is not limited to this. As another example, for example, the return rack 58 can be disposed outside the drive rack 46.

  Moreover, although the said 2nd Embodiment demonstrated the example which comprised the acceleration mechanism 106 with the sun gear 107, the planetary gear 108, and the internal gear 109, it is not restricted to this. The acceleration mechanism 106 can have other configurations.

1 ... Thermal printer 2 ... Casing (printer body)
3 ... Printer cover 4 ... Platen unit 5 ... Head unit 8 ... Printing unit 22 ... Movable blade 22a ... Base 22b ... Blade edge 24 ... Movable blade drive mechanism (drive mechanism)
25,102 ... Lock release lever 26,103 ... Return mechanism 27 …… Lock release mechanism 33 …… Platen roller 34 …… Fixed blade 45 …… Drive pinion 46 …… Drive rack 47 …… Drive rack teeth 48 …… Pinion support Shaft (support pin of drive pinion)
57 …… Return pinion 57a… Pinion teeth 58 …… Return rack 59 …… Return rack teeth (rack teeth)
105 ... first gear 107 ... sun gear 108 ... planetary gear 109 ... internal gear (internal gear)
112 ... 1st tooth part P ..... Recording paper (paper)
P1 ... Cutting position P2 ... Standby position

Claims (8)

A head unit having a thermal head for printing on recording paper;
A platen unit that conveys the recording paper, and a platen unit that is detachably combined with the head unit;
A fixed blade provided on any one of the head unit and the platen unit;
A movable blade that is provided on the other of the head unit and the platen unit and slides relative to the fixed blade;
A drive mechanism for sliding the movable blade between a standby position away from the fixed blade and a cutting position on the fixed blade;
An unlocking lever for unlocking the platen unit with respect to the head unit;
In a state where the movable blade is stopped at the cutting position, in conjunction with the lock release lever, a return mechanism that moves the movable blade to the standby position before unlocking the platen unit;
A printing unit characterized by comprising: The return mechanism is
A return rack formed on the drive rack of the drive mechanism;
A return pinion that meshes with the rack teeth of the return rack and can be interlocked with the unlocking lever;
The printing unit according to claim 1, further comprising: The return mechanism is
A first gear and a sun gear that are rotatably supported coaxially at the rotation center of the unlocking lever;
A planetary gear that is rotatably supported to mesh with the sun gear and revolves following the movement of the unlocking lever;
An internal gear meshing with the planetary gear,
The printing unit according to claim 2, wherein the first gear is formed so as to be able to mesh with the return pinion. The return rack is
The cutting edge of the movable blade is engaged with the return pinion while the return rack is disposed at the cutting position, and is released from the engagement with the return pinion when the return rack is disposed at the standby position. 4. The printing unit according to claim 2, further comprising rack teeth formed on the opposite side. The return pinion is
The printing unit according to any one of claims 2 to 4, wherein the printing unit is rotatably provided on a support shaft of a drive pinion of the drive mechanism that meshes with the drive rack.   6. The printing unit according to claim 1, wherein one of the pinion teeth is removed from the return pinion. The first gear is
The printing unit according to claim 3, further comprising a first tooth portion that can first mesh with the return pinion and can be retracted radially inward. In the thermal printer which has a printing unit of any one of Claims 1-5,
The movable blade is provided in a printer main body having a recording paper storage unit for storing the recording paper, and
A thermal printer, wherein the fixed blade is provided on a printer cover that is rotatably connected to the printer main body and opens and closes the recording paper container.

Images