JP2022147152A - Printing unit and thermal printer - Google Patents

Abstract

To provide a printing unit and a thermal printer that enable design of respective components with a high degree of freedom while achieving both a platen roller locking function and a platen roller locking release function.SOLUTION: A printing unit includes: a head unit; a platen unit; an operating lever; a lock arm 140; and a detachment arm 200. The lock arm 140 is disposed swingably around a connecting shaft portion 141 in between: a locked state that a platen roller 45 is locked with a platen bearing 51 fitted inside an accommodation groove 62; and an unlocked state that the platen bearing 51 can be detached from the accommodation groove 62 through an opening 62a. The detachment arm 200 rotates around an arm support shaft 210 extending along a lateral direction L3 at a position different from the connecting shaft portion 141, and presses the platen bearing 51 from inside the accommodation groove 62 toward the opening 62a side so as to detach the platen bearing 51 from the accommodation groove 62.SELECTED DRAWING: Figure 13

Description

The present invention relates to printing units and thermal printers.

As a thermal printer, there is known one in which a thermal head and a platen roller are separably combined.
For example, there is known a thermal printer in which a head unit having a thermal head is provided on the side of a housing that accommodates roll paper, and a platen unit having a platen roller is provided on the side of a printer cover that is connected to the housing so as to be openable and closable. It is According to this thermal printer, the thermal head and the platen roller can be separably combined together with the opening and closing operation of the printer cover.

Usually, thermal printers of this type often have a lock mechanism that holds the platen roller in order to prevent the thermal head and the platen roller from being separated at unintended timing when the thermal head and the platen roller are combined. .

Patent Literature 1 discloses a configuration including a lock arm, a cam, and a pressure spring. In this configuration, the lock arm locks the platen roller bearing. The cam is provided to release the engagement of the platen roller bearing by the lock arm. A pressure spring is provided between the lock arm and a head support that supports the thermal head. The pressure spring presses the thermal head against the platen roller when the bearing of the platen roller is locked, and pushes up the platen roller via the thermal head when the bearing of the platen roller is unlocked.

Japanese Patent Application Laid-Open No. 2000-318260

However, in the configuration disclosed in Patent Document 1, the lock arm has the function of locking the bearing of the platen roller, and the thermal head is pushed by the pressure spring when the locking of the platen roller bearing is released by the cam. and a function of pressing against the platen roller. Therefore, in order to achieve both functions, it is difficult to optimize the design of each of the function of locking the bearings of the platen roller and the function of releasing the locking of the platen roller. For this reason, there is no choice but to design by searching for compromises such as the position of the center of rotation of the lock arm, the amount of rotation, etc. where both functions can be compatible, and it has been difficult to design with a high degree of freedom.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a printing unit and a thermal printer in which each part can be designed with a high degree of freedom while realizing both a platen roller locking function and a platen roller locking release function. do.

To achieve the above object, a printing unit according to an aspect of the present invention includes a head unit having a thermal head that prints on a recording paper, a platen roller that extends in a first direction and feeds the recording paper, and A pair of platen bearings that rotatably support both ends of the platen roller in the first direction are provided in the head unit and recessed on one side in the second direction perpendicular to the first direction. A platen unit that is detachably combined with the head unit and a lock position that locks the platen unit with respect to the head unit by making it possible to insert and remove the pair of platen bearings into and from the pair of housing grooves. an operating lever swingable about a first swing shaft extending in the first direction between an unlocking position for unlocking the platen unit with respect to the head unit; and the operating lever being at the locking position. Sometimes, when the platen rollers are locked in a state in which the pair of platen bearings are fitted in the pair of housing grooves, and when the operation lever is in the unlocked position, the pair of platen bearings through the openings of the pair of housing grooves and the unlocked state in which the pair of platen bearings can be separated from the housing grooves toward the other side of the second direction, the second swing shaft along the first direction As the lock arm swingably provided therearound and the operation lever rotate from the lock position toward the unlock position, the first swing shaft rotates at a position different from the second swing shaft. a detachment arm that rotates about a third swing axis along the direction to press the platen bearing from the interior of the housing groove toward the opening side, thereby detaching the platen bearing from the housing groove; Prepare.

According to this configuration, when the platen unit is combined with the head unit and the operation lever is positioned at the lock position, the pair of platen bearings are housed in the pair of housing grooves. In this state, the lock arm locks the platen roller with the platen bearings fitted inside the pair of housing grooves, thereby preventing the platen bearings from slipping out of the housing grooves.
When the operating lever is rotated from the locked position to the unlocked position, the detachable arm is rotated accordingly, and presses the platen bearing from the inside of the accommodation groove toward the opening side. In this state, the lock arm rotates from the locked state to the unlocked state, whereby the platen bearing is separated from the housing groove by the separation arm.

In such an arrangement, the locking arm and the release arm are provided as separate parts. For this reason, the lock arm does not have a function of disengaging the platen bearing from the accommodation groove, and only needs to realize a function of locking the platen roller while the platen bearing is fitted inside the accommodation groove. Further, the detachable arm does not have the function of locking the platen roller while the platen bearing is fitted inside the housing groove, but only the function of detaching the platen bearing from the housing groove. Therefore, the degree of freedom in designing each of the lock arm and the detachment arm is increased, and optimum design is facilitated. As a result, each part can be designed with a high degree of freedom while realizing both the platen roller locking function and the platen roller locking release function.

In the printing unit according to one aspect of the present invention, at least part of the third swing shaft may overlap the maximum outer diameter portion of the platen roller in the second direction.

According to this configuration, when the platen bearing is removed from the opening of the accommodation groove, the separation arm can efficiently press the platen bearing toward the opening.

In the printing unit according to one aspect of the present invention, the operating lever and the detachable arm are arranged adjacent to each other in the first direction, and the detachable arm is arranged to move the third rocking shaft relative to the third rocking shaft. The operating lever has a boss formed radially outwardly of the drive shaft and protruding toward the operating lever along the first direction, and the operating lever rotates from the locked position toward the unlocked position. It may have an abutting surface that abuts against the outer peripheral surface of the boss when moved.

According to this configuration, when the operating lever is rotated from the locked position toward the unlocked position, the abutment surface abuts against the outer peripheral surface of the boss. As a result, the boss provided on the radially outer side of the third swing shaft is pressed, the detachable arm rotates around the third swing shaft, and the platen bearing can be detached from the housing groove.

In the printing unit according to an aspect of the present invention, the contact surface of the operating lever contacts the outer peripheral surface of the boss when the operating lever moves from the locked position toward the unlocked position by a predetermined angle. You may do so.

With this configuration, it is not necessary to rotate the detachable arm at the same time when the operating lever starts to rotate from the locked position toward the unlocked position. Therefore, it is possible to perform the rotation operation of the operating lever and the rotation operation of the detachment arm at appropriate timings. In this respect as well, it is possible to increase the degree of freedom in designing the operating lever and the detachable arm.

In the printing unit according to an aspect of the present invention, the boss is located on the opposite side of the platen bearing across the third swing shaft in a third direction orthogonal to the first direction and the second direction. You may make it arrange|position.

According to this configuration, when the abutting surface of the operating lever abuts against the boss, the pressing force of the operating lever against the boss can be efficiently transmitted to the platen bearing.

In the printing unit according to one aspect of the present invention, the first swing shaft is arranged on the opposite side of the third swing shaft across the platen bearing in the third direction. good too.

With this configuration, it is possible to secure a long distance from the first swing shaft, which is the center of rotation of the operating lever, to the boss, and when the operating lever is rotated from the locked position toward the unlocked position, , the boss can be efficiently pressed. Therefore, the operation force required to turn the operation lever to move the platen bearing out of the housing groove is small.

In the printing unit according to an aspect of the present invention, the inner side surface of the accommodation groove is formed so that the opening width narrows from the open mouth side toward the groove bottom side of the accommodation groove, and the platen bearing is formed as described above. An inclined guide projection is formed to guide toward the bottom of the groove, and the detachable arm presses the platen bearing so that the roller center of the platen roller moves toward the opening side rather than the vertex of the guide projection. You may make it

According to this configuration, by moving the operating lever to the unlocking position side, the detachable arm moves the platen roller center of the platen roller toward the opening side of the top portion of the guide projection in the accommodation groove. forcefully push up. As a result, the platen bearing can be pushed up to the vicinity of the opening of the housing groove, and can be moved to a substantially disengaged state, thereby facilitating the work of separating the head unit and the platen unit.

In the printing unit according to one aspect of the present invention, the detachable arm may be provided on at least one side in the first direction.

According to this configuration, by providing the detachment arm on at least one side in the first direction, it is possible to detach the roller bearing from the housing groove and separate the platen roller from the head unit.

A thermal printer according to an aspect of the present invention includes a printing unit as described above and a recording paper storage section for storing the recording paper, and is attached with one of the head unit and the platen unit. and a printer cover that is rotatably connected to the printer body and to which the other of the head unit and the platen unit is attached.

According to this configuration, it is possible to provide a thermal printer equipped with a printing unit capable of designing each part with a high degree of freedom while realizing both the locking function of the platen roller and the unlocking function of the platen roller. becomes possible.

According to one aspect of the present invention, each part can be designed with a high degree of freedom while realizing both the locking function of the platen roller and the unlocking function of the platen roller.

1 is a perspective view of a thermal printer according to an embodiment of the present invention, showing a state in which a printer cover is closed; FIG. 2 is a perspective view of the thermal printer with the printer cover shown in FIG. 1 opened; FIG. 3 is a perspective view of the printing unit shown in FIG. 2; FIG. FIG. 4 is a perspective view of the printing unit showing a state in which a gear cover and the like are removed from the state shown in FIG. 3; FIG. 5 is a perspective view of the printing unit showing a state in which a platen frame and the like are removed from the state shown in FIG. 4; FIG. 5 is a perspective view of the platen unit shown in FIG. 4; FIG. 6 is a side view seen from the direction of arrow A shown in FIG. 5, showing the relationship between the housing groove and the platen bearing; 4 is a perspective view showing a state in which recording paper is cut between a fixed blade and a movable blade; FIG. It is the side view seen from the arrow A direction shown in FIG. FIG. 10 is a perspective view of each mechanism shown in FIG. 9; FIG. 10 is a side view showing a state in which a return gear and the like are removed from the state shown in FIG. 9; It is the perspective view which looked at the operation lever and the periphery of a return mechanism from the other side. FIG. 12 is a perspective view showing a state in which an operation lever is removed from the state shown in FIG. 11; It is the perspective view which looked at the periphery of the operating lever from the other side. FIG. 10 is a side view showing a state in which the operating lever is pushed down from the locked position from the state shown in FIG. 9; 16 is a side view showing a state in which the operating lever is further pushed down from the state shown in FIG. 15; FIG. FIG. 17 is a side view showing a state in which the operating lever is further pushed down from the state shown in FIG. 16 and the abutting surface of the operating lever abuts against the boss of the detachable arm; FIG. 18 is a side view showing a state in which the operation lever is further pushed down from the state shown in FIG. 17 to be positioned at the unlocked position, and the platen bearing is pushed up to the opening of the accommodation groove;

Hereinafter, embodiments for implementing a printing unit and a thermal printer according to the present invention will be described with reference to the accompanying drawings. However, the invention is not limited to this embodiment only.
As shown in FIGS. 1 and 2, the thermal printer 1 is a printer capable of printing on a roll of recording paper (thermal paper) P and using the recording paper P as, for example, tickets or receipts. be.

The thermal printer 1 is installed, for example, at a shop front, and its operation is controlled by an information processing device (not shown). Therefore, the thermal printer 1 is controlled to print various information transmitted from the information processing device on the recording paper P and to discharge the printed recording paper P. FIG.

The thermal printer 1 is installed, for example, on an installation surface S of a store, and is formed in a cube shape as a whole. In the present embodiment, in the state shown in FIGS. 1 and 2, the direction perpendicular to the installation surface S is referred to as the up-down direction L1, and the directions orthogonal to each other in the plane parallel to the installation surface S are the forward and backward directions ( second direction) L2 and left-right direction (first direction) L3. Note that, in the front-rear direction L2, the front is indicated by an arrow FW, and the rear is indicated by an arrow BK. Therefore, in FIGS. 1 and 2, the lower left side of the paper surface is the front FW, and the upper right side is the rear BK.

The thermal printer 1 includes a casing (printer main body according to the present invention) 2, a printer cover 3, and a printing unit 4 composed of a head unit 5 and a platen unit 6, and a recording paper P is discharged forward FW. It is considered to be a so-called advance type. In the illustrated example, the platen unit 6 is provided on the printer cover 3 side, and the head unit 5 is provided on the casing 2 side.
However, the present invention is not limited to this case, and for example, the head unit 5 may be provided on the printer cover 3 side and the platen unit 6 may be provided on the casing 2 side.

(casing)
The casing 2 is made of a synthetic resin material, a metal material, or an appropriate combination thereof, and is formed into a cube shape having an opening in the front FW. . However, the shape of the casing 2 is not limited to this case, and may be changed as appropriate.

Among the plurality of outer surfaces 10 , the outer surface facing the bottom surface 11 in the vertical direction L<b>1 is called a top surface 12 . Among the plurality of outer surfaces 10 , the outer surface positioned on the front FW side is referred to as a front surface 13 , and the outer surface positioned on the rear BK side is referred to as a rear surface 14 . The front surface 13 and the rear surface 14 face each other in the front-rear direction L2. Furthermore, among the plurality of outer surfaces 10, the outer surfaces facing each other in the left-right direction L3 are referred to as a pair of side surfaces 15. As shown in FIG.

Inside the casing 2 , a recording paper storage section 16 is formed through an opening formed in the front surface 13 of the casing 2 to store the roll-shaped recording paper P. As shown in FIG. As a result, when the printer cover 3 is opened, the roll-shaped recording paper P can be loaded into the recording paper storage section 16 from the front FW.

The printer cover 3 is connected to the lower part of the casing 2 on the front face 13 side via a rotary shaft part 17, and closes the opening so as to be openable. The printer cover 3 is connected so as to rotate around the rotary shaft portion 17 within an angle range of approximately 90 degrees.
As shown in FIG. 1, when the printer cover 3 is closed, it is designed to leave a slight gap between the tip of the printer cover 3 and the casing 2 . The recording paper P is pulled forward FW from the inside of the casing 2 using this gap and discharged. Therefore, this gap functions as an ejection port 18 for the recording paper P. As shown in FIG.

The casing 2 and printer cover 3 configured as described above are locked together with the combination of the platen unit 6 and the head unit 5 when the printer cover 3 is closed. As a result, the printer cover 3 is locked in the closed state.

Furthermore, as shown in FIG. 1, the casing 2 has a lock for unlocking the platen unit 6 and the head unit 5 at the corner where the front surface 13, top surface 12, and one side surface 15 intersect. A lever 19 is provided. As a result, the lock of the printer cover 3 can be released as shown in FIG. 2, and the printer cover 3 can be opened. Note that the lever 19 can be operated to be pushed downward, for example.

The printer cover 3 is provided with operation buttons 3a such as a power button and a paper feed button. The operation button 3a is arranged on the outer surface of the printer cover 3 so as to be exposed so that it can be pressed. In the illustrated example, the operation buttons 3a are arranged in a line in the vertical direction L1 below the lever 19. As shown in FIG.

(printing unit)
As shown in FIGS. 2 to 5, the printing unit 4 includes a head unit 5 provided on the casing 2 side, and a platen unit 6 provided on the printer cover 3 side and combined with the head unit 5 in a separable manner. , is equipped with

The head unit 5 includes a head frame 20 made of synthetic resin, for example, which forms a basic skeleton of the head unit 5, and a head frame 20 made of metal, for example, which is combined with the head frame 20 so as to cover the head frame 20 from the front FW and the left-right direction L3. A head cover plate 21 and gear covers 22 and 23 made of metal, for example, are combined with the head frame 20 so as to cover the head frame 20 in the left-right direction L3.

Further, the head unit 5 has at least a thermal head 25 , a movable blade 26 , a drive mechanism 27 , an operation lever 28 , a return mechanism 29 and a platen lock mechanism 30 . These thermal head 25 , movable blade 26 , drive mechanism 27 , operation lever 28 , return mechanism 29 and platen lock mechanism 30 are mounted mainly using head frame 20 and covered by head cover plate 21 and gear covers 22 and 23 . It is

The head unit 5 configured as described above is attached inside the casing 2 . Specifically, the head unit 5 is arranged above the recording paper storage section 16 and near the front surface 13 of the casing 2 , and is attached to the casing 2 mainly by fastening the head frame 20 with screws.
In this embodiment, the head unit 5 is attached so that the cutting edge 26a of the movable blade 26 faces downward. Note that the head unit 5 will be described later in detail.

The platen unit 6 includes a platen frame 40 made of synthetic resin, for example, which forms a basic frame of the platen unit 6, and a platen frame 40 made of metal, for example, which is combined with the platen frame 40 so as to cover the platen frame 40 from the front FW and the left-right direction L3. A platen cover plate 41 is provided.
Further, the platen unit 6 has at least a platen roller 45 and a fixed blade 46 . These platen roller 45 and fixed blade 46 are mainly attached using the platen frame 40 and covered with the platen cover plate 41 .

The platen unit 6 configured as described above is attached to the inner surface of the printer cover 3 mainly via the platen cover plate 41 . At this time, the platen unit 6 is attached to a position where it can be separably combined with the head unit 5 as the printer cover 3 is opened and closed.
In this embodiment, the platen unit 6 is attached so that the blade edge 46a of the fixed blade 46 faces upward.

The platen unit 6 will be explained in detail.
As shown in FIGS. 3 to 6, the fixed blade 46 is supported by the platen frame 40 so that the blade edge 46a faces the head unit 5 side when the head unit 5 and the platen unit 6 are combined. As shown in FIG. 6, the platen frame 40 is formed with a platen storage space 47 for storing the platen roller 45 in a portion located on the rear side BK of the fixed blade 46. A support wall 48 that supports the platen roller 45 is formed so as to face each other in the left-right direction L3.

The platen roller 45 is a rubber roller that conveys the recording paper P to the outside of the printer cover 3, and is wound around a platen shaft 50 extending in the horizontal direction L3. The platen roller 45 is housed in a platen housing space 47 with a part of its outer peripheral surface exposed to the head unit 5 side, and is rotatably supported by a support wall 48 .
Specifically, cylindrical platen bearings 51 are placed on both ends of the platen shaft 50 extending outward in the left-right direction L3 from the platen roller 45 . Thereby, even if the pair of platen bearings 51 are pressed, the platen roller 45 can be rotated. A driven gear 52 is fixed to one end of the platen shaft 50 on the outer side of the platen bearing 51 in the left-right direction L3.

The support wall 48 sandwiches and fixes the platen bearing 51 using, for example, a slit hole. As a result, the platen roller 45 is rotatably supported by the pair of support walls 48 via the pair of platen bearings 51 while being housed in the platen housing space 47 .
The pair of platen bearings 51 extends outward in the left-right direction L3 from the support wall 48, and when the printer cover 3 is closed, as shown in FIG. Each is housed within a groove 62 .
Note that FIG. 5 mainly shows the platen roller 45 and the platen bearing 51 of the platen unit 6 .

Next, the head unit 5 will be described in detail.
As shown in FIGS. 3 to 5, the head unit 5 includes at least a thermal head 25, a movable blade 26, a drive mechanism 27, an operating lever 28, a return mechanism 29 and a platen lock mechanism 30. FIG.

As shown in FIG. 5, the thermal head 25 has a plurality of heat generating elements (not shown) arranged in a line along the horizontal direction L3. is attached to the head frame 20 so as to face the Note that the recording paper P can pass between the platen roller 45 and the thermal head 25 .
A coil spring (not shown) is interposed between the thermal head 25 and the head frame 20 to bias the thermal head 25 toward the platen roller 45 side. As a result, the thermal head 25 can be reliably pressed against the recording paper P sent out by the platen roller 45, and good printing by the printing unit 4 is possible.

The head frame 20 has a pair of side walls 60 and 61 located outside the support wall 48 of the platen frame 40 in the platen unit 6 in the left-right direction L3.
A pair of housing grooves 62 into which the pair of platen bearings 51 can be individually fitted are formed in the pair of side wall portions 60 and 61, respectively.
As shown in FIG. 7, the accommodation groove 62 is formed in a U-shape in a side view recessed to the rear BK (one side in the second direction) in the front-rear direction L2, and has an opening 62a at the front FW toward the platen unit 6 side. is formed with the A groove bottom portion 62b of the accommodation groove 62 is formed flat.
FIG. 7 shows the housing groove 62 formed in one side wall portion 60 and omits the illustration of other components as appropriate.

On the inner surface of the accommodation groove 62, an inclined guide projection 63 is formed so as to narrow the opening width from the opening 62a toward the groove bottom 62b and guide the platen bearing 51 toward the groove bottom 62b. formed. Thus, the accommodating groove 62 is formed so that the opening 62a has the widest opening width, and the guide projection 63 has the narrowest opening width near the vertex 63a.
Since the guide projections 63 are formed in the housing grooves 62, the platen bearings 51 can be guided along the guide projections 63 so as to drop toward the groove bottom 62b.

Since the accommodation grooves 62 are formed in the pair of side wall portions 60 and 61 as described above, when the head unit 5 and the platen unit 6 are combined, the pair of platens are arranged as shown in FIGS. The bearing 51 is fitted into the pair of housing grooves 62 and is housed inside. At this time, the platen bearing 51 is housed in the housing groove 62 while being in contact with the groove bottom 62b.

As shown in FIG. 4, the movable blade 26 is attached to the head frame 20 via the drive mechanism 27 so that the blade edge 26a faces the platen unit 6 side when the head unit 5 and the platen unit 6 are combined. ing. At this time, the movable blade 26 is arranged so as to face the fixed blade 46 in the vertical direction L1, and is arranged so as to overlap the fixed blade 46 in the front-rear direction L2 when moved to the cutting position P1. ing.
As shown in FIG. 8, the movable blade 26 is a V-shaped plate blade formed so that the length from the base to the cutting edge 26a gradually decreases from both ends toward the center. 8 is a perspective view showing a state in which the movable blade 26 is moved to the cutting position P1 and the recording paper P is cut between the fixed blade 46 and the movable blade 26. FIG.

As shown in FIG. 4 , the movable blade 26 is attached to a drive rack 71 of the drive mechanism 27 via a movable blade holder 70 . The movable blade 26 is configured to be movable in the vertical direction L<b>1 with respect to the head frame 20 by the operation of the drive mechanism 27 . Thereby, the movable blade 26 is supported so as to be movable in the vertical direction L1 with respect to the fixed blade 46 .

As shown in FIGS. 4, 9 and 10, the driving mechanism 27 is a mechanism for moving the movable blade 26 between the cutting position P1 and the standby position P2. The cutting position P1 is a position where the movable blade 26 rides on the fixed blade 46 to cut the recording paper P together with the fixed blade 46 (see FIG. 8). The standby position P2 is a position where the movable blade 26 is appropriately separated from the fixed blade 46 (see FIG. 4).
The drive mechanism 27 includes a drive motor 75 , an intermediate drive wheel 76 , a two-stage intermediate wheel 77 , a drive pinion 78 and a drive rack 71 .

As shown in FIG. 10 , the driving motor 75 is a motor that can rotate forward and backward, and is fixed inside one side wall portion 60 of the head frame 20 . A drive shaft of the drive motor 75 is connected to a reduction mechanism 75a. Furthermore, the output shaft 75b of the reduction mechanism 75a protrudes outward in the left-right direction L3 from one side wall portion 60 of the head frame 20. As shown in FIG. The drive intermediate wheel 76 is arranged outside in the left-right direction L3 of one side wall portion 60, and is connected to the output shaft 75b of the reduction mechanism 75a. Therefore, the drive intermediate wheel 76 rotates with the rotation of the drive motor 75 via the reduction mechanism 75a.

As shown in FIGS. 9 and 10 , the two-stage intermediate wheel 77 is arranged between the drive intermediate wheel 76 and the drive pinion 78 and is rotatably supported on the intermediate support shaft 80 .
The two-stage intermediate wheel 77 includes a large-diameter intermediate wheel 77a and a small-diameter intermediate wheel 77b having a smaller diameter than the large-diameter intermediate wheel 77a. The large-diameter intermediate wheel 77a meshes with the drive intermediate wheel 76 when the operating lever 28 is positioned at the lock position P3. As a result, the entire two-stage intermediate wheel 77 rotates as the drive intermediate wheel 76 rotates. The small-diameter intermediate wheel 77b is arranged outside the large-diameter intermediate wheel 77a in the left-right direction L3 and meshes with the driving pinion 78. As shown in FIG.

The drive pinion 78 is located closer to the operation lever 28 than the small-diameter intermediate wheel 77b and closer to the drive rack 71, and is coaxial with the pinion support shaft 81. It is fixed to the support shaft 81 . As a result, the drive pinion 78 and the pinion support shaft 81 rotate together.
Further, the drive pinion 78 meshes with the small-diameter intermediate wheel 77 b and also meshes with the drive rack teeth 71 a of the drive rack 71 .

As shown in FIG. 4, the drive racks 71 are arranged not only on one side wall portion 60 side of the head frame 20 but also on the other side wall portion 61 side of the head frame 20, and are arranged on both sides in the left-right direction L3 across the head frame 20. It is The pinion support shaft 81 is formed to penetrate the head frame 20 in the left-right direction L3, and connects the pair of drive pinions 78 arranged on both sides in the left-right direction L3. Thereby, the pair of drive pinions 78 can rotate together in a synchronized state via the pinion support shaft 81 .

The drive racks 71 are attached to both ends of the movable blade holder 70 along the horizontal direction L3 and extend along the vertical direction L1. Thereby, the drive rack 71 is combined with the movable blade 26 via the movable blade holder 70 .
Drive rack teeth 71a are formed over the entire area of the drive rack 71 . A pair of drive pinions 78 mesh with the drive rack teeth 71a. Accordingly, as the pair of drive pinions 78 rotate, the movable blade 26 can be moved between the standby position P2 and the cutting position P1 via the drive rack 71 .

Hereinafter, in order to facilitate understanding of the configuration, the drive pinion 78 and the drive rack 71 located on one side wall portion 60 side (driving motor 75 side) will be described in detail, and the drive pinion 78 and the drive rack 71 located on the other side wall portion 61 side will be described in detail. Descriptions of the driving pinion 78 and the driving rack 71 are omitted.

Since the drive mechanism 27 is configured as described above, as shown in FIGS. The drive pinion 78 can be rotated via the wheel 77b). Therefore, the drive rack 71 can be moved in the arrow F1 direction together with the later-described return rack 130 of the return mechanism 29, and the movable blade 26 can be moved in the same direction. Thereby, the movable blade 26 can be moved from the standby position P2 to the cutting position P1.

On the other hand, by rotating the drive motor 75 in the reverse direction, the drive pinion 78 can be rotated in the reverse direction via the intermediate drive wheel 76 and the two-stage intermediate wheel 77 . Therefore, the drive rack 71 can be moved in the arrow F2 direction together with the return rack 130, and the movable blade 26 can be moved in the same direction. As a result, the movable blade 26 can be moved from the cutting position P1 to the standby position P2 and then returned.

By the way, the intermediate support shaft 80 that supports the two-stage intermediate wheel 77 described above is fixed to a swing plate 90 arranged so as to be able to swing about the pinion support shaft 81 .
As shown in FIGS. 7, 9, and 11, the swing plate 90 is formed with an insertion hole (not shown) that penetrates the swing plate 90 in the left-right direction L3 and allows the pinion support shaft 81 to pass therethrough. . The swing plate 90 is arranged swingably along the wall surface of one side wall portion 60 with the pinion support shaft 81 inserted in an insertion hole (not shown).

The swing plate 90 includes a first plate portion 92 extending between the drive intermediate wheel 76 and the drive rack 71, and a second plate portion 93 extending toward the swing axis O2 of the lock arm 140, which will be described later. I have.

The intermediate support shaft 80 is formed to extend outward in the left-right direction L3 from the first plate portion 92 . As a result, the two-stage intermediate wheel 77 supported by the intermediate support shaft 80 can swing about the pinion support shaft 81 with the swing plate 90 .
An engagement pin 95 is formed on the second plate portion 93 so as to protrude outward in the left-right direction L3.

The swing plate 90 configured in this manner is constantly urged in the direction in which the large-diameter intermediate wheel 77 a of the two-stage intermediate wheel 77 meshes with the drive intermediate wheel 76 by the urging force of the first urging member 100 . .
The first biasing member 100 is, for example, a coil spring, and includes a coil portion 100a supported by a coil support shaft 105 projecting from one side wall portion 60 and a first coil end locked to the head frame 20. a portion 100 b and a second coil end portion 100 c locked to the locking projection 94 of the swing plate 90 .

As a result, the second plate portion 93 of the swing plate 90 is urged toward the operation lever 28 by the urging force (elastic restoring force) of the first urging member 100, so that the large-diameter intermediate wheel 77a is driven. It is positioned while pressed against the intermediate wheel 76 .
Note that the first biasing member 100 is not limited to a coil spring, and may be, for example, a leaf spring.

In addition, the swing plate 90 is pushed up by the push-up cam 113 (described later) along with the operation of the operating lever 28 , and the pinion support shaft 81 is moved against the biasing force of the first biasing member 100 . , and the two-stage intermediate wheel 77 is separated from the drive intermediate wheel 76 . Thereby, it is possible to release the engagement between the two-stage intermediate wheel 77 and the drive intermediate wheel 76 .

As shown in FIGS. 4, 9 and 10, the operating lever 28 is arranged on one side wall 60 side of the head frame 20, extends in the left-right direction L3, and is arranged parallel to the platen roller 45. It is rotatably supported via a lever support shaft (first swing shaft) 106 .
The operating lever 28 rotates about the lever support shaft 106 from the lock position P3 toward the engagement release position P4 or the lock release position P5, which will be described later, with one side wall portion 60 being reversed when viewed from the outside in the left-right direction L3. It is configured so that it can be pushed in clockwise.

The lever support shaft 106 protrudes from the inner surface of the gear cover 22 toward the one side wall portion 60 side. Note that the central axis of the lever support shaft 106 is the rotation axis O1 of the operating lever 28. As shown in FIG.

A lock position P3 is a position where the platen unit 6 is locked with respect to the head unit 5 . At the disengagement position P4, the swing plate 90 is swung by the later-described push-up cam 113 of the operating lever 28, and the engagement between the large-diameter intermediate wheel 77a of the two-stage intermediate wheel 77 and the drive intermediate wheel 76 is released. say the position. The unlocked position P5 is a position where the lock of the platen unit 6 with respect to the head unit 5 is released.

As shown in FIGS. 5 and 9 to 11, a lever plate 110 having a fan-like shape when viewed from the side is formed at the proximal end of the operating lever 28. As shown in FIG.
A planetary shaft 111 projects outward in the left-right direction L3 from the outer surface of the lever plate 110 . The lever plate 110 is formed with a push-up cam 113 and a restricting projecting piece 114 bulging outward in the radial direction.

The planetary shaft 111 is formed at a position offset with respect to the lever support shaft 106 . The push-up cam 113 is arranged on the clockwise side of the engaging pin 95 formed on the swing plate 90, and when the operating lever 28 rotates from the locking position P3 toward the unlocking position P5, the engaging pin 113 95 can be contacted. Further, the outer surface of the push-up cam 113 is formed with a locking projection 115 projecting outward in the left-right direction L3.

The restricting projecting piece 114 is arranged on the clockwise side of the push-up cam 113, and rotates clockwise with respect to the restricting wall portion 116 formed on the head frame 20 when the operating lever 28 is positioned at the lock position P3. contacted from the side.
Therefore, the entire operation lever 28 is restricted from further clockwise rotation, and is thus positioned at the lock position P3.
When the operating lever 28 is moved to the unlocked position P5 and further pushed downward, it can contact the restricting wall portion 117 of the gear cover 22 shown in FIG. 3 from the counterclockwise direction. ing. Therefore, the operation lever 28 is restricted from being further pushed down beyond the unlocked position P5.

The tip of the operating lever 28 is fitted inside a connecting body 19a (see FIG. 2) of the lever 19 provided on the casing 2. As shown in FIG. Therefore, the operating lever 28 is operated in conjunction with the operation of the lever 19 . Accordingly, by operating the lever 19, it is possible to operate the operating lever 28 from the lock position P3 toward the unlock position P5 in conjunction therewith.

As shown in FIGS. 9 and 10, the operating lever 28 configured as described above is constantly urged in the direction (clockwise direction) toward the lock position P3 by the urging force of the second urging member 120. .
The second biasing member 120 is, for example, a coil spring, and includes a coil portion 120a supported by a coil support shaft (not shown) projecting from the inner surface of the gear cover 22, and a second biasing member 120a engaged with the inner surface of the gear cover 22. It has a first coil end portion 120 b and a second coil end portion 120 c locked to the locking projection 115 of the operating lever 28 .

As a result, the operating lever 28 is urged clockwise by the urging force (elastic restoring force) of the second urging member 120, so that the distal end portion of the operating lever 28 is urged in the direction toward the lock position P3. ing. As described above, since the restricting projection 114 of the operating lever 28 contacts the restricting wall portion 116 of the head frame 20, further rotation is restricted and the lever is positioned at the lock position P3.
In addition, the second biasing member 120 is not limited to a coil spring, and may be a leaf spring or the like.

As shown in FIG. 4, the return mechanism 29 moves the operation lever 28 from the lock position P3 to the unlock position P5 in a state where the movable blade 26 is stopped at the cutting position P1 due to, for example, a paper jam. It is a mechanism that uses an operating force (rotational force) to move the movable blade 26 from the cutting position P1 to the standby position P2 before the platen lock mechanism 30 switches the platen roller 45 to the unlocked state.

10 and 12, the return mechanism 29 includes a return rack 130 formed on the drive rack 71, a return pinion 131 meshing with the rack teeth 130a of the return rack 130, and a rotation axis O1 of the operation lever 28. A planetary gear 134 meshing with a return gear 132 rotatably supported around the rotation axis O1 and a sun gear 133 provided integrally with the return gear 132 and revolving along with the movement of the operation lever 28. and an internal gear 135 with which the planetary gear 134 meshes. The sun gear 133, planetary gear 134, and internal gear 135 constitute an acceleration mechanism 136 (see FIG. 12).

The return pinion 131 is rotatably supported by the pinion support shaft 81 while being arranged outside the drive pinion 78 in the left-right direction L3. Thereby, the return pinion 131 is arranged coaxially with the drive pinion 78 . The return pinion 131 can mesh with a return gear 132 that rotates in conjunction with the operation of the operating lever 28 , and is rotated by the rotational force from the return gear 132 .
Furthermore, the return pinion 131 can mesh with the rack teeth 130 a of the return rack 130 .

As shown in FIG. 10, the return rack 130 is formed integrally with the drive rack 71 in a state of being arranged outside the drive rack 71 in the drive mechanism 27 in the left-right direction L3. Return rack 130 has a plurality of rack teeth 130a. The plurality of rack teeth 130a are formed so as to be positioned not on the cutting edge 26a side of the movable blade 26 but on the root side thereof. As a result, the return rack 130 is engaged with the return pinion 131 when the movable blade 26 is positioned at the cutting position P1, and is disengaged with the return pinion 131 when the movable blade 26 is positioned at the standby position P2.

Although the drive rack 71 and the return rack 130 are integrally formed in the illustrated example, the present invention is not limited to this case, and the return rack 130 may be formed separately from the drive rack 71 . . However, by integrally forming the drive rack 71 and the return rack 130, the return rack 130 can be provided without increasing the number of parts, so the configuration can be simplified and the cost can be reduced. It is preferable because it is possible to

Of the plurality of rack teeth 130a, the rack teeth 130a positioned on the cutting edge 26a side of the movable blade 26 are displaceable rack teeth 130b.
The rack teeth 130 b are formed at the tip of the rack arm 139 . The base end of the rack arm 139 is connected to the end of the return rack 130 located on the cutting edge 26 a side of the movable blade 26 . Therefore, the rack arm 139 is a cantilever arm that can be elastically deformed in a direction away from the return pinion 131 with the base end as a fulcrum.
As a result, the rack arm 139 can be elastically deformed in a direction away from the return pinion 131 , and the rack teeth 130 b can be retracted radially outward of the return pinion 131 .

The reason why the rack teeth 130b of the return rack 130 are formed so as to be retractable radially outward of the return pinion 131 will be briefly described.
For example, when the return rack 130 moves in the direction of arrow F1 shown in FIG. In this case, the movement of the return rack 130 may be blocked by the tip of the return pinion 131 .
In consideration of this, by forming the rack teeth 130b at the tip of the rack arm 139, the rack teeth 130b are retracted radially outward of the return pinion 131 by elastic deformation of the rack arm 139. It is configured so that it can be overcome. Therefore, after the rack teeth 130b get over the tooth tip of the return pinion 131, the rack teeth 130b are returned to their original positions by utilizing the elastic restoring force of the rack arm 139, and the returned rack teeth 130b are moved to the next positions of the return pinion 131. It is possible to properly mesh with the teeth of As a result, the rack teeth 130b of the return rack 130 and the return pinion 131 can be properly meshed without causing the inconvenience of obstructing the movement of the return rack 130. FIG.

As shown in FIGS. 9 and 10, the return gear 132 is rotatably supported by the lever support shaft 106 while being arranged outside the lever plate 110 of the operation lever 28 in the left-right direction L3. Thereby, the return gear 132 is arranged coaxially with the rotation axis O<b>1 of the operation lever 28 .

The return gear 132 includes a gear plate 132a and a plurality of gear teeth 132b formed along the outer peripheral edge of the gear plate 132a. The plurality of gear tooth portions 132b are formed not over the entire circumference of the gear plate 132a, but over approximately half the circumference. The plurality of gear teeth 132 b can be meshed with the return pinion 131 .

Among the plurality of gear tooth portions 132b, the gear tooth portion 132b that first meshes with the return pinion 131 by operating the operation lever 28 from the lock position P3 toward the unlock position P5 is positioned radially inward of the return gear 132. It can be displaced toward and retracted from the teeth of the return pinion 131 .

The gear tooth portion 132b is formed at the tip portion of the elastic arm portion 132c. The base end of the elastic arm portion 132c is formed integrally with a portion of the outer peripheral edge of the gear plate 132a where the gear tooth portion 132b is not formed, and extends circularly in the clockwise direction along the outer peripheral edge of the gear plate 132a. . As a result, the elastic arm portion 132c is cantilevered on the outer peripheral edge of the gear plate 132a via the base end portion, and is elastically deformable in the radial direction with the base end portion serving as a fulcrum.
As a result, the elastic arm portion 132 c is elastically deformed toward the gear plate 132 a side, so that the gear tooth portion 132 b can be displaced radially inward of the return gear 132 and retracted from the tooth portion of the return pinion 131 . It is possible to

As shown in FIG. 12, the sun gear 133 is integrally formed on the inner surface of the gear plate 132a and arranged coaxially with the rotation axis O1 of the operating lever . As a result, the sun gear 133 and the return gear 132 are rotatable about the rotation axis O1.

The planetary gear 134 is rotatably supported by the operating lever 28 via the planetary shaft 111 while meshing with the sun gear 133 . As a result, the planetary gear 134 revolves around the rotation axis O1 following the movement of the operation lever 28 as the operation lever 28 rotates about the rotation axis O1.
An internal gear 135 with which a planetary gear 134 meshes is formed on the inner surface of the gear cover 22 . Therefore, the planetary gear 134 revolves along with the movement of the operating lever 28, and thus can rotate while meshing with the internal gear 135. As shown in FIG.

As the planetary gear 134 rotates in this manner, the sun gear 133 and the return gear 132 can be rotated around the rotation axis O1, and the gear teeth 132b of the return gear 132 can mesh with the return pinion 131. It is possible.

As shown in FIG. 5, the platen lock mechanism 30 includes lock arms 140 and 150 that can swing about a swing axis O2 parallel to the platen roller 45. It is a mechanism for switching between the unlocked state and the unlocked state.

As shown in FIGS. 5, 9 and 10, one lock arm 140 is arranged on one side wall portion 60 side of the head frame 20, and the other lock arm 150 is arranged on the other side wall portion 61 side. .
These pair of lock arms 140 and 150 press the platen bearing 51 housed in the housing groove 62 from the side of the opening 62a when the operating lever 28 is positioned at the locking position P3, and the operating lever 28 is locked. As it moves from the position P3 toward the unlocked position P5, it swings from the platen unit 6 toward the head unit 5 about the swing axis O2, and separates from the platen bearing 51 into the housing groove 62. allows the platen bearing 51 to disengage from the

Therefore, the platen lock mechanism 30 of this embodiment can simultaneously lock and unlock the pair of platen bearings 51 using the pair of lock arms 140 and 150 .

One lock arm 140 and the other lock arm 150 extend along the left-right direction L3 and are connected via a long connecting shaft portion (second swing shaft) 141 arranged parallel to the platen roller 45. there is
The connecting shaft portion 141 is a columnar shaft, as shown in FIG. supported as possible. Note that the center axis of the connecting shaft portion 141 is the swing axis O2.

One lock arm 140 and the other lock arm 150 are connected to both end portions of the connecting shaft portion 141, respectively. As a result, the one lock arm 140 and the other lock arm 150 are synchronously swingable about the swing axis O<b>2 via the connecting shaft portion 141 .

The connecting shaft portion 141 is positioned between the accommodation groove 62 and the return gear 132 in the vertical direction L1, and is positioned rearward BK of the accommodation groove 62 in the front-rear direction L2.

In this embodiment, the pair of lock arms 140 and 150 arranged in the left-right direction L3 are connected to each other via the connecting shaft portion 141 so as to be able to swing. It is not limited. For example, the pair of lock arms 140 and 150 and the connecting shaft portion 141 may be formed as a single member by bending a single sheet metal or the like and integrally forming them.

One lock arm 140 will be described in detail.
As shown in FIG. 13, the lock arm 140 is arranged above the accommodation groove 62 and is formed to extend in the front-rear direction L2. A base end portion of the lock arm 140 is connected to an end portion of the connecting shaft portion 141 . A lock claw portion 145 is formed at the tip of the lock arm 140 to cover the platen bearing 51 accommodated in the accommodation groove 62 from the side of the opening 62 a of the accommodation groove 62 . As a result, the platen bearing 51 can be held so that the platen bearing 51 is sandwiched between the lock claw portion 145 and the groove bottom portion 62b of the accommodation groove 62 .

The outer surface of the lock claw portion 145 forms an inclined guide surface 145b that guides the platen bearing 51 into the accommodation groove 62 when the platen bearing 51 is set in the accommodation groove 62 . This guide surface 145b is formed so as to define a V-shaped V-groove in a side view between the guide projection 63 on the accommodation groove 62 side.

Further, an engagement wall portion 146 is formed at the base end portion of the lock arm 140 and protrudes outward in the left-right direction L3. When the operating lever 28 is operated from the locking position P3 toward the unlocking position P5, the engaging wall portion 146 is formed after the push-up cam 113 swings the swing plate 90 via the engaging pin 95. 28 is a wall with which a lever projection 112 (see FIG. 14) contacts.

As a result, the lock arm 140 as a whole is pushed from the lever protrusion 112 via the engagement wall portion 146 in response to the operation of the operating lever 28, and swings clockwise around the swing axis O2. It is That is, the lock arm 140 is configured to swing upward about the swing axis O2 from the platen unit 6 side toward the head unit 5 side.
Therefore, the lock claw portion 145 of the lock arm 140 gradually separates from the platen bearing 51 as the operation lever 28 is operated, and when the operation lever 28 reaches the lock position P3, the lock claw portion 145 moves out of the accommodation groove 62 toward the head unit 5 side. Withdraw and open the opening 62a. This allows the platen bearing 51 to be removed from the housing groove 62 .

As shown in FIGS. 5, 11 and 13, the platen lock mechanism 30 has a detachable arm 200. As shown in FIG. In this embodiment, the detachable arm 200 is provided on the side wall portion 60 on one side in the left-right direction L3. The detachable arm 200 is swingably provided on an arm support shaft (third swing shaft) 210 projecting outward in the left-right direction L3 from the side wall portion 60 . The arm support shaft 210 extends in the left-right direction L3 and is arranged parallel to the platen roller 45 .

The arm support shaft 210 is arranged at a different position from the connection shaft portion 141 that swingably supports the lock arm 140 and the lever support shaft 106 that swingably supports the operating lever 28 . As shown in FIG. 11, at least a portion of the arm support shaft 210 overlaps the maximum outer diameter portion of the platen roller 45 in the front-rear direction L2. Furthermore, at least a portion of the arm support shaft 210 overlaps the platen bearing 51 in the front-rear direction L2. Further, in the vertical direction L1, the arm support shaft 210 is arranged on the opposite side of the lever support shaft 106 with the platen bearing 51 interposed therebetween.

As shown in FIG. 5, the detachable arm 200 is arranged adjacent to the operating lever 28 in the horizontal direction L3. The detachment arm 200 is arranged inside the operation lever 28 in the left-right direction L3. As shown in FIG. 13 , the detachment arm 200 includes an arm body 201 , a boss 203 and a detachment pressing surface 205 .

The arm body 201 has a plate shape along a plane perpendicular to the left-right direction L3. The arm body 201 is provided swingably around the arm support shaft 210 by the arm support shaft 210 penetrating in the left-right direction L3.

The boss 203 is formed radially outside the arm support shaft 210 in the arm body 201 . The boss 203 protrudes from the arm body 201 to the outside in the left-right direction L3, that is, to the operation lever 28 side. As shown in FIGS. 11 and 14, the operating lever 28 is formed with a boss receiving groove 118 into which the boss 203 can be inserted. The boss housing groove 118 is recessed so as to extend in a tangential direction of an imaginary circle centered on the arm support shaft 210 and having a radius of curvature between the arm support shaft 210 and the boss 203 . The boss accommodation groove 118 has an abutment surface 118f that abuts against the outer peripheral surface of the boss 203 when the operating lever 28 is rotated from the lock position P3 toward the unlock position P5. The abutment surface 118f of the operating lever 28 is formed so as to abut against the outer peripheral surface of the boss 203 when the operating lever 28 moves from the lock position P3 toward the unlock position P5 by a predetermined angle. The timing at which the operating lever 28 reaches the boss abutment position P6 (see FIG. 17) where the abutment surface 118f abuts against the outer peripheral surface of the boss 203 is, for example, when the platen bearing 51 is locked from the movement trajectory when the platen bearing 51 is separated from the accommodation groove 62. This is when the arm 140 is in a retracted state. The timing at which the operating lever 28 reaches the boss abutment position P6 is not limited to this, but at least the lock arm 140 begins to shift from the locked state to the unlocked state, and the platen bearing 51 is disengaged from the housing groove 62 by the lock arm 140. It is acceptable as long as it is not constrained to do so. When the operating lever 28 is further rotated toward the unlocked position P5, the arm body 201 rotates around the arm support shaft 210 by pressing the boss 203 with the abutment surface 118f.

Here, as shown in FIG. 11, the boss 203 is arranged on the opposite side of the platen bearing 51 with the arm support shaft 210 interposed therebetween in the vertical direction L1. As a result, a long distance from the lever support shaft 106, which is the center of rotation of the operating lever 28, to the boss 203 can be ensured. Therefore, when the operation lever 28 is rotated from the lock position P3 toward the unlock position P5, the boss 203 can be pressed efficiently.

As shown in FIG. 13, the detachment pressing surface 205 is formed on the arm main body 201 on the side opposite to the boss 203 with the arm support shaft 210 interposed therebetween in the vertical direction L1. The detachment pressing surface 205 is formed facing the front FW. When the arm body 201 rotates around the arm support shaft 210 , the detachment pressing surface 205 presses the platen bearing 51 housed inside the housing groove 62 forward FW. At this time, the detachment pressing surface 205 is preferably formed at an angle as close as possible to perpendicular to the groove bottom 62b of the housing groove 62 when it abuts against the platen bearing 51 in contact with the groove bottom 62b. In other words, the detachment pressing surface 205 is preferably formed so as to extend in the vertical direction L1 while abutting against the platen bearing 51 in contact with the groove bottom portion 62b of the accommodation groove 62 . As a result, the pressing force of the detachable pressing surface 205 can be efficiently transmitted to the platen bearing 51 in the accommodation groove 62 .

The detachable arm 200 as described above rotates about the arm support shaft 210 as the operating lever 28 rotates from the locked position P3 toward the unlocked position P5. The platen bearing 51 is separated from the receiving groove 62 by pressing from the inside toward the opening 62a.

5, when the platen unit 6 of the present embodiment is combined with the head unit 5, the driven gear 52 is mounted on a platen wheel (not shown) arranged on the other side wall portion 61 side of the head frame 20. It can be meshed with the row mechanism. The platen train wheel mechanism operates by receiving power from a drive motor (not shown) for driving the platen roller 45 and plays a role of transmitting the power to the driven gear 52 .
As a result, when the head unit 5 and the platen unit 6 are combined, the platen roller 45 can be rotated to feed the recording paper P. FIG.

(Action of thermal printer)
Next, the operation of the thermal printer 1 configured as described above will be described.
First, the case of combining the head unit 5 and the platen unit 6 will be described.
In this case, as shown in FIG. 2, the platen unit 6 can be removed by inserting and setting the roll-shaped recording paper P in the recording paper storage portion 16 of the casing 2 and then closing the printer cover 3 . It can be made close to the head unit 5 . Then, as shown in FIG. 1, by completely closing the printer cover 3, the head unit 5 and the platen unit 6 can be combined with the recording paper P sandwiched between the thermal head 25 and the platen roller 45. can.

As the printer cover 3 is closed, the platen bearing 51 of the platen roller 45 is fitted into the accommodation groove 62 while being guided by the guide protrusion 63 of the accommodation groove 62 and the guide surface 145b of the lock claw portion 145. It is guided and housed in the housing groove 62 .

After being pushed by the platen bearing 51, the lock arms 140 and 150 swing about the swing axis O2 by the biasing force of a return spring (not shown) and return to their original positions, using the lock claw portion 145. Then, the platen bearing 51 is pressed from the opening 62a side of the housing groove 62. As shown in FIG.
As a result, as shown in FIG. 5, the pair of platen bearings 51 accommodated in the pair of accommodation grooves 62 can be held by using the pair of lock arms 140 and 150, respectively. It is possible to prevent the platen bearing 51 from slipping out of. Therefore, the platen lock mechanism 30 can be used to maintain the platen roller 45 in the locked state. In the closing operation of the printer cover 3, when the lock arms 140 and 150 are pushed by the platen bearing 51, the abutment surface 118f should not contact the boss 203 (not reach the boss abutment position P6). is preferred. As a result, it is possible to suppress the movement of the detachable arm 200 when the printer cover 3 is closed. However, the detachment arm 200 may move slightly as long as the platen bearing 51 does not come into contact with the detachment pressing surface 205 until the lock arms 140 and 150 are returned by the return springs.

As a result, the combination of the head unit 5 and the platen unit 6 can be locked, and the printer cover 3 can be locked with respect to the casing 2 at the same time.
By combining the head unit 5 and the platen unit 6, the thermal head 25 and the platen roller 45 are brought into pressure contact with a predetermined pressure with the recording paper P sandwiched therebetween. After passing between the movable blade 26 and the fixed blade 46 , the recording paper P is pulled out of the casing 2 through the discharge port 18 . Furthermore, the driven gear 52 of the platen roller 45 is in a state of meshing with the platen gear train mechanism on the head unit 5 side.

Next, a case where various information is printed on the recording paper P will be briefly described.
In this case, the driving motor is driven to rotate the driven gear 52 via the platen train wheel mechanism. As a result, the platen roller 45 can be rotated, and the recording paper P sandwiched between the thermal head 25 and the thermal head 25 can be fed toward the discharge port 18 .
At the same time, a control signal corresponding to the print data is output to the thermal head 25 to appropriately heat the heating element. As a result, various characters, graphics, etc. can be clearly printed on the recording paper P being fed.
Note that the printed recording paper P passes between the fixed blade 46 and the movable blade 26 .

Next, the case of cutting the recording paper P will be briefly described.
In this case, the drive motor 75 is driven to rotate the drive intermediate wheel 76 shown in FIG. As a result, the drive pinion 78 can be rotated via the two-stage intermediate wheel 77 (the large-diameter intermediate wheel 77a and the small-diameter intermediate wheel 77b), and the drive rack 71 can be moved in the arrow F1 direction together with the return rack 130. . Therefore, the movable blade 26 can be moved from the standby position P2 to the cutting position P1, and the recording paper P can be sandwiched between the fixed blade 46 and cut as shown in FIG. As a result, the cut recording paper P can be used as a receipt, a ticket, or the like.

After cutting the recording paper P, the driving motor 75 is rotated in the reverse direction. As a result, the drive pinion 78 can be reversely rotated via the intermediate drive wheel 76 and the two-stage intermediate wheel 77, and as shown in FIG. can. Therefore, the movable blade 26 can be moved from the cutting position P1 to the standby position P2 and then returned.

When the recording paper P is cut, the return pinion 131 is disengaged from the gear teeth 132b of the return gear 132, and idle rotation is allowed. Therefore, even if the return pinion 131 meshes with the rack teeth 130a and 130b of the return rack 130 when the movable blade 26 moves to the cutting position P1, the return pinion 131 can be idly rotated. Therefore, the drive rack 71 and the return rack 130 can be moved without being affected by the return pinion 131, and the recording paper P can be cut.

Next, when a paper jam occurs between the movable blade 26 and the fixed blade 46, by operating the operation lever 28, the platen unit 6 is unlocked while the paper jam is cleared, and the printer is operated. A series of operations for opening the cover 3 will be described.
If a paper jam occurs while the recording paper P is being cut, as shown in FIG. Operate toward the P5 side. As a result, the operation lever 28 can be moved to rotate counterclockwise about the rotation axis O1, and as the operation lever 28 moves, the planetary gear 134 meshing with the internal gear 135 is moved to the planetary axis. It can rotate clockwise about 111 and revolve counterclockwise about the rotation axis O1.
As the planetary gear 134 rotates, the sun gear 133 and the return gear 132 can be rotated counterclockwise about the rotation axis O1.

As shown in FIG. 16 , by rotating the operating lever 28 counterclockwise, the push-up cam 113 contacts the engaging pin 95 and applies an external force to the swing plate 90 via the engaging pin 95 . Give. Therefore, by further operating the operating lever 28, the swing plate 90 can be pushed up by the push-up cam 113, and the swing plate 90 can be moved around the pinion support shaft 81 against the biasing force of the first biasing member 100. It can be swung clockwise.

As a result, the two-step intermediate wheel 77 attached to the swing plate 90 can be separated from the driving intermediate wheel 76, and the engagement between the two-step intermediate wheel 77 and the driving intermediate wheel 76 can be released.
Therefore, the position of the operating lever 28 at this time corresponds to the disengagement position P4.

Simultaneously with the swinging of the swing plate 90, the sun gear 133 and the return gear 132 rotate counterclockwise with the operation of the operating lever 28, so that the two-stage intermediate wheel 77 and the driving intermediate wheel 76 are disengaged. At this timing, the first gear tooth portion 132b of the return gear 132 can be meshed with the return pinion 131. As shown in FIG. Thereby, the return pinion 131 can be rotated clockwise.

Therefore, by further operating the operation lever 28 from the engagement release position P4 toward the lock release position P5 shown in FIG. , the return pinion 131 can be continuously rotated clockwise.
Therefore, the return rack 130 meshing with the return pinion 131 can be moved in the direction of the arrow F2, and the movable blade 26 can be forcibly returned from the cutting position P1 to the standby position P2. As a result, the state in which the movable blade 26 overlaps the fixed blade 46 can be eliminated, and the paper jam can be cleared.

When the return pinion 131 is used to return the movable blade 26 to the standby position P2, the drive rack 71 moves together with the return rack 130, so the drive pinion 78 rotates. At this time, as described above, the engagement between the two-stage intermediate wheel 77 and the drive intermediate wheel 76 is released, so that the drive pinion 78 and the two-stage intermediate wheel 77 meshing therewith can be idly rotated. can. Therefore, the movable blade 26 can be returned to the standby position P<b>2 without being affected by the drive pinion 78 and the two-step intermediate wheel 77 .

Note that the rack teeth 130 a and 130 b of the return rack 130 are removed from the return pinion 131 by returning the movable blade 26 to the standby position P<b>2 . Therefore, the rack teeth 130a and 130b of the return rack 130 and the return pinion 131 can be disengaged when the movable blade 26 is returned to the standby position P2 to clear the paper jam.

Also, at the timing when the movable blade 26 returns to the standby position P2, the lever projection 112 of the operating lever 28 contacts the engaging wall portion 146 of one of the lock arms 140, and locks via the engaging wall portion 146. An external force is applied to the arm 140 . As a result, the lock arm 140 can be swung about the swing axis O2 from the platen unit 6 side toward the head unit 5 side. Therefore, the lock claw portion 145 can be gradually separated from the platen bearing 51 as the lock arm 140 swings.

Further, as shown in FIG. 17, when the operation lever 28 is rotated by a predetermined angle from the lock position P3 toward the unlock position P5 and reaches the boss abutment position P6, the abutment surface 118f contacts the outer peripheral surface of the boss 203. bump into. When the operating lever 28 is further rotated toward the unlocked position P5, the boss 203 provided radially outwardly of the arm support shaft 210 is pressed, and the detachable arm 200 rotates around the arm support shaft 210. The platen bearing 51 is pressed from the inside of the housing groove 62 toward the opening 62a.

As shown in FIG. 18, when the operation lever 28 is rotated to the unlocked position P5, the lock arm 140 is rotated from the locked state to the unlocked state, and the platen bearing 51 is moved out of the housing groove 62 by the detachable arm 200. be separated. At this time, the separating arm 200 presses the platen bearing 51 until the roller center of the platen roller 45 moves toward the opening 62 a from the vertex 63 a of the guide projection 63 .

By positioning the operating lever 28 at the unlocked position P5 in this manner, the platen roller 45 can be switched to the unlocked state using the platen lock mechanism 30, and the head unit 5 and the platen unit 6 can be separated. be able to. As a result, the printer cover 3 to which the platen unit 6 is attached can be opened.

As described above, according to the printing unit 4 and the thermal printer 1 of the present embodiment, when the operation lever 28 is rotated from the lock position P3 toward the unlock position P5, the separation arm 200 is rotated accordingly. Then, the platen bearing 51 can be separated from the accommodation groove 62 . In such a configuration, locking arm 140 and release arm 200 are provided as separate components. Therefore, the lock arm 140 does not have the function of disengaging the platen bearing 51 from the accommodation groove 62 , and only has the function of locking the platen roller 45 while the platen bearing 51 is fitted inside the accommodation groove 62 . Just do it. Further, the detachable arm 200 does not have the function of locking the platen roller 45 while the platen bearing 51 is fitted in the housing groove 62, but only the function of detaching the platen bearing 51 from the housing groove 62. good. Therefore, in each of the lock arm 140 and the detachable arm 200, the degree of freedom in design is increased, and optimum design is facilitated. As a result, each part can be designed with a high degree of freedom while realizing both the locking function of the platen roller 45 and the unlocking function of the platen roller 45 .

Further, at least a portion of the arm support shaft 210 overlaps the maximum outer diameter portion of the platen roller 45 in the front-rear direction L2 as viewed in the left-right direction L3. With such a configuration, when the platen bearing 51 is removed from the opening 62 a of the accommodation groove 62 , the separation arm 200 can efficiently press the platen bearing 51 upward toward the opening 62 a.

Further, when the operation lever 28 is rotated from the lock position P3 toward the unlock position P5, the abutment surface 118f abuts against the outer peripheral surface of the boss 203. As shown in FIG. As a result, the boss 203 provided on the radially outer side of the arm support shaft 210 is pressed, the detachable arm 200 rotates around the arm support shaft 210 , and the platen bearing 51 can be detached from the housing groove 62 .

Furthermore, the abutment surface 118f of the operating lever 28 abuts against the outer peripheral surface of the boss 203 when the operating lever 28 moves from the lock position P3 toward the unlock position P5 by a predetermined angle. With such a configuration, it is not necessary to rotate the detachable arm 200 at the same time when the operating lever 28 starts rotating from the locking position P3 toward the unlocking position P5. Therefore, the operation lever 28 can be rotated and the detachable arm 200 can be rotated at appropriate timings. In this respect as well, the degree of freedom in designing the operating lever 28 and the detachable arm 200 can be increased.

The boss 203 is arranged on the opposite side of the platen bearing 51 with the arm support shaft 210 interposed therebetween. According to such a configuration, when the abutting surface 118 f of the operating lever 28 abuts against the boss 203 , the pressing force of the operating lever 28 against the boss 203 can be efficiently transmitted to the platen bearing 51 .

The lever support shaft 106 is arranged on the opposite side of the arm support shaft 210 with the platen bearing 51 interposed therebetween. With such a configuration, it is possible to secure a long distance from the lever support shaft 106, which is the center of rotation of the operating lever 28, to the boss 203. When rotated, the boss 203 can be efficiently pressed. Therefore, the operation force required to turn the operation lever 28 to move the platen bearing 51 out of the housing groove 62 is small.

Further, when the platen bearing 51 is separated from the accommodation groove 62 by using the separation arm 200, the separation arm 200 is arranged so that the roller center of the platen roller 45 moves toward the opening 62a from the vertex 63a of the guide protrusion 63. The platen bearing 51 is forcibly pushed up. Therefore, the platen bearing 51 can be pushed up to the vicinity of the opening 62a of the housing groove 62, and can be moved to a substantially disengaged state. can.

Although embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. Embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. Embodiments and modifications thereof include, for example, those that can be easily imagined by those skilled in the art, those that are substantially the same, and those within an equivalent range.

For example, in the above-described embodiment, the detachable arm 200 is provided to correspond to the platen bearing 51 on one side in the left-right direction L3, but the detachable arm 200 is provided to correspond to the platen bearings 51 on both sides in the left-right direction L3. You may make it each provide.

Furthermore, in the above-described embodiment, the pair of lock arms 140 and 150 are used to hold down both of the pair of platen bearings 51. However, the present invention is not limited to this case, and one lock arm is used. At least one of the platen bearings 51 may be pressed down.

Further, the shape of the detachable arm 200 and the lock arm 140, the position of the center of rotation, etc. can be appropriately changed according to the function of the detachable arm 200. FIG.
For example, in the above embodiment, at least a portion of the arm support shaft 210 overlaps the maximum outer diameter portion of the platen roller 45 in the front-rear direction L2, but the configuration is not limited to this. The arm support shaft 210 may be arranged so as not to overlap the maximum outer diameter portion of the platen roller 45 in the front-rear direction L2.
Further, for example, the arm support shaft 210 may be arranged on the side opposite to the platen bearing 51 with respect to the connecting shaft portion 141 .

Further, in the above-described embodiment, the detachable arm 200 is configured to be rotated by the operation of the operating lever 28, but the configuration is not limited to this. For example, the release arm 200 may be rotated by the action of the lock arm 140 . That is, the detachable arm 200 may be configured to be connected to the lock arm 140 . At this time, if the lock arm 140 does not restrict the separation of the platen bearing 51 from the accommodation groove 62, the separation arm 200 may start moving at the same timing as the movement of the lock arm 140. The movement may be started with a time lag from the movement start of the lock arm 140 .

Furthermore, in the above-described embodiment, an example in which the operating lever 28 is interlocked with the rotating operation of the lever 19 provided on the casing 2 has been described, but the present invention is not limited to this case. For example, the tip of the operating lever 28 may be exposed outside the casing 2 so that the operating lever 28 can be directly operated from outside the casing 2 .

1... Thermal printer 2... Casing (printer body)
3 Printer cover 4 Printing unit 5 Head unit 6 Platen unit 16 Recording paper storage 25 Thermal head 28 Operation lever 45 Platen roller 51 Platen bearing 62 Accommodating groove 62a Opening 62b Groove bottom 63... Guide projection 63a... Vertex 106... Lever support shaft (first swing shaft)
118f... Abutment surface 140... Lock arm 141... Connection shaft portion (second swing shaft)
150... Lock arm 200... Withdrawal arm 203... Boss 210... Arm support shaft (third swing shaft)
L2...Fore-and-aft direction (second direction)
L3... left-right direction (first direction)
P... Recording paper P3... Locked position P5... Unlocked position

Claims (10)

a head unit having a thermal head for printing on recording paper;
a platen roller that extends in a first direction and feeds the recording paper; and a pair of platen bearings that rotatably support both end portions of the platen roller in the first direction. A platen unit separably combined with the head unit by making it possible to insert and remove the pair of platen bearings into a pair of housing grooves recessed on one side in a second direction perpendicular to the first direction. When,
Rocking about a first rocking axis extending in the first direction between a lock position at which the platen unit is locked with respect to the head unit and an unlock position at which the platen unit is unlocked from the head unit a possible operating lever,
A locked state in which the platen rollers are locked with the pair of platen bearings fitted in the pair of housing grooves when the operating lever is at the locked position, and a locked state in which the operating lever is at the unlocked position. between the unlocked state in which the pair of platen bearings can be disengaged from the pair of housing grooves in the other side in the second direction through the openings of the pair of housing grooves; a lock arm swingably provided around a second swing shaft along the first direction;
As the operating lever rotates from the locked position toward the unlocked position, it rotates around the third swing shaft along the first direction at a position different from the second swing shaft. a detachable arm that presses the platen bearing from the interior of the housing groove toward the opening side, and detaches the platen bearing from the housing groove. 2. The printing unit according to claim 1, wherein at least part of said third swing shaft overlaps the maximum outer diameter portion of said platen roller in said second direction. the operating lever and the detachable arm are arranged adjacent to each other in the first direction;
the detachable arm has a boss formed radially outward of the third swing shaft and protruding toward the operation lever along the first direction;
3. The printing unit according to claim 1, wherein the operating lever has an abutting surface that abuts against the outer peripheral surface of the boss when the operating lever is rotated from the locked position toward the unlocked position. 4. The printing unit according to claim 3, wherein the abutment surface of the operating lever abuts against the outer peripheral surface of the boss when the operating lever moves from the locked position toward the unlocked position by a predetermined angle. 5. The boss according to claim 3, wherein the boss is disposed on the opposite side of the platen bearing across the third swing shaft in a third direction orthogonal to the first direction and the second direction. printing unit. 6. The printing unit according to claim 5, wherein said first swing shaft is arranged on the opposite side of said third swing shaft across said platen bearing in said third direction. The printing unit according to any one of claims 1 to 6, wherein the third swing shaft is arranged at a position closer to the center of the platen bearing than the second swing shaft. An inclined guide protrusion formed on the inner surface of the housing groove so that the width of the opening narrows from the opening side toward the groove bottom side of the housing groove, and guides the platen bearing toward the groove bottom. is formed and
The printing according to any one of claims 1 to 7, wherein the detachable arm presses the platen bearing so that the center of the platen roller moves toward the opening from the apex of the guide projection. unit. The printing unit according to any one of claims 1 to 8, wherein the detachable arm is provided corresponding to the platen bearing on at least one side in the first direction. a printing unit according to any one of claims 1 to 9;
a printer main body having a recording paper storage section for storing the recording paper, and to which one of the head unit and the platen unit is attached;
A thermal printer, comprising: a printer cover rotatably connected to the printer main body and to which the other of the head unit and the platen unit is attached.

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