JPH1199726A - Thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermal printer capable of alleviating a necessary force by preventing damage of a thermal head in the case of setting sheets. SOLUTION: An upper part of a body having a thermal head 7 is automatically locked to a lower part of the body having a platen 4 via an urging part 24 and a hook 21. A pressurizing frame 14 movable to a pressurizing position for operating applied pressure of a pressurizing member 16 at the head 7 and a pressure releasing position FP for releasing the applied pressure is provided. In this case, the frame 14 is disposed at the pressurizing position at a first rotary position of an operating unit 10, the frame 14 is disposed at the position FP at a second rotary position of the unit 10, and automatically locked at a third rotary position. Accordingly, in the case of closing an upper part 3 of the body, the unit 10 is disposed at the second position P2, and hence the head 7 is not strongly collided with the platen 4. And, the upper part 3 of the body can be closed by a light force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer having a platen at a lower part of a main body and a thermal head at an upper part of the main body which can be opened and closed with respect to the lower part of the main body.

[0002]

2. Description of the Related Art For example, a thermal printer which prints on a label is of a type having a platen and a thermal head at the lower part of the main body, and a thermal head at the upper part of the main body having a platen at the lower part of the main body. There is a method. The type having a thermal head on the upper side of the main body is advantageous in that paper can be easily set.

That is, a thermal printer of the type having a platen and a thermal head on the lower side of the main body (the former type)
Then, after passing the paper between the platen and the thermal head, press the thermal head against the platen,
Further, after that, a complicated and many operations of closing the upper part of the main body such as the upper cover and locking it to the lower part of the main body are required. On the other hand, in a thermal printer of the type having a thermal head on the upper side of the main body (the latter type), a paper transport path is formed between the lower part of the main body and the upper part of the main body. Thereafter, the thermal head can be brought into contact with the platen with a predetermined pressing force via the sheet only by closing the upper part of the main body and locking it to the lower part of the main body. That is, such a thermal printer generally has a structure in which sheet setting is completed by an extremely easy operation of simply opening the upper part of the main body, setting paper on the lower part of the main body, and closing the opened upper part of the main body.

[0004]

However, in a thermal printer in which a platen is provided on the lower part of the main body and a thermal head is provided on the upper part of the main body, a strong impact is applied to the thermal head when the upper part of the main body is closed. There is a problem that it is easily damaged. In addition, since the operation of closing the upper part of the main body with respect to the lower part of the main body includes the operation of bringing the thermal head into contact with the platen with a predetermined pressure,
There is also a problem that operability is poor due to the necessity of a force for that.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a thermal printer which can easily set a sheet.

Another object of the present invention is to provide a thermal printer which can prevent a thermal head from being damaged when a sheet is set.

It is still another object of the present invention to provide a thermal printer which can reduce the required force when setting sheets.

Still another object of the present invention is to facilitate paper setting operation, to prevent damage to the thermal head when setting paper, and to reduce the required force. The idea is to get a thermal printer.

[0009]

According to the present invention, a platen is provided at a lower part of a main body, and an upper part of a main body having a thermal head is attached to the lower part of the main body so as to be openable and closable. In a thermal printer for pressurizing a thermal head with a predetermined pressing force, a hook is provided rotatably at an upper portion of a main body, and is rotatable to engage and disengage an engaging portion provided at a lower portion of the main body. A pressurizing frame that is freely provided and is movable between a pressurizing position for applying a pressurizing force of a pressurizing member to the thermal head and a pressurizing release position for releasing the pressurizing force, and is rotatably provided at an upper portion of the main body. An operating unit, a first rotating position of the operating unit, a pressing mechanism for positioning the pressing frame at the pressing position when the operating unit is at the first rotating position, and a first rotating operation of the operating unit. The second pivoted from the moving position In the moving position, the pressure release mechanism that positions the pressure frame at the release position for releasing the pressure of the pressure frame by the pressure mechanism, and the first rotation position and the second rotation position of the operation unit. A disengagement mechanism for rotating the hook in a disengagement direction by a rotation operation of the operation unit at a third rotation position further rotated from the second rotation position of the operation unit without acting on the hook; Is provided.

Therefore, when the operating portion is turned from the first turning position to the second turning position, the pressing force of the thermal head against the platen is released, and the operating portion is further turned to the third turning position. Then, the hook is disengaged from the engaging portion and the upper portion of the main body can be opened. On the other hand, when the upper part of the main body is closed, when the upper part of the main body is rotated in the closing direction and the operation part is rotated in the opposite direction, the hook is engaged with the engaging part and the upper part of the main body is closed. At this time, since the operation unit is located at the second rotation position, the pressure frame is located at the release position, and the pressing force of the pressure member does not act on the thermal head. Therefore, when the upper part of the main body is closed, the thermal head does not strongly collide with the platen, and damage to the thermal head is avoided. Further, when the upper part of the main body is closed, the pressing member of the thermal head does not become a reaction force, and the upper part of the main body can be closed with a light force.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. This embodiment is an example of application to a label printer.

FIG. 1 is an overall perspective view, and FIG. 2 is a perspective view when the paper is set. As shown in these drawings, the thermal printer 1 of the present embodiment includes a main body lower part 2 and a main body upper part 3, and the main body upper part 3 is supported by a shaft (not shown) with respect to the main body lower part 2, and can be freely opened and closed. is there. A roll-shaped platen 4 (not shown in FIGS. 1 and 2) and a paper storage space 5 are provided in the lower part 2 of the main body, and a label paper wound and held in a roll shape is provided in the paper storage space 5. 6 are stored and held. A thermal head 7 is attached to one main body upper part 3, and when the main body upper part 3 is closed,
The entire structure is configured so that the thermal head 7 can be brought into contact with the platen 4 with a predetermined pressing force. Also,
An operation unit 8 and a display unit 9 are provided on the upper surface of the main body upper part 3.

Here, an operation unit 10 is provided on the upper part 3 of the main body. The operation unit 10 provides two functions to the thermal printer 1 by the operation. One is an effect that the upper part 3 of the main body can be opened by rotating the operation part 10. The other is that by rotating the operation unit 10, the main body upper part 3 is closed with respect to the main body lower part 2,
The function is to release the pressing force of the thermal head 7 on the platen 4. Hereinafter, a structure for realizing the two functions will be described with reference to FIGS.

First, the operation unit 10 is rotatably supported by a support shaft 11 attached to the upper part 3 of the main body. The operation unit 10 is provided with an operation lever 12 that can be operated from outside the thermal printer 1.
Is rotated around the support shaft 11 by the above operation.

Next, the thermal head 7 is held so as to be covered by the head bracket 13. The head bracket 13 is rotatably mounted on a support shaft (not shown), and a pressure frame 14 located above the head bracket 13 is rotatably mounted on the same support shaft. A pressure plate 15 is fixed to an upper portion of the head bracket 13, and a pressure spring 16 as a pressure member is attached between the pressure plate 15 and the pressure frame 14. Here, a head pressure cam 17 is fixed to the upper surface of the pressure frame 14, and the head pressure cam 17 interferes with a head lock shaft 18 provided in the operation unit 10, and the pressure is thereby reduced. The rotation of the frame 14 is restricted. Therefore, the pressing spring 16 interposed between the pressing plate 15 and the pressing frame 14 is in a compressed state, and the thermal head 7 contacts the platen 4 with a predetermined pressing force (see FIG. 3). For convenience, the operation unit 1 shown in FIG.
The position of 0 is referred to as a first rotation position P1, and the position of the pressing frame 14 at this time is referred to as a pressing position PP.

Here, a head pressure cam 17 provided on the upper surface of the pressure frame 14 and a head lock shaft 18 provided on the operation unit 10 are connected to a head pressure cam mechanism 19.
Is configured. That is, the head pressure cam mechanism 19 uses the head lock shaft 18 as a driving node, and the head pressure cam 1
A cam mechanism having the follower 7 is constituted. Therefore, when the head lock shaft 18 retreats from the head pressing cam 17, more specifically, when the operation lever 12 is operated to rotate the operation unit 10, the head lock shaft 18
Is released, the compression state of the pressure spring 16 is loosened, and the pressing force of the thermal head 7 on the platen 4 is released (see FIG. 4). For convenience, the position of the operation unit 10 shown in FIG. 4 is referred to as a second rotation position P2, and the position of the pressure frame 14 at this time is referred to as a pressure release position FP. As described above, the head pressure cam mechanism 19 selectively positions the pressure frame 14 between the pressure position PP and the pressure release position FP, and maintains the pressure of the thermal head 7 against the platen 4, or Release the pressure. Therefore, the head pressure cam mechanism 1
Reference numeral 9 forms a main part of the pressure mechanism and the pressure release mechanism.

Next, a pair of clamp pins 20 are provided on both sides of the main body lower part 2 as engagement parts, and the main body upper part 3 is provided.
On both sides of the clamp pin 2
A pair of hooks 21 that can be freely attached to and detached from the shaft 0 are rotatably mounted around their support shafts 22. In other words, the upper part 3
The hook 21 is positioned at a closed position when the hook 21 is engaged with the clamp pin 20, and is opened when the engagement is released. This is because a spring (not shown) is interposed at the connecting portion between the main body lower part 2 and the main body upper part 3, and the main body upper part 3 is urged in the opening direction by this spring. Therefore, the hook 21 with respect to the clamp pin 20
Is disengaged, the main body upper part 3 turns itself in the opening direction. Further, the hook 21 is provided with a spring 2 as an urging portion which is bridged between the hook 21 and a support shaft 23 provided on the upper part 3 of the main body.
4 is urged in the direction of engagement with the clamp pin 20. The hook 21 is formed with an inclined portion 25 for contacting the clamp pin 20 and releasing the interference by the action of the rotation of the hook 21 when the upper body 3 is closed. Thus, when the upper body 3 is closed, the interference with the clamp pin 20 is released by the rotation of the hook 21, and the hook 21 finally engages with the clamp pin 20, and the upper body 3 becomes the lower body 2. Will be automatically clamped.

The hook 21 is driven to rotate in a direction in which the engagement with the clamp pin 20 is released by the rotation of the pair of left and right engagement release cams 26 rotatably attached to the support shaft 23. . That is, a cam groove 27 is formed in the hook 21, and a cam pin 28 inserted into the cam groove 27 is provided on the engagement release cam 26. When the disengaging cam 26 rotates counterclockwise in FIGS. 3 to 5, the cam pin 28 is displaced in the lower right direction in FIGS. 3 to 5 while sliding in the cam groove 27. Hook 2
1 rotates clockwise in FIGS. 3 to 5 around the support shaft 22. Thus, the clamp pin 20
Is released from the hook 21 (see FIG. 5).
Here, the engagement release cam 26 is rotated by the operation unit 1.
0. In other words, the operation unit 10 includes the operation unit 10 shown in FIG.
When further rotated from the second rotation position P2 shown in FIG. 5, the engagement lever 26 engages with the engagement release cam 26, and rotates the engagement release cam 26 counterclockwise in FIGS. Is provided. For convenience, the position of the operation unit 10 shown in FIG. 5 is referred to as a third rotation position P3. At this time, the pressure frame 14 is located at the pressure release position FP. in this way,
In the present embodiment, the hook 2
As the disengagement mechanism for disengaging the engagement 1, the disengagement lever 29 and the disengagement cam 2 provided on the operation unit 10 side are provided.
6 is the prime mover and the cam groove 2 provided on the hook 21 side.
Disengagement cam mechanism 30 which is a cam mechanism having a driven member 7
Is provided.

In such a configuration, when the upper part 3 of the main body is closed with respect to the lower part 2 of the main body as shown in FIG. 1, the operating part 10 is located at the first rotation position P1 (FIG. 3).
reference). On the other hand, when the operation lever 10 is operated to rotate the operation unit 10 to the third rotation position P3, the engagement of the hook 21 with the clamp pin 20 is released by the operation of the engagement release cam mechanism 30, and The upper part 3 of the main body is opened (see FIGS. 2 and 5). Thereby, replenishment of the label paper 6 and various maintenance operations can be performed.

On the other hand, the operation unit 10 is moved to the first rotation position P1.
In the process of turning from the second turning position P3 to the third turning position P3. In the second rotation position, the engagement of the hook 21 with the clamp pin 20 is not released, so that the upper part 3 of the main body remains locked to the lower part 2 of the main body. That is, the head lock shaft 18 provided on the operation unit 10 is retracted from the head pressure cam 17 provided on the upper surface of the pressure frame 14, whereby the compression state of the pressure spring 16 is loosened and the thermal head for the platen 4 is moved. 7 is released (see FIG. 4). Here, when the upper part 3 of the main body is opened as shown in FIG.
4 returns to the initial position, that is, the position where it engages with the clamp pin 20 when the upper body 3 is closed. Therefore, when the upper part 3 of the main body is open, the operation part 10 is located at the second rotation position P2. At the second rotation position P2, as described above, since the pressure frame 14 is located at the pressure release position FP, the compression state of the pressure spring 16 is loosened, and the pressing force of the thermal head 7 against the platen 4 is released. Have been. Therefore, when the thermal head 7 contacts the platen 4 when closing the upper body 3, the thermal head 7 can move in a direction away from the platen 4, and the thermal head 7 does not strongly collide with the platen 4, Avoid damage. Further, at this time, the pressure spring 16 of the thermal head 7 does not become a reaction force, and the upper portion 3 of the main body can be closed with a light force. In addition, as an operation for releasing the pressing force of the thermal head 7, it is required to rotate the operation unit 10 by operating the operation lever 12. A head pressing cam mechanism for releasing the pressing force of the thermal head 7 is required. 19
Since it is a cam mechanism, it does not require large force for operation. Therefore, a large force is not required for operating the operation lever 12 when opening the upper part 3 of the main body, and the operability is not impaired.

[0021]

The present invention is constructed as described above.
A complicated operation and many operations are not required when setting the paper, and the paper setting operation can be facilitated. Further, since the pressing force of the thermal head can be released when setting the paper, it is possible to prevent the thermal head from being damaged when closing the upper part of the main body, and to reduce the required force. .

[Brief description of the drawings]

FIG. 1 is an overall perspective view showing an embodiment of the present invention.

FIG. 2 is a perspective view when the paper is set.

FIG. 3 is a side view showing a state of a thermal head and a hook when an operation unit is located at a first rotation position.

FIG. 4 is a side view showing a state of a thermal head and a hook when an operation unit is located at a second rotation position.

FIG. 5 is a side view showing a state of a thermal head and a hook when the operation unit is located at a third rotation position.

[Explanation of symbols]

 2 Lower Body 3 Upper Body 4 Platen 7 Thermal Head 10 Operating Unit 16 Pressing Member (Pressing Spring) 19 Head Pressing Mechanism 20 Engaging Unit (Clamp Pin) 21 Hook 24 Energizing Unit (Spring) 30 Disengagement Cam Mechanism PP Pressure position FP Pressure release position P1 First rotation position P2 Second rotation position P3 Third rotation position

Claims (1)

[Claims] 1. A platen is provided at a lower part of a main body, and an upper part of a main body having a thermal head is attached to the lower part of the main body so as to be openable and closable, and the thermal head is fixed to the platen with the upper part of the main body closed. In a thermal printer pressurized by a pressurizing force, a hook rotatably provided on the upper portion of the main body, being rotatably engaged with and disengaged from an engaging portion provided on the lower portion of the main body, and being rotatable on the upper portion of the main body. A pressurizing frame which is movable to a pressurizing position for applying a pressurizing force of a pressurizing member to the thermal head and a pressurizing release position for releasing the pressurizing force; and is rotatably provided on the upper portion of the main body. An operating unit, a pressing mechanism for positioning the pressing frame at the pressing position when the operating unit is at the first rotating position in a first rotating position of the operating unit; No. A pressure release mechanism that positions the pressure frame at the release position where the pressure of the pressure frame is released by the pressure mechanism at a second rotation position rotated from the rotation position of The operation unit does not act on the hook in the first rotation position and the second rotation position of the unit, and in the third rotation position further rotated from the second rotation position of the operation unit, And a disengagement mechanism for rotating the hook in the disengagement direction by the rotation of the thermal printer.