JPH0725041A - Thermal printer - Google Patents

Abstract

PURPOSE:To maintain a position of a head unit with respect to a frame by engaging a spring member provided between the frame and the head unit with the head unit or the frame. CONSTITUTION:A hole 2-1 provided on a side face of a spring receiving member 2 engages with a protrusion 7a of a side face spring 7 at a position where a proper clearance is formed between a print head section 1 and a platen 6 and there is no hindrance of a head unit to surrounding. The side face spring 7 always adds side pressure to the side face of the spring receiving member 2 and the protrusion 7a engages with the hole 2-1 when the hole 2-1 comes to the protrusion 7a. By the engagement of the hole 2-1 and the protrusion 7a, the position of the head unit with respect to a printer frame 4 is maintained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer, and more particularly to maintaining the position of a thermal head with respect to a frame.

[0002]

2. Description of the Related Art In a conventional thermal printer, the position of a thermal head unit with respect to a frame is maintained.
Just press and fix the thermal head to the platen,
As shown in FIG. 7, the thermal head 21 is only released from the platen 20 when the paper is inserted or when the paper is jammed, and the thermal head 21 is not held. Alternatively, the thermal head is only slightly moved away from the platen by the release lever and the work is performed.

[0003]

However, in the state where a very small gap can be provided between the thermal head and the platen, the workability is poor, and it is desired that the opening be as large as a finger can enter.

A conventional example in which the position of the thermal head with respect to the frame is not maintained when the thermal head and the platen are wide open will be described with reference to FIG. When it is necessary to separate the thermal head 21 from the platen 20 by a paper jam or the like, the thermal head 21 hits an obstacle (frame 23 in FIG. 7) and stops, and the cover or the like (cutter unit 22 in FIG. 7) is closed. At this time (the direction opposite to the arrow D in the figure), the cover 22 may hit the thermal head 21 and the normal state may not be restored. Also, when returning the thermal head to the normal state (state in which it abuts on the platen), due to the structure of the printer and the mounting posture, the hand (fingers) does not reach the thermal head, resulting in poor workability or hand (fingers) during work. The contact with other parts sometimes caused a failure in other mechanical parts.

Especially, when the printer is mounted on a wall other than a horizontal wall, for example, a vertical wall, such an obstacle is large.

Although not described with reference to the drawings, in order to increase the clearance between the platen and the thermal head by the release lever, the rotation angle of the release lever should be increased or the release lever should be increased to increase the working radius. Inevitably, the area occupied by the printer becomes large.

Recently, there is a tendency to shy away from technical contents even during maintenance of printers, and simplicity is required.
In addition, since the printer is required to be compact and the printer can be mounted in any posture, it is difficult to restore the printer to a normal state and the printer occupies a large area. It was a big problem.

The present invention is intended to solve such a conventional problem, and an object thereof is to provide a mechanism for holding the position of the head unit with respect to the frame in a state where the head unit is opened sufficiently large from the platen. It is provided compactly.

[0009]

In order to solve the above-mentioned problems of the prior art, the present invention includes a print head unit for holding a recording sheet together with a platen and is rotatably attached to the frame. It is characterized in that it has a head unit and a spring member, and the position of the head unit with respect to the frame is held by the engagement of the spring member between the frame and the head unit.

Further, a head unit, which includes a print head unit for sandwiching the recording paper together with the platen, is rotatably attached to the frame, and one or more holes provided on the side surface of the head unit. A spring member installed on the frame, the spring member is provided with a protrusion so as to engage with one of the holes, and the hole provided at an arbitrary position is engaged with the protrusion. By doing so, the position of the head unit with respect to the frame is maintained.

[0011]

According to the present invention, the position of the head unit with respect to the frame can be maintained by the spring member provided between the frame and the head unit engaging with the head unit or the frame.

Further, according to the present invention, the position of the head unit with respect to the frame is brought about by engaging one or more holes provided on the side surface of the head unit with the protrusions provided on the spring member provided on the frame. Can be held.

Further, according to the above configuration of the present invention, it is possible to share the thrust rattle of the head unit, which is rotatably supported, with the spring member that moves in one direction.
The number of parts does not increase, and the position of the compact head unit with respect to the frame can be maintained.

[0014]

EXAMPLES The present invention will be described below based on examples. FIG. 1A is a sectional view of a line thermal printer according to the present invention, showing a normal printing state. Figure 1
FIG. 1B is a side view of FIG. The print head unit 1 and the spring receiving member 2 are rotatably supported by a head support shaft 3 provided on the printer frame 4 in an engaged state.
The springs 5 are compression coil springs that press the print head unit 1 around a roller-shaped platen 6 and press against the thermal paper fed. The springs 5 are arranged at equal intervals in the print line direction between the spring receiving member 2 and the print head unit 1. A plurality is provided. The print head unit 1, the spring receiving member 2, and the spring 5 constitute a head unit.

The side spring 7 is provided so that the protrusion 7a engages with holes 2-1 and 2-2 provided in the side surface of the spring receiving member 2 which rotates about the head support shaft 3. .

The printer cover 8 is rotatably supported by a cover support shaft 9 provided on the printer frame 4, and an automatic cutter unit (not shown) is mounted inside the printer cover 8.

In this printer, it is possible to open and close the head for removing the paper when the paper is jammed and cleaning the head portion.
Is rotated in the direction of arrow A to perform the opening / closing operation (shown in FIG. 2). Further, in consideration of mounting the printer on a vertical wall or the like, the side spring 7 applies an appropriate side load to the head unit so that the head unit does not move freely even when the printer cover 8 is opened. When the operator moves the spring receiving member 2 in the direction of the arrow B, the print head unit 1 is engaged with the spring receiving member 2 and therefore moves in conjunction with the movement of the spring receiving member 2.

FIG. 3 shows a partially enlarged view of FIG. The hole 2-1 provided on the side surface of the spring receiving member 2 is provided in the print head unit 1.
And a platen 6, and a proper gap is formed between the platen 6 and the platen 6, and the head unit is provided so as to engage with the protrusion 7a of the side spring 7 at a position where it does not interfere with the surroundings. The side spring 7 constantly applies a lateral pressure to the side surface of the spring receiving member 2, and when the hole 2-1 comes to the protruding portion 7a, the protruding portion 7a engages with the hole 2-1. By engaging the hole 2-1 and the protrusion 7a, the position of the head unit with respect to the printer frame 4 is held.

The holes 2-2 are provided so as to engage with the protrusions 7a when the head unit is positioned with respect to the frame so that the print head unit 1 contacts the platen (shown in FIG. 4). . Therefore, after opening the head unit, work can be performed without holding the head unit by hand during the work of returning to the normal state.

Although the embodiment described above is an example in which the head unit has a hole and the spring member has a protrusion, the reverse case is also possible. Further, it is possible to fix the spring member to the head unit and engage the hole or the protrusion of the frame.

Another embodiment of the present invention will be described with reference to FIG.

Numerals 10-1 and 10-2 are concave portions provided in a part of the head unit 10 rotatably supported with respect to the frame 12, and engage with the convex portions of the spring member 11. Thus, the position of the head unit 10 with respect to the frame 12 is maintained.

Another embodiment of the present invention will be described with reference to FIG.

Reference numerals 15-1 and 15-2 are ridge lines provided on a part of the head unit 15 rotatably supported with respect to the frame 17, and by engaging with the spring member 16, the heads are The position of the unit 15 with respect to the frame 17 is maintained.

In another embodiment of the present invention, a spring member attached to the frame is pressed against the head unit, and the friction between the spring member and the head unit holds the position of the head unit with respect to the frame.

[0026]

As described above, according to the present invention, a spring member is provided between the rotatable head unit and the frame, and the head unit and the frame are engaged with each other via the spring member. Thus, the position of the head unit with respect to the frame can be held with an appropriate force.

Therefore, there is an effect that the position of the head unit with respect to the frame can be maintained even if vibration occurs in a state where the printer cover is open.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a printer according to the present invention (normal printing state).

FIG. 2 is a sectional view of a printer according to the present invention (head open state).

FIG. 3 is a partially enlarged cross-sectional view of the printer according to the present invention.

FIG. 4 is a partially enlarged cross-sectional view of the printer according to the present invention.

FIG. 5 is a partially enlarged sectional view of a printer according to another embodiment of the present invention.

FIG. 6 is a partially enlarged sectional view of a printer according to another embodiment of the present invention.

FIG. 7 is a sectional view of a conventional printer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 print head part 2 spring receiving member 2-1, 2-2 hole 3 head support shaft 4 printer frame 7 side spring 7a protrusion part 10, 15 head unit 10-1, 10-2 notch part 11 spring member 15-1 , 15-2 Ridge line portion 16 Spring member

Claims (2)

[Claims] 1. A head unit, which includes a print head unit that holds a recording sheet together with a platen, is rotatably attached to the frame, and a spring member. The spring member is provided between the frame and the head unit. A thermal printer characterized by holding the position of the head unit with respect to the frame depending on the combination. 2. A head unit that includes a print head unit that holds a recording sheet together with a platen and is rotatably attached to the frame, and one or more holes and a frame provided on a side surface of the head unit. A spring member installed on the spring member, the spring member is provided with a protrusion so as to engage with one of the holes, and the hole provided at an arbitrary position is engaged with the protrusion. The thermal printer according to claim 1, wherein the position of the head unit with respect to the frame is maintained.