JP2989024B2 - Thermal head unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal head unit for recording an image on thermosensitive recording paper or recording an image on plain paper using a heat-fusible carbon film.

[0002]

2. Description of the Related Art As disclosed in Japanese Utility Model Application Laid-Open No. 64-7538 or Japanese Utility Model Application Laid-Open No. 2-15361, a thermal head unit having a thermal head substrate fixed on a supporting substrate having a heat radiation effect. Has been proposed.

When such a thermal head unit is used for a long time, the heating element is worn out or the heat generation characteristics are deteriorated, so that the recorded image is deteriorated. In such a case, it is necessary to replace it with a new one.

There are various types of thermal head substrates having different dot pitches, that is, linear densities and sizes of one dot. Even at the same linear density, depending on the difference in dot size, there are some suitable for each recorded image, such as kanji, alphanumeric characters or figures.

For this reason, the user may want to replace the thermal head substrate according to the purpose of use.

In a conventional thermal head unit, a thermal head substrate and various members are formed on a supporting substrate by screwing or double-sided adhesive tape.

[0007]

Therefore, when only the thermal head substrate is to be replaced, a driver suitable for the screw used and a tool for peeling off the adhesive are required. Further, since each member must be accurately mounted in a predetermined positional relationship, replacement work is difficult.

Therefore, when replacing the thermal head substrate, the entire thermal head unit is replaced with a new one. However, in this case, the cost is increased and usable parts other than the thermal head substrate are wasted.

As described above, conventionally, when replacing the thermal head substrate, there has been a problem that the operation is difficult and the cost is high.

It is an object of the present invention to provide a thermal head unit which can solve the above-mentioned problems and can replace a thermal head substrate with a simple operation and at low cost.

[0011]

According to the thermal head unit of the present invention, the thermal head substrate is fixed at a predetermined position on the support substrate by engaging the concave and convex portions formed on the support substrate and the thermal head substrate with each other. A locking mechanism for stopping, and a fixing release mechanism for pressing the thermal head substrate toward the support substrate side and fixing the thermal head substrate at the fixed position, releasing the fixing and freely attaching and detaching the thermal head substrate, A paper guide slope for guiding the paper toward the thermal head substrate is formed on the surface of the fixing release mechanism.

[0012]

The thermal head substrate can be easily attached to and detached from the supporting substrate without using a tool, and can always be fixed at a fixed position without being conscious of the mounting position when mounting. Can be replaced very easily. In addition, since a slope of the paper guide is formed on the surface of the fixing release mechanism for fixing or releasing the thermal head substrate, there is no need to provide a paper guide as a separate member, thereby reducing the number of members and cost. Further, the sheet is smoothly conveyed to the thermal head via the sheet guide slope, so that the disturbance of the recorded image due to the sheet feeding failure or the like is prevented.

[0013]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of a thermal head unit according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view thereof. In these figures, the radiation base 1
Is a rectangular metal plate, and cut and raised portions 1a and 1b are formed on both short sides thereof. A hole 1c is formed in the cut and raised portion 1a, and a cutout 1d is formed in the cut and raised portion 1b. Also, two pins 1e are erected on the upper surface of the heat radiation base 1. Also, on one side, four screw holes 1f
Are drilled.

A thermal head substrate 2 and a flexible substrate 3 are mounted on the upper surface of the heat radiation base 1.
On one side of the upper surface of the thermal head substrate 2, a heating section 2 is provided.
a, an integrated circuit 2b is formed at the center, and a terminal 2c is formed at the other side. The heating section 2a is a heating element corresponding to a recording pixel, and the integrated circuit 2b controls energization of these heating elements. The terminal unit 2c is a terminal for inputting a control signal. Also, the pin 1 of the heat radiation base 1
The hole 2d which engages with e is formed.

The flexible substrate 3 is formed by fixing a flexible substrate 3a on a support substrate 3b.
One end of the flexible substrate 3a protrudes from the flexible substrate 3a, and a terminal portion 3c is formed on the lower surface of the end. The terminal portion 3c is connected to the thermal head substrate 2
In contact with the terminal portion 2c.

A terminal 3d is also formed on the opposite side of the flexible substrate 3, and both are connected by a conductive pattern material. A connector 4 is fitted to the terminal 3d, and a signal cable 5 is connected to the connector 4. The flexible substrate 3 has a hole 3e corresponding to the screw hole 1f on the heat radiation base 1 side.

A substrate pressing mechanism 6 is provided above the flexible substrate 3. The substrate pressing mechanism 6 includes a base 6
The movable member 6c is mounted on the movable member 6a via a hinge mechanism 6b. The hole 6d is provided with a hole 6d, and the movable member 6c is provided with a hole 6e corresponding to the hole 3e of the flexible substrate 3.

FIG. 3 is a side sectional view of the thermal head unit.
e, and is screwed into the screw hole 1f of the heat dissipation base 1. Thereby, the substrate pressing mechanism 6 and the flexible substrate 3 are fixed to the heat radiation base 1. Hinge mechanism 6b
Is for rotating the movable member 6c to some extent with respect to the base 6a. For example, the movable member 6c is made thin by making the member thin, or made of a flexible material.

A leaf spring 6f is provided on one side of the hinge mechanism 6b.
Is attached, whereby one side of the movable member 6c is pushed up. As a result, the lower end 6g on the other side presses down the thermal head substrate 2 and fixes it to the heat radiation base 1. Further, an elastic member 6h such as rubber is fixed to a lower portion in the middle of the side, and the flexible substrate 3 of the flexible substrate 3 is fixed.
a has been pressed. Thereby, the terminal portion 3c and the terminal portion 2
c.

The side upper surface 6i of the movable member 6c is formed as a smooth slope. On the opposite side end,
A nail 6j is formed. Base 6a corresponding to that position
A lever 6k is formed at the side end of the lever, and a claw 61 is formed on the lever 6k.

When the thermal head unit is arranged in various devices with the above configuration, the shaft is passed through the hole 1c of the heat radiation base 1 and the shaft is fixed to the device side.
Further, the platen roller 8 is disposed at the position shown in FIG.
The shaft 8a is engaged with the notch 1d.

When recording an image, the thermal recording paper 9 is inserted between the thermal head substrate 2 and the platen roller 8.
At this time, since the upper surface 6i on one side of the movable member 6c is formed as a smooth slope, it functions as a paper guide function. Then, a predetermined control signal is input from the signal cable 5 while rotating the platen roller 8. Thus, an image is recorded on the thermal recording paper 9.

As described above, the heat generating portion 2a of the thermal head substrate 2 is worn out or deteriorates in the heat generation characteristic, and the image quality of the recorded image is deteriorated due to long-term use. Further, there is a case where the thermal head substrate 2 needs to be replaced according to the image to be recorded.

In such a case, as shown in FIG. 4, the operator pushes down one side of the movable member 6c of the substrate pressing mechanism 6 in the direction F1 in FIG. As a result, the claw 6j of the pushed-down end is locked by the claw 61 of the lever 6k and stops in that state, and the opposite side of the movable member 6c is raised.

In this state, the thermal head substrate 2 becomes detachable, and is replaced here with a desired one. In this case, the terminal portion 2c of the thermal head substrate 2 and the flexible substrate 3
a with the terminal portion 3c, and the hole 2d is
e. Thereafter, the lever 6k is once bent in the direction F2 in FIG. Thereby, the claws 6j and 6j
1 is released, and the newly mounted thermal head substrate 2 is fixed.

As described above, in this embodiment, the thermal head substrate 2 is fixed to the radiation base 1 by the substrate pressing mechanism 6 utilizing the repulsive force of the leaf spring 6f, and the operator manually operates the substrate pressing mechanism 6 By operating, the fixing of the thermal head substrate 2 is released, and the thermal head substrate 2 can be arbitrarily attached and detached. Thus, the thermal head substrate 2 can be easily replaced without requiring any special tool.

Further, the thermal head substrate 2 is locked at a fixed position by fitting the hole 2d of the thermal head substrate 2 with the pin 1e of the heat radiation base 1, so that the operator particularly needs to set the mounting position. It can be easily and accurately attached to a predetermined position without being conscious.

As described above, since only the thermal head substrate 2 is replaced and the heat radiation base 1 and other fixing parts can be used as they are, the replacement cost is reduced.

In the above embodiment, the substrate pressing mechanism 6
Is screwed to the heat radiating base 1, but may be bonded or formed integrally. In addition, heat dissipation base 1
Is designed to support the thermal head substrate 2 and dissipate heat, but the support substrate and the radiator plate may be provided separately.

[0031]

As described above, according to the present invention, the thermal head substrate can be easily attached to and detached from the supporting substrate without using a tool, and the mounting position can be easily set without being conscious of the mounting position. The thermal head substrate can be fixed at a fixed position at all times, making it possible to replace the thermal head substrate very easily. In addition, since a slope of the paper guide is formed on the surface of the fixing release mechanism for fixing or releasing the thermal head substrate, there is no need to provide a paper guide as a separate member, thereby reducing the number of members and cost. Further, the sheet is smoothly conveyed to the thermal head through the sheet guide slope, and the effect of preventing the recorded image from being disturbed due to sheet feeding failure or the like is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a thermal head unit according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the thermal head unit.

FIG. 3 is a side sectional view of the thermal head.

FIG. 4 is a side sectional view of the thermal head when a thermal head substrate is replaced.

[Explanation of symbols]

 Reference Signs List 1 heat radiation base 2 thermal head substrate 3 flexible substrate 4 connector 5 signal cable 6 substrate pressing mechanism 6a base 6b hinge mechanism 6c movable member 6f leaf spring 6h elastic member 6j, 6l pawl 6k lever

Claims (1)

(57) [Claims] In a thermal head unit having a thermal head base fixed on a support substrate, the thermal head substrate is fixed by engaging the concave and convex portions formed on the support substrate and the thermal head substrate with each other. A locking mechanism for locking the thermal head substrate toward the support substrate and fixing the thermal head substrate to the fixed position while releasing the fixing and freely attaching and detaching the thermal head substrate. And a sheet guide slope for guiding the sheet toward the thermal head substrate is formed on the surface of the fixing release mechanism.