JPH09216394A - Method for attachment and detachment of thermal printer and thermal head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily attach and detach of a line dot type thermal head by simple work in the attachment and detachment of a thermal printer and a thermal head. SOLUTION: A thermal head 1 having first support shafts 11 provided to both opposed side end surfaces thereof in a protruding state and a second support shafts 12 provided near to the central parts of both side end surfaces thereof from the first support shafts 11 and a housing 2 having first support grooves 21 permitting the first support shafts 11 to move and having round bottoms becoming the bearing parts 23 of the first support shafts 11 and second support grooves 22 permitting the second support shafts 12 to move when the thermal head 1 is rotated around the support shafts 11 supported on the bearing parts 23 to allow the thermal head to rotate toward a platen 3 provided to both side walls thereof are provided and, when the head 1 is mounted, the first support shafts 11 are set to the bearing parts 23 of the first support grooves 21 and the second support shafts 12 are subsequently rotated toward the platen 3 along the second support grooves 22 and, when the head is detached, reverse operation is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of attaching and detaching a thermal printer and a thermal head, and in particular, in a line dot type thermal printer, a thermal head assembling work or a replacement work of a thermal head which has become defective due to disconnection or abrasion. The present invention relates to a thermal printer and a thermal head attaching / detaching method that are easy to perform.

In recent years, the demand for printers, which are information output devices, has increased more and more due to the progress of computerization, but thermal printers are small and lightweight, their printing speed is moderately fast, and they are low in noise and maintenance-free. Because of its features, it is widely used not only for so-called personal use centering on personal computers but also for printing tickets, labels, barcog, etc., and measuring instruments, medical instruments, financial terminals, POS terminals, and other commercial fields.

Among the thermal printers, the line dot type has a fixed thermal head, so that the mechanism is simpler and the advantages of the thermal printer can be utilized. But,
Since the recording medium is driven by friction (friction), mechanical wear of the head cannot be avoided. Further, the head has a structure in which hundreds to thousands of heating dots are arranged in the width direction perpendicular to the traveling direction of the recording medium, which causes problems such as disconnection of wiring and burning of heating dots. Therefore, it is desired that the head can be easily replaced when such a problem occurs.

[0004]

2. Description of the Related Art FIG. 3 is a block diagram of an essential part of an example of a line dot type thermal printer, and FIG.
(B) is another conventional example.

In the figure, 1 is a thermal head, 1a is a head support member, 1b is a support shaft, 2 is a housing, 3 is a platen,
Reference numeral 4 is a recording medium, 5 is a head lifting mechanism, 7 is a biasing means, and 10 is a thermal printer.

The basic construction of the line dot type thermal printer 10 is that the thermal head 1 is a platen 3. The thermal head 1 elastically contacts the platen 3 via the recording medium 4. The platen 3 is generally configured to have a rubber coating on its surface and is driven to rotate.

The thermal head 1 is a so-called line dot type thermal head in which a large number of heating dots are arranged side by side at a predetermined pitch, and is supported by the head support member 1a so as to make uniform elastic contact over the entire width of the platen 3. Has been done.

The platen 3 is for feeding a recording medium 4 such as a thermal paper (thermal paper) which directly develops color by heat while continuously or intermittently rotating, and the thermal head 1 is interlocked with the feeding pitch. Are electrically driven.

By the way, in the line dot type thermal printer 10, the paper is fed by the thermal head 1 and the recording medium 4, with the recording medium 4 being sandwiched between the thermal head 1 and the platen 3 elastically contacting the platen 3. Platen 3
This is performed by utilizing the difference in friction coefficient between the recording medium 4 and the recording medium 4. That is, the coefficient of friction between the rubber coating on the surface of the platen 3 and the recording medium 4 is better than the thermal head 1 and the recording medium 4.
It is based on the fact that it is overwhelmingly larger than the friction coefficient between and, which is why it is called friction (friction) drive.

Therefore, in order for the recording medium 4 to be fed uniformly without meandering, the thermal head 1 must be uniformly elastically contacted with the platen 3 via the recording medium 4. Also,
In order to print uniformly in the width direction of the recording medium 4,
It is necessary that the thermal head 1 is in uniform contact with the recording medium 4 in the width direction.

When the support shaft 1b of the thermal head 1 is arranged in the central portion as shown in FIG. 3A, one end is urged by urging means 7 such as a spring and the other end is urged. The thermal head 1 is elastically contacted with the lower platen 3. Further, when the support shaft 1b is located at one end as shown in FIG. 3B, the intermediate portion is urged by the urging means 7 such as a spring to move the thermal head 1 at the other end downward. It is designed to elastically contact the platen 3. In this way, the thermal head 1 is pressed against the platen 3 with a sufficient pressing force. When the thermal head 1 is levitated, for example,
Biasing means 7 is operated by operating the head lifting mechanism 5 such as biting.
To extinguish

[0012]

As described above, in the line dot type thermal printer 10, the thermal head 1 is strongly pressed against the platen 3 so that the thermal head 1 makes uniform elastic contact with the recording medium 4. Pressed by force. Therefore, the support shaft 1b of the thermal head 1
As shown in FIG. 3 (C), is securely pivoted so that, for example, the side wall of the housing 2 is not biased.

By the way, the surface of the thermal head 1 is heated to a high temperature during the printing operation, and is constantly rubbed against various kinds of recording media 4, so that the surface is worn away. It is unavoidable that there is a life due to it. In addition, there is a life due to burning of the heating dots and disconnection of the wiring.

However, in the conventional thermal head supporting structure, not only the number of parts is large and the assembly is troublesome, but also the replacement of the thermal head when such a problem occurs is complicated and requires a lot of man-hours. .

Therefore, according to the present invention, the thermal printer can be easily attached and detached by the two pairs of support shafts provided on the thermal head and the two support grooves provided on the side wall of the housing. It is intended to provide a way.

[0016]

SUMMARY OF THE INVENTION In the thermal printer in which the thermal heads are installed on both side walls of the housing according to claim 1, the thermal heads are provided on both end faces facing back in a projecting manner. And the first support shaft,
A second support shaft closer to the center than the first support shaft,
The both side walls are movable along the first support shaft, and a first support groove having a round bottom serving as a bearing part of the first support shaft, and the first support groove axially supported by the bearing part. A thermal printer configured to have a second support groove along which the second support shaft can move when rotated about the one support shaft.

That is, the first support shaft is projected from both end surfaces of the thermal head facing back, and the second support shaft is projected closer to the center than the first support shaft. The first support shaft serves as the center of rotation when the thermal head moves.

On the other hand, on both side walls of the housing on which the thermal head is installed, facing each other, a first supporting groove is provided which allows the first supporting shaft and the second supporting shaft to move in parallel in series. The round bottom of the one support groove serves as the bearing portion of the first support shaft. Further, the second support groove has an arc shape so that the second support shaft can move when the thermal head is rotated while the first support shaft is in contact with the bearing portion.

Thus, when the thermal head is rotated so that the second support shaft traces the second support groove while the first support shaft is in contact with the bearing portion of the first support groove, the thermal head is The first support shaft is supported by the bearing portion of the first support groove, and the second support shaft is supported by the second support groove. Moreover, since the second support shaft freely moves in the second support groove around the first support shaft, the thermal head can be elastically contacted with the platen without any trouble.

A second aspect of the present invention is a method of attaching and detaching the thermal head, wherein when the thermal head is attached,
The first support shafts projectingly provided on both end faces facing back are moved along the first support groove provided on the both side walls and having the round bottom serving as a bearing portion of the first support shafts. The first support shaft against the bearing portion, and then a second support shaft projecting closer to the center than the first support shaft is attached to the second support shafts on both side walls. When the thermal head is attached and detached by rotating the first support shaft along the groove as the rotation center and pressing it against the platen, the second support shaft is rotated about the first support shaft. Is rotated along the second support groove to be separated from the platen to be removed from the second support groove, and then the first support shaft fixed to the bearing portion is fixed to the first support shaft. A solution is provided by a method of attaching and detaching a thermal head configured to be pulled out along a support groove.

That is, in mounting the thermal head in the thermal head, first, the first support shaft is moved along the first support groove, and the first support shaft is moved by the first support shaft. Make sure that it comes into contact with the bearing at the bottom of the groove. Then, with the first support shaft as the center of rotation, the second support shaft is rotated in the direction of the platen along the second support groove and tilted,
Make sure the platen is pressed.

In order to detach the thermal head, in reverse to the mounting procedure, first, the second support shaft is moved in the direction away from the platen along the second support groove with the first support shaft as the rotation center. Rotate to disengage from the second support groove.
Then, the first support shaft that is stopped by the bearing portion is pulled out along the first support groove.

As described above, according to the present invention, the first support shaft of the thermal head is struck or disengaged with the bearing portion of the first support groove provided on both side walls of the housing, or the first support shaft is released. The thermal head can be easily attached or detached by a combination of simple operations such that the second support shaft is moved toward or away from the platen along the second support groove with the support shaft as the rotation center. Can be easily incorporated into a thermal printer or replaced when a problem occurs.

[0024]

1 is a perspective view showing the construction of a thermal printer according to the present invention, and FIG. 2 is an enlarged perspective view showing the main part of FIG. In the figure, 1 is a thermal head, 2 is a housing, 3 is a platen, 4 is a recording medium, 10 is a thermal printer, 11 is a first support shaft, 12 is a second support shaft, and 21 is a first support groove. , 22 is a second support groove, and 23 is a bearing portion.

1 and 2, a thermal printer 10 according to the present invention has a line dot type thermal head 1 mounted on opposite side walls of a housing 2 and elastically contacted with a platen 3 via a recording medium 4. It is configured to.

The thermal head 1 generally has a structure in which a head supporting member made of, for example, a steel plate is supported by a thick film or thin film head manufactured by a process of forming a thick film or a thin film on a ceramic substrate, for example. This is collectively called the thermal head 1. A first support shaft 11 is provided so as to project on both end faces of the thermal head 1 facing back, and a second support shaft 12 is provided so as to project closer to the center than the first support shaft 11. It is provided in.

The shape of the main part of the housing 2 is the thermal head 1.
In the case of a small thermal printer 10 with a narrow width, the side walls on which are erected so as to stand upright, may be integrally formed with a plastic mold, but if the width becomes wider, for example, a steel plate Is composed of sheet metal processing and cutting processing. A first support groove 21 having a width that allows the first support shaft 11 to move in the vertical direction is provided on both side walls of the housing 2, and the round bottom of the first support groove 21 is the first support shaft. 11
It is the bearing portion 23 of. Then, when the first support shaft 11 is stopped against the bearing portion 23, the second support shaft 12 has a width that allows the second support shaft 12 to rotate in the direction of the platen 3 with the first support shaft 11 as the center of rotation. The groove 22 is provided in an arc shape.

To mount the thermal head 1, as shown by the white arrow in FIG.
The first support shafts 11 projecting from the both end surfaces are moved to the first support grooves 21 provided in the opposite side walls of the housing 2 and abutted against the bearing portion 23. Next, the second support shaft 12 is rotationally moved in the direction of the platen 3 along the second support groove 22 with the first support shaft 11 as the center of rotation. Thermal head 1
Is the first support shaft 11 by the bearing portion 23 at the bottom of the first support groove 21, and the second support shaft 12 along the second support groove 22 with the first support shaft 11 as the center of rotation. It is supported so that it does not move in any direction other than the rotation direction. Therefore, the thermal head 1 can be elastically contacted with the platen 3 by using an urging means (not shown).

To detach the thermal head 1, as shown by the hatched arrow in FIG. 2, after releasing the biasing means not shown here, the second support shaft 12 is removed from the platen 3. When moved along the second support groove 22 so as to separate, when the second support shaft 12 is disengaged from the second support groove 22,
It can be easily removed by moving the first support shaft 11 along the first support groove 21.

Although the first support shaft 11 is illustrated as a cylindrical shape, if a cylindrical metal having a square hole with one side opened is fitted in the bearing portion 23, the first support shaft 11 is a prism that is fitted into the opening of the square hole. The second support shaft 12 may not be a column as long as it fits in the second support groove 22 and can slide in the normal direction without play.

[0031]

In the line dot type thermal printer, conventionally, the assembling work of the thermal head and the replacing work when a defect occurs have been complicated, but according to the present invention, the thermal head can be installed by a simple work. It can be attached and detached.

As a result, it is possible to reduce the number of parts of the thermal printer, which is indispensable to assemble and replace the head, and to improve the efficiency of the assembling / replacement process. The present invention is directed to a maintenance-free thermal printer. It greatly contributes to the further expansion of marketability.

[Brief description of drawings]

FIG. 1 is a configuration perspective view of a thermal printer according to the present invention.

FIG. 2 is an enlarged perspective view of a main part of FIG.

FIG. 3 is a configuration diagram of a main part of an example of a line dot thermal printer.

[Explanation of symbols]

 1 Thermal Head 2 Housing 3 Platen 4 Recording Medium 10 Thermal Printer 11 First Support Shaft 12 Second Support Shaft 21 First Support Groove 22 Second Support Groove 23 Bearing Section

Claims (2)

[Claims] 1. A line dot type thermal printer in which thermal heads installed on both side walls of a housing press a platen, wherein the thermal heads are provided with first support shafts projecting from both end faces facing back. A second support shaft closer to the center than the first support shaft, the side walls can move along the first support shaft, and the round bottom has a bearing portion of the first support shaft. A second support shaft along which the second support shaft can rotate in the direction of the platen when rotated about a first support groove that is And a supporting groove for the thermal printer. 2. The method for attaching and detaching a thermal head according to claim 1, wherein when the thermal head is attached, first support shafts projecting from both end faces facing back are provided on the both side walls. The first support shaft is provided with a round bottom and is moved along a first support groove serving as a bearing part of the first support shaft to stop the first support shaft from contacting the bearing part. A second support shaft projecting closer to the center than the support shaft in the direction of the platen about the first support shaft as a rotation center along the second support grooves provided on the both side walls. When detaching the thermal head, the second support shaft is moved away from the platen along the second support groove about the first support shaft as a rotation center. And then the first support shaft fixed to the bearing portion is removed from the first support shaft. A method of attaching and detaching the thermal head, which is characterized in that the thermal head is pulled out along the groove.