JPS6019549A - Thermal head for thermosensitive recording - Google Patents

Abstract

PURPOSE:To improve the reliability and the heat radiating property along with a smaller size by providing a cover having a function of retaining a matrix connection section of a film lead with an opening formed at a part thereof. CONSTITUTION:A matrix connection section 21a on a film lead 21 is retained with a retaining section 23a provided in a cover 23 and is shut out of an external force such as bending during the handling to prevent disconnection at the connection section 21a. The matrix connection section 21a is built into the cover 23 to enable the bending of the film lead 21 exposed from the cover 23 at any position thereby making lessening of the outline of the thermal head. In addition, an opening 23b is provided at a part of the cover 23 and the retaining section 23a to promote the heat radiation of a semiconductor element 4. This makes the thermal head smaller while elevating the reliability with a higher heat radiating property.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a thermal head for thermal recording using a thermal recording method, which applies Joule heat generated by energizing a minute heating resistor to thermal paper to perform printing or printing. It is related to.

Conventional Structures and Their Problems As is well known, the thermal recording method is applied to various terminal printers as a recording method that is easy to maintain. In particular, recently, in addition to the conventional color-forming heat-sensitive recording method, a transfer heat-sensitive recording method has been developed, and full-color recording has become possible with this method.

Color recording is performed by sequentially transferring three or four colors of cyan, magenta, yellow, and black thermal transfer paper onto plain paper using a thermal head for thermal recording (hereinafter referred to as a thermal head) to print. , the printing time is 3 to 4 times longer than conventional monochrome printing. In addition, thermal transfer paper generally uses a pigment-based colorant instead of the dye-based coloring material of color-forming thermal recording paper, so in order to record gradation, it is necessary to
So-called area gradation, which prints by changing the area, is required.

For these reasons, thermal heads are required to have higher speeds and higher densities.

In response to these demands, conventionally the thermal head was driven and controlled by an external circuit, but now a certain number of semiconductor elements (generally shift registers, launch drivers, etc.) that have the functions of this external circuit are installed inside the thermal head. (integrated semiconductor elements) are used. At this time, the leads connected to the drive terminals of the semiconductor element are connected via through-holes to the leads formed on both sides of the flexible film for matrix connection, which increases the external size of the thermal head and increases its reliability. The problem is that it gets worse.

A conventional thermal head will be explained below with reference to FIGS. 1, 2, and 3.

FIG. 1 is an external perspective view of a conventional thermal head.

In FIG. 1, 1 is a base, 2 is a heating element substrate, 3 is a plurality of heating resistors arranged in a row, 4 is a semiconductor element for driving the heating resistors, 5 is a plurality of electrode extraction parts, and 6 is an electrode. A film lead that connects the lead pressed against the extraction part 5 and at least a part of the lead in a matrix connection part 6a, 7 is an elastic material such as silicone rubber, 8 is a cover that protects the semiconductor element 4, and 9 is a cover 8. A fixing screw 10 fixes the device to the base 1 and also presses the electrode extraction portion 5 and the film lead 6 into contact with each other via the elastic material 7. A connector 10 constitutes a thermal head. FIG. 2 shows a sectional view of the thermal head shown in FIG. 1. In FIG. 2, numerals 1 to 10 indicate the same parts as in FIG. 1.

11 is a power supply electrode connected to the heating resistor 3; 12 is the heating resistor 3. A wear-resistant film that protects the power supply electrode 11, 13
The semiconductor element 4 is connected to the power supply electrode 11 and the electrode area 1' heat η13.
A wire lead 5 is connected by wire bonding, and a film lead 6 is formed on one side of the flexible film 6b at a position corresponding to the electrode extraction part 5.
and a part 6d are formed on the back surface and are matrix-connected in a matrix connection part 6a via a through hole 6e, and an insulating film 6f is formed to cover the leads 6G and 6d.

FIG. 3 is a schematic diagram of a recording state using the conventional thermal head of FIG. 1. In FIG. 3, 14a is image receiving paper, 14b is transfer paper, and in this configuration, image receiving paper 14
a and the transfer paper 14b together constitute the recording paper 14. 16 is a paper feed roller, 16 is a thermal head,
Base 11 heating element substrate 22 heating resistor 3. Cover 8. Film lead 61 consists of a 7-trix film lead connection part 6a and a connector 1o.

In FIG. 3, when the paper feed roller 15 brings the image receiving paper 14a and the transfer paper 14b into pressure contact with the heating element 3 of the thermal head 16 and feeds them in the direction of the arrow, heating the heating element 3 according to a signal, the image receiving paper 14a Recordings can be made on.

Although FIG. 3 shows transfer type recording, if direct coloring type thermal recording paper is used instead of the image receiving paper 142L and transfer paper 14b, coloring type thermal recording type recording can be performed.

Using the thermal head configured as shown in Figs. 1 and 2,
When recording in the recording state shown in FIG. 3, the following problems arise.

First, the matrix connection portion 6a formed on the film lead 6 is connected to the leads 6C and θd formed on both sides of the flexible film 6b via a through hole 6e. Due to the reliability of the film lead 6, even though a flexible film lead 6 is used, it can only be bent at a point other than the matrix connection part 6a, making the head outer shape thicker, and ultimately preventing the thermal head from attaching to the device. This has the problem of reducing the mounting clearance and increasing the external size of the device.

Secondly, there is no mechanical holding of the film lead 6 other than the press-contact part, and there is a problem that external force such as bending is applied to the matrix connection part 6a during handling, causing wire breakage at the matrix connection part 6a. ing.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned problems, and aims to provide a thermal head that is small in size and has improved reliability.

Structure of the Invention The present invention provides a heating element substrate in which a plurality of heating resistors, a plurality of semiconductor elements for driving the heating resistors, and a plurality of electrode lead-out portions are formed in rows and electrically connected to each other. and,
A film lead formed with a plurality of leads is press-contacted to the electrode lead-out portion of the heating element substrate, and the film lead is extended and held onto the semiconductor element on the heating element substrate, and the film lead is held and mechanically This is a thermal head consisting of a cover that has the functions of protection, mechanical protection of the semiconductor element, and pressure contact between the electrode extraction part and the lead formed on the film lead.The cover function to hold the film lead makes it compact and easy to install in the equipment. It is possible to provide a thermal head with a large margin and improved reliability.

DESCRIPTION OF EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. 4, 6, and 6.

FIG. 4 is an external perspective view of the thermal head in the first embodiment. 1 to 10 (excluding 6 and 8) in Figure 4
indicates the same location as in Figure 1.

Reference numeral 21 denotes a film lead that connects a lead that is pressed into contact with the electrode extraction part 5 and at least a part of the lead in a matrix connection part 21a, and 22 a holding part that holds part or all of the matrix connection part 21a of the film lead 21. 22a, and is a cover that connects the electrode extraction portion 6 and the film lead 21 in a compressive manner via an elastic lead.

FIG. 5 is a sectional view of the thermal head in the first embodiment of FIG. 4.

In FIG. 5, 1 to 13 indicate the same locations as in FIG. 2, and 22 indicate the same locations as in FIG. 4. 21 is a film lead, and a lead 21C formed on one side of the flexible film 21b at a position corresponding to the electrode extraction part 5 and a part 21d formed on the back side are connected to the 7 trinox connection part 21 & through a through hole 216. Matrix connection is made, and the insulating film 21f is connected to the lead 2IC,
This is a film lead formed to cover 21d.

FIG. 6 is a schematic diagram of a recording state using the thermal head in the first embodiment of FIG. 4.

In Figure 6, 1+ 2p 3+ 10.14,151
21ν 21 &, 22.22 & indicate the same locations as in FIG. 23 is a thermal head, which includes a heating element substrate 2, a heating resistor 3. Cover 22. The film lead 21 is composed of a matrix connection part 21a of the film lead, a holding part 22a inside the cover 22 that holds the matrix connection part 21a, and a connector 1o.

The operation in FIG. 6 is similar to that in FIG. 3.

As described above, according to this embodiment in which recording is performed in the recording state shown in FIG. 6 using the thermal head having the configuration shown in FIGS. 4 and 6, the matrix connection portion formed on the film lead 21' is 21& is connected to leads 21c and 21d formed on both sides of the flexible film 21b via a through hole 21e.
By providing the holding part 222L that holds the matrix connection part 222L inside the cover 22, the matrix connection part 21& is mechanically protected, and external forces such as bending during handling are cut off to the matrix connection part 211.
It is possible to prevent wire breakage at 1a. In addition, by incorporating the matrix connection portion 212L of the film lead 21 into the cover 22, the film lead 21 exposed from the cover 22 can be bent at any position, making it possible to reduce the external size of the head. It is possible to increase the mounting margin and reduce the external size of the device.

A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 7 is an external perspective view of a thermal head showing a second embodiment of the present invention.

In Figure 7, 1 p 2+ 3+ 4r 6y 7
19110.21 and 21a have the same configuration as that shown in FIG.

What is different from the configuration shown in FIG. 4 is the cover 23 and the holding part 23.
The point is that an opening 23b is provided in a part of &.

As described above, by providing an opening in a part of the cover 23 and the holding part 23&, heat generated by the semiconductor element 4 during recording can be effectively dissipated into the air through the opening 23b, and the semiconductor element 4 can improve heat dissipation.

In the first and second embodiments, the semiconductor elements 4 are arranged in one line, but the semiconductor elements 4 may be arranged in a plurality of lines.

Further, in the second embodiment, the opening 23b is one through hole, but it goes without saying that the opening 23b may be formed of a plurality of through holes.

Effects of the Invention The thermal head of the present invention connects a heating element substrate provided with a plurality of heating resistors, semiconductor elements, and electrode extraction parts, and a film lead connected to the electrode extraction parts of the heating element substrate by pressure contact. By providing a cover with a function to hold the matrix connection part of the film lead in a part of the cover and an opening in the holding function and part of the cover, the thermal head can be made smaller and the matrix connection part of the film lead can be made smaller. It has features such as improved reliability and heat dissipation characteristics of semiconductor elements, and its practical effects are outstanding.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of a conventional thermal head, FIG. 2 is a sectional view of the thermal head in FIG. 1, FIG. 3 is a schematic diagram of the recording state of the thermal head in FIG. 1, and FIG. 4 is an inventive invention. FIG. 6 is a partially cutaway external perspective view of the thermal head in the first embodiment, and FIG. 6 is a sectional view of the thermal head in FIG.
The figure is a schematic diagram of the recording state of the thermal head in Figure 4, and Figure 7.
The figure is a partially cutaway circumcentric perspective view of a thermal head in a second embodiment of the present invention. 1...Base, 2...-Heating element board, 3...
...Heating resistor, 4...Semiconductor element, 5...
...Electrode extraction part, 21 ...Film lead, 2
1a...Matrix connection part, 22...Cover, 22a...Holding part, 23b...Opening part. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure 4 Figure 5 Figure 6

Claims (2)

[Claims] (1) A heating element substrate formed by arranging a plurality of heating resistors, a plurality of semiconductor elements for driving the heating resistors, and a plurality of electrode lead-out portions in a row and electrically connecting them. and a film lead formed with a plurality of leads that are press-contacted to the electrode extraction part, and at least both of the film leads are extended and held onto the semiconductor element to mechanically protect the semiconductor element and the press-contact part. A thermal head for heat-sensitive recording having a cover. (2) The thermal head for heat-sensitive recording according to claim 1, characterized in that a part of the cover has an opening.