JP2807395B2 - Thermal head and apparatus provided with the thermal head - 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 and an apparatus having the thermal head, and more particularly to an improvement in the structure of the thermal head.

[0002]

2. Description of the Related Art Conventionally, page printers, word processors,
In various devices such as facsimile machines, thermal heads are used as print heads. The thermal head is configured to cause a heating resistor provided on the substrate to generate heat by energization, and to print on thermal paper passing over the substrate while contacting the heating resistor by the heat. In addition, the thermal head is provided with heat on the rear surface of the substrate in order to prevent the substrate or the thermal head from being overheated by the heat generated in the heating resistor as described above, thereby causing heat loss of the thermal head or deterioration of printing performance. A heat dissipation plate with good conductivity is provided to prevent the thermal head from storing heat.

In a conventional thermal head, a substrate and a heat radiating plate are bonded by a silicon-based, acrylic-based, or epoxy-based adhesive. However, in recent years, in order to simplify the manufacturing process of the thermal head, the substrate and the heat radiating plate have been bonded with a double-sided adhesive tape.

[0004]

However, the double-sided adhesive tape does not greatly expand when pressed, unlike the adhesive. The bonding surfaces of both the substrate and the heat sink to be bonded are flat. For this reason, air remains between the double-sided adhesive tape and the substrate and between the double-sided adhesive tape and the heat sink at the time of bonding. It is difficult to completely remove the remaining air with a pressure that does not damage the device built in the thermal head, and this air causes uneven bonding. As a result, there is a problem in that the thermal head causes uneven heat radiation and print unevenness.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a thermal head and a thermal head for preventing non-uniform bonding in bonding a substrate and a heat sink using a double-sided adhesive tape. Device is provided.

[0006]

In order to achieve the above object, a thermal head according to the present invention comprises a substrate having a heat-generating portion and a heat radiator fixed to the back surface of the substrate via a double-sided adhesive tape. Plate and heat generated on the heat sink
And a resistor , on the surface of the radiator plate adhered to the substrate, along the longitudinal direction of the radiator plate, and so as to avoid the lower part of the heating resistor,
The heat radiating plate and the double-sided adhesive tape and the substrate and the double-sided adhesive tape each have at least one or more grooves for releasing air that inhibits the adhesion existing on each bonding surface to the outside when the double-sided adhesive tape is bonded. Features.

Further, the apparatus provided with the thermal head according to the present invention comprises a feed-in tray for storing the stacked originals, and a feed-in for drawing and conveying the uppermost sheet from the feed-in tray for storing the stacked originals. A document supply unit including a roller and an image sensor that reads characters of the document conveyed by the feed roller as an image signal, a recording sheet for transferring the document, and a platen roller for recording sheet for conveying the recording sheet; , a record for paper supply unit consisting of a device having a thermal head comprising a thermal head for printing the image read by said image sensor to said recording sheet to said recording paper, said thermal head, A substrate having a heat generating portion, and a heat sink fixed to the back surface of the substrate via a double-sided adhesive tape The formed heat radiating plate on the heating resistor
An antibody, on the surface of the radiator plate adhered to the substrate, along the longitudinal direction of the radiator plate, and so as to avoid the lower part of the heating resistor, the radiator plate and the It is characterized in that it is provided with a double-sided adhesive tape and at least one or more grooves for releasing air that inhibits adhesion existing on each bonding surface when bonding the substrate and the double-sided adhesive tape to the outside.

[0008]

In the thermal head and the apparatus having the thermal head according to the present invention having the above configuration, the surface of the heat radiating plate adhered to the substrate of the thermal head is disposed along the longitudinal direction of the heat radiating plate. Since one or a plurality of grooves are provided, it is possible to release the air that inhibits the bonding existing on each bonding surface when bonding the heat sink to the double-sided adhesive tape and the substrate and the double-sided adhesive tape to the outside by pressing. it can.

[0009]

Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

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

The basic structure of the thermal head of the present invention is as follows.
It has almost the same configuration as the conventional one. That is,
As shown in FIG. 1, a heat generating resistor 14 as a heat generating portion, a driving circuit 26 for driving the heat generating resistor 14, and a comb for supplying power to the driving circuit 26 are provided on one end of the heat radiating plate 10. A ceramic substrate 12 having a toothed input terminal portion (not shown) on the surface is fixed. An external connection board 15 is provided on the heat sink 10 and the board 12.
Is provided. Furthermore, this external connection board 15
A translucent synthetic resin film 16 having a comb-shaped connection terminal portion corresponding to the input terminal is provided at one end of the back surface, and a heat sink is provided so that the connection terminal is superimposed on the input terminal portion of the substrate 12. It is superimposed on 10. The protective cover 20 is placed on the external connection substrate 15 with the pressing rubber 18 sandwiched between the lower portion thereof and the upper surface corresponding to each of the terminal portions in the overlapping contact state of the film 16. Screws 2 on the external connection board 15 and the heat sink 10
2 screwed.

FIG. 2 is an enlarged cross-sectional view showing an enlarged Y portion in FIG.

As shown in FIG. 2, the substrate 12 and the heat sink 10
Is fixed via a double-sided adhesive tape 24. Normally, first, one surface of the double-sided adhesive tape 24 is attached to the back surface of the substrate 12, and then the other surface of the double-sided adhesive tape 24 is further attached to the aluminum radiator plate 10, and the two are adhered. Further, the double-sided adhesive tape 24 in this embodiment is used.
Is a resin mainly composed of a polymer of an acrylic monomer having improved heat resistance.

In recent years, using a double-sided adhesive tape,
A thermal head in which the heat sink 10 is bonded to the heat sink 10 is manufactured. As described above, air remaining between the substrate 12 and the double-sided adhesive tape 24 and between the heat sink 10 and the double-sided adhesive tape 24 at the time of bonding is later formed. It was difficult to remove completely by pressing.

A feature of the present invention is that at least one groove for easily releasing the residual air at the time of bonding to the outside by pressing is provided on the surface of the heat radiating plate 10 bonded to the substrate 12. That is, as in the present embodiment (as shown in FIGS. 1 and 2), the grooves 11a and 11b are provided along the longitudinal direction of the heat sink 10. Thus, after bonding the substrate 12 and the heat radiating plate 10, the residual air can be efficiently released from the grooves 11 a and 11 b to the outside by pressing the substrate 12 from above with the silicon rubber roller. Therefore, the substrate 12 and the heat sink 1
A value of 0 is adhered by the double-sided adhesive tape 24 having a uniform film thickness, and uneven bonding is eliminated. Therefore, the heating resistor 1
4 is transferred from the substrate 12 to the radiator plate 10,
A thermal head having a constant thermal conductivity can be obtained.

The grooves 11a and 11b of this embodiment are
The heat radiation plate 10 may be formed at the time of die extrusion molding, or may be formed after the die molding.

Further, in the case of the present embodiment, the grooves are two grooves 11a and 11b, but the present invention is not limited to this. Further, the position of the groove formed in the heating plate 10 is not limited to the position shown in FIG.
Any position may be used as long as it is a position where the residual air generated according to the material of the heat sink 10 can be efficiently removed.

Next, an apparatus including a thermal head according to the present invention, for example, a printer will be described. FIG. 3 is a cross-sectional view showing one embodiment of the internal structure of the printer including the thermal head according to the present invention.

The printer comprises a document supply section, a recording paper supply section, a thermal head 37 of the present invention, a system control board 32, and a power supply 33. First, the document supply unit includes a feed-in tray (not shown) for storing the document 30, a supply roller 31a for feeding the document 30, a platen roller 31b, an image sensor 31c, and a light source 31d. The recording sheet supply unit includes a recording platen roller 36 for feeding the recording sheet 17 onto which the document is transferred. In the present invention, these functions do not have a main role, and thus detailed description is omitted. On the other hand, the recording paper 17 supplied by the recording paper supply unit is thermally transferred by the above-described thermal head 37 of the present invention. If the thermal head 37 of the present invention and a printer having the same are used at the time of the thermal transfer, extremely clear printing without printing unevenness can be performed.

[0020]

As described above, the thermal head according to the present invention and the apparatus having the thermal head are provided on the surface of the heat radiating plate bonded to the substrate of the thermal head along the longitudinal direction of the heat radiating plate. Since one or a plurality of grooves are provided, air that inhibits the adhesion existing on the bonding surface between the heat sink and the double-sided adhesive tape and between the substrate and the double-sided adhesive tape can be released to the outside by pressing.

Thus, even if the surfaces of the substrate and the heat radiating plate are flat, it is possible to prevent the bonding unevenness in the bonding between the substrate and the heat radiating plate. Can be prevented.

In addition, the provision of the groove in the heat sink allows the use of a double-sided adhesive tape instead of the adhesive.
Therefore, the manufacturing process of the thermal head can be simplified.

[Brief description of the drawings]

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

FIG. 2 is an enlarged cross-sectional view in which a Y part in FIG. 1 is enlarged.

FIG. 3 is a sectional view showing an embodiment of an internal structure of a printer including a thermal head according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Heat sink 11a, 11b, groove 12 Substrate 14 Heating resistor 15 External connection board 16 Film 17 Recording paper 18 Pressing rubber 20 Protective cover 22 Screw 36 Recording platen roller

Claims (2)

(57) [Claims] 1. A thermal head comprising: a substrate provided in a heat generating portion; a heat radiating plate fixed to a back surface of the substrate via a double-sided adhesive tape ; and a heat generating resistor formed on the heat radiating plate . On the surface of the radiator plate bonded to the substrate , avoid the lower part of the heating resistor along the longitudinal direction of the radiator plate.
As described above, the heat sink and the double-sided adhesive tape, and at least one or more grooves for releasing air that inhibits the adhesion existing on each bonding surface when bonding the substrate and the double-sided adhesive tape to the outside, thermal head is characterized in that there. 2. A feed-in tray for stocking stacked documents, a feed roller for drawing and conveying the uppermost sheet from the feed-in tray for stocking stacked documents, and a document conveyed by the feed roller An image sensor for reading the characters of the image as an image signal, a document supply unit, a recording sheet for transferring the document, a recording sheet platen roller for conveying the recording sheet,
A record for paper supply unit consisting of the thermal head to the image read on the recording paper by the image sensor printed on the recording paper, a device having a thermal head including the thermal head, heating A substrate having a portion, a heat sink fixed to the back surface of the substrate via a double-sided adhesive tape, and a heat generating resistor formed on the heat sink , wherein the thermal head includes: On the surface of the heat sink , avoid the lower part of the heating resistor along the longitudinal direction of the heat sink.
As described above, the heat sink and the double-sided adhesive tape, and at least one or more grooves for releasing air that inhibits the adhesion existing on each bonding surface when bonding the substrate and the double-sided adhesive tape to the outside, apparatus having a thermal head is characterized in that there.