JPS6140168A - End face type thermal head - Google Patents

Abstract

PURPOSE:To provide excellent heat-releasing characteristics, reduce size, enhance convenience in use and facilitate manufacturing a heating element board and lead wiring for electrodes, by providing a heating element board comprising heating elements on an end face of a plate form substrate. CONSTITUTION:The heating element board 20 comprises a glass glaze layer 22 on the plate form substrate 21 formed of a ceramic or the like, with the heating elements 26 provided on the end face 25 in a row. Image signal electrodes 28 are provided on a major surface 23 continuous with the end face, and a common electrode 27 is extended on a mafor surface 24. The end face 25 provided with the heating elements 26 and the two major surfaces 23, 24 provided respectively with the image signal electrodes 28 and the common electrode 27 are substantially plane surfaces, whereas edge parts 29, 30 at which the end face 25 intersects with the major surfaces 23, 24 are constituted of curved surfaces. The board 20 is fitted to a base 31 through a heat-releasing insulating elastic member 32. A heat-transmitting 40 is provided between the board 20, exclusive of the end face 25 provided with the heating elements 26, and an end part 39 of the base 31.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Use The thermosensitive recording method is easy to maintain, so it is used as printers for many terminals including facsimile machines. Furthermore, in recent years, thermal transfer methods have been developed, making it possible to perform multicolor recording or full color recording, and are being developed as new recording equipment. The present invention relates to a thermal head used in such a heat-sensitive recording method.

2. Description of the Related Art Conventional Structures and Problems Conventionally, recording devices employing a thermal recording method using a thermal head have been mainly used for black and white binary recording, such as facsimile machines.

However, in recent years, there has been a sudden increase in demand for devices that can perform multi-tone recording, multi-color recording, and full-color image recording.

Under these circumstances, a thermal transfer recording system as shown in FIG. 1 has recently been proposed as a recording system that can perform multi-gradation recording and full-color image recording. This method is the first
As shown in the figure, a transfer sheet 3 coated with, for example, a heat-melting pigment or heat-sublimable dye is placed on an image-receiving paper 2 wound around a rotating drum 1, and thermal recording is performed using a thermal head 4. , the pigment or dye on the transfer sheet 3 is transferred onto the image receiving paper 2 for recording.

Therefore, the transfer sheet 3 described above was replaced with one in which the transfer layers of yellow (7), magenta and cyan (C1) were painted separately as shown in FIG. However, by transferring each color to the same image receiving paper 2, it is possible to record a color image by a so-called subtractive color method.

The thermal head 4 that performs thermal recording in the above-described recording apparatus is a planar thermal head in which a heating element array 6 is formed on the main plane of a heating element substrate 6, as shown in FIG. This is thought to be because the thermal head 4 is generally manufactured using a thin film forming technique, so the planar type is easier to manufacture and there are fewer factors that increase the price.

However, in constructing an apparatus or recording a color image using such a planar thermal head, there are the following drawbacks.

That is, as shown in FIG. 3, the planar thermal head 4 has a semiconductor element 7 or a heating element connected to each heating element to facilitate heating of the heating element array 6 on the side where the heating element array 6 is formed. A semiconductor protection cover 10 for mechanically protecting the lead wires 9 and the like connected to the common electrode section 8 of the row 6. Each electrode protection cover 11 was provided. Therefore, these protective covers and transfer sheets 3. It is necessary to prevent the image receiving paper 2 and the rotating drum 1 from coming into contact with each other, which increases the size of the heat generating substrate 5, which not only increases the cost of the thermal head but also increases the size of the apparatus.

Further, since the heating element substrate 6 is plate-shaped, the heating element forming surface 12 on which the heating element rows 6 are formed is affected by warping and bending of the substrate, and the heating element substrate 5 is bonded to the base 13. Therefore, the flatness in the vicinity of the heating element array 6 was poor due to uneven thickness of the heating element substrate 6, uneven thickness of the adhesive, and the like. Unfortunately, a good head contact condition between the thermal head 4, transfer sheet 3, and image receiving paper 2, which is necessary when performing color recording, cannot be ensured, and as a result, a good color recorded image cannot be obtained. was.

By the way, a color image is an image that is a combination of multiple colors and multiple gradations, so when recording such a color image, the most important thing required of a thermal head is to check the heating state of each heating element 1. The goal is to eliminate variations and reduce unevenness in recording density.

For this reason, as mentioned above, the flatness near the heating element array is poor,
Variations in the contact between the transfer sheet and the image-receiving paper can cause uneven color density of pigments and dyes on the transfer sheet, making it impossible to record good color images.
It is.

Recently, these shortcomings have been solved, and a thermal head suitable for color image recording using the thermal transfer method has been developed, as shown in Figure 4, which uses a cylindrical heating element substrate and has a row of heating elements mounted on the top of the substrate. Thermal heads have been proposed.

(Hereinafter, this type of thermal head will be referred to as an edge-type thermal head to distinguish it from a flat-type thermal head, and will be used in the following explanations in the text.) However, in this type of edge-type thermal head, Although this solves the problem of thermal heads to some extent, it still has the following drawbacks.

That is, since the heating element row 15 is formed on the top of the cylindrical heating element substrate 14, the transfer sheet 3. Since the image receiving paper 2 and the rotating drum 1 are not in contact with each other, the device can be significantly downsized. On the other hand, the contact state between the heating element row 15 and the transfer sheet 3 is close to point contact, and good head contact can be achieved stably. It was difficult to maintain.

In addition, a high-density heating element row 1 is placed on the cylindrical substrate surface (on a curved surface).
It is difficult to accurately form the electrodes 5 and 16, and since the electrodes are formed on curved surfaces, it is difficult to take out and connect the electrodes.

Furthermore, since the flat thermal head has the entire heating element formed on the main plane of the root-shaped heating element substrate, the distance from the heating element to the base surface is only the thickness of the board, which is extremely close.
Since the heating element of the edge type thermal head is cylindrical, the distance from the heating element array 15 to the surface of the base 17 is long, and the thermal resistance to the base is much larger than that of the flat type thermal head. Heat accumulation phenomenon occurs due to poor heat dissipation,
When recording color images, this caused ghosting and tailing.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional problems, and provides a small and easy-to-use end-face type thermal head with excellent heat dissipation characteristics, which is provided with a heating element substrate in which a heating element is formed on the end surface of a plate-shaped substrate. The purpose is to

Structure of the Invention In order to achieve this object, the present invention forms a plurality of heating elements in a row on the end face of a plate-shaped substrate, and also provides a picture signal electrode and a common electrode on each of two main planes following the end face. the formed heating element substrate; an insulating member having heat dissipation properties provided facing the common electrode surface of the heating element substrate; a base to which the heating element substrate is mounted via the insulating member; and the heating element substrate. and a mounting member that presses and clamps the heating element substrate to the base surface, the end surface of the heating element substrate is provided to protrude from the end of the base, and the mounting member connects the common electrode surface of the heating element substrate through an insulating member having heat dissipation properties. A compact and easy-to-use end-face type thermal thermal module with excellent heat dissipation properties of the heat generating board by pressing it tightly against the base and filling the space between the protruding part of the heat generating board and the end of the base with a thermally conductive material. It provides the head.

DESCRIPTION OF THE EMBODIMENTS The configuration of an end face type thermal head according to an embodiment of the present invention will be described in detail below with reference to the drawings.

5 and 6 are perspective views of an end face type thermal head in one embodiment of the present invention, and FIG. 7 is a sectional view, respectively.

In FIGS. 5 and 6, a heating element substrate 2o has a glass glaze layer 22 provided on a plate-shaped substrate 21 made of ceramic or the like, and heating elements 26 are provided in rows on an end surface 25 thereof. . Further, on the main plane 23 following the end surface, there is an image signal electrode 2.
8 are extended and provided, and a common electrode 27 is also provided to extend on the main plane 24.

Note that the glass glaze layer 22 is provided in order to improve the thermal efficiency when the heating element 26 generates heat and perform thermal recording, and to facilitate pattern formation of the electrodes. However, this glass glaze layer 22 has a large thermal resistance when dissipating heat.
It is not provided on the common electrode surface 24 that is in contact with the base 31 because it hinders heat radiation.

Also, the end surface 26 on which the heating element 26 is formed and the image signal electrode 2
The two main planes on which the common electrode 27 and the common electrode 27 are formed are substantially flat, but the ridges 29 and 3 where the end face 26 and the two main planes intersect
0 is composed of a curved surface.

Therefore, the image signal electrodes 28 . When forming the common electrode 27, it is possible to form a pattern more easily and accurately than in the case of forming a pattern on a conventional cylindrical substrate.

Incidentally, the wiring density of the heating element 26 and the image signal electrode 28 is a wire/U to 16 wires/B, and the ease of pattern formation improves the yield of head manufacturing, which in turn leads to lower costs. be.

In FIGS. 5 and 7, the base 31 is the heating element substrate 20.
is attached via an insulating elastic member 32 having heat dissipation properties, and is made of a metal material such as aluminum. When attaching the heat-shielding substrate 20 to the base 31, the heat-generating substrate 2o is attached so as to protrude from the end portion 39 of the base 31, as shown in FIG. This is to prevent the glass glaze layer 22 constituting the heating element substrate 2o from coming into contact with the substrate portion and causing problems such as breakage or short-circuiting due to breakage of the glass glaze layer 22.

In addition, as shown in FIG.
In order to prevent the base 31 portion and the transfer sheet 45 from coming into contact with each other when recording is performed using the heater 3, the end portion of the base is configured such that the heating element substrate 20 protrudes slightly.

Further, an insulating heat conductive member 40 is filled between the base end 39 and the portion of the heat generating substrate 2° that protrudes from the base end 39 excluding the end surface 25 where the heat generating element 26 is formed. This is because the heating element substrate 20 is provided to protrude from the base 31 for the above-mentioned reason.
This eliminates an increase in thermal resistance due to an increase in the distance between the heating element 26 and the base 31, that is, poor heat radiation. That is, by filling the space between the protruding portion of the heating element substrate 20 and the end portion of the base with the insulating thermally conductive member 40, thermal resistance is lowered and heat radiation is improved.

Incidentally, as the thermally conductive member 40 having insulation properties, a silicone paste for heat dissipation, a thermally conductive rubber made of a polyolefin elastomer and a special Mu1203 filler, or the like is used.

Note that the thermally conductive member 40 having insulating properties is filled so as not to come into contact with the transfer sheet 45, as shown in FIG.

The wiring board 41 is attached to the base 31 and the image signal electrode 28 of the heating element board 20 is also attached to the base 31.
A driving IC 33 for the heat generating element 26 is mounted between the heat generating element 26 and the common electrode 27, and the common electrode 27 is connected by wiring through a film-like wiring board 34.

For mounting, the member 35 is attached to the heating element board 20 and the wiring board 4.
1 to the base 31 and clamp it, spacer 3
It is fixed to the base with screws 38 via 6.37. At this time, the common electrode surface 24 of the heating element substrate 2o is fixed in close contact with the base surface 31 via the insulating elastic member 32 having heat dissipation properties.

Further, the wiring board 41 is provided with a wiring connector 42 as shown in FIG.

Note that the wear-resistant layer 60 protects the heating element 26.

FIG. 8 shows an example of a thermal transfer recording apparatus using an edge type thermal head according to an embodiment of the present invention. In FIG. 8, the end face type thermal head 43 is yellow (Y) and cyan (C).

A transfer sheet 45 coated with a transfer layer 44 made of a heat-melting or sublimable pigment or dye of Magenta CM)
and is pressed against a rotating drum 47 via an image-receiving paper 46.

In this state, while rotating the rotary drum 47 in the true direction of the arrow, the heating element 26 is transferred through the yellow (Y) transfer layer, for example.
When the is heated according to the image signal, the pigment or dye on the transfer sheet 46 is transferred onto the image receiving paper 46, resulting in yellow (Y
) to form an image.

Note that when forming a color image, the same image receiving paper 46 is used.
Yellow (Y), magenta (M), cyan (C) on top
) are sequentially transferred to form a color image by a subtractive color method using superimposition.

At this time, the heating element 26 on the heating element substrate 20 repeats the cycle of heat generation and radiation cooling according to the image signal, but if the heat radiation during cooling is not performed well, heat may accumulate near the heating element. In addition, the same state of heat generation occurs even in places where no image signal is originally applied, making it impossible to record gradations, causing phenomena such as ghosts and tailing on images, and significantly shortening the lifespan of the heating element 26. This was the cause of the decline. However, in the end-face type thermal head according to the present invention, such drawbacks can be overcome because heat dissipation cooling after heat generation in the heating element, that is, heat dissipation, is performed extremely smoothly and efficiently.

That is, in color image recording that requires multiple colors and multiple gradations, heat dissipation from the heat generating substrate is one of the most important factors.The end face of the present invention will be described below.

In the present invention, since the heating element substrate 20 is constituted by a plate-shaped substrate and the heating element 26 is formed on the end surface 26 of the substrate,
It becomes possible to attach the heating element substrate 20 and the base 31 on the main plane 24 having a large area, and the contact heat radiation area with the base 31 can be increased.

Furthermore, since the common electrode surface 24 of the heating element substrate 20 is not provided with the glass glaze layer 22 having high thermal resistance, the heat generated near the heating element is directly transferred to the base 31 via the substrate 21 made of ceramic or the like. Heat is transferred and radiated.

Incidentally, the common electrode 27 does not need to be a high-density pattern electrode like the image signal electrode 28, and can be a simple planar electrode, which makes it possible to eliminate the glass blaze layer.
For example, by thickening the plating layer of the electrode, further improvement in heat dissipation efficiency can be expected.

Furthermore, the common electrode surface 24 of the heating element substrate 20 described above is firmly attached and fixed to the base surface 31' by the mounting member 36 via the heat dissipating material 32, so that the thermal resistance during heat dissipation is further reduced. It can be lowered.

As described above, in the present invention, it is possible to sufficiently reduce the thermal resistance at the contact portion between the base surface 31' and the heat generating substrate 20, and also to reduce the thermal resistance at the portion where the heat generating substrate 2° and the base 31 do not contact, that is, the base plate 20. Even in the part of the heating element substrate protruding from the stand 31, an insulating heat conductive member 4o having heat dissipation properties is provided.
By filling the contact area with the base 31, the contact area with the base 31 is increased, the thermal resistance is lowered, and heat radiation is improved. For this reason, the heat generated in the heating element portion is quickly radiated through the base 31 without being stored in the heating element substrate.

As described above, according to the embodiment of the present invention, the thermal resistance during heat dissipation after recording is performed by making the heating element 26 generate heat can be kept extremely low, and the heat accumulation associated with recording can be minimized.
It is possible to provide bt with an end-face type thermal head suitable for multi-color, multi-gradation recording that can perform smooth heat dissipation.

In addition, since the heating element substrate 20i is composed of a plate-shaped substrate and the heating element 26 is formed on the substantially flat end surface 25, it is easier to manufacture than the conventional cylindrical heating element substrate, and the heating element is Since it is located on a flat surface rather than on the top of a cylinder, it is possible to provide a large contact area with a transfer sheet, etc., and an end face type thermal head with extremely good head touch can be provided.

Note that FIG. 10 shows a recording device using a plurality of edge-type thermal heads 43, and FIG. 3 shows another embodiment of the present invention filled with members.

Effects of the Invention As described above, according to the present invention, a heating element array is formed on the end face of a plate-shaped heating element substrate, and a picture signal electrode and a common electrode are formed on each of the two main planes following the end face. a body substrate, an insulating member having heat dissipation provided facing the heat generating body substrate, a base to which the heat generating body substrate is attached via the insulating member, and a base with the heat generating body substrate protruding from an end of the base. A mounting member for mounting and suppressing and clamping the heating element board on the base is provided, and the heating element board protruding from the end face of the base and the end of the base are filled with an insulating thermally conductive member. By configuring the type thermal head, it is possible to increase the contact heat dissipation area between the heating element board and the base, and shorten the distance between the heating element and the base, resulting in low thermal resistance between the heating element board and the base. It is possible to provide an end face type thermal head with excellent heat dissipation. Furthermore, since the mounting member tightly adheres and fixes the common electrode surface of the plate-shaped heating element substrate, which is not provided with a glass glaze layer, to the base surface via an insulating member having heat dissipating properties, the efficiency of heat dissipation is improved. can be partially increased.

In addition, since the heating element substrate is composed of a plate-shaped substrate, and the heating element, image signal electrode, and common electrode are formed on a substantially flat end surface and main plane, it is possible to manufacture the heating element substrate and take out the electrodes. Not only is connection easy, but since the heating element is formed on the end surface of the substrate, good head contact between the heating element and the transfer sheet or thermal recording paper can be stably obtained.

According to the present invention, it is possible to obtain a head that is suitable for multi-color, multi-tone recording, and has heat dissipation properties that enable high-quality recorded images to be obtained without ghosts or tails. It is possible to provide an excellent, small, and easy-to-use end face type thermal head.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the structure of a thermal transfer recording device using a conventional thermal head, Figure 2 is a perspective view of a transfer sheet used for color recording, and Figures 3 and 4 are conventional planar type and edge type, respectively. Perspective views of the thermal head, Figures 5 and 6.
The figure is a perspective view of an edge-type thermal head according to an embodiment of the present invention, FIG. 7 is a sectional view thereof, and FIGS. 8 and 9 are perspective views of an apparatus using an edge-type thermal head according to an embodiment of the present invention. and enlarged sectional views near the heating element, FIGS. 10 and 11
The figures are a block diagram and a large-scale sectional view of the vicinity of the heating element in another device using the end-face type thermal head according to the present invention. 2o... heating element board, 21... board,
22...Glass glaze layer, 26...
Heating element, 27... Common electrode, 28...
Image signal electrode, 31... Base, 32...
Insulating member, 36...Mounting member, 4o...
...Thermal conductive material. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 Figure 5 Figure 8 Figure 9 -20 Figure 10 Figure 11 π

Claims (1)

[Claims] A plate-shaped heating element substrate in which a plurality of heating elements are formed in a row on an end surface of the plate-shaped substrate, and a picture signal electrode and a common electrode are respectively formed on each of two main planes following the end surface, and this heating element substrate. a base that is attached to a common electrode surface of the base via an insulating member having heat dissipation properties, a mounting member that presses and clamps the heating element substrate to the base surface, and an end surface of the heating element substrate on which the heating element is formed from the end surface of the base. 1. An end-face type thermal head characterized by being provided with a thermally conductive member that protrudes and fills between the protruding portion of the heat-generating body substrate excluding the end face of the base plate on which the heat-generating body is formed, and the end face of the base.