JPS6019550A - End-face type thermal head - Google Patents

Abstract

PURPOSE:To improve the straightness and flatness of a heat generating body train by providing a step portion thin at the end section made up of the end face of a heat generating body substrate on the opposite side of the surface thereof for forming a heat generating body and the end of the surface thereof for forming a picture signal electrode. CONSTITUTION:In a heat generating body substrate 14, a plurality of heat generating bodies 13a are arranged in a row at the end face thereof, a picture signal electrode 14a is formed on the one side thereof while a common electrode 14b on the other side thereof and a step 14c is formed at the end thereof. The substrate is fixed on a base 15 with the step section 14c pressed and grasped by a grasping plate 15a. A semiconductor element 19 for driving the heat generating body 13a is connected between leads of a flexible film carrier 20 and one connection lead block of the semiconductor element is connected to the picture signal electrode 14a while the other lead block to a conductor 16a on a distribution plate 16. Here, the step 14c eliminates the projection of the grasping plate 15a from the electrode forming surface thereby enabling free arrangement of a semiconductor element integrated with a film carrier. Thus, the straightness and the flatness of the heat generating body train can be improved to elevate the printing quality.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Use The thermosensitive recording method is easy to maintain and is therefore used as printers for many terminals including facsimile machines.

Furthermore, in recent years, thermal transfer methods have been developed, and multicolor or full color recording has become possible, and new recording devices are being developed. The present invention relates to a thermal head used in this heat-sensitive recording method.

Problems with the configuration of conventional examples A conventional thermal head will be explained below.

FIG. 1 shows a thermal transfer recording device using a conventional thermal head. 1a is an image receiving paper and 1b is a transfer paper. In this configuration, the image receiving paper 1a and the transfer paper 1bid are integrated, and the recording paper 1 is is forming. 2 is a paper feed roller, 3
is a thermal head, and since the thermal head 3 has a heating element array 3b formed on one of the two main planes of the heating element substrate 3a, this system will hereinafter be referred to as a planar thermal head.

In FIG. 1, the transfer paper 1b and the receiver paper 1 are moved by the paper feed roller 2.
When the heating element array 3b is heated in accordance with both signals while being brought into pressure contact with the heating element array 3b of the thermal head 3 and being fed in the direction of the arrow, recording can be performed on the image receiving paper 1a. Further, if a direct coloring type thermal recording paper is used in place of the transfer paper 1b and image receiving paper 1a in FIG. 1, recording can be carried out using a normal direct coloring type thermal recording system. In such a planar thermal head, the thermal head 3 has a semiconductor element connected to each heating element or a common electrode part of the heating element on the side where the heating element 3b is formed to facilitate heating of the heating element 3b. An electrode protection cup 30 and a semiconductor protection cover 3d were respectively provided to mechanically protect the connected and one-tone wires. Receiving paper 1 to transfer paper 1b or paper feed row 22
It is necessary to avoid contact with anything other than the heating element 3b, and therefore, as the diameter of the paper feed roller 2 increases, the heating element substrate 3a becomes larger, resulting in problems of larger thermal heads and higher costs.

On the other hand, a device having a recording section as shown in FIG. 2 is also used.

In FIG. 2, the thermal head 5 is constructed by forming a heating element array 5b on one of four surfaces (end surface) of a heating element substrate 6a parallel to the thickness direction.

Hereinafter, a head having a configuration not shown in FIG. 2 will be referred to as an end-face type thermal head.

As can be seen from the comparison between Figures 1 and 2, it is better to configure the recording section using an edge-type thermal printer (7) because it allows you to see the recording state from a distance and allows you to use the recording paper more effectively. have. In addition, the recording paper 1 shown in FIGS. 1 and 2
1 shows a case where the image receiving paper 1a and the transfer paper 1b are constructed as one unit, but generally the image receiving paper 1a and the transfer paper 1b are fed from separate feeding mechanisms and are configured to be pressed into contact with each other by a thermal head. Even in such a case, the end-face type thermal head is more advantageous because there are fewer restrictions on device manufacturing.

Furthermore, when performing color recording using the thermal transfer recording method, the edge-type thermal head can solve the problem of color shift in multiple colors with a simple configuration as shown in FIG.

In FIG. 3, the image-receiving paper 1a is wound around the paper feed roller 2 and fixed, and in this state, the image-receiving paper 1a is attached to the heating element array of the thermal head 6 (provided on the end surface that contacts the transfer paper 1b. image receiving paper 1b is pressed into contact with the image receiving paper 1b via the transfer paper 1b, and as the roller 2 rotates, the image receiving paper 1b is sent in the direction of the arrow.

The transfer paper 1b is sequentially coated with cyan 11b, magenta 12b, yellow 13b, and black 14b in the same width as the receiving paper and a length slightly larger than the length of one revolution of the roller 2 as shown in the figure. . Note that the order of the above-mentioned coating layers formed on the transfer paper 1b changes depending on the conditions of the ink such as the dye or pigment used. Each rotation of the paper feed roller transfers the colors cyan, magenta, yellow, and blank (operation in which a heating element is heated according to the image signal and only the heated portion of the dye or pigment on the transfer paper is printed onto the receiving paper). If you do this, you can record in color.

The advantage of using the image receiving paper 1a wrapped around the roller 2 is that the device mechanism is simple as shown in the figure, and the overlapping position of each color can be easily and reliably adjusted by adjusting the rotational position of the paper feeding roller. be.

It is also possible to construct a recording section as shown in FIG. 3 even by using the flat head shown in FIG. 1. However, in this case, it is necessary that the surface of the thermal head shown in FIG. 1 on which the heating element is formed does not come into contact with the image receiving paper, the transfer paper, or the roller except for the part on which the heating element is formed. This limitation is a major problem with conventional planar heads. That is, in the conventional planar thermal head, as shown in FIG. 1, an electrode protection cover 30 and a semiconductor protection force are provided on the surface of the heating element substrate 3a on which the heating element array 3b is formed.
3d is provided.

On the other hand, in order to perform color recording using the method shown in FIG. 3, the length of the outer periphery of the roller around which the image receiving paper 1a is wound must be at least longer than the short side of the recording screen. In the case of monochromatic recording as shown in Fig. 1, the roller diameter is usually about 20 mm, but in order to record 86 plates using the method shown in Fig. 3, the roller diameter is about 60 mm. It is necessary to do so. The diameter of this roller increases as the size of the recording paper increases. As a result, in order to configure the recording section as shown in FIG. 3 with a flat thermal head, the heating element substrate 32L
must be made considerably thicker than in the case of monochromatic recording. Increasing the size of the heating element substrate greatly increases the cost of the thermal head, and also increases the size and price of the color recording device itself.

In addition, there is another problem as follows.

In color recording, the heating element row of the head is required to contact the transmitting paper and the receiving paper with a very uniform pressure contact force, but flat thermal heads are designed to have a flatness that satisfies this requirement. It is difficult to obtain this with a heating element board of

On the other hand, as shown in Figure 3, with an end-face type thermal head, the head shape is not affected even if the roller diameter changes, and it can be made smaller.Moreover, flatness can be ensured because the heating element array is formed on the end face. is also possible.

From these points of view, the planar thermal head, which is currently most commonly used, has major problems when constructing a color recording device δ, and there is a demand for the development of an end-face type thermal head.

On the other hand, although edge-type thermal heads can ensure better flatness of the surface forming the heating element array than flat thermal heads, edge-type thermal heads have their own problems. This causes problems with the straightness of the

The explanation will be given below from A, B, C, and D in FIG.

In FIG. 4, A is an external perspective view of the heating element board 5a, and B
, C, and D are views of the heating element substrate 5a viewed from the direction of the arrow A.

From the viewpoint of print quality and applied power, the heating element substrate 6a is a substrate made of alumina, etc., which is insulating and has good thermal conductivity, and a glass layer which is insulating and has poor thermal conductivity is formed several tens of microns thick on the surface of this substrate. The heating element array 5b has been formed, but since the heating element substrate 5a is a sintered body made by sintering alumina powder at a high temperature of 1000'c'' or more, the heating element array 5b has convex or concave h as shown in C and D in Fig. 4.
Most of the substrates have a warpage of
If printing as shown in Fig. 2 is performed without correcting the warpage h, the straightness of the heating element row 6b will be as poor as 5QO microns, and the contact point of the roller 2 and the heating element row will be 5b hit is maximum 500 microns deviation, heating element row 5b
Pressure force at the center and end of transfer paper 1 and heating element row 6b
There is a gap between the two, resulting in problems such as deterioration of print quality (uneven density between the center and the edges).

Purpose of the Invention The present invention solves the above-mentioned conventional problems, and improves the straightness and flatness of the heating element array, provides good printing quality, reduces costs, and reduces design constraints for the device. An object of the present invention is to provide an edge-type thermal head suitable for can recording using a thermal transfer method.

Structure of the Invention The present invention provides an end portion of a heating element substrate having heating elements formed in rows on its end surface, which is composed of an end surface portion on the opposite side to the heating element forming surface and an end portion of a picture signal electrode forming surface on one main plane. The straightness and flatness of the heating element array of the edge-type thermal head are improved by providing a stepped part with a thin and curving thickness on the surface of the head, and by providing an additional means for holding the heating element substrate to the base at this stepped part. However, the printing quality is good, and the constraints on cost reduction and device design can be reduced.

DESCRIPTION OF THE EMBODIMENTS FIG. 6 is a diagram showing a recording apparatus using an edge-type thermal head according to an embodiment of the present invention.

In FIG. 5, 11 is recording paper, 12 is a paper feed roller,
13 is an end face type thermal head. Paper feed row 212
The recording paper 11 is heated by the heating element 13 of the edge-type thermal head 13.
? When the heating element 13a is heated in accordance with the image signal while feeding the recording paper 11 in the direction of the arrow in pressure contact with L, the recording paper 1
1 can be recorded on.

The details of the end face type thermal head 13 are shown in FIG. 6 below.
This will be explained using FIGS. 7 and 8.

FIG. 6 is a partial perspective view of the heating element substrate in the first embodiment. FIG. 7 is a perspective view showing mounting means for holding the heating element substrate to the base in the first embodiment. FIG. 8 is a perspective view showing a part of the end face type thermal head in cross section in the first embodiment.

In FIG. 6, 14 is a heating element substrate, 142L is an image signal electrode, 14b is a common electrode, and 140 is a stepped portion.

A plurality of heating elements 131L are formed in a row on the second end surface of the heating element substrate 14, and a picture signal electrode 14a is formed on one side of the two main planes, and a common electrode 14b is formed on the other side so as to reach the heating element 13a. A stepped portion 14C is provided so that the thickness is reduced at the end formed by the end surface opposite to the heating element forming surface and the end of the picture signal electrode forming surface. The stepped portion 140 is the heating element 13
a, the electrodes 14a and 14b may be formed either before or after the formation. Further, although the wear-resistant film formed on the heating element is not shown in this figure, it goes without saying that it is formed. The heating element substrate 14 on which the heating element 131L is formed as described above is mounted on a base as shown in FIG. 7 (=1 mounted on a base).

In FIG. 7, 15 is a base, 1sal] holding plate, 15
16 is a set screw, 16 is a wiring board, 16a is a plurality of conductors formed on the wiring board, 17 is a heat sink, and 18 is a common lead.

Double-sided tape is attached to the base 15 so that the surface on which the common electrode 14b (not shown) of the heating element substrate 14 formed with the heating element 132L formed at the end (not shown by the dashed line) is pasted and the surface on which the heating element is formed protrudes. The holding plate 15a is attached to the base with set screws 15b so that the thin part of the holding plate 15a presses and holds the stepped portion 14C of the heating element substrate 14. 15, but at this time, the clamping plate 16a,
The upper surface of the set screw 15b is configured not to protrude from the main plane of the heat generating substrate 14. In addition, the holding plate 16a and the stepped portion 14
It is also possible to press and hold it between C and C via an elastic material such as a rubber sheet. The wiring board 16 is a wiring board in which a plurality of conductors 16a are formed on an insulating base material, and is adhesively fixed to the base 16. The heat sink 1 is a heat sink that improves the heat dissipation effect of the semiconductor element shown in FIG. It is configured and fixed to the base 15 so as not to protrude further. One end of the common lead 18 is connected to a common electrode 14b (not shown) of the heating element 14 by solder or the like, and the other end is connected to a conductor (not shown) on the wiring board 16. As described above, the heating element substrate is clamped and fixed to the base by the clamping plate, and as shown in FIG. 8, the semiconductor element,
An end face type thermal head is constructed by adding additional covers etc.

In FIG. 8, 19 is a semiconductor element, 2o is a film carrier, 21 is a cover, and 22 is a connector. The semiconductor element 19 that drives the heating element 13a is connected between the leads of a film carrier 20 formed on a flexible film and made up of multiple leads, and the other end of the lead group connected to one connection part of the semiconductor element generates heat. Image signal electrode 1 of body substrate 14
4a (not shown) and the lead l! connected to the other connection. '( is connected to the conductor 16a on the wiring board 16. At this time, as explained in FIG. 6, the holding plate 15a is provided with a step on the heating element substrate and does not protrude from the electrode forming surface, so it is integrated into the film carrier. The semiconductor elements can be freely arranged and configured.

The cover 21 presses and fixes the heating element substrate 14 and the wiring board 16 to the base 16 via the elastic member 21& by means of a set screw 21b. One end of the lead wire 22a is connected to a conductor (not shown) on the wiring board 16, and the other end is connected to the connector 22, thereby forming an end face type thermal head.

As described above, in this embodiment, the thickness is reduced at the end formed by the end of the heating element substrate opposite to the heating element forming surface and the image signal electrode forming surface ψ11.1. By providing a stepped portion and fixing the heating element substrate to the base using a clamping plate that presses and clamps the heating element substrate at the stepped portion, the straightness of the heating element array of the heating element substrate having a warp h (not shown in Fig. 4C and D) can be improved. Furthermore, it is possible to provide an end face type thermal hesode which can improve flatness, have good print quality, reduce costs, and reduce constraints on the role of the device.

In the first embodiment, the clamping plate 15a is clamped at three locations, one in the center and two on the left and right sides of the stepped portion 1'4C of the heating element substrate 14.
4. Depending on the shape of the warp h, multiple locations or stepped portions 140
It may be held across all ``1'' of ``1''.

If the warp h of the heating element substrate 14 is rounded, or if it is a simple convex warp as shown in FIG. Needless to say, it's a good thing.

In particular, the difference between an edge-type thermal head and a flat-type thermal head as shown in the conventional example in Figure 1 is that in the recording state, in the case of a flat-type thermal head, a pressure contact force acts between the base and the heating element substrate. As for the ten shearing force acting with the seven shearing forces,
It is sufficient to provide an abutting part and lock it in place, and there is no force that would cause the base to separate from the heating element board.In contrast, in the case of the end face type, as shown in Figure 5, Since force acts on the end face of the heating element substrate in the recording state, a force that peels off the substrate acts.

Therefore, as mentioned above, by fixing the end of the heating element substrate opposite to the heating element, a pressure contact force can be applied to the substrate and the base, improving the reliability of the connection part of the semiconductor element. You can also write it down.

Effects of the Invention The present invention provides an end portion of a heating element substrate having heating elements formed in rows on its end surface, which is composed of an end surface portion on the opposite side to the heating element forming surface and an end portion of the picture signal electrode forming surface on one main plane. By providing a stepped portion with a thinner thickness and providing a mounting means for sandwiching the heating element substrate to the base at this stepped portion, the straightness and averageness of the heating element array can be improved, resulting in good printing quality. As a result, the cost can be reduced, there are few design constraints on the equipment, and an edge-type thermal head can be easily constructed using a semiconductor element integrated with a film gear, which has great practical effects. .

[Brief explanation of the drawing]

Figure 1 shows a thermal transfer recording device using a conventional planar thermal head, Figure 2 shows a thermal transfer recording device using an edge type thermal head, and Figure 3 shows a thermal transfer recording device using an edge type thermal head. FIG. 4 is a diagram showing a substrate shape of a heating element substrate for an end-face type thermal head, and FIG. 5 is a diagram showing an end-face in an embodiment of the present invention. FIG. 6 is a diagram showing a heating element substrate of the edge-type thermal head shown in FIG. 6, and FIG. 7 is based on the heating element substrate of the edge-type thermal head shown in FIG. FIG. 8 is a perspective view showing a cross section of a part of the edge-type thermal head shown in FIG. 6 that is mounted on a film carrier; FIG. FIG. 7 is a diagram showing an additional issue means of another embodiment in which the heating element substrate of FIG. 13...Thermal head, 13a...
Heating element, 14... Heating element board, 15...
- Base, 161L... Holding plate, 16... Wiring board, 19... Semiconductor element, 20... Film carrier, 21... Cover. Figure 1 Figure 3 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6! 86 Figure

Claims (1)

[Claims] A plurality of heating elements are formed in a row on the end face, and a picture signal electrode is formed on one side of the two main planes and a common electrode is formed on the other side so as to reach the heating element on the end face. A plate-shaped heating element substrate having a stepped part so that the thickness is thinner at the end consisting of the end face and the edge of the image signal electrode forming surface, and a base to which the heating element forming surface of this heating element substrate is attached with protrusion. a pedestal; a mounting means for holding the heating element substrate between the bases at least in a part of the stepped portion of the heating element substrate and without protruding from the image signal electrode forming surface of the heating element substrate; and a mounting means fixed to the base; forming a plurality of conductors on an insulating substrate/a wiring board, and forming a plurality of leads electrically connecting the picture signal electrode of the heating element substrate and the plurality of conductors of the wiring board on a flexible film; and a film carrier in which a semiconductor element for driving a heating element of the heating element substrate is mounted between the plurality of leads.