JPH05138914A - Thermal head and thermal printer - Google Patents

Abstract

PURPOSE:To make the installation on an equipment or maintenance thereof easy by extending a selective electrode all over from an inclined face to one main surface and forming a common electrode connected in common to respec tive heat generating bodies to the rear face. CONSTITUTION:An inclined face 4 inclining from one main surface to an end side along one side of a ceramic base 2 in its longitudinal direction is formed. One main surface and the inclined face 4 are coated with glass glazed layers. Heat generating bodies 6 are disposed in a row along the main scanning direction on the inclined face 4, and selective electrodes 8 selecting respective heat generating bodies individually are disposed from the inclined face all over to one main surface on one main surface side of the array of the heat generating body 6. A common electrode 10 is disposed on the end side of the array of the heat generating body 6 on the inclined face 4, and formed from the side of end side of the inclined face 4 passing through the end side all over to the rear face of the base 2. Silver paste and gold paste are double side printer on the common electrode 10 by the thick film printing method and formed by by firing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal head, a thermal printing apparatus such as a printer or a facsimile, and a thermal recording unit equipped with the thermal head.

[0002]

2. Description of the Related Art The thermal heads currently used are
When roughly classified, the heating element is divided into a flat type thermal head in which the heating element is formed on the main surface of the insulating substrate and an end surface type thermal head in which the heating element is formed on the end surface of the insulating substrate. An example of the end surface type thermal head is disclosed in, for example, JP-A-60-8081,
JP-A-60-8082, JP-A-60-19550
It is described in the official gazette. The flat type thermal head has an advantage that the manufacturing process for forming the heating element and the electrode is easy. However, the driving semiconductor integrated circuit device is mounted on the main surface on which the heating element is formed, and the upper part thereof is the protective cover. The recording medium does not come into contact with the protective cover when printing is performed by pressing the heat-sensitive recording paper or a stack of transfer paper and recording paper (hereinafter referred to as recording medium) onto the heating element with the platen roller. Need to be bent. Therefore, it has a drawback that it is difficult to print on a hard recording medium such as a card or tag paper, or on a flat plate.

On the other hand, the end surface type thermal head has an excellent printing characteristic that it can print on a hard material such as a card or a tag paper, but an electrode connected to the heating element is formed on the end surface of the substrate. Since it must be formed by patterning from its end face to the main surface of the substrate,
The manufacturing process becomes complicated, special specialized equipment is required,
Further, it has a drawback that the manufacturing yield is deteriorated and the cost is increased. Further, in the end face type thermal head, an insulating substrate with high component accuracy is required. The present applicant has already proposed, as another type of thermal head for improving printing characteristics, a thermal head which should be called an inclined surface type in which an inclined surface is formed on an insulating substrate and a heating element is arranged on the inclined surface ( See Japanese Utility Model Laid-Open No. 63-113655).

In the thermal printer, a platen roller is used to press the recording medium against the thermal head. Double-sided printing or double-sided printing may be performed with the thermal transfer method.In this case, to print on one side, turn the recording medium over and pass it between the thermal head and platen roller again to print on the other side. A method of preparing two sets of a platen roller and a platen roller and sequentially performing printing on the front surface side and the back surface side is adopted. When the thermal head is attached to the thermal recording device or the thermal recording unit, the thermal recording device or the thermal recording unit is inevitably large in size when the planar thermal head is attached.

Further, in a thermal recording apparatus for performing color printing, if high-speed printing is to be performed, three or four yellow, magenta, and cyan primary colors or four black-added primary colors are used. Use a thermal head. In this case, the size of the color thermosensitive recording device is further increased. Even when an end surface type thermal head is used instead of the flat type thermal head, the problem that the color thermal recording apparatus becomes large still remains.

[0006]

In the inclined surface type thermal head, as shown in FIG. 1, for example, an inclined surface 4 extending from one main surface to an end side is formed along the long side of the substrate 2,
The heating elements 6 are formed on the inclined surface 4 in a row. In order to individually select the heating elements 6 for printing, the selection electrode 8 is formed from the inclined surface to one main surface, and the common electrode 10 is provided between the heating element array 6 and the edge with the inclined surface.
Is formed, and the common electrode 10 is normally connected from both ends in the longitudinal direction to the portion 12 on one main surface.

As long as the electrodes are arranged as described above, the inclined surface type thermal head is the same as the planar type thermal head in terms of wiring layout. Therefore, when the recording width is long or when a large current is consumed, the width of the common electrode 10 is widened in order to increase the current capacity of the common electrode 10 as in the case of the flat type thermal head. It is necessary to increase the thickness. As a result, there arises a problem that the width of the heat generating substrate becomes large. Further, since the regions 12 for guiding the common electrode 10 from the inclined surface to the one main surface are required at both ends in the longitudinal direction, the length of the heat generating substrate is required to be twice as long as the width X of the region 12. become. In order to increase the current capacity of the common electrode 10, it is usually 10 to 20.
A μm electrode layer is used. Therefore, the first aspect of the present invention
The purpose of is to increase the current capacity without increasing the width and thickness of the common electrode, and to eliminate the need for a region for guiding the common electrode to one main surface at both ends in the longitudinal direction. It is to make it small.

A thermal recording apparatus having a platen roller is large in size. When performing double-sided printing, it is necessary to properly synchronize the rotation of the platen roller with the timing of data transfer and printing, which complicates the configuration of the device. Therefore, a second object of the present invention is to reduce the weight and size of the thermosensitive recording apparatus, shorten the time required for double-sided printing, and easily synchronize the data transfer timing. Another object of the present invention is to provide a thermal printing device that can print on the front surface and the back surface at the same timing.

In the conventional thermal recording apparatus, the thermal head is fixed to the device with a screw or the like. This mounting work becomes more complicated in a color recording apparatus using a plurality of thermal heads. Therefore, a third object of the present invention is to provide a thermal recording unit capable of facilitating the work of attaching the thermal head to the device and the maintenance work to improve the efficiency, and further downsizing the device even when attached to the device. Is to provide.

[0010]

In order to achieve the object of reducing the size of the heat generating substrate, in the thermal head of the present invention, the substrate is provided with an inclined surface inclined from one main surface to the end surface, and the inclined surface is formed on the inclined surface. Is a common electrode in which a heating element is arranged, a selection electrode connected to each heating element and individually selecting each heating element extends from the inclined surface over the one main surface, and is commonly connected to each heating element. Are formed from the inclined surface to the back surface.

In order to achieve the purpose of reducing the weight and size and facilitating double-sided printing, the thermal printing apparatus of the present invention comprises:
Two thermal heads having a heating element on the end surface or the inclined surface of the substrate are brought into contact with the end surface or the inclined surface having the heating element facing each other, and the recording medium is sandwiched and pressed between the facing surfaces. Pass and print. In this case, it is preferable to use a thermal head in which a glazing layer extending in the main scanning direction and protruding is partially formed on an end surface or an inclined surface of the substrate, and heating elements are arranged on the partial glaze layer. .

In order to facilitate the work of attaching the thermal head to the equipment and the maintenance work, and to achieve the purpose of downsizing the equipment, the thermal recording unit of the present invention has an inclination inclined from one main surface to the end surface of the substrate. A surface is formed, and one or a plurality of thermal heads in which a heating element is arranged on the inclined surface, and a connector which holds the thermal head in a predetermined position and electrically connects to the thermal head It is equipped with a holder. This heat-sensitive recording unit is combined with a platen roller for pressing the recording medium onto the heating element of the thermal head.

[0013]

FIG. 2 shows an embodiment of an inclined surface type thermal head. (A) is a schematic plan view and (B) is a left side view thereof. An inclined surface 4 is formed along one side of the ceramic substrate 2 in the longitudinal direction from one main surface 3 to an end side 5. The main surface 3 and the inclined surface 4 are covered with a glassy glaze layer. The heating elements 6 are formed on the inclined surface 4 in a row along the main scanning direction (longitudinal direction). On the one main surface side of the heating element array 6, a selection electrode 8 for individually selecting each heating element is formed so as to be arranged from the inclined surface to one main surface, and on the inclined surface 4, an end side of the heating element array 6 is formed. The common electrode 10a is formed on the fifth side. The common electrode 10a passes from the end side of the inclined surface to the end side 5 and passes through the substrate 2
Extends to the back side of. A feature of this embodiment is that a common electrode is provided on the back surface of the substrate 2.

In order to form the common electrode from the inclined surface 4 to the end side 5 and the back surface, silver paste or gold paste can be printed on both sides by a thick film printing method and baked. In the case of the thin film method, Al, Au, Cu or the like can be formed on the inclined surface 4, the edge 5 and the back surface by a vapor deposition method. In this embodiment, since the entire back surface can be used as the common electrode, it is not necessary to provide a thick electrode film for reinforcement in order to increase the current capacity, as compared with the common electrode 10 shown in FIG.

FIG. 3 shows an example in which the heat generating substrate of the embodiment of FIG. 2 is fixed to a support plate together with a printed wiring board to form a thermal head. (A) is a first example thereof, and the heat generating substrate 1
Is fixed to the support plate 18 together with the printed wiring board 16. Through holes 14 are formed in the heat generating substrate 1 to take out the common electrode on the back surface to the front surface side.
The common electrode is taken out on the surface side through the conductor inside.
In order to connect the common electrode to the wiring of the printed wiring board 16, wire bonding with a wire 20 such as gold is performed.

FIG. 3B shows a second example in which the thermal head is assembled. (C) is a bottom view of (B). The heat generating board 1 and the printed wiring board 16 are fixed to a support plate 18. The common electrode on the back surface of the heat generating substrate 1 is soldered to the wiring of the printed wiring board 16 by a jumper wire 22. The support plate 18 is provided with a partially cutout portion for guiding the jumper wire 22 from the rear surface of the heat generating substrate 1 to the front surface of the printed wiring board 16. Figure 3 (B)
By using the jumper wire 22 as described above, it is not necessary to provide a through hole in the heat generating substrate 1, and it is necessary to provide a space for bonding the common electrode and the printed wiring board 16 on one main surface of the heat generating substrate 1. Therefore, the width of the heat generating substrate 1 can be further narrowed.

FIG. 4 shows an embodiment of a thermal printing apparatus which prints by a thermal head without using a platen roller. As in (A) or (B), two inclined surface type or end surface type thermal heads 30 and 32 are made to face each other with the surface having the heating element, and the recording medium 34 is sandwiched between the surfaces having the heating element. Printing is performed while pressing the recording medium 34 and passing it through the recording medium 34. When both 30 and 32 are thermal heads, if the recording medium 34 is sandwiched between recording sheets for thermal transfer and thermal transfer sheets are overlapped on both sides, double-sided printing is performed by the thermal heads 30 and 32 on both sides of the recording sheet. Can be done. In that case, both sides can be printed at the same time, and the printing time is shortened. Further, by using two thermal heads, data signals can be input at the same time, and the timing of the signals can be easily adjusted.
The structure of the drive circuit is simplified, and the size and cost of the system can be reduced. In addition, since the platen roller is not used, the size and weight of the device can be reduced. In FIG. 4, one of the thermal heads 30 and 32 can be a dummy head. In that case, printing is performed with only one thermal head.

The inclined surface type or end surface type thermal head used in the embodiment of FIG. 4 is shown in FIG.
(A) is formed by arranging heating elements on the inclined surface or the end surface along the main scanning direction, and (B) is formed by forming a protrusion along the main scanning direction of the inclined surface by a partial glaze 36, and the partial glaze The heating element is arranged on the top. (C) shows three rows of partial glaze layers 36 along the main scanning direction on the inclined surface.
a, 36b, 36c are formed, and the heating element is formed on the central glaze layer 36b. By forming the partial glaze as in (B) and (C), the contact with the recording medium is improved and the printing quality is improved. FIG. 5 (B),
In order to form the partial glaze as shown in (C), a glaze layer is partially applied by a screen printing method or the like and baked, a heating element is formed on the glaze layer, and an electrode connected to the heating element is formed. ..

FIG. 6 shows an embodiment in which the present invention is applied to a thermal recording unit for color printing. FIG. 1A is a schematic configuration diagram of the whole, in which a holder 40 has a recess for accommodating a platen roller 42, and three inclined surface type thermal heads 44a, 44b, 44c are respectively fitted in the recesses so as to be electrically connected. In order to make a connection, a recess having a connector is formed at the back. Inclined surface type thermal heads 44a, 44
b and 44c are shown as 44 in (B), and the heat generating substrate 46 has an inclined surface along one side of the ceramic substrate and is covered with a glaze layer from the inclined surface to one main surface. The heating element 48 is formed on the glaze layer. The heat generating substrate 46 is fixed to the support plate 52 together with the printed wiring board 50. A driving semiconductor integrated circuit device is mounted on the printed wiring board 50. 54 is a cover.

Such an inclined surface type thermal head 44a
To connect ~ 44c to holder 40, holder 4
As shown in (C), a connector 56 is provided at the back of the recess 45 of 0. The connector 58, which is electrically connected to the connector 56, is the printed wiring board 5 of the thermal head.
It is set to 0. As shown in (D), the thermal head 44 slides along the guide rail portion 47 of the recess 45, whereby the connectors 56 and 58 are electrically connected. In FIG. 6A, each thermal head 44a to 44c
Feeding rollers 62a and 62b are provided between the platen roller 42 and the platen roller 42 to sandwich the recording medium 60 and press it to perform printing.

According to the thermal recording unit of FIG. 6, since the thermal head can be easily incorporated in the holder 40 and the platen roller 42 is positioned with respect to the holder 40, the thermal heads 44a to 44c are connected to the platen roller 42. Easier to position with respect to. Since the thermal heads 44a to 44c can be inserted into and removed from the holder 40, the thermal recording unit can be easily assembled and maintained.

Since the thermal recording unit shown in FIG. 6 uses the inclined surface type thermal head, it can be made compact. This is compared with the case where an end face type thermal head is used. FIG. 7A shows the case where the end surface type thermal heads 64a, 64b, 64c are used. FIG. 6B shows the embodiment of FIG. 6, and by adopting the inclined surface type, the thickness of the holder becomes thin and the holder becomes compact. In the case of the end face type, as shown in (C), the platen roller 42
On the other hand, the end surface of the thermal head 64 must be properly abutted, but in the case of the inclined surface type, there is a margin in the angle as in (D), and even if the positioning accuracy with respect to the platen roller 42 is low, there is no problem. Also in this respect, assembly and maintenance are easy. The present invention is not limited to the one presented in the embodiment, but can be variously modified and utilized.

[0023]

In the thermal head of the present invention in which the common electrode commonly connected to each heating element is formed from the inclined surface to the back surface in the inclined surface type thermal head, the width and thickness of the common electrode need not be increased. Also, the current capacity can be increased, and a region for guiding the common electrode to one main surface is not required at both ends in the longitudinal direction, and the heat generating substrate can be made small. Using two end face type or inclined face type thermal heads,
The heat-sensitive printing apparatus of the present invention which prints by making the end faces or inclined faces having the heating element face each other and contact each other, and sandwiching the recording medium between the facing faces to pass it while pressing it The size can be reduced and double-sided printing can be easily performed. When a thermal head in which a glazing layer extending in the main scanning direction and protruding is partially formed on the end surface or inclined surface of the substrate and a heating element is arranged on the partial glaze layer is used, The contact is improved and the print quality is improved. The thermal recording unit of the present invention in which the inclined surface type thermal head is attached to the holder having the connector for holding the thermal head at a predetermined position and electrically connecting to the thermal head is a thermal recording unit of the present invention. The work can be facilitated and the device can be downsized.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a proposed inclined surface type thermal head, (A) is a schematic plan view, and (B) is a left side view thereof.

2A and 2B are views showing an embodiment of an inclined surface type thermal head, in which FIG. 2A is a schematic plan view and FIG. 2B is a left side view thereof.

3A and 3B are diagrams showing an example of a thermal head in which an inclined surface type heat generating substrate is fixed to a support plate together with a printed wiring board, and FIG. 3A is a side view showing an example of the heat generating substrate in section, and FIG. The side view which shows another example, (C) is a bottom view of (B).

FIGS. 4A and 4B are schematic side views showing an embodiment of a thermal printing apparatus that performs printing with a thermal head without using a platen roller.

5A and 5B are side views showing an inclined surface type thermal head used in the embodiment of FIGS. 4A and 4B, in which FIG. 5A is a view in which heating elements are arranged on the inclined surface along the main scanning direction, and FIG. In which the heating element is arranged on the ridge of the partial glaze along the main scanning direction of (3), (C) is a heating element on the ridge in the center of the ridges of three rows of the partial glaze along the main scanning direction on the inclined surface. Is arranged.

FIG. 6A is a side sectional view showing an embodiment in which the present invention is applied to a thermal recording unit for color printing, and FIG. 6B is a side view showing an inclined surface thermal head used in FIG. (C) is a sectional view showing an electrical connection between the holder and the thermal head, and (D) is a sectional view showing a guide rail portion between the thermal head and the holder.

FIG. 7 is a diagram comparing the sizes of the thermal recording units in the case of using the end surface type thermal head and in the case of using the inclined surface type thermal head. FIG. (B) shows a contact state between the end surface type thermal head and the platen roller, (C) shows a contact state between the end surface type thermal head and the platen roller, when using the inclined surface type thermal head. FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Heat generating substrate 2 Substrate 4 Sloping surface 6 Heating element array 8 Selective electrode 10a Common electrode 30, 32, 44, 44a, 44b, 44c Sloping surface type thermal head 34, 60 Recording medium 36, 36a, 36b, 36c Raising by partial glaze 40 Holder 42 Platen Roller 45 Recess 56, 58 Connector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Higashiguchi 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (72) Masatoshi Ota 1-3-6 Nakamagome, Ota-ku, Tokyo Shares In Ricoh Company (72) Inventor Kyoji Hattori 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh (72) Inventor Hideo Abe 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh

Claims (5)

[Claims] 1. A selection electrode for forming an inclined surface inclined from one main surface to an end surface on a substrate, a heating element disposed on the inclined surface, connected to each heating element, and individually selecting each heating element. Extending from the inclined surface to the one main surface, and a common electrode commonly connected to each heating element is formed from the inclined surface to the back surface. 2. A thermal medium having two heating elements on an end surface or an inclined surface of a substrate is brought into contact with the end surface or the inclined surface having the heating element so as to face each other, and a recording medium is sandwiched between the opposed surfaces. A thermal printing device that prints by pressing and passing. 3. A thermal head in which a raised glaze layer extending in the main scanning direction is partially formed on an end face or an inclined face of a substrate, and heating elements are arranged on the partial glaze layer. Item 3. The thermal printing device according to Item 2. 4. A substrate is provided with an inclined surface inclined from one main surface thereof to an end surface, and one or a plurality of thermal heads having a heating element disposed on the inclined surface, and the thermal head having a predetermined size. A thermal recording unit comprising: a holder having a connector which is held in a position and electrically connected to the thermal head. 5. A substrate is provided with an inclined surface inclined from one main surface thereof to an end surface, and one or a plurality of thermal heads having a heating element disposed on the inclined surface, and the thermal head having a predetermined size. A thermal recording unit comprising a holder having a connector which is held in a position and electrically connected to the thermal head, and a platen roller which presses a recording medium onto a heating element of the thermal head.