JPS60172553A - Thermal head - Google Patents

Abstract

PURPOSE:To obtain a thermal head which is effective particularly for a pattern printing while making the outline of a drawing clear by sandwitching resistors arranged in plurality between upper and lower layers of electrodes to enable easy improvement in the density of the resistors. CONSTITUTION:An lower layer electrode 22 is mounted as a film on one surface of an insulation substrate 21 and patterns of resistors 31a, 31b, 31c... separated with an insulation layer 23 are formed thereon. Then, a conductor layer 26 is applied on the same plane made up of the resistors 31a, 31b, 31c... and the insulation layer 23. For example, when ''NIPPON'' is given as the pattern of the resistors 31a, 31b, 31c..., a voltage is applied between conductor layers 26 serving as the lower layer electrode 22 and an upper layer electrode. This enables generation of heat from all the resistors to make simultaneous transfer of patterns possible. The surface of the thermal head thus obtained is so flat entirely as to make the drawing clear.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal head, which is used, for example, in a word processor.

[Technical background of the invention]

Thermal head used in word processors, (t
The medical hsad) is configured as shown in Figure 1. A resistor 13 constituting a minimum unit is placed on a glass substrate 11 via an insulating undercoat 12.
m, 13b. 13c and 2 are arranged in tandem, each resistor 13a,
Nos. 3b and 13c- are respectively provided with input electrodes 14a. 14b. 14c... and output electrodes 15a. 15
b. 15c... are connected. The upper surfaces of the resistor and electrode are coated with an overcoat 16 made of glass.
is applied.

In the above-mentioned multi-head, a DC voltage is applied to a resistor selected by a character or main turn signal during its horizontal scanning, and the resistor generates heat, which causes the heat-sensitive sheet 17 to generate heat. By doing so, it is possible to print the entire character or turn. Now, when the resistor 13a generates heat for a certain period of time, a horizontal line is printed on the printing paper, and the resistor 13a.

1,? When b, 1.1c... simultaneously instantaneously generate heat, a vertical line is printed.

[Problems with background technology]

According to the conventional thermal head described above, the resistor's manual electrode and output electrode are provided on the undercoat 12 in a planar manner. In this method, a resistor is formed across the input electrode and output electrode.

Therefore, as can be seen from FIG. 1, in the conventional type, the overcoat 16 of the resistor portion has a raised shape. For this reason, uniform heat transfer to the heat-sensitive sheet 17 cannot be achieved between the edge portions and the center portion of the resistor, resulting in a problem that the outline becomes unclear.

Furthermore, if the density of the resistor is increased to make drawing lines finer, the number of electrodes will be twice as many as the number of resistors on the same plane, requiring advanced manufacturing technology and lowering the manufacturing yield. Furthermore, since the input electrodes and output electrodes are formed on the same plane, when the density is increased, the degree of freedom of wiring in consideration of the direction in which the electrodes are drawn is significantly reduced.

[Purpose of the invention]

This invention has been made in view of the above-mentioned circumstances, and it is possible to obtain a simplified resistor that can easily increase the density of the resistor, and is therefore easy to manufacture and has a good yield, and furthermore, the electrode wiring has a greater degree of freedom. It is an object of the present invention to provide a thermal head which is effective especially when performing pattern printing and which can provide clear outlines of drawing.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram for explaining the basic steps for manufacturing the head of the present invention. On one side of the insulating base 1N21 made of glass or ceramic, there is a lower layer ηj made of copper foil or the like,
The pole 22 is deposited by a method such as printing or vapor deposition. Next, an insulating layer 23 made of photoresist or the like is formed on the upper surface of the lower layer 4J; Its 22 by coating.

In the next step, a mask 24 for obtaining a resistor pattern is provided on the upper surface of the insulating layer 23, and light exposure is performed through the mask 24.

This causes dew on the insulating layer 23 during the development process.
1 (S) remains as a single part, and the other part, the shunting resistor pattern part, is removed.

Therefore, the resistor 25a is placed in this R-turn portion.

Print or print 25br25c...? By noting, the resistors 25 a , 25 b , 25 c
- is a turn separated by an insulating layer. Next, a conductor layer 26, for example, 10
A foil coat of good conductivity with a thickness of ˜20 μm is applied.

The head of the present invention is manufactured by the manufacturing process described above.

According to this invention, the structure is such that the input and output electrodes for the resistor are separated into a lower layer side and an upper surface side. Therefore, input on the same ■■ as before.

Compared to providing an output electrode, in the present invention, it is sufficient to provide either the manual electrode or the output electrode on the same surface, which allows for more space. Therefore, it is suitable for increasing the density of the resistor and obtaining precise drawing. It is also effective as a head that simultaneously prints predetermined turns. Furthermore, the degree of freedom in wiring the electrodes is also improved.

Next, according to the present invention, a resistor is completely buried in the nine-turn hole formed in the insulating layer 23 by printing or depositing, and a flat conductor layer 26 is formed on the upper surface thereof. Therefore, uneven portions do not occur on the printing surface of the head, unlike in the conventional case. Therefore, the heat conduction efficiency with respect to the heat-sensitive sheet is uniform in the center portion and the estuary portion of the resistor, and the outline of the printed image becomes extremely clear. This, in addition to the above-mentioned effect, is effective in obtaining detailed and clear drawings.

FIG. 3 shows an example of a head 30 to which the present invention is applied. In the case of this example, pre-printing! The turn has been decided. For example, it is effective for use in ticket vending machines. In this embodiment, a resistor 31a is used.

31b': , 91c... is an example in which the pattern is "Japan", and if a voltage is applied between the lower electrode 22 and the conductor layer 26 which becomes the upper electrode, all the resistors will generate heat at the same time. This enables simultaneous transfer of multiple turns.

In this case, the vmii pole and the top electrode each serve as a common electrode. In this example, the surface is entirely flat;
The outline of the drawing becomes clearer. Still, the printing speed can be significantly improved compared to conventional methods.

FIG. 4 shows an example of a head 40 to which the present invention is fully applied.

40 connects the lower electrode 22 to each resistor 418 .
Independent electrodes 22h, 22b, 22c are formed by etching or turn printing in correspondence with 41b, 41c...
It was formed as... A common electrode is formed on the conductor layer 26' on the upper surface. This head 40 i'
t, during the horizontal scanning movement, the electrode 22
a.

By selectively applying a voltage to 22b, 22c, etc., a printed pattern can be formed.

In the case of this embodiment as well, the density of the resistor can be increased, and the surface becomes flat, so that the outline of the drawing becomes clear.

FIG. 5 shows 500 examples of heads to which this invention is applied,
It is designed to be flexible by allowing various types of pattern printing to be performed on a frame-by-frame basis. That is, in the case of this embodiment, the lower layer electrodes 22 are, for example, line electrodes 2 forming rows.
2a, 22b.

22c..., and the conductor layer 26 is formed as line electrodes 26a, 26b, 26c... forming columns. A resistor is arranged at each intersection of each matrix line. Note that the 2-in electrodes 26a and 26b on the upper surface.

26c... An insulator is coated between them to make the surface smooth. According to this embodiment, arbitrary turns can be printed by selectively applying a voltage to arbitrary electrodes on the lower layer side and the upper surface side, and it can be used in the same way as the head shown in FIG. This is possible, and it is also possible to use it in the same way as the head shown in FIG. Moreover, the printing speed is also significantly improved compared to the conventional method.

As described above, according to the present invention, by using a +16 structure in which a resistor is sandwiched between the electrodes, it is possible to obtain a printed image with a clear outline without unevenness unlike the conventional one. In addition, there are many advantages such as free electrode wiring area, ease of manufacturing and design, improved yield, improved reliability, increased density, and enable high-speed printing. Furthermore, there is a degree of freedom in electrode wiring, and all terminals can be led out to a convenient level depending on the purpose of use.

[Brief explanation of the drawing]

1(a) and 1(b) are a plan view and a cross-sectional view, respectively, for explaining a conventional thermal head, FIG. FIG. 4 is a perspective view and a sectional view showing one embodiment of this invention, FIG. 4 is a perspective view and sectional view showing another embodiment of this invention, and FIG. 5 shows an electrode structure in still another embodiment of this invention. FIG. 2 No.. Insulating substrate, 22.. Lower layer electrode, 23..
Insulating layer, 25 a , 25 b , 25 c ・=
Resistor, 26... conductor layer. Applicant's agent Patent attorney Suzue Takehikofi 11"1 (a) (b) "I-Ko■: Figure 2, Figure 3r?1

Claims (4)

[Claims] (1) A lower layer electrode provided on the upper surface of the insulating substrate, a plurality of resistors arranged on the lower layer electrode, and a resistor provided on the upper surface formed by the resistor so as to be sandwiched between the resistor and the hL2 lower layer electrode. A thermal head characterized by comprising a top electrode. (2) The arrangement of the resistors is a fixed pattern, and the lower electrode and the upper electrode are common electrodes for the output side of all the resistors, respectively. Thermal head described. (3) The lower layer electrode and the upper surface electrode are characterized in that one of them is a common electrode of the resistor, and the other is a plurality of electrodes corresponding to the resistor. thermal head. (4) The lower layer electrode and the upper surface electrode are matrix-like line electrodes that form lines in the direction of one row and one column corresponding to each of the resistors, respectively. The thermal head according to item 1.