JPS627567A - Thermal head - Google Patents

Abstract

PURPOSE:To obtain a thermal head having an arbitrary shape and favorable characteristics, by vitrifying the surface of a substrate formed of a crystallized galss and disposed beneath heating resistors. CONSTITUTION:A crylstalliced glass material 1a is cut, and is ground and polished to obtaine a semicylindrically shaped head substrate 1. The crystallized glass 1a has extremely favorable machinability, and can be ground to an arbitrary shape. Then, the glass 1a is annealed to vitrify the surface 1b thereof, thereby lowering the thermal conductivity. A predetermined number of heating resistors 2 are provided at a top part of the vitrified surface 1b the crystallized glass 1a, and electrodes 3, 3 are provided in connection with the resistors 2. The head substrate 1 has an ideal two-layer construction comprising a heat- insulating layer 1a. Accordingly, heat from the resistors 2 on the surface 1b which accumulates much heat is efficiently transferred to an ink ribbon and a printing paper, and printing free from blurring, trailing of ink image or the like can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal head used in, for example, a thermal transfer printer.

[Summary of the invention]

The present invention relates to a thermal head used in a thermal transfer printer, for example, in which a heating resistor is provided on a head substrate, and a crystallized glass substrate is used as the head substrate. By vitrifying at least the surface of the crystallized glass substrate immediately below the heating resistor, a thermal head of any shape with good characteristics can be obtained.

[Conventional technology]

Thermal heads shown in Figures 2 and 3 are conventionally used in thermal transfer printers! is proposed. In Figs. 2 and 3, (1) indicates a semicylindrical head substrate;
.

A predetermined number of heating resistors (2) are provided at equal intervals on the top of the head substrate (1) on the sliding contact surface with the ink ribbon, and electrodes (3) (3) are connected to the heating resistors (2). is being extended. The head board (IJ
A conductive pattern corresponding to one electrode (3) (3) on both sides
4) Place (4) on the end surface of the plate-shaped base (5) made of alumina or the like, and place the electrode (4) on the head substrate tII.
31 (31 and the corresponding conductive pattern (4) on the substrate (5)
) (4) and a thin piece of silver Ag or aluminum 5M etc. between it?
Electrical connection is made by wire bonding using jM(6).

In a printer equipped with such a thermal head, the thermal head is brought into contact with photographic paper fixed to a platen via an ink ribbon, and the photographic paper and paper are moved perpendicularly to the thermal head at a predetermined speed. While sliding the ink ribbon, a current corresponding to the information signal is supplied to a predetermined number of heating resistors (2) arranged in the horizontal direction of this thermal head to cause the heating object (2) to generate heat. , characters, figures, etc. were printed according to this information signal.

[Problem that the invention seeks to solve]

Glazed alumina is generally used as the material for the head substrate (1) of the thermal head of such a thermal transfer printer, but this glazed alumina has poor workability and is extremely difficult to form into shapes other than child shapes. There is a certain drawback.

Further, it is possible to use glass as a material for the head substrate (1) of this thermal head, but glass has the disadvantage that it accumulates a large amount of heat and tends to bleed and cause two tails on the print.

Furthermore, the use of crystallized glass as the material for the head substrate (1) of this thermal head was proposed in Japanese Utility Model Application No. 58-21,446, but this crystallized glass has better heat storage than glazed alumina. Although the heat generation resistor (2) has a relatively large heat dissipation through the crystallized glass head substrate (1), there is a disadvantage that the efficiency of the thermal head is low.

In view of these points, the present invention proposes a thermal head that can have an arbitrary shape and has relatively high efficiency as a thermal head.

[Means for solving problems]

The present invention provides a thermal head in which a heating resistor (2) is provided on a head substrate (1) as shown in FIG. 1, in which a crystallized glass substrate (1a) is used as the head substrate (IJ) and At least the surface of the crystallized glass substrate (1a) immediately below the heating resistor (2) (Ib) is vitrified.

[Effect]

According to the present invention, since the crystallized glass substrate (1g) is used as the head substrate (1) of the thermal head, it has good workability and can be formed into any shape. Since the surface directly below the heating resistor (2) is glassified, the glass directly under the heating resistor (2) stores a large amount of heat, and the heat is transferred from the heating resistor (2) to the photographic paper via the ink ribbon. The heat supplied is large (and the efficiency of the thermal head can be improved).

〔Example〕

Hereinafter, one embodiment of the thermal head of the present invention will be explained with reference to FIG. 1. In FIG. 1, parts corresponding to FIGS. is omitted.

This Figure 1 shows the manufacturing process of the thermal head of this example. First, as shown in Figure 1, a crystallized glass material (glass ceramic material'> (la) is cut into a prismatic shape. (1a) is ground and polished to form a semicylindrical head substrate (1) as shown in FIG. This is extremely good compared to other materials, and it can be ground into any desired shape.

Next K, this kamabako-shaped crystallized glass (LA)? By annealing, as shown in Figure 1C, the surface m (lb) of this semicircular-shaped crystallized glass (1g) is vitrified, and the thermal conductivity of the surface # (lb) of this crystallized glass (1a) is reduced. do.

Next, as shown in FIG. 1DK, a predetermined number of heating resistors (2) are provided at equal intervals on the top of the vitrified table m (lb) of this crystallized glass (1a), and the heating resistors (
2) and extend the electrode (3) (3). In this case, the heating resistor (2) is TaSi2 and LaCrO.
Using a mixture of 3 and 3 at a ratio of 7=3, the electrode <3)
As (3), an alloy of aluminum, υ and copper Cu is used, and the heating resistor (
2) and electrode (3J (3J part is 5i02 and Ta2
C) Cover with a protective layer consisting of two layers of 5 and 5. Next, apply the second layer.
As shown in the figure, a head substrate (1) made of crystallized glass (1a) whose surface (1b) is vitrified is connected to a conductive pattern (4) corresponding to the electrode (31 (3J) of the head substrate (1) 4) is placed on the end face of a plate-shaped base (5) made of alumina or the like, and the electrode (31 (3) on this head substrate (1) and the corresponding conductive pattern on the base (5) (4) Electrical connection is made between (4) by wire bonding using a thin wire (6) of silver A or aluminum M, etc., and the other configuration is the same as the conventional one.

According to this example, the head substrate (13) is crystallized glass (13).
a) is used, and this crystallized glass (1a) has good processing characteristics such as grinding and can be ground into any shape, making it possible to obtain a head substrate (1) of any shape. In addition, in this example, the table m of crystallized glass (1a)
Since (lb) is vitrified, this table m (Ib)
has lower thermal conductivity than crystallized glass (1 m), so this head substrate (1) has an ideal two-layer structure of a heat insulating layer (1b) and a heat dissipation layer (1a), and this heat storage is The heat from the heating resistor (2) on this large surface (1b) is efficiently transferred to the ink ribbon and photographic paper, and the K
It is possible to print without causing smearing or tailing. By the way, J! for the good characteristics of this example! This will be explained with reference to FIG.

A thermal head according to this example, a conventional thermal head using crystallized glass as the head substrate (11), a conventional thermal head using glazed alumina as the head substrate (1), and a conventional thermal head using glass as the head substrate (1). Looking at the temperature response changes when applying a pulse of 3filJeG to the heating resistor (2) in the conventional thermal head, the changes are as shown in the curves a%b, -C, and d in Figure 4, respectively. The one using glazed aluminum for the head substrate (1) has too good heat dissipation as shown in characteristic curve @C and does not heat up sufficiently, and the one using glass for the head substrate (1) has heat storage as shown in characteristic curve d. The temperature rises to about 400°C, which is sufficient for printing. However, due to poor heat dissipation, printing causes smudges, uneven density, and uneven density, making it difficult to obtain good prints. Also, the head substrate ( As shown in characteristic surface MAb, the one using crystallized glass as 1) has higher heat storage than the characteristic curve c using glazed aluminum, but is only halfway good as a heat insulating material and has low efficiency.

On the other hand, in the characteristic surface @a according to this example, the temperature rises to about 400°C, which is sufficient for printing, and rapid heat dissipation occurs, resulting in good prints without bleeding, tails, or density unevenness. can be done.

In the above embodiment, the entire surface m (lb) of the crystallized glass (1a) constituting the head substrate (13) was annealed and vitrified.
It is easy to understand that the same effect as described above can be obtained even if only the surface directly below the heating resistor (2) provided with the heating resistor (2) is vitrified by laser or the like, and the present invention is not limited to the above-mentioned embodiment. The present invention is not limited to this, and it goes without saying that various other configurations may be adopted without departing from the gist of the present invention.

〔Effect of the invention〕

According to the present invention, since the crystallized glass substrate (1a) is used as the head substrate (1) of the thermal head, there is an advantage that the processability is good and it is possible to obtain a thermal head of any shape. Since the table m (lb) below the heat generating resistor (2) of the glass-containing glass substrate (1a) is vitrified, the glass below this heat generating resistor (2) has a large amount of heat storage. ) can be sufficiently raised and heat can be dissipated quickly, which has the advantage that good printing can be performed without bleeding, tailing, or density unevenness.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the manufacturing process of an embodiment of the thermal head of the present invention, Fig. 2 is a perspective view showing an example of the thermal head, Fig. 3 is a sectional view of Fig. 2, and Fig. 4 is the invention FIG. (1) is a head substrate, (1a) is crystallized glass, (1b
) is glass, (2) is a heating resistor, and (3) is the 'rt pole.

Claims (1)

[Claims] A thermal head in which a heating resistor is provided on a head substrate, characterized in that a crystallized glass substrate is used as the head substrate, and at least a surface of the crystallized glass substrate directly below the heating resistor is vitrified. thermal head.