JPH0582305B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal printing device used as a printer such as a word processor or a typewriter.

FIG. 1 is a plan view of a thermal printing apparatus for explaining the prior art, and FIG. 2 is an equivalent circuit diagram thereof. In this thermal printing device, a large number of resistance heating elements 2 forming heating dots are formed in a row in the left-right direction in FIG. 1 on one surface of a flat substrate 1 made of an electrically insulating material such as ceramics or glass. has been done. A common conductor 3 is connected to the upper end of one end of the resistance heating element 2. Further, at the lower end of the other end of the resistive heating element 2, a plurality of individual drive signal lines generally indicated by reference numerals A1 to An are formed at intervals from each other. The individual drive signal lines A1 to An are generally designated by reference numbers Da1 to Dn of the integrated circuit elements D1 to Dn.
A plurality of terminals Da1 to Dan indicated by Da2 are connected. The integrated circuit elements D1-Dn include a plurality of control signal lines, generally designated by reference characters B1-Bn;
The above integrated circuit elements D1 to Dn denoted by E1 to En
A power supply line E1~ which supplies electricity to each resistance heating element 2 via
En is the general reference numeral Db1 of the integrated circuit element D1.
Multiple terminals indicated by ~Dbn and terminals De1~Den
are connected to each.

The integrated circuit element D1 responds to a control signal input via the control signal line B1, and selectively connects the power supply line E1 and each of the individual drive signal lines A1 to conduction. Each of the individual drive signal lines A1 is individually connected to the resistance heating element 2. Note that the same applies to the remaining integrated circuit elements D2 to Dn.

In FIG. 1, the thermal recording paper is moved in a direction (vertical direction in FIG. 1) perpendicular to the extending direction of the resistance heating element 2 (horizontal direction in FIG. 1). Along with this movement,
A power supply path E is provided to the resistance heating element 2 constituting each heating dot.
1 to En, individual drive signal lines A1 to An, and the common conductor 3, voltages are applied to each heating dot to selectively generate heat, thereby printing dots on the sensitive recording paper.

However, in this prior art, as shown enlarged in FIG. 3, the resistive heating element 2 and the integrated circuit element D1
The individual drive signal lines A1 to A32 connecting these lines are usually made of aluminum (Al) to increase wiring density.
Although these metals are formed to have the same line width and thickness using a thin film method such as vapor deposition or sputtering, and an etching process, the distance from the resistance heating element 2 of each terminal Da1 to Da32 in the integrated circuit element D1 is Since they are different from each other, the individual drive signal lines A1 to A32 have different wiring lengths and different electrical resistances. Therefore, during printing, even if the same voltage is applied between the common conductor 3 and the terminals Da1 to Da32, the voltage applied to each resistance heating element 2 will vary because the electrical resistance of each individual drive signal line is different. , so that each resistance heating element 2
This method has the disadvantage that it is not possible to uniformly generate heat to a predetermined temperature, resulting in uneven printing and a marked deterioration in printing quality.

The present invention was devised in view of the above-mentioned drawbacks, and its purpose is to suppress variations in the electrical resistance of individual drive signals, and to improve print quality by always uniformly heating the heat of each resistance heating element to a predetermined temperature. Our objective is to provide an extremely superior thermal printing device.

The present invention provides a plurality of resistance heating elements on one surface of an electrically insulating substrate, a common conductor commonly connected to one end of the resistance heating element, and a resistance heating element connected to the other end of the resistance heating element. the same number of individual drive signal lines, a switching integrated circuit element connected to the other end of the individual drive signal line, a control signal line connected to the integrated circuit element, and each resistor via each of the integrated circuit elements. In a thermal printing device in which a power supply path for supplying electricity to a heating element is attached and formed, the common conductor and power supply path are formed with a thick film, the individual drive signal lines and control signal lines are formed with a thin film, and the individual drive signal lines are formed with a thin film. A feature is that the wiring thickness is made to vary depending on the wiring length.

Hereinafter, the present invention will be explained in detail based on the embodiment shown in FIGS. 4 and 5.

In the figure, the same parts as in the conventional product are given the same reference numerals.

FIG. 4 shows a partially enlarged view of the vicinity of the integrated circuit element of the thermal printing apparatus of the present invention, in which the individual drive signal lines generally indicated by reference numeral A1 are individually indicated by reference numerals A101 to A101 for each heating dot. A132 respectively. Similarly, control signal lines B1 are individually designated by reference numerals B101 to B105. Further, the terminals Da1 of the integrated circuit element D1 are individually indicated by reference marks Da101 to Da132, and the terminals Db1 are individually indicated by reference marks Db101 to Db.
105.

In manufacturing such a thermal printing device, first, a resistance heating element 2 is formed on the surface of an electrically insulating substrate 1 made of ceramic, glass, or the like. Next, the common conductor 31 and the power supply path EX1 are formed, and finally the individual drive signal lines A1 (A101 to A132) and the control signal lines B1 (B101 to B105) are formed. The common conductor 31 and the power supply line EX1 are made of, for example, gold (Au), silver (Ag), copper (Cu), or a metal containing these as main components, and are formed by a conventionally well-known thick film method. . This common conductor 31
Since the power supply path EX1 is formed of a good electrical conductor, even if the width of the conductive path is narrowed due to high-density wiring, the electrical resistance can be kept to an extremely low value. Therefore, even if a relatively large current flows through the common conductor 31 and the power supply path EX1 during printing, no large voltage drop occurs in the common conductor 31, etc., and the heat generated by the resistance heating element 2 is always kept at a predetermined temperature. be able to.

In the present invention, it is important to vary the wiring thickness of the individual drive signal lines connecting the heating resistor and the integrated circuit element in accordance with the wiring length. Therefore, in the embodiment shown in FIGS. 4 and 5, the individual drive signal lines A116 and A117 have the longest wiring length.
Individual drive signal line A10 with the shortest wiring length from
1 and A132, a thin wall portion X is provided that gradually becomes longer toward A132. The individual drive signal lines A101 to A115 and A118 to A132 are provided with a thin wall portion X corresponding to the wiring length and the wiring thickness is changed.
32 have the same electrical resistance, making it possible to uniformly apply a constant voltage to all the resistance heating elements 2.

The thin portions X of the individual drive signal lines A101 to A132 are formed by a conventionally known etching process.

The individual drive signal lines A101 to A132 and control signal lines B101 to B105 are the same as in the conventional product.
It is made of metal such as Al or Ni, and is formed on the insulating substrate 1 by employing a conventionally well-known thin-wall method. Although these individual drive signal lines A101 to A132 and control signal lines 101 to B105 have a high resistance value because the width of the conductive path is narrow due to high density wiring, the current flowing through each signal line is
This is a relatively small value (40 to 50 mA), and no voltage drop occurs in each signal line. Note that each of the individual drive signal lines A101 to A132 is formed so as to be attached to the resistive heating element 2 so that a part thereof is connected to both ends of each resistive heating element 2.

Further, the individual drive signal lines A101 to A132,
The control signal lines B101 to B105 and the power supply line EX1 each have a terminal Da101 of the integrated circuit element D1.
~Da132, Db101~Db105, and De
are electrically connected to each other via a conductive adhesive or the like, and the integrated circuit element D1 is connected to the control signal lines B101 to B101.
The power supply path EX1 and individual drive signal lines A101 to A13 correspond to the control signal input via B105.
2 are selectively made conductive.

Although the above description has been made in relation to the integrated circuit element D1, the same applies to the remaining integrated circuit elements.

Thus, according to the thermal printing apparatus of the present invention, the common conductor and the power supply path are formed with a thick film, and the wiring thickness of each individual drive signal line is adjusted so that the electrical resistance of all the individual drive signal lines is substantially the same. By making the difference according to the wiring length, it is possible to effectively prevent variations in the voltage applied to each resistance heating element during printing, and the printing quality can be improved by keeping the heat generation temperature of all resistance heating elements constant at all times. An extremely excellent and highly reliable thermal printing device can be obtained.

Note that the present invention is not limited to the above embodiments, and various changes can be made without departing from the gist of the present invention.

[Brief explanation of the drawing]

Figure 1 is a plan view to explain the prior art;
The figure is an equivalent circuit diagram of the thermal printing device shown in FIG.
FIG. 3 is a partially enlarged sectional view for explaining the prior art, FIG. 4 is an enlarged plan view of the vicinity of the integrated circuit element D1 showing an embodiment of the present invention, and FIG. 5 is a Y--
It is a sectional view taken along the Y line. 1... Board, 2... Resistance heating element, 3, 31...
Common conductor, A1~An, A101~A132...
Individual drive signal lines, B1 to Bn, B101 to B10
5...Control signal line, D1-Dn...Integrated circuit element,
Da1~Dan, Db1~Dbn, De1~Den... terminal,
E1, EX1...Power supply path, X...Thin section.

Claims (1)

[Claims] 1. On one surface of an electrically insulating substrate, a plurality of resistance heating elements, a common conductor commonly connected to one end of the resistance heating elements, and the same number of resistance heating elements connected to the other end of the resistance heating elements. individual drive signal line, a switching integrated circuit element connected to the other end of the individual drive signal line, a control signal line connected to the integrated circuit element, and each resistance heat generating element via each of the above integrated circuit elements. In a thermal printing device in which a power supply path for supplying current to the body is formed, the common conductor and the power supply path are formed with a thick film, the individual drive signal lines and the control signal line are formed with a thin film, and the wiring of the individual drive signal lines is A thermal printing device characterized in that the thickness varies depending on the length of the wiring.