JPS61187463A - Thermal head - Google Patents

Abstract

PURPOSE:To attain miniaturization and low cost by constituting a drive IC of two units having respectively a shift register, a latch and a driver to make the shift direction of the output symmetrical mutually thereby avoiding increases in area or multi-layered wiring. CONSTITUTION:A head consists of the 1st unit A and the 2nd unit B, and each unit has respectively independent shift register 11, latch 12 and driver 13. The driver output of each unit corresponds to each column of the heater of the thermal head and connected through a drive electrode lead. The direction of input data shift of the shift register of each unit is made reverse to make the shift direction of the output, that is the arrangement of the driver output symmetrical together. Since both the units are arranged with the drive electrode leads, it is not required to reverse the arrangement of the wires on a head base. Further, one ship is enough to drive two columns of heater resistors.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a thermal device.

[Conventional technology]

Printers using thermal heads have a simple mechanism, low noise, and low cost, and are attracting attention as peripheral devices for personal combinators, word processors, and the like.

Thermal is an array of dot-shaped heating resistors, and by passing a pulsed current through any heating resistor)
It instantly generates heat and records desired numbers, letters, etc.

FIG. 2 shows a conventional thermal head for a serial printer. In the same figure, 21 is a substrate made of ceramic, resin, etc., 22 is a drive electrode lead wire, 23 is a heating resistor, 2
4 is a common electrode lead wire. Recently, a double-row type thermal paper as shown in the same figure is used because it can increase the printing speed compared to the - size type.

Further, by changing the pitch of the heat generating resistors in one row, it is also possible to print characters of a certain size.

Conventionally, a shift register, two
．． When mounting a drive IC chip on a thermal circuit with a built-in circuit, two identical drive IC chips are installed corresponding to each row of heating resistors.
C-chip was used.

In other words, when a drive IC chip as shown in FIG. 3(a) is used, the configuration of the thermal head is as shown in FIG. 3(b). Here, 11, 12, and 13 indicate a shift register, 31, 32, and 33 indicate a driver, a substrate, a drive IC chip, and a drive electrode lead wire, respectively.

[Problem that the invention seeks to solve]

In such a two-row type thermal head, the common electrode is provided between the heat generating resistor rows, so the drive electrode lead wires connected to the drive ICC chip are arranged symmetrically in the left and right rows. , when two same drive IC chips are used, the arrangement of the driver outputs of one drive IC chip is as follows:
There was a problem that the arrangement of the drive electrode lead wires was reversed. For this reason, it may be necessary to increase the area to reverse the arrangement of the wiring on the head board, as shown in Figure 3(b).
This required multilayer wiring. Another drawback was that the resistance values of the left and right lead wires were different.

SUMMARY OF THE INVENTION In view of these drawbacks, it is an object of the present invention to provide a thermal head that does not require changing the arrangement of wiring on a printed circuit board.

[Means for solving problems]

The thermal head of the present invention is equipped with a thermal head drive IC composed of a shift register, a latch, and a driver, and the drive fc is composed of two units, each unit having a shift register, a latch, and a driver. , the sheet directions of the outputs are symmetrical to each other.

〔Example〕

The present invention will be explained below with reference to illustrated embodiments.

FIG. 1 shows an embodiment of the present invention. 11 is a shift register, 12 is a shift register, 13 is an output driver. As shown in the figure, it is composed of a first unit A and a second unit B, and each unit has an independent shift register, latch, and driver. The driver output of each unit corresponds to each row of heating resistors of the thermal head and is connected to the drive electrode lead wire.

Since the input data shift directions of the shift registers of each unit are opposite to each other, the output shift directions, that is, the arrangement of driver outputs are opposite to each other. As a result, since both units match the arrangement of the drive electrode lead wires, there is no need to reverse the wiring on the second substrate. Furthermore, only one chip is required to drive two rows of heating resistor rows.

〔Effect of the invention〕

As described above, according to the thermal head driving IC chip of the present invention, there is no need for an increase in area, multilayer wiring, etc.

Since only one chip is required for the drive IC, it is possible to make the thermal head smaller and lower in price.

Furthermore, if each unit of the thermal head driving IC chip of the present invention is completely symmetrical in shape, the design of the thermal head can also be completely symmetrical, and furthermore, the driving ICC chip design and mask turn fabrication can be simplified. Therefore, it is clear that it is preferable.

[Brief explanation of the drawing]

FIG. 1 shows a thermal head drive I in an embodiment of the present invention.
FIG. 2 is a circuit diagram showing a C chip; FIG. 2 is a plan view showing a thermal circuit in a conventional example; and FIG. 3(a). (b) is a plan view showing a thermal drive IC chip and a thermal head in a conventional example. 11...Shift register, 12...Latch, 13...Output driver, 21...
- Head board, 22... Drive electrode lead wire, 23... Heat generating resistor, 24... Common electrode lead wire. Early 2 @ D7L-----------D2 C to W (OL) (bun Tatsumi 3 Figure, 3/

Claims (2)

[Claims] (1) In a thermal head equipped with a drive IC chip consisting of a shift register, latch, and driver,
The thermal head is characterized in that the driving IC chip is composed of two units, each unit having a shift register/latch and a driver, and output shift directions are symmetrical to each other. (2) The thermal head according to claim (1), wherein the two units are symmetrical to each other.