JPS6292865A - Thermal head driver - Google Patents

Abstract

PURPOSE:To enable simpler wiring on a printed board, by arranging connecting terminals for heating resistors along the opposed major sides of a driving IC, while input and output terminals for logical circuits along the minor sides of the driving IC. CONSTITUTION:A driving IC20 is so disposed that a major side 21 thereof is opposed to heating resistors R. Connecting terminals 11 for the heating resistors are evenly distributed along the opposed major sides 21, 22 of the IC20, and input terminals 10 and output terminals 12 for logical circuits are arranged along the opposed minor sides 23, 24 of the IC20. Accordingly, since the four sides of the driving IC20 are effectively utilized, the simpler wiring on a printed board 25 can be contrived, a high-density mounting can be performed, and it is possible to reduce the size of the printed board 25 and hence, the overall size of a thermal head. Further, since the number of bondings for each of the four sides of the driving IC can be reduced, the pitch of the bondings can be enlarged, and highly reliable bonding can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a thermal head driving device that drives a thermal head by energizing a heating resistor within the thermal head.

[Technical Background of the Invention and its Problems 1] FIG. 2 is a circuit diagram of a drive integration port and path applied to a thermal head drive device. Drive integrated circuit (hereinafter referred to as “
(referred to as a driving ICJ) 1 includes a shift register 4 that shifts the print data input to the print data input terminal 2 at the timing of a clock pulse input to the tarlock input pane 3; , a latch circuit 6 that holds the latch signal at the timing of the latch signal input to the latch input terminal 5, and a plurality of logic circuits that calculates the AND of the output of the latch circuit 6 and the enable signal input via the enable input terminal 7. It includes a product circuit 8 and a plurality of driver circuits 9 that heat and drive a heating resistor (not shown) using the output of the AND circuit 8.

Enable signal input terminal 7. Latch signal input terminal 5. Print data input terminal 2. Since the clock input terminal 31 is the legitimate child for receiving various input signals such as an enable signal into the driving ICI, that is, into the logic circuit, the above-mentioned terminals are collectively referred to as the logic circuit input terminal 10. Further, 11 is a heating resistor connection terminal to which a heating resistor is connected;
2 is a logic circuit output terminal.

Due to manufacturing issues with drive IC1, drive IC1
is generally configured as a 32-bit output, but in the thermal head, the number of heating resistors is far greater than the number of output bits of the driving IC 1, so
It is necessary to arrange a plurality of drive ICs 1 shown in FIG. The arrangement of the driving IC1 on the printed circuit board is the driving IC1.
It is determined by taking into consideration the positional relationship of each terminal provided in C1.

FIG. 3, FIG. 4, and FIG. 5 are explanatory diagrams showing a conventional thermal head driving device. The drive IC 1 shown in FIGS. 3 to 5 also has a larger number of terminals than the one shown in FIG. 2 because power input terminals, ground terminals, etc. are also shown.

In FIGS. 3 and 4, the heating resistor R is arranged so as to face one side of the opposite shorter side of the driving IC 1. In this case, the logic circuit input terminal 10° and the heating resistor connection terminal 1 are provided on the opposite long sides of the driving IC 1.
1 and a logic circuit output terminal 12 are provided.

However, such an arrangement has the disadvantage that the area of the printed circuit board becomes large, making it impossible to downsize the thermal head.

In FIG. 5, the heating resistor R is arranged so as to face one of the opposing long sides of the drive C1. In this case, a heating resistor connection terminal 11 is provided on one of the opposing long sides of the driving IC 1, and a logic circuit input terminal 10 and a logic circuit output terminal 12 are provided on the other side.

There is an advantage that the wiring can be simplified compared to the cases shown in FIGS. 3 and 4.

However, since the opposing long sides of the driving ICI are not used equally, the chip surface area of the IC becomes large, which has the disadvantage that the cost of the driving IC 1 increases. On the other hand, if the pitch of the heat generating resistor connection terminals 11 is made smaller, the bonding pitch within the driving IC 1 becomes smaller, resulting in new problems such as reduced bonding reliability.

[Object of the Invention] The present invention has been made in view of the above circumstances, and its purpose is to create a compact thermal head by simplifying the wiring on the printed circuit board and downsizing the printed circuit board. The purpose of the present invention is to provide a driving device.

[Summary of the Invention] The present invention for achieving the above object has a logic circuit input terminal for taking an input signal into an internal logic circuit, a logic circuit output terminal for outputting a logic circuit output to the outside,
It is equipped with a heating resistor connection terminal to which a plurality of heating resistors in the thermal head are connected, and is composed of a plurality of driving integrated circuits arranged to heat and drive the heating resistors based on input data taken in. In the thermal head drive device,
The driving integrated circuit is characterized in that heating resistor connection terminals are arranged on opposite long sides, and logic circuit input terminals and logic circuit output terminals are arranged on opposite short sides. I have something to do.

[Embodiments of the invention] Hereinafter, the present invention will be explained in detail using examples.

FIG. 1 is an explanatory diagram of a thermal head driving device according to an embodiment of the present invention.

In the driving IC 20 applied to the device of this embodiment, heating resistor connection terminals 11 are arranged on opposing long sides 21 and 22, and logic circuit input terminals 10 are arranged on opposing short sides 23 and 24, respectively. ．． It is formed by arranging logic circuit output terminals 12.

A plurality of driving ICs 20 are arranged on a printed circuit board 25 such that their long sides 21 and heat generating resistors R face each other.

The heating resistor connecting terminals 11 arranged on the long side 21 and the heating resistor connecting terminals 11 arranged on the long side 22 are slightly shifted in arrangement position. In addition, heating resistor connection terminal 1
1 are arranged alternately on opposite long sides 21° 22. With this arrangement, the bonding pitch inside the IC is 1/1 of the arrangement pitch of the heating resistor connection terminals 11.
It only takes about 2.

As described above, in the device of this embodiment, the driving ICs 20 are arranged so that the long side 21 and the heating resistor R face each other, and furthermore, the driving ICs 20 are arranged on the opposite long side 2'1.22. The heating resistor connection terminals 11 are equally divided and arranged, and the logic circuit input terminals 1 are arranged on the opposing short sides 23° 24.
0. By arranging the logical circuit output children 12, the four sides of the driving IC 20 are effectively utilized, so that wiring on the printed circuit board 25 can be simplified and high-density packaging can be achieved. Printed circuit board 2 due to high-density mounting
5 can be made smaller, and the entire thermal head can be made smaller. Further, by effectively utilizing the four sides of the drive IC 20, the number of bondings per -side is reduced, so the bonding pitch can be increased, and highly reliable bonding is possible.

Although one embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to the above-mentioned embodiment, and can be modified as appropriate within the scope of the gist of the present invention.

[Effects of the Invention] As described in detail above, according to the present invention, a compact thermal head driving device can be provided by simplifying the wiring on the printed circuit board and downsizing the printed circuit board.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a thermal head driving device according to an embodiment of the present invention, FIG. 2 is a circuit diagram of a driving integrated circuit applied to the thermal head driving device, and FIGS. 3 to 5 are diagrams of a conventional thermal head driving device. FIG. 2 is an explanatory diagram of a head driving device. 10...Logic circuit input terminal, 11...Heating resistor connection terminal, 12...Logic circuit output terminal, 20...Drive integrated circuit, R...Heating resistor. - Melon 1 Figure 4 Figure 5

Claims (2)

[Claims] (1) A logic circuit input terminal for taking input signals into an internal logic circuit, a logic circuit output terminal for outputting logic circuit output to the outside, and a heat generating resistor to which multiple heat generating resistors in the thermal head are connected. In a thermal head driving device comprising a plurality of driving integrated circuits arranged in a plurality of driving integrated circuits each having a connecting terminal and heating and driving the heat generating resistor based on input data taken in, the driving integrated circuits are arranged on opposing longitudinal sides. 1. A thermal head drive device comprising: heat generating resistor connection terminals arranged on the top, and logic circuit input terminals and logic circuit output terminals arranged on opposite short sides. (2) A plurality of the driving integrated circuits are arranged such that one side of the opposing long sides faces the heating resistor, and one side of the opposing short sides faces each other. The thermal head drive device according to item 1.