| 摘要 |
PURPOSE:To enable a plurality of kinds of thermal heads differing in the size of print dots to be constructed with small number of component parts, by providing a head-discriminating circuit for discriminating the kind of a given thermal head by measuring the resistance of a dot-discriminating resistor element. CONSTITUTION:A dot-discriminatiang resistor element 4 having an intrinsic resistance R' according to the size of print dots is provided at a part of a chip together with resistor elements 11-1n. One end of the resistor element 4 is connected to an output terminal of a D/A converter 2 for generating a predetermined voltage Vs, while the other end is connected to a common potential point through a series circuit of a fixed resistor 5 having a resistance (r) and a switching element 5. With this construction, the need for a resistor element for discriminating the kind of a chip which element has been conventionally provided at a part of a printed wiring board to be fitted with the chip is eliminated, a common printed wiring board can be used irrespective of the kind of the chip, and the number of component parts can be reduced. |
