PURPOSE: To alleviate local concentration of current density upon driving a heating element by electric power and contrive a longer useful life of the heating element, by a construction wherein the resistor having a bent part and constituting a heating element is provided with an appropriate nonuniform sheet resistance distribution.
CONSTITUTION: In a thermal head comprising a resistor having a bent part, the sheet resistance of the bent part of the resistor is set to be increased from the inside toward the outside of the bend. As a result, the sheet resistance of the resistor 1 is highest on the inside 3 of the bent part and is lowest on the outside 4 of the bent part. By providing the heating element with such an appropriate sheet resistance distribution, it is possible to set a resistance ratio R23/R22 to 1. Accordingly, the current density in the bent part of the resistor is restrained from being concentrated on the inside of the bent part, and the current density in the resistor can be uniformly distributed.
MOTOYOSHI YUKIO
SHIRAISHI SADAZUMI
KUWABARA SEIJI
| JPS58211470A | 1983-12-08 | |||
| JPS5836474A | 1983-03-03 |