| 摘要 |
PURPOSE:To enable printing with a fixed density to be performed through controlling the quantity of electric currents supplied to heat generating resistors, by outputting a predetermined signal according to the combination of an output signal from a detecting part for the temperature of a thermal recording head with an output signal from a detecting part for the average resistance of the head. CONSTITUTION:The temperature of a thermal head 1 detected by a thermistor 5 and a monitor resistance of resistance heat generating elements 4 detected through a monitor resistor 6 are supplied to a CPU 9 after A/D conversion by an A/D converter 7. The A/D converted value (e) concerning the monitor resistor 6 is one of 00H-FFH when the converter 7 is an 8-bit unit. A head number is obtained by referencing a 'head number table' (a) in an ROM 8, and based on this, a starting address for a 'pulse width table' (c) is obtained by referencing a 'starting address table for pulse width table' (b). The A/D converted value (f) concerning the thermistor 5 also is one of 00H-FFH, and a 'temperature table' (d) is referenced to obtain the temperature T of the head 1. Based on this, a pulse width is obtained from the 'pulse width table' (c), and interpolation is performed by the CPU 9. |
