THERMAL RESISTOR TRIMMING OF THERMAL HEAD

摘要

PURPOSE:To enable correction of the resistance value of a thermal resistor to pretermined value in a short time and with high precision without any adverse effect upon printing performance or a thermal resistor by measuring the resistance value of the thermal resistor and repeating the application of the predetermined number of a voltage pulse until a predetermined resistance value is obtained. CONSTITUTION:A pulse voltage generator 10 and a selector switch 8 are controlled to apply a predetermined voltage pulse to a thermal resistor 6 via a probe device 7. Thereafter, the selector switch 8 and a resistance measuring device 9 are controlled to measure the resistance value of the thermal resistor 6. When this measured resistance value has not yet decreased to a predetermined target resistance value, the measurement of resistance value is repeated after application of a pulse voltage at the same level and a point of time when the resistance value has decreased to a prearranged level is regarded as the completion of trimming and further pulses are no longer applied.