| 摘要 |
A thermal head of a thermal printer has plural heating elements arranged along a line and connected in parallel with one another. A respective one of the heating elements is connected to one of plural heat control switches, which are selectively turned on/off for driving the heating elements individually by applying electrical energy to generate heat. To measure resistance data of at least one of the heating elements, a capacitor is connected in parallel with the plural heating elements. A reference resistor is connected in parallel with the plural heating elements and the capacitor. The capacitor is charged, and then discharged via the reference resistor or the one of the heating elements. A voltage across the capacitor is detected. An amount of discharging time required to decrease the capacitor voltage from a predetermined high voltage to a predetermined low voltage is measured while the capacitor is discharged, in association respectively with the reference resistor and the heating elements. Resistance data for the heating elements is determined in accordance with the discharging time of the heating elements, respectively, with reference to the discharging time of the reference resistor.
|
