METHOD AND DEVICE FOR MEASUREMENT OF THERMAL HEAD RESISTANCE DATA AND THERMAL PRINTER EQUIPPED WITH THE DEVICE

摘要

PROBLEM TO BE SOLVED: To improve the accuracy in measuring resistance data and at the same time, shorten time required for measuring the resistance data by making constant the charging voltage of a capacitor at the time of beginning the measurement. SOLUTION: A capacitor 46 is charged when a charging transistor 58 is turned ON, and the charging is stopped when the charging voltage Vc of the capacitor 46 exceeds a voltage V1 for starting measurement. Next, the capacitor 46 is discharged through a reference resistance 52 or one of heating elements 201 -20n . During this discharge, time required for the discharge until the charging voltage Vc of the capacitor 46 reaches a second reference voltage V2 from a first reference voltage V1 is measured. After the measurement of the discharge time Ts of the reference resistance 52 and the discharge time Tx1-Txn of each of the heating elements 201 -20n , resistance data Di=Txi/Ts(i=1, 2...n) which expresses the magnitude of the relative resistance value of each of the thermal elements 201 -20n is calculated based on the discharge time Ts and the discharge time Tx1-Txn which are obtained.