| 摘要 |
PURPOSE:To enhance correction accuracy by shortly setting the thermal time constant of a temp. estimating operation circuit by correcting the estimation result of temp. on the basis of the detection result of the temp. sensor of a thermal head to expand a correction area range. CONSTITUTION:Since a thermistor 15 is attached to an aluminum base 5, the detection value of the thermistor 15 accurately shows the temp. of the aluminum base 5 and the temp. of the aluminum base 5 contains atmospheric temp. and the temp. rise due to the supply of a current. Therefore, the thermal time constant of a temp. estimating operation circuit 11 can be set to that of the part near to a heating resistor 4 without considering the thermal time constant of the aluminum base 5. By this constitution, the output of the operation circuit 11 shows the temp. of ceramic base 2-glaze 3 when the aluminum base 5 is at certain constant temp. and an estimation value is corrected on the basis of the temp. of the aluminum base 5 detected by the thermistor 15 by a temp. correcting operation circuit 13 to obtain the estimate temp. of the part near to the heating resistor 4. |
