| 摘要 |
PURPOSE:To carry out fine control by controlling applied energy of a head in accordance with outputs of thermistors arranged on a thermal head and on the circumference of the head. CONSTITUTION:Temperature of a head is detected by a first partial pressure point 15 of a first resistor circuit consisting of a thermistor 11 and a resistor 13. Ambient temperature is detected by a second partial pressure point 16 of a second resistor circuit consisting of a thermistor 12 and a resistor 14. Outputs of the first and second partial pressure points 15 and 16 are inputted to an A/D converter 35 through a selection circuit 20. In such a constitution, when a printing data is inputted from an interface 34, a CPU 3 outputs an H level to the selection circuit 20, the ambient temperature is measured at the A/D converter 35, and a reference position on a data table is decided. Then, the CPU 3 outputs an L level to the selection circuit 20, the temperature of the head is measured, and ratio of a pulse width with respect to a reference value is obtained. The pulse width is operated, a built-in timer is actuated, and a power supply for 1 dot line is completed through a head drive circuit 36. |
