| 摘要 |
PURPOSE:To control pulse width more ideally, and to improve the quality of printing largely by controlling printing pulse width applied to a thermal head according to the temperature of the thermal head sensed by a temperature sensor and printing speed. CONSTITUTION:A printing data is stored in a latch memory 22 through a line memory 40 and further a shift register 21 by a command from a slave CPU 30. The temperature of a thermal head 20 sensed by a sensor 70 is input to the slave CPU 30 through an inverse logarithm amplifier 80 and an A/D converter 90, and the slave CPU 30 determines printing pulse width from the temperature of the thermal head 20 and computed printing speed. A control transistor 24 group for a heating resistor is driven selectively by the determined printing pulse width on the basis of the data of the latch memory 22 while a platen roller 60 is driven in response to printing speed through a drive CTL 50, and thermal transfer is conducted. Accordingly, the quality of printing can be improved largely. |
