| 摘要 |
PURPOSE:To enable energy impressed on a thermal head to be appropriately selected, by determining the energizing time of a heating element by an output from a pulse-generating circuit. CONSTITUTION:When a thermal head comes to a printing position, a trigger pulse is inputted to IN1, a discharging transistor 7 is instantaneously turned ON, charging is immediately started through the second resistor means 5, and a predetermined pulse width tw is outputted by a comparing circuit 10. A dot pattern is outputted from a CPU 13, and appropriate electric power is supplied to a heating element 3 selected by a signal from the circuit 10. When printing a character with a generally used density, a low-level signal is impressed on IN2 to turn ON a short-circuiting transistor 8. When printing a character with high density, velocity of a thermal head 2 is reduced, and the transistor 8 is turned OFF, charging of a capacitor 6 is conducted through the first resistor means 4, and the pulse width tw is enlarged. |
