| 摘要 |
PURPOSE:To obtain a stable printing quality for varying voltage, by controlling the width of a energy controlling pulse according to a head driving voltage and varying a full conduction time. CONSTITUTION:A full conduction pulse generator circuit 8 generates a pulse P1 with a fixed width T1. By triggering the rise of the pulse P1 an energy control pulse generator circuit 10 generates an energy control pulse P2 with a variable pulse width T2. The pulse width T2 is varied by the control signal S2 of a voltage detector circuit 11 according to a head drive voltage V so as to keep a printing energy constant. By triggering the fall of a pulse P2 a chopping pulse generator circuit 9 generate a chopping pulse P3. The frequency and duty of the pulse P3 is constant. A synthetic pulse P4 is applied to the base of a transistor 1 by an AND gate 6 and NOR gate 5, and T'2 varies with a drive voltage V. To the base of a transistor 2 a full conduction pulse P1 is applied. |
