| 摘要 |
<p>PURPOSE:To decrease the number of driver ICs, and to reduce cost by installing one driver circuit element to each two heating resistor, respectively dividing other ends into two common electrodes and con necting the common electrodes, and changing over the voltage levels of the common electrodes and conducting time division drive. CONSTITUTION:A heating resistor R represents 2048 elements, a common electrode C is divided into two and mounted, heating resistors R1, R3...R2047 in odd numbers are connected to the common electrode C2, and heating resistors R2, R4...R2048 in even numbers are connected to the common electrode C1. Other ends of the heating resistors R1 and R2, R3 and R4...R2047 and R2048 in odd numbers and even numbers are connected, and two elements in odd numbers and even numbers are paired and connected to each drive transistor tr for a driver IC. Push-pull switching circuits SW1, SW2 change over the common electrodes C1, C2 to supply voltage E and a GND (ground) level, and control signals S1, S1', S2, S2' are input to the switching circuits. Accordingly, the constitution of a thermal head is simplified, the number of driver ICs is decreased, and cost is reduced.</p> |
