| 摘要 |
<p>PURPOSE:To reduce memory capacity of a circuit for previously storing data, required for conduction control of thermal head, in relation to gray level. CONSTITUTION:A counter circuit 51 counts clocks C4 representative of conduction period and delivers a signal representative of the number of conduction periods within one recording period. A data memory circuit 52 previously stores data representative of average quantity of energy to be applied to a thermal head during each split interval of one recording period in relation to gray levels. The data memory circuit 53 receives a gray level data D3 and a signal C11 representative of the number of conduction periods and then delivers two data D31 representative of average quantities of applying energy concurrently. A selector circuit 531 selects one of two data based on a signal C12 and delivers the selected one as data D32. A comparator circuit 532 compares the data D3 with a signal C14 representative of the number of conduction periods thus producing a conduction data D4. The signal C14 is obtained by reversing bit arrangement of signal C13.</p> |
