| 摘要 |
<p>PURPOSE:To permit a printing to be effected at the optimum density for each printing rate and realize the printing in an intermediate tone without reducing the resolution by changing the period or number of the clock signals to determine the printing time according to the computed printing rate. CONSTITUTION:A clock period generating part 6 has a plurality of comparative tables of printing rate alpha versus clock period beta according to usage modes and reads the table according to the printing rate alpha and sends out the corresponding clock period beta. A control circuit 2 sends the clock period beta to a dividing circuit 10, which, in turn, divides the clock of a clock generating circuit 8 according to the beta and sends it out. A shift register 14 receives one block of the printing data from the control circuit 2 and a clock counter 12 detects the block from the number of clock signals CLK. Upon reception of the clock signals in a block, the clock counter 12 latches the data of the shift register 14 with a latch circuit 16 and, at the same time, controls a dynamic drive circuit 18 so as to successively shift LED blocks L1-Ln to be operated one by one.</p> |
