| 摘要 |
PURPOSE:To perform correct beam scanning by exactly performing treatment of a coincident circuit when the X and Y counters get full count while seeking synchronization with power supply. CONSTITUTION:When an overflow detector 19 detects an overflow of the X- counter 21, the Y-counter is counted up and the X-counter 21 is cleared up through the delay circuit 15 while driving the X blank circuit decision circuit 4. A scanning repeating signal is generated by an output pulse of the circuit 4 for repeating the same operation. On the other hand, when the overflow detector 20 detects an overflow of the Y-counter 22, FF51 of the scanning repeating signal recognition circuit 5 is preset in order to clear the Y-counter 22 by a signal through the delay circuit 16. When Ycoin SYNC PULSE is supplied to the scanning repeating signal generation circuit 3 through the NAND circuits 13, 11 and 2, FF61 of the clock pulse transit permit circuit is preset while repeating a similar operation from the beginning. |
