| 摘要 |
PURPOSE:To perform light-pen inputting operation with less malfunction by storing address data picked up on display device at a certain interval of time with a light pen and by using it as effective one when the result of comparing discrimination shows coincidence or as ineffective one when it shows noncoincidence. CONSTITUTION:A signal obtained by detecting a raster with light pen 7 and then converted into an electric signal is amplified by light pen interface 8 to sent the timing to setting circuit 9, which permits the interface to receive the signal a certain time later. Address latch circuit 10, on the other hand, latches address data outputted from X and Y address counters 5 and 6 with a pulse signal from interface 8, and also stores them in memory 1 of memory part 11. The 2nd address data are then stored in memory 2 of the memory part in response to a signal acceptance signal for a reread from circuit 9. Then, both address data are read out and compared mutually for decision 12 and when the both coincide mutually, they are outputted to position signal processing circuit 13. |
