| 摘要 |
<p>PURPOSE:To improve the detecting resolution of a light pen by extending a display timing signal of a grid at least on one side of front and back directions of a scanning direction. CONSTITUTION:A picture memory 7 of a light pen input device successively outputs display data on the basis of an address supplied from a display control circuit 1. The display data are latched by a latch 6A and then supplied to a CRT display device 10 through a pattern generator 8, a PIS converter 9, etc. When the light pen 4 is abutted upon the CRT screen, a light pen control circuit 2 accelerates the grid display to a grid display circuit 3 to display the grid. The light pen 4 detects the grid display and a display address is stored and compensated by a compensation arithmetic circuit 5, so that the abutted position can be detected. In addition, latches 6E, 6F for a display timing signal, an OR circuit 02 and a counter circuit 11 are connected, the display timing signals of the real display and grid display are formed independently to measure the time width of the detecting signals.</p> |
