| 摘要 |
<p>PURPOSE:To secure an input from both the CRT display screen and the operation part comprising the light emitting element via the same light pen, by installing a control circuit to give a flashing control to the light emitting element which is provided in the outside of the CRT screen. CONSTITUTION:The lamp controlling circuit 7 is provided to give a flashing control to the light emitting element of the lamp 8 at the operation part provided in the outside of the screen of the CRT1. The circuit 7 lights up the lamps 8 successively for a fixed time in synchronization with the counter output data within the flyback time during which the video signal does not exist any more for the CRT1. When the light pen 2 indicates a certain lamp, the optical detection signal is delivered from the pen 2. The contents of the counter output are set to the register 4 in the timing of output of the optical detection signal. According to the contents set to the register 4, the lamp designated is decided to secure an input of the indication of operation corresponding to the lamp. Thus an input is possible from both the display screen of the CRT1 and the operation part comprising the lamps by means of the same light pen 2.</p> |
