| 摘要 |
PURPOSE:To increase the effective image resolution of a light pen without increasing the visual fatigue of an operator, by giving a decentralized array of light emission of mobile dots on a CRT display screen for a short time through the photodetecting part of the light pen. CONSTITUTION:A light pen 7 is pressed to a CRT display screen 6, and a light pen switching signal 14 is produced. Thus a switch 5 switches a video signal 11 to a head signal 15 by the signal 14. The signal 15 is fed to the CRT6, and mobile dots are discretely arrayed and displayed on the CRT6 through the photodetecting part of the pen 7. Receiving the light emission of the dots, a timing signal 16 is produced through the photodetecting part of the pen 7 to stop the operation of a light pen counter 4 having the synchronizing revolution with a clock signal 17 given from a CRT controller 2. At the same time, the switch is reset to set the dot display back to the video display. A computer 1 can know the information of the position of the pen 7 by reading the value of the counter 4. |
