| 摘要 |
PURPOSE:To prevent the operator's eyestrain, by making dots, which are not used for display of information in a designated area, luminous with the color of a high detection sensitivity of a light pen. CONSTITUTION:Data is transmitted from a processing device CPU to a control part CNT of a display control device DCNT. The part CNT writes characters and patterns in a picture memory M in accordance with this data. Bits read out from the memory M are inputted to a video signal generating circuit VD from NAND gates NA1-NA3 synchronously with a clock generator CLK and are displayed on a monitor MON. In this case, a region where characters are not displayed in the display region is displayed with the color such as blue of a high detection sensitivity of a light pen LP. Consequently, when an indication area is designated by the light pen LP, the light pen LP is pressed to the blue to designate it. |
