| 摘要 |
<p>PURPOSE:To reduce light spots of a CRT and to alleviate fatigue of eyes by reversing the state of an image process region at the time of displaying a screen by way of superimposing plural image process regions independent from each other. CONSTITUTION:At the time when an operator wants to white-and-black reverse an optional window, a reversal command is input from a keyboard 5 or input by moving a carsol to a white-and-black reversal function of the window by a pointing device. A screen operation processor 3 reverses all bits of a corresponding window buffer, and a window white-and-black reversed by a screen composition video control 4 is projected on to a CRT 7. At the time of writing a character and the like relative to the white-and-black reversed window buffer, as a base is reversed, it is necessary to carry out contrary process in such a way that process to put a bit on is to put it off.</p> |
