公开(公告)号：JPH0372398A

公开(公告)日：1991-03-27

申请号：JP20704089

申请日：1989-08-11

Applicant: IBM

Inventor： MINAMI TOSHIYA ,  SATO HIROSHI ,  SATO TAKANOBU

IPC: G09G5/00 ,  G09G3/20 ,  G09G3/36 ,  G09G5/22 ,  G09G5/30

Abstract: PURPOSE: To eliminate a difficulty to watch and to prevent the eyestrain of an operator by providing a signal generating means for generating a control signal for displaying a foreground dot with a low luminance and a background dot with a high luminance or a control signal for displaying the foreground dot with zero luminance and the background dot with high a luminance corresponding to a mode signal. CONSTITUTION: This device is composed of a controller 1, column/line/ row counter 2, address generating circuit 3, character code buffer 4, attribute buffer 5, character code register 6, font memory 7, parallel/serial switching circuit 8, mixer circuit 9, signal generating circuit, namely, mode switching circuit 10, video circuit 11 and CRT display device 12. Then, in response to the ordinary mode signal, the control signal is generated for displaying the foreground dot with low luminance and the background dot with high luminance and in repsonse to the high luminance mode signal, the control signal is generated for displaying the foreground dot with zero luminance and the background dot with high luminance. Thus, there is no difficulty to watch and the eyestrain of the operator can be prevented.