| 摘要 |
PURPOSE:To enable the prevention of possible flickering, by arranging a reference control signal generation means, a display signal generation means, a CRT and to brightness control circuit to keep the brightness constant regardless of the amount of information to be displayed. CONSTITUTION:A reference control signal generation means 24 generates a reference control signal with the timing thereof determined according to maximum indicatable information while a display signal generation means comprising a vector generator 18, a character generator 20 and a display RAM22 generates a display signal with respect to each variable information according to the reference control signal. A CRT38 displays variable information by deflecting an electron beam according to the display signal, while fixed information is set at a specified position of a display screen beforehand. On the other hand, a brightness control circuit 36 interrupts the electron beam of the CRT38 during a corresponding display period free from a display of no variable information. The ratio is always kept constant between the display period per display unit of variable information and the total display period thereof to allow the prolonging of the display period per display unit of information, thereby enabling the prevention of flickering in the display with a constant display brightness.
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