| 摘要 |
PURPOSE:To maintain proper brightness without letting a driver feel a deficiency in brightness at the time of brightness setting and to prolong the life of a display body by decreasing the brightness gradually to a specific value when the brightness of the display body is set above the specific value. CONSTITUTION:A brightness setting switch 18 is turned to the side of a contact U or D and then a brightness control circuit 16 increases or decreases its brightness control output to control the brightness of the display body 11 between its 100% brightness and lowest brightness. Therefore, when the driver resets the switch 18 at the time of proper brightness, the circuit 16 holds the brightness state. If the brightness set value when the switch 18 is reset is still high brightness exceeding the specific value, the circuit 16 starts control operation for decreasing the brightness gradually to specific brightness under the command of a brightness decrease indicating circuit 19, whose command is stopped at the specific brightness while the decrease in brightness is stopped.
|
