| 摘要 |
PURPOSE:To surely reduce the intensity of the panel illumination when the duty ratio of the panel control signal is set to a low level. CONSTITUTION:When the relay switch 14 of a relay 12 is excited, a panel illumination LED 11 is illuminated according to the level of an ILL signal line 17. The level of the ILL signal line 17 has the duty ratio changed according to the panel control. The intensity of the LED 11 is nearly proportional to the duty ratio. A micro-computer 20 detects the duty ratio of the ILL signal line 17, and it stops the excitation of a relay coil 15 when the value of the duty ratio becomes smaller than the reference value. When the excitation of the relay coil 15 is stopped, the relay switch 14 is cut off, and the LED 11 is turned off. |
