| 摘要 |
PURPOSE:To ease seeing car indicators by inputting the ambient brightness based on the informations of the sunlight intensity detected for sun-light correction and lowering the indicator brightness when the detected sun-light intensity becomes lower than the predetermined value. CONSTITUTION:A control panel is provided with switches 1a and 1b for manual operation of an air-conditioner and light emitting diode (LED) 2a and 2b for indicating the manual setting state. Meanwhile, a photo-diode 6 that forms a sun- lignt source is provided, and its output is put in a microcomputer 3 via both an amplifier 7 and an A/D converter 8. Then, from the input sun-light intensity, forward current corresponding to the sunlight intensity is obtained, according to the characteristics stored in the memory, in order to calculate an LED lighting time t corresponding to an LED driving cycle. In other words, in daytime LEDs 2a and 2b are lit brightly through continuous electrification, while in night time they are electrified intermittently to lower the forward current and consequently the brightness. |
