| 摘要 |
The power consumption of an electronic device, preferably a portable device with a power supply, e.g. a mobile phone or laptop computer, is reduced by detecting when the device is in use, detecting the background lighting conditions in which the device is being used and controlling the level of illumination of a display of the device in response to the background lighting conditions. The display, for example an LCD, may be backlit by one or more LEDs 560 and the illumination level of the display may be changed either by varying the LED brightness, using means 540 to varying the current through or voltage across an LED, or by altering the number of LEDs that are lit, via switching means 550. The ambient lighting conditions may be detected periodically, e.g. using a photodetector 520. |
