Automatic brightness control for displays
An automatic brightness adjustment for devices with displays includes the capability to assess ambient light. The assessment may be made using circuitry, such as a light meter circuit, by exploiting exposure control circuitry, or using other approaches. The ambient light value is sent to a brightness adjustment driver, which may employ a look-up table to keep track of brightness adjustments for particular ambient conditions. The look-up table may include distinct adjustment values based upon the type of display.
1. A processor-based mobile information device, comprising:
a processor;
a display coupled to the processor;
an ambient light sensor, wherein the ambient light sensor comprises a charge coupled device; and
circuitry on the mobile information device to:
store display brightness information based on a current ambient light condition sensed by the ambient light sensor, wherein the brightness information is to be derived from at least one of a first eye adaption process which takes into account a slow sensitivity adjustment of an eye to the average luminance of an object being viewed and a second eye adaption process which takes into account a reaction of the eye to an average luminance of a surrounding environment; and
automatically adjust a brightness of the display based on the stored information and changes in the ambient light condition sensed by the ambient light sensor.
2. The processor-based mobile information device of claim 1 , wherein the changes in the ambient light condition sensed by the ambient light sensor are based on an integration interval.
3. The processor-based mobile information device of claim 1 , wherein the charge coupled device is part of an image capture circuit for a camera.
4. The processor-based mobile information device of claim 1 , wherein the circuitry to store display brightness information based on a current ambient light condition further comprises circuitry to perform a calibration operation to store display brightness information based on a current ambient light condition sensed by the ambient light sensor.
5. The processor-based mobile information device of claim 4 , wherein the circuitry on the mobile information device comprises a lookup table.
6. The processor-based mobile information device of claim 5 , wherein the lookup table is configured to store information representing ambient light conditions and corresponding display brightness information.
7. The processor-based mobile information device of claim 6 , wherein the lookup table is configured to store information representing ambient light conditions and corresponding display brightness information based on the calibration operation.
8. The processor-based mobile information device of claim 1 , wherein the ambient light sensor comprises a charge coupled device.
9. The processor-based mobile information device of claim 8 , wherein the charge coupled device is part of an image capture circuit for a camera.