Automatic brightness control system and method for a display device using a logarithmic sensor

摘要

This invention provides an automatic brightness control system for display devices, which may have a lighted display, a sensor, and control circuitry. The sensor logarithmically generates a first signal in response to the ambient light near the lighted display. The control circuit selects a display luminance from one or more luminance adjustment sequences having essentially constant ratio steps. The display luminance is a fractional power function of the ambient light near the display. The fractional power function may be adjusted by a constant luminance ratio offset.