Patent ID: 7468722

Claim:
A visual information display system with ambient light correction comprising: a visible light sensor configured to output a sensor current signal in proportion to the level of ambient light; a dimming control input signal determined by a user to indicate a desired brightness level for one or more light sources, wherein the dimming control input signal is represented by a user adjustable pulse-width-modulation logic signal; a multiplier circuit configured to generate a brightness control signal based on a mathematical product of the sensor current signal and the dimming control input signal, wherein the multiplier circuit comprises: a pair of current steering diodes configured to multiply the sensor current signal by the user adjustable pulse-width-modulation logic signal to generate the brightness control signal, wherein anodes of the current steering diodes are coupled to an output of the visible light sensor to receive the sensor current signal; a network of resistors coupled to cathodes of the current steering diodes and configured to scale the brightness control signal; and at least one capacitor coupled to the network of resistors and configured as a low pass filter for the brightness control signal; and a display driver configured to adjust brightness levels of the light sources in response to the brightness control signal.