US Patent 7608815 Photo detector with compensated output and method involving same

A method of compensating a photo sensor (and a corresponding photo sensor with compensation) insures the accuracy of the photo sensor, e.g., over environmental variations or photo cell variations. The method comprises: providing a first signal indicative of a light level; providing a second signal indicative of an environmental parameter, e.g., temperature; and calculating, responsive to the first signal and the second signal, a compensated signal that is indicative of an absolute light level. The calculating can be performed by a processor and utilize calibration and compensation information or parameters, which can be obtained experimentally.