Patent ID: 7214922

Claim:
A semiconductor photosensor device comprising: a plurality of photodiode sections having different illuminance-output characteristics; a switch which selects any one of the plurality of photodiode sections on a basis of an illuminance of incident light irradiated on the photodiode sections; an output section which outputs an output signal from the selected photodiode section through the switch; a mode detecting circuit which compares output voltages from the photodiode sections with a first reference voltage to control the switch by a first logic signal based on a first comparison comparison result in the mode detecting circuit; a comparator circuit which compares an output signal from one of the photodiode sections selected by the switch with a second reference voltage to output a second logic signal based on a second comparison result in the comparator circuit; and a logic circuit connected to the mode detecting circuit and the comparator circuit and logically calculating the first logic signal and the second logic signal.