Patent ID: 7532044

Claim:
A photodetector comprising: a plurality of photodetecting elements; and an I/F converter connected to each of the plurality of photodetecting elements, wherein the I/F converter includes: an input terminal; switching means having: a first output terminal, and a second output terminal; said switching means selectively connecting the input terminal to one of the first output terminal and the second output terminal; a first capacitor connected to the first output terminal via one end of the first capacitor; first discharging means connected to said first capacitor, for discharging charges accumulated in the first capacitor; a first comparing portion having: a first input terminal, a second input terminal, and an output terminal, wherein said first input terminal of said first comparing portion is connected to the first output terminal of said switching means, wherein said second input terminal of said first comparing portion is connected to a first reference voltage, wherein said first comparing portion compares a magnitude of a voltage at the one end of the first capacitor with a reference voltage and outputs a first comparison signal representing the compared result from the output terminal thereof; a second capacitor connected to the second output terminal of the switching means via one end of the second capacitor; second discharging means connected to said second capacitor, for discharging charges accumulated in the second capacitor; and a second comparing portion having: a first input terminal; a second input terminal, and an output terminal; wherein said first input terminal of said second comparing portion is connected to the second output terminal of the switching means, wherein said second input terminal of said second comparing portion is connected to a second reference voltage, wherein said second comparing portion compares a magnitude of a voltage at the one end of the second capacitor with the second reference voltage, and outputs a second comparison signal representing the compared result from the output terminal thereof.