Patent ID: 8759739

Claim:
An optical sensor comprising: an accumulation node; a reset signal line for supplying a reset signal to the accumulation node; a readout signal line for supplying a readout signal to the accumulation node; a photodetecting element that is connected to the accumulation node and through which an electric current flows according to an amount of received incident light; a reference element that is connected to the photodetecting element via the accumulation node and that has a light-shielding layer with respect to incident light; a first switching element that outputs a potential of the accumulation node in response to the readout signal, the potential of the accumulation node varying with the electric current flowing through the photodetecting element and an electric current flowing through the reference element during a sensing period from supply of the reset signal to supply of the readout signal; and a second switching element that is provided between the accumulation node and the reference element, and that electrically separates the accumulation node and the reference element from each other when the potential of the accumulation node to which the readout signal is supplied is higher than a potential on a side of the reference element opposite to the accumulation node.