A first pixel circuit has a plurality of photodiodes of different sizes. A second pixel circuit is connected to the first pixel circuit, and has a holding portion that holds a first optical signal and a second optical signal. The peripheral circuit drives and controls the second pixel circuit, and determines whether a voltage value of the first optical signal is equal to or greater than a predetermined value. When it is determined that the voltage value of the first optical signal is equal to or greater than the predetermined value, a signal obtained by adding the second optical signal to the first optical signal is set as an output signal. When it is determined that the voltage value of the first optical signal is less than the predetermined value, the first optical signal is set as an output signal.