Patent ID: 8785834

Claim:
A solid-state image sensor comprising: a plurality of unit pixels each including a photoelectric transducer which generates a charge corresponding to an amount of incident light and accumulates the charge therein, a first transfer gate which transfers the charge accumulated in the photoelectric transducer, a charge holding region in which the charge transferred from the photoelectric transducer by the first transfer gate is held, a second transfer gate which transfers the charge held in the charge holding region, a floating diffusion region in which the charge transferred from the charge holding region by the second transfer gate is held to be read out as a signal, a charge discharging gate which transfers the charge received from the photoelectric transducer, to a charge discharging part, and a structure including an overflow path formed in a boundary portion between the photoelectric transducer and the charge holding region, the overflow path being formed at a potential for determining a predetermined charge amount and transferring a charge exceeding the predetermined charge amount as a signal charge from the photoelectric transducer to the charge holding region, wherein as a channel electric-potential of the charge discharging gate, an electric-potential lower than an electric-potential of the overflow path is set, or an electric-potential higher than the electric-potential of the overflow path and lower than an electric-potential causing the photoelectric transducer to be completely depleted is set.