Patent ID: 7985993

Claim:
An image sensor comprising: a first transistor connected between a power source voltage and a sensing node, the first transistor controlled by a first signal; a second transistor connected between the sensing node and a first node, the second transistor controlled by a second signal; a photodiode connected between the first node and a ground voltage; a third transistor connected between a fifth node and a second node, the third transistor controlled by the sensing node; a fourth transistor connected between the power source voltage and the fifth node, the fourth transistor controlled by the fifth node; a fifth transistor connected between the power source voltage and a third node, the fifth transistor controlled by the fifth node; a sixth transistor connected between the third node and a fourth node, the sixth transistor controlled by a reference voltage signal; a sixth node connected between the fourth node and the second node; and a current source connected between the sixth node and the ground voltage.