Patent ID: 7002626

Claim:
An image sensor comprising: a plurality of pixels on a semiconductor substrate, wherein each pixel includes: a photoactive region in the semiconductor substrate; a sense node; a first electrode disposed near a surface of the semiconductor substrate, wherein, during operation, a bias signal on the first electrode sets a potential in a region of the semiconductor substrate between the photoactive region and the sense node; a power supply node; and a second electrode disposed near the surface of the semiconductor substrate, wherein, during operation, a bias signal on the second electrode sets a potential in a region of the semiconductor substrate between the photoactive region and the power supply node; and a controller that, during operation, causes bias signals to be provided to the electrodes so that photocharges generated in the photoactive region are accumulated in the photoactive region during a pixel integration period, the accumulated photo-charges are transferred to the sense node during a charge transfer period, and additional photocharges generated in the photoactive region are transferred to the power supply node during a third period without passing through the sense node, wherein the transfer of the accumulated photocharges to the sense node is achieved by raising a bias voltage on the first electrode and lowering a bias voltage on the second electrode.