Patent ID: 7683957

Claim:
An image sensing apparatus comprising: an image sensing element at which a plurality of photoelectric conversion elements are two-dimensionally arrayed, the image sensing element having a photoelectric conversion region which generates and stores signal charges of an object, an optical black region which outputs an optical black signal by shielding a part of the photoelectric conversion elements from light, a vertical transfer portion which vertically transfers the signal charges stored in the photoelectric conversion region in accordance with a vertical transfer pulse, a horizontal transfer portion which horizontally transfers the signal charges transferred from the vertical transfer portion in accordance with a horizontal transfer pulse, a horizontal drain portion which drains unnecessary charges overflowing from the horizontal transfer portion, and a charge detection portion which converts the signal charges transferred from the horizontal transfer portion into a signal voltage; and an OB clamping circuit which clamps the optical black signal output from the optical black region to a reference voltage, the OB clamping circuit having a switch which inputs the reference voltage from a reference power supply, and a capacitor, wherein the image sensing element is configured in such a way that the vertical transfer portion is driven with high-speed by providing the vertical transfer pulse and the unnecessary charges generated in the vertical transfer portion are transferred to the horizontal transfer portion, providing the horizontal transfer pulse to the horizontal transfer portion is stopped, and resetting operation of the charge detection portion and clamping operation of the OB clamping circuit are continued while the signal charges are stored in the photoelectric conversion region.