IMAGE SENSOR, PORTABLE ELECTRONIC DEVICE INCLUDING THE SAME, AND METHOD OF DRIVING AN IMAGE SENSOR

摘要

An image sensor includes a pixel array, a correlated double sampling unit, an analog-digital conversion unit, a control unit, and an overflow power supply voltage control unit. The pixel array is provided with a plurality of unit pixels generating accumulated charges corresponding to incident light in a photoelectric conversion section and outputting an analog signal based on the accumulated charges in a read-out section. The correlated double sampling unit generates an image signal by performing a correlated double sampling operation on the analog signal. The analog-digital conversion unit converts the image signal to a digital signal. The control unit controls the pixel array, the correlated double sampling unit, and the analog-digital conversion unit. The overflow power supply voltage control unit controls an overflow power supply voltage applied to the unit pixels to have a low voltage level in the photoelectric conversion section and controls the overflow power supply voltage applied to the unit pixels to have a high voltage level in the read-out section.