SOLID-STATE IMAGE-PICKUP DEVICE, CAMERA SYSTEM, AND METHOD FOR DRIVING THE SAME

摘要

A solid-state image-pickup device includes a plurality of pixels, each of which is operable to convert an incident-light quantity into a respective electrical signal. The image-pickup device includes a plurality of analog-to-digital converters that each converts an analog signal obtained from a respective one of the pixels into a digital signal. Each analog-to-digital converter includes an output having a plurality of bits and a plurality of comparators. Each of the comparators compares a respective one of a plurality of reference voltages changing over time to the analog signal from the same one of the pixels. At least first and second reference voltages are transmitted to respective ones of the comparators. The analog signal is read from the pixel two times for each row, and a difference between a result of first reading and a result of second reading is calculated.