US Patent 9407839 Solid-state imaging device

A solid-state imaging device including an AD converter and a pixel array is provided. The AD converter performs a ramp comparison and a successive-approximation. The AD converter determines a digital value by performing one of the ramp comparison and the successive-approximation as a former comparison operation and then performing the other as a latter comparison operation in the range narrowed down by the former comparison operation. The pixel array supplies, to the AD converter, a reference signal corresponding to a reset level of the pixel, and an image signal having image information. The AD converter performs the latter comparison operation without performing the former comparison operation, when the reference signal is supplied.