High-dynamic-range active pixel sensor

Abstract

A new pixel structure for high dynamic range imaging is proposed. The internal pixel circuit resets the pixel each time the well capacity nears saturation and a counter, implemented in the pixel itself (or in an external memory), records the number of resets per integration time. The increase in the dynamic range is given by a factor of (m + 1) where m is the number of internal resets per integration time. The peak signal-to-noise ratio will be increased due to the effective increase in the well capacity. A multiple sampling technique can be used in the combination with this proposed structure to achieve a further increase in dynamic range.