A computational image sensor with adaptive pixel-based integration time

An image sensor is proposed in which the pixel adapts its integration time to motion and light. The integration time of each pixel is shortened if motion is detected in the pixel or pixel intensity becomes saturated. The adaptivity of motion and light significantly enhances temporal resolution and dynamic range of the sensor. Because the integration time differs pixel-by-pixel, a scene containing both a bright and a dark region will be captured by pixels of shorter and longer integration times. Because the integration time adapts to motion, higher temporal resolution is obtained in a moving area and a higher signal-to-noise ratio in a static area. The control of the integration time is done on the sensor focal plane, with column parallel processing circuits integrated in CMOS image sensor. A prototype of 32×32 pixels has been fabricated by using 1-poly 2-metal CMOS 1-μm process. The fundamental functions have been verified. By the experiments, it has been verified that the sensor can reduce motion blur by adapting the integration time to motion and achieve wide dynamic range by adapting to light when the minimum integration interval is 680 μs