Patent attributes
An image sensor chip and a sensing method thereof are disclosed. The image sensor chip includes pixel units. Each pixel unit includes a reset switch, a sampling switch, a light sensing element, a capacitor, and an output circuit. The sampling switch is coupled between the reset switch and the light sensing element. The capacitor is coupled between the sampling switch and the output circuit. The output circuit outputs difference information corresponding to a difference between a plurality of sensing results of the light sensing element in different frame periods to a corresponding readout line. The sampling switch has an ON-time length during an exposure period and an OFF-time length during a readout and clean-up period. A ratio of the ON-time length to the OFF-time length is related to a ratio of a capacitance of the light sensing element to a capacitance of the capacitor.
