Image sensor and sensing pixel array for reading out charge of sensing signal and charge of reset signal of one sensing pixel unit after another

Abstract

A sensing pixel array used in an image sensor includes sensing pixel units each including a photodiode, a row reset transistor, a buffer transistor, and a column control transistor at least. Photodiode converts light into a sensing signal. Row reset transistor is coupled to a reference reset signal and photodiode, and is controlled by a row reset signal. Buffer transistor is coupled to the output of photodiode to receive and buffer the sensing signal. Column control transistor is electrically connected to the control end or the output of the buffer transistor and is used as a switch which can be closed or open according to a column control signal to control whether to transfer charge of the reference reset signal to a capacitor when the row reset transistor becomes conductive.