CMOS IMAGE SENSOR AND METHOD FOR SELECTING THE PHOTO CURRENT PATH ACCORDING TO QUANTITY OF LIGHT INCIDENT

摘要

A CMOS image sensor for selecting a current path according to quantity of an incident light and an image sensing method are provided to improve transfer efficiency of an output signal by arranging two floating diffusion nodes at one photo diode. A first pixel(P11) and a second pixel(P21) are alternatively arranged on a pixel array. The first pixel has a first photo diode(PD1), a pair of first transistors, a first floating diffusion node(FD1) having a first capacitance. The second pixel has a second photo diode(PD2), a pair of second transistors, and a second floating diffusion node(FD2) having a second capacitance. The first transistor of the pair of first transistors is connected between the first photo diode and the first floating diffusion node. The second transistor of the pair of first transistors is connected between the first photo diode and the second floating diffusion node. The first transistor of the pair of second transistors is connected between the second photo diode and the second floating diffusion node. The second transistor of the pair of the second transistors is connected between the second photo diode and the first floating diffusion node.