Image sensor having wide dynamic range based on pixels with plurality of photoelectric conversion elements, operating method of the same and electronic device

A method of operating a pixel including a first photoelectric conversion element group and a second photoelectric conversion element group, a first floating diffusion region and a second floating diffusion region respectively connected to the first photoelectric conversion element group and the second photoelectric conversion element group, and a third floating diffusion region separated from the first floating diffusion region and the second floating diffusion region and connected to a gate of a driving transistor, wherein a number of photoelectric conversion elements in the first photoelectric conversion element group is greater than a number of photoelectric conversion elements in the second photoelectric conversion element group, the method comprising:

• resetting the first floating diffusion region and the third floating diffusion region;
• sampling a first reset level of a voltage of the third floating diffusion region while controlling a first switching transistor positioned between the first floating diffusion region and the third floating diffusion region to couple the first floating diffusion region and the third floating diffusion region;
• sampling a second reset level of a voltage of the third floating diffusion region while controlling the first switching transistor to not couple the first floating diffusion region and the second floating diffusion region;
• sampling a first image signal level of a voltage of the third floating diffusion region while controlling the first switching transistor to couple the first floating diffusion region and the third floating diffusion region in a first output period based on electric charge generated by the first photoelectric conversion element group;
• sampling a second image signal level of a voltage of the third floating diffusion region while controlling the first switching transistor to not couple the first floating diffusion region and the third floating diffusion region in a second output period;
• and
• sampling a third reset level and a third image signal level associated with the second photoelectric conversion element group.

An electronic device comprising:

• a pixel array in which a plurality of pixels are arranged;
• and
• a controller configured to transmit a control signal to a plurality of transistors in the plurality of pixels, and wherein a first pixel of the plurality of pixels comprises:
• a driving transistor;
• a first switching transistor;
• a plurality of photoelectric conversion element groups comprising different numbers of photoelectric conversion elements;
• a first floating diffusion region connected to a first photoelectric conversion element group through a first transfer transistor;
• a second floating diffusion region connected to a second photoelectric group through a second transfer transistor;
• a third floating diffusion region connected to a gate of the driving transistor, separated from the first floating diffusion region, separated from the second floating diffusion region, by the first switching transistor;
• and
• a reset transistor comprising a first end to which a reset voltage is applied and a second end connected to the third floating diffusion region, wherein the driving transistor is configured to output an image signal based on a voltage of the third floating diffusion region through a selection transistor.