Patent ID: 9006635
Filing Date: 2015-04-14
Classification: G01T,H01L,H04N

Abstract:
1. A photodetector circuit comprising: a photoelectric conversion element; a first transistor; a second transistor; a third transistor; and a fourth transistor, wherein a gate of the third transistor is electrically connected to a first terminal of the photoelectric conversion element through the first transistor, wherein a gate of the fourth transistor is electrically connected to the first terminal of the photoelectric conversion element through the second transistor, wherein the first transistor is configured to hold a gate potential of the third transistor in accordance with an amount of light entering the photoelectric conversion element when light is emitted from a light source, and wherein the second transistor is configured to hold a gate potential of the fourth transistor in accordance with an amount of light entering the photoelectric conversion element when light is not emitted from the light source.