Dynamic range compressing for CMOS-image sensor with quasi-individual resetting

Abstract

A CMOS-image sensor capable of dynamic range compression is proposed. This sensor has two main features. First, it employs a negative-feedback technique to set photo-diode (PD) capacitance in the pixel circuit to any intermediate voltage during charge accumulation. Second, it incorporates a quasi-holding function by resetting the pixel-output voltage in PD capacitance. pixels and by setting an intermediate voltage or performing quasi-holding with respect to each pixel. Output data has a polygon-like form corresponding to a change from high sensitivity to low sensitivity as optical intensity becomes stronger