System for determining a video offset from dark photosensors in an image sensor array

摘要: In a photosensitive device wherein voltages are read sequentially from dark, or dummy, photosensor and plurality of active photosensors with each series scans, circuit downstream the resets offset value voltage signals, based on successive readings dark photosensor. An RC averaging maintains running average over large number scans. Signals first time into circuit, then signals directly to video circuitry. This double readout dark-photosensor enables precise calibration both on-chip circuitry