Patent ID: 7176544
Filing Date: 2007-02-13
Classification: H01L,Y02E

Abstract:
1. A method of extracting red and green signals from an active pixel sensor, comprising: providing a pixel comprising a P type silicon substrate, a deep N well formed in said substrate, a number of P wells formed in said deep N well, an N electrically isolating said P wells and said deep N well, after resetting the potential between each of said P wells and said substrate to a first voltage and the potential between said deep N well and said substrate to a second voltage, accumulating charge at the PN junctions between each of said P wells and said deep N well, and determining the potential between each of said P wells and said deep N well, wherein the potential between each of said P wells and said deep N well provides a red/green signal at each of said P wells; electrically isolating said P wells and maintaining said deep N well at a third voltage, after resetting the potential between each of said P wells and said substrate to said first voltage and the potential between said deep N well and said substrate to said second voltage, accumulating charge at the PN junctions between each of said P wells and said deep N well, and determining the potential between each of said P wells and said deep N well, wherein the potential between each of said P wells and said deep N well provides a green signal at each of said P wells; and determining a red signal at each of said P wells by subtracting said green signal at each of said P wells from said red/green signal at that said P well.