Patent ID: 7847821
Filing Date: 2010-12-07
Classification: H04N

Abstract:
1. An on-chip test method for photon transfer curve and dark current testing to determine pixel reliability in an image sensor device, comprising: (a) providing a substrate and a sensor array having a plurality of pixels rows and columns formed thereon wherein each pixel is comprised of a charged photo gate at the base of a light column and a capacitor (storage node) for storing charge transferred from the photo gate, said substrate is linked to a tester device; (b) exposing the sensor array with a uniform light source such that a first plurality of x (c) transferring a residual charge in the photo gate to a capacitor for each pixel and subsequently sending residual charge information for each pixel to an image processor where an image for a first frame (F1) is generated, said image has a top and bottom and two sides; (d) resetting the photo gate to the same charged state as in step (a); (e) repeating steps (b)-(d) in succession to form an image having a top and bottom and two sides for a second frame (F2) in said image processor wherein illumination values for F1, F2, and (F2−F1) may be calculated and a difference frame (F2−F1) determined; (f) resetting the photo gate to the same charged state as in step (a); and (g) generating a third frame with no illumination to determine the dark current contribution by transferring the residual charge in the photo gate for each pixel in the first region after a time period t