Patent ID: 6882367
Filing Date: 2005-04-19
Classification: H04N

Abstract:
1. A plurality of storage pixel sensors disposed on a semiconductor substrate, each of the plurality of storage pixel sensors comprising: a photodiode having a first terminal coupled to a first potential and a second terminal; a reset transistor having a first terminal coupled to the second terminal of the photodiode, a second terminal coupled to a reset reference potential that reverse biases the photodiode, and a control gate coupled to a RESET signal node; a photocharge integration node coupled to said first terminal of said reset transistor, said photocharge integration node comprising the control gate of a source-follower transistor, said source-follower transistor having a drain, coupled to a source-follower drain supply voltage node, and a source coupled to means for generating a bias current; a capacitive storage node, coupled to the source of the source-follower transistor, comprising the input of a readout amplifier transistor having an output; and an exposure transistor having a source directly connected to the source of said source-follower transistor and a drain coupled to a global current-summing node, said exposure transistor having a control gate coupled to a saturation level control voltage, said exposure transistor and said source-follower transistor acting as a common-source differential pair to divide said bias current between said source-follower transistor and said exposure transistor according to the relative values of integrated photosignal on said control gate of said source-follower transistor and said saturation level control voltage on said gate of said exposure transistor.