Patent ID: 6535247
Filing Date: 2003-03-18
Classification: H04N

Abstract:
An apparatus comprising:a pixel comprising: (a) a photodetector element having a node; (b) a first transistor having a control leg connected to said node and second and third legs, the third leg being connected to a power supply voltage; (c) a second transistor having a control leg and fourth and fifth legs, the fourth leg connected to the second leg of said first transistor; (d) a third transistor having a control leg and sixth and seventh legs, the seventh leg being connected to a reset voltage source; and a feedback loop including a waveform generator for supplying a reset voltage waveform to the control leg of said third transistor to reset said photodetector, said reset voltage waveform comprising a ground voltage level followed by a first reset voltage pulse for resetting the photodetector followed by an offset cancellation voltage pulse of a duration selected to cancel reset noise generated by resetting said photodetector.