Patent ID: 8488027

Claim:
A method of operating an imaging array to generate an image, said imaging array comprising a plurality of light pixels and a sense amplifier, each light pixel being connectable to said sense amplifier in response to a control signal coupled to that light pixel, wherein each light pixel comprises a photodetector that couples a signal indicative of a light exposure to a light pixel node; a readout circuit for outputting a signal related to potential on said light pixel node, and a light pixel mixer that mixes a signal on said light pixel node with a pixel oscillator signal having a first frequency, said method comprising: transferring charge from said photodetector to said pixel node in one of said pixels; coupling an oscillator signal having a first frequency to that pixel node; connecting that pixel to said sense amplifier; receiving an AC signal generated by said readout circuit of that pixel; filtering said AC signal through a band pass filter having a low frequency cutoff that blocks noise from said readout circuit in that pixel to create a filtered AC signal; and demodulating said filtered AC signal to provide a signal indicative of said transferred charge.