Patent ID: 8310569

Claim:
A pixel sampling circuit, comprising: a readout circuit coupled to a plurality of pixels arranged in rows to receive analog pixel signals from each row of pixels of the plurality of pixels; and a noise correction circuit coupled to the readout circuit operable to sense noise, the noise correction circuit comprising: a plurality of dark reference pixels arranged in rows, each dark reference pixel of a row of dark reference pixels of the plurality of dark reference pixels being coupled to a respective pixel of a row of pixels of the plurality of pixels, wherein each dark reference pixel is operative to provide at least one reference signal that corresponds to the noise sensed for each respective pixel of the row of pixels to remove at least a portion of a noise component of the pixel signals received from the row of pixels while the pixel signals are analog signals; and a reference unit comprising a separate dark reference pixel, a transistor, and a capacitor, the separate dark reference pixel not being coupled to the plurality of pixels, and wherein a signal of the separate dark reference pixel is sampled on the capacitor to provide a separate reference signal that is operable to reset an output line of the readout circuit.