Patent ID: 7456879
Filing Date: 2008-11-25
Classification: H04N

Abstract:
1. An imaging system comprising: an array of pixel sensors; a first bank of sample-and-hold circuits connected to the pixel sensors; a second bank of sample-and-hold circuits connected to the pixel sensors; a first analog-to-digital converter; a second analog-to-digital converter; and a selection circuit operable to select and connect a sample-and-hold circuit from the first bank to the first analog-to-digital converter and simultaneously select and connect a sample-and-hold circuit from the second bank to the second analog-to-digital converter; wherein the sample-and-hold circuit from the first bank is selectively connected to a row of the array for sampling a succession of reset voltages only from corresponding columns of the selected row, and the sample-and-hold circuit from the second bank of the array is selectively connected to the same row of the array for sampling a succession of integrated voltages only from the corresponding columns of the same selected row; wherein the first and second banks of sample-and-hold circuits are directly connected to the pixel sensors, the first and second analog-to-digital converters, respectively, are connected to the first and second banks of sample-and-hold circuits for independently digitizing the sampled succession of the reset and integrated voltages, respectively, a FIFO buffer is coupled to receive a digital output signal from the first analog-to-digital converter; and an adder is coupled to determine a difference between a digital output signal from the FIFO buffer and a digital output signal from the second analog-to-digital converter.