Patent ID: 6441852
Filing Date: 2002-08-27
Classification: H04N

Abstract:
An extended dynamic range (XDR) imager, comprising:an array of pixels for providing an output signal for each pixel related to an amount of light captured for each pixel during an integration period; circuitry that resets the pixels in a selected row of the array to an initial output signal value before the integration period begins and that applies an XDR clamp level signal to the pixels in a selected row of the array of pixels at a predetermined time before the integration period ends; a row of sample and hold circuits having a sample and hold circuit for each column of the array for capturing, during a first time interval, an XDR signal for each column of the selected row that is related to a difference between the output signal and the XDR clamp level signal, and for capturing, during a second time interval distinct from the first time interval, a linear signal for each column of the selected row, the linear signal being related to a difference between the initial output signal and the greater of the output signal and the XDR clamp level signal.