Cmos sensor having analog delay line for image processing

Abstract

The present invention is directed to an analog delay line for a color CMOS image sensor which is compatible with MOS fabrication technology. The invention allows for the simultaneous reading of pixel signals from two rows of pixels so that combinations of signals from pixels in different rows may be obtained. The delay line includes a set of storage capacitors on which the pixel signals are stored, and a means for writing the signals from the pixels onto the capacitors in sequence. The stored analog pixel signals may then be read out from the delay line at the appropriate time so that they may be combined with pixel signals from adjacent pixels in different rows. In one embodiment, two delay lines are used, so that pixel signals from a current row can be written into one delay line, while the pixel signals from a previous row are being read out from the other delay line. In another embodiment, a single delay line is used in combination with a single pixel delay circuit. When the single pixel delay circuit is used, the pixel signals from a previous row are read out from the delay line and temporarily stored in the single pixel delay circuit, one at a time, shortly after which the pixel signals from the next row are written into the delay line. The pixel signals from the single pixel delay circuit are then read out at the same time that the pixel signals from the next row are being read in, so that signals from adjacent pixels in adjacent rows are available to the processing circuitry at the same time.