Removal of line selection artifacts from trace portions of line transfer CCD imager video output signals

摘要

There is electrostatic coupling of the forward clocking signals used in a CCD imager of line transfer type to the underlying bulk semiconductor and then to the output charge sensing stage. Changes in forward clocking signal application during the line selection process in the image register tend to introduce transient disturbances leaving visible artifacts in television pictures reconstructed from the video signals generated from the CCD imager output signal samples. This tendency can be obviated in CCD imagers of line transfer type by introducing additional clocked delay to place the disturbances in the line retrace interval. The disturbances can then be removed from video signals by line retrace blanking.