Patent ID: 6499663
Filing Date: 2002-12-31
Classification: H04N

Abstract:
An image input system comprising a solid state image pickup device and a preprocessor performing correlated double sampling amplification on an output signal of the solid state image pickup device and outputting a video signal,wherein the preprocessor includes a correlated double sampling amplifier outputting signal information corresponding to a difference voltage between a black level in a feedthrough period of the solid state image pickup device and a signal level in a charge signal output period; and offset cancelling means for applying an offset cancelling voltage for cancelling an offset voltage corresponding to the difference voltage between the black level in the feedthrough period of the solid state image pickup device in a state where the solid state image pickup device is optically interrupted and the signal level in the charge signal output period to an input terminal of the correlated double sampling amplifier, and the correlated double sampling amplifier performs cancellation between the offset voltage and the offset cancelling voltage as signal components of polarities opposite to each other.