White balance control wherein valves of control signals are fixed or converged within a renewable, variable region

摘要

A white balance control device is provided for use in a video camera or a still video camera in which white balance control signals are controlled so that an object may be photographed without the occurrence of color failure. A microcomputer of the white balance control device detects a difference between integral averaged values for two color difference signals R-Y and B-Y and a reference value. Depending on the difference, values of the white balance control signals Rcont and Bcont may be changed when the brightness of an object is changed by more than a predetermined amount. However, the values are positioned within a variable region and when the values of the white balance control signals Rcont and Bcont become constant, the variable region is renewed.