White balance control device employing zoom information for photographing an object without the occurrence of color failure

摘要

A white balance control device is provided for use in a video camera or a still video camera, each having zoom capabilities, in which white balance control signals are controlled so that an object may be photographed without the occurrence of color failure. A recognition level or threshold is set as a function of zoom information. 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 the recognition level. 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.