| 摘要 |
A white balance adjusting device for video camera performs white balance control at high speed for an image which does not include a white colored portion under artificial illumination outside blackbody radiation while maintaining stability for usual illumination condition. An iris detector for detecting an iris value of an iris mechanism a, fluorescent light detector for determining whether or not an illumination source is a fluorescent lamp and correction apparatus responsive to an output of the fluorescent light detector to correct said white balance control signal suitably are provided. In order to obtain a high speed response to a variation of illumination, an integration circuit for averaging color-difference signals, amplifier circuits responsive to the averaged color-difference signals to control gains of chrominance signals to thereby produce white balance control signal for regulating white balance, a hold apparatus for holding white balance control signal temporarily and a converter apparatus for converting the content of the hold apparatus into signal for driving the chrominance signal gain control circuit, and a change apparatus for changing a timing of rewriting the content of the hold apparatus are further provided.
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