Automatic balance control device especially for video camera with CCD image sensor

摘要

The black and white balance control device provides automatic balance of the white signal when a white image is projected onto the CCD image sensor and automatic balance of the black signal when a black image is directed onto the CCD image sensor. The device evaluates the mean level of the brightness signal by comparing with a reference value. The output signal from the comparator (15) is coupled to a switch (16) for activating either a white or black balancing stage (9,19) under control of a manual push-button (12).