| 摘要 |
In a video camera, black level correction is turned off in a backlight correction condition or when an AGC gain is high, video signals are converted to digital signals by an A/D converter, the digital video signals are compared with a reference value by a data comparator, and a number of times that the comparison is less than the reference value is counted by an integrator. The reference value, where the counted number of times is the predetermined number of times or more, is determined by a microcomputer, a black level correction value according to the determined reference value is set, and clamp circuits are provided with the black level correction value to correct the black level, thereby preventing a bad influence due to black level correction during exposure correction or when the AGC gain is high, and making black level correction by digital processing.
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