| 摘要 |
PURPOSE:To improve the picture quality of an image by automatically performing aperture correction according to zoom magnification of a zoom lens by detecting the zoom magnification, and then performing the aperture correction according to the detected value. CONSTITUTION:A TV camera mounting a zoom lens 7 is provided, and the zoom magnification of this zoom lens 7 is detected by a voltage detection part 8 in the form of a voltage value to send an aperture correction signal to an amplifier 9. a video signal from a signal source 1 is matched with a delay circuit 3 through a characteristic impedance element 2, and a signal delayed by the delay circuit 3 and the undelayed signal are supplied to a subtracter 4, which detects the edge component of the video signal. The edge component detected by the subtracter 4 is applied to an amplifier 9, whose gain is varied by the aperture correction signal generated by the detection part 8, thus controlling the amplitude of the edge component. Then, an aperture is corrected automatically according to the zoom magnification of the zoom lens 7 to improve the picture quality of the image signal. |
