| 摘要 |
PURPOSE:To make stable tracking and search possible by switching automatically light quantity control between light quantity control based on an average luminance in a screen and that based on an average luminance in a gate in accordance with a tracking state signal to pick up the image of a tracking target quickly in an optimum light quantity state. CONSTITUTION:An incident light has the quantity adjusted by an optical stop 8, and the image is converted to an electric video signal by a sensor 9 and is supplied to a tracking target extracting part 10 to detect the position of the target, and a tracking gate 4 is set around a target 3, and an average voltage level in the tracking gate 4 is detected by an intra-gate average voltage level detecting part 12. When tracking is not performed, a stop controller 13 uses an average voltage outputted from an intra-screen average voltage level detecting part 11 to control the optical stop 8. When a tracking indication signal 17 is outputted through an operation panel 15, a state signal is transmitted from a microcomputer 16 to the stop controller 13 to switch automatically light quantity control. |
