FRAME GRABBER WITH FUNCTION OF CONTROLLING IRIS

摘要

PURPOSE: A frame grabber with a function of controlling the iris is provided to always photograph an accurate image regardless of an instant change in brightness at night. CONSTITUTION: A camera interface(40) receives an image of a camera(10) for converting the image into digital. A shutter signal input unit(30) receives the image of the camera from the camera interface according to an output state of a sensor(20) sensing a photographing point. An automatic shutter signal generator(110) is provided to periodically receive the image of the camera. An image brightness judging unit(120) calculates and outputs a mean brightness of the image according to an output signal of the automatic shutter signal generator. An analog video signal generator(50) outputs a mean bright image into an analog image for controlling the iris of a camera lens(60). A storing unit(70) stores the digital image. A register(80) memorizes a control value for operating a frame grabber. A day and night judging unit(130) judges day and night by comparing a day and night judging reference value and the mean brightness value, and transmits the result to the register. A control unit(90) controls the operation of the frame grabber, stores the digital image at the storing unit, and controls output of the digital image stored at the storing unit.