Automatic aperture adjusting method and device

Abstract

The invention provides an automatic aperture adjusting device and method based on self-adaptive adjustment. The automatic aperture adjusting device comprises an automatic aperture lens, an average brightness calculation unit, an automatic aperture control unit and an automatic aperture motor, wherein the automatic aperture lens is used for collecting images; the average brightness calculation unit is used for calculating the average brightness of an image acquired by the automatic aperture lens; the automatic aperture control unit is used for generating a control signal which controls the size of the aperture according to the difference of the average brightness calculated by the average brightness calculation unit and target brightness; and the automatic aperture motor is used for controlling the size of the aperture of the automatic aperture lens according to the control signal outputted by the automatic aperture control unit. The size of the aperture can be adaptively controlled byanalyzing the current state of the aperture, so that the device can be applied to various automatic aperture lenses, and avoids the problems such as manually adjusting parameters and the like.

Description

field of invention [0001] The present invention relates to an automatic aperture adjustment device and its method, more specifically, to an automatic aperture adjustment device and its method based on self-adaptive adjustment. Background technique [0002] As we all know, the automatic aperture of the camera lens refers to a mechanism in the lens that can adjust the size of the opening. Use a certain strategy to adjust the size of the aperture opening to control the amount of light that can pass through the aperture and reach the photosensitive chip per unit time, so as to obtain moderately exposed images under different lighting conditions. A reasonable aperture size can increase sharpness and control depth of field. [0003] At present, the automatic iris lens is roughly divided into two types: video drive and DC drive. The automatic iris referred to in the present invention is a DC drive iris (DC-iris) commonly used in surveillance cameras and other products. The tradi...

AI Technical Summary

Problems solved by technology

So some parameters in this patent, such as reference voltage Vo, reference voltage range V N , V L etc. It needs to be adjusted according to different lenses; on the other hand, it is quite difficult to find suitable parameters for different lenses, and generally can only be manually adjusted based on experience

However, the ΔIRIS calculated by wrong parameter setting will not be able to stabilize the automatic iris, causing problems such as overshooting and back and forth oscillations.

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