Zoom optical system with high resolution ratio, large image surface and low tolerance sensitivity

Abstract

The invention relates to a zoom optical system with high resolution ratio, large image surface and low tolerance sensitivity. The zoom optical system comprises a first lens group with positive focal distance, a second lens group with negative focal distance, a variable diaphragm, a third lens group with positive focal distance, a fourth lens group with positive focal distance and a light-sensitivechip sequentially from an object side to an image side; the first lens group, the variable diaphragm and the third lens group are fixed relative to the light-sensitive chip; the second lens group andthe fourth lens group can move back and forth relative to the light-sensitive chip; in the process of changing from short focal distance to long focal distance by the optical system, the focusing effect is realized when the second lens group gradually moves towards the third lens group and the fourth lens group moves relative to the light-sensitive chip; a lens in the middle of the second lens group and a lens at the back end of the third lens group are aspheric lenses; and in the scheme, the aspheric lenses can correct aberration and reduce distortion, so that the zoom optical system obtainsrelatively high imaging quality.

Description

Technical field [0001] The present invention relates to the technical field of optical lenses, in particular to a zoom optical system with high resolution, large image area, and low tolerance sensitivity. Background technique [0002] At present, zoom lenses are widely used in people's daily life. The current market is developing towards high resolution and high image quality. In order to obtain better imaging quality, using chips with larger pixels and more pixels is the solution to the problem. One of the fundamental ways, but the current security monitoring and road condition monitoring devices have the following shortcomings: [0003] Ordinary zoom lenses are often unable to achieve large image area and volume compatibility. An increase in the image area will cause a sharp change in the lens volume. At present, large-screen surveillance lenses on the market, such as 1″ lenses, have an image surface size of 16.0. mm, its volume is relatively large, and most of it is a fixed foc...

AI Technical Summary

Problems solved by technology

[0003] Ordinary zoom lenses are often not compatible with large image area and volume. The increase of image area will cause a sharp change in lens volume. Currently, large-screen surveillance lenses on the market, such as lenses with a size of about 1″, have an image area of ​​16.0 mm, its volume is relatively large, and most of them are fixed-focus lenses, which are difficult to control when the monitoring distance changes;

[0004] At present, the mainstream high-quality surveillance cameras on the market have a low resolution, mostly 1080p, with 2 million pixels. However, with the improvement of data transmission speed, higher-quality image transmission becomes possible. It cannot meet the demand; the current mainstream 1080P lens image plane is mainly 1 / 2.8″, using a 1 / 2.8″ CMOS chip with an effective imaging plane diagonal of 6.2mm, its pixel size is only 2.8μm, and the resolution Not very high; and because the pixels are small, its photosensitivity and color reproduction are not very ideal, and performance improvement is urgently needed;

[0005] Most of the surveillance lenses currently on the market are non-infrared confocal lenses. Therefore, in occasions with many optical wavelength bands, such as in the evening, or when there is some lighting at night, the captured picture cannot be clear as a whole, and there will always be some blurring;

[0006] Surveillance lenses currently on the market seldom eliminate the stray light of the lens through the optical structure. When the light source is strong or sunny, the lens stray light phenomenon is serious, which makes the actual imaging effect of the lens poor;

[0007] The use of aspheric surfaces in lens design can effectively reduce aberrations, but at the same time it will increase lens sensitivity. Generally, the more aspheric surfaces of a lens, the higher the sensitivity, the lens is difficult to process, and the lens assembly yield is very low.

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