Lens focusing device

Abstract

The invention discloses a lens focusing device. The lens focusing device comprises a base; a lens connecting base which is movably arranged on the base; a guide shaft which is arranged in the lens connecting base in a penetrating manner, and one end of which is connected with the base; and a motor which is arranged on the base. The output end of the motor is connected with a lead screw and can drive the lead screw to rotate, the length direction of the lead screw being the same as that of the guide shaft; the lead screw is sleeved by a connecting piece; the connecting piece is connected with the lens connecting base; and the connecting piece can do reciprocating motion in the length direction of the lead screw along with rotation of the lead screw so as to drive the lens connecting base todo reciprocating motion in the length direction of the guide shaft. The lens connecting base can be driven to reciprocate in the length direction of the guide shaft by controlling the motor to rotateforwards and backwards, and thus the purpose of automatic focusing is achieved; and the lens connecting base is only matched with the guide shaft, and the matching surface between products is small,so that the precision is easier to guarantee on the mold, and the problem that the matching precision between parts of a self-focusing module of a traditional gearbox cannot be balanced is solved.

Description

technical field [0001] The invention relates to the technical field of cameras, in particular to a lens focusing device. Background technique [0002] With the maturity of the lens industry and the improvement of security awareness of the general public, the requirements for security lenses in the market are also getting higher and higher. From the initial VGA (Video Graphics Array, that is, Video Graphics Array) to the current 4K lens, The image surface has also evolved from the largest 1 / 4" to the current 1 / 1.8" or even larger. This evolution has undoubtedly added a lot of difficulty to the design of the optical system. The dual requirements of high pixels and large image surface If the lens is lowered, the back focus of the lens is sensitive and the length of the back focus is shortened. As far as the issue of back focus sensitivity is concerned, the traditional operation of connecting the screw to the base and manually rotating the lens to focus can no longer meet the a...

AI Technical Summary

Problems solved by technology

[0002] With the maturity of the lens industry and the improvement of security awareness of the general public, the requirements for security lenses in the market are also getting higher and higher. From the initial VGA (Video Graphics Array, that is, Video Graphics Array) to the current 4K lens, The image surface has also evolved from the largest 1 / 4" to the current 1 / 1.8" or even larger. This evolution has undoubtedly added a lot of difficulty to the design of the optical system. The dual requirements of high pixels and large image surface lower, resulting in lens back focus sensitivity and shortened back focus length

As far as the issue of back focus sensitivity is concerned, the traditional operation of connecting the thread to the base and manually rotating the lens to focus can no longer meet the precision requirements of the optical system, so it is necessary to use a high-precision auto-focus module to achieve focus

[0003] The traditional auto-focus module uses a gearbox system to achieve the purpose of self-focusing. However, although the gearbox system has high focusing accuracy, its structure always has a certain amount of draft due to the existing mold production. The inclination causes the automatic focus module to have a certain gap in the position of the mechanical dead point at both ends, and the matching accuracy between the parts cannot be balanced. Often, the bottom can fit but the end gap is too large, resulting in problems such as shaking; or The end fits well but the bottom fits tight, resulting in stuck and serious out-of-step problems

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