Lens assembly capable of realizing automatic focusing by adopting fixed focus lens

Abstract

The invention relates to a lens assembly capable of realizing automatic focusing by adopting a fixed focus lens. The lens assembly comprises a main board chip, a lens mounting seat, a lens fixing sleeve, the fixed focus lens, an adjustable ring and an automatic focusing control motor, wherein a radial outwardly-extended guiding nail is arranged on the outer peripheral wall of the fixed focus lens; a guiding sliding groove, matched with the guiding nail in a guiding manner, is formed in the inner peripheral wall of the adjustable ring; a run-through groove is formed in the sleeve wall of the lens fixing sleeve; the automatic focusing control motor is connected with the adjustable ring through a transmission apparatus; the main board chip has an automatic focusing control function; and a control line and a power line of the automatic focusing control motor are connected with an automatic focusing control interface in the main board chip. According to the lens assembly, factors of distance changes, day and night co-focusing, temperature drift and the like of a shot object are not needed to be taken into consideration in lens design, so that the design difficulty and cost of the lens are lowered; in addition, automatic focusing can be realized through the moving of the fixed focus lens in distance changes, day and night switching and high temperature and low temperature changes of the shot object, so as to obtain a clear image.

Description

technical field [0001] The invention belongs to the technical field of optical lenses and security monitoring cameras, and in particular relates to a lens assembly which adopts a fixed focal length lens to realize automatic focusing. Background technique [0002] At present, in the application field of security surveillance cameras, in order to maintain high-definition imaging in different environments (temperature, day and night), high requirements are placed on the design of the lens, that is, infrared visible (day and night) confocal, and extreme High and low temperature -40 degrees to +80 degrees without losing focus. This causes the design of the lens to be very difficult and costly. And even though day and night confocal, high and low temperature confocal are considered in the design, the result is still unsatisfactory, and there is also the problem of depth of field. At present, there are mainly two solutions. One is to use electric zoom, and to control the motor th...

AI Technical Summary

Problems solved by technology

However, in security cameras, the size of the chip is relatively large, and the chip is generally fixed on the main board. To drive the entire camera main board module, the requirements for the driving motor are high, and the unreliability is increased.

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