Oblique image telecentric lens with high precision and large depth of field

Abstract

The embodiment of the invention discloses an oblique image telecentric lens with high precision and large depth of field. The oblique image telecentric lens comprises an objective lens group, a liquid lens module, a diaphragm and an eyepiece group which are sequentially arranged from an object side to an image side, the oblique image telecentric lens is provided with a to-be-measured oblique object plane and an oblique image plane, and the extension plane of the to-be-measured oblique object plane, the extension plane of the oblique image plane and the lens plane, perpendicular to the optical axis, of the oblique image telecentric lens intersect on the same straight line. Each of the objective lens group and the eyepiece group comprises at least three lenses, the objective lens group and the eyepiece group have positive focal power, and the liquid lens module can change the curvature of a liquid lens by changing current or voltage so as to adjust the diopter of the oblique image telecentric lens. According to the embodiment of the invention, problems of small depth of field, complex lens mechanical movement system and long response time during oblique shooting of the existing machine vision lens are solved, full-view-field clear imaging of an oblique object and high-precision large-depth-of-field measurement perpendicular to an oblique plane are realized, the mechanical complexity of the system is reduced, and the response time is shortened.

Description

technical field [0001] Embodiments of the present invention relate to the technical field of optical lenses, in particular to an oblique telecentric lens with high precision and large depth of field. Background technique [0002] With the gradual acceleration of the global industrialization process, the requirements for industrial lenses in the field of machine vision are also getting higher and higher. In some specific application scenarios, when the lens needs to be tilted to shoot due to the occlusion of the field of view or limited space, the use of ordinary lenses will be affected by the imaging law of near, large and far, and the limitation of depth of field, resulting in deformation of the image and part of the field of view. Out-of-focus phenomenon, and the oblique image lens based on Sham's law can solve the above problems that occur when the lens is tilted. [0003] But further, if there is a large depth of field requirement in the direction perpendicular to the i...

AI Technical Summary

Problems solved by technology

However, the disadvantages of the mechanical movement method are as follows: 1. It increases the complexity of the system and requires higher mechanism design; 2. The response time of the system is long, and it cannot be measured quickly

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