telecentric lens

Abstract

A method and a device for the optical viewing of objects, the method comprising the stages of illuminating an object with ultraviolet radiation, and acquiring an image of the object thereby illuminated using a lens comprising at least a forward optical group and an aperture diaphragm exhibiting a transparent window located at a focal point of the forward optical group defined for the ultraviolet radiation.

Description

technical field [0001] The invention relates to a telecentric lens for use in a device for artificial vision, in particular for performing dimensional measurements of objects. Background technique [0002] It is well known that artificial vision typically uses telecentric lenses for dimensional measurement applications. figure 1 An optical diagram of a telecentric lens according to the prior art is shown. [0003] The telecentric lens 10 has a main opto-mechanical axis X and comprises a front optical group 12 adapted to receive rays from an object to be viewed and a front optical group 12 adapted to transmit said rays to a sensor of a vision device. Rear optical group 14. Telecentric lens 10 differs from conventional, or "entocentric" lenses in that a telecentric lens receives only the center of the gravity ray (or principal ray) from the object being A cone of rays R parallel to the axis X. To this end, the telecentric lens must have a front lens FL at least as wide as ...

AI Technical Summary

Problems solved by technology

[0007] The complexity of making such negative lenses 30 and 32, combined with the type of shape required and the overall number of optical components required to make the telecentric lens, complicates its manufacture, in addition to high cost, because these configurations factors that make it more difficult to obtain optimal alignment of the lens assembly

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