Basic classification of telecentric lenses

Date:2017-06-08 Author:admin Click:

Telecentric lenses are mainly divided into object-side telecentric lenses, image-side telecentric lenses, and bilateral telecentric lenses.

Object lens

The object-side telecentric lens is to place the aperture stop on the image-side focal plane of the optical system. When the aperture stop is placed on the image-side focal plane, even if the object distance changes, the image distance changes, but the There is no change, ie the measured object size does not change. Object-side telecentric lenses are used for industrial precision measurement with minimal distortion and high performance can achieve distortion-free.

Image side lens

For the telecentric lens on the image side, by placing an aperture stop on the object-side focal plane, the main light on the image side is parallel to the optical axis, so that although the installation position of the CCD chip is changed, the size of the projection image on the CCD chip is not changed.

Bilateral lens

Bilateral telecentric lenses combine the advantages of the above two telecentric lenses. In industrial image processing, only object-side telecentric lenses are generally used. Occasionally there are telecentric lenses on both sides (of course the price is higher). In the field of industrial image processing / machine vision, lenses like Fang Telecentric generally do not work, so this industry basically does not use it.