Telecentric Lens

1. The object-side telecentric optical path is to place the aperture diaphragm on the image-side focal plane of the optical system. The object-side principal ray is parallel to the optical axis and the convergence center of the principal ray is located at the object-side infinity, which is called: object-side distance Heart Light Path. Its function is: it can eliminate the reading error caused by the inaccurate focusing of the object side.

Schematic diagram of the object-side telecentric optical path

2. The image-side telecentric optical path is to place the aperture diaphragm on the object-side focal plane of the optical system. The image-side principal ray is parallel to the optical axis and the convergence center of the principal ray is located at infinity on the image side, which is called: image-side distance Heart Light Path. Its function is: it can eliminate the measurement error caused by inaccurate focusing on the image side.

Schematic diagram of the telecentric optical path of the image side

3.The double-sided telecentric lens combines the advantages of the above two telecentric lenses. In industrial image processing, generally only object-side telecentric lenses are used. Occasionally there are telecentric lenses on both sides, (of course, the price is higher). In the field of industrial image processing/machine vision, the telecentric lens generally does not work, so this industry basically does not use it.