Briefly describe the design principles and functions of telecentric lenses

The telecentric lens is a lens specially designed to correct the parallax of traditional lenses. It can be within a certain object distance range so that the magnification of the image obtained does not change with the change of the object distance. This does not mean that the object being measured is not the same. The situation on the object surface is a very important application.

Telecentric lenses bring a qualitative leap to machine vision precision inspection based on their unique optical characteristics: high resolution, ultra-wide depth of field, ultra-low distortion, and unique parallel light design. However, because the application fields are not very wide, telecentric lenses have always been mysterious and not well known. Let's first analyze the design principles of telecentric lenses for you by Chengdu Xiwang.

(1) The design principle and function of telecentric light path:

The object-space 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 the object-space telecentric optical path. Its function is: it can eliminate the reading error caused by inaccurate focusing of the object side.

(2) Design principles and functions of telecentric optical path:

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 object-side, which is called the image-side telecentric optical path. Its function is to eliminate the measurement error caused by inaccurate focusing of the image side.

(3) Design principles and functions of telecentric optical paths on both sides:

It combines the dual functions of object space/image space and telecentricity. Mainly used in the field of visual measurement and inspection.

It can be seen from the design principles of the above types of telecentric lenses that telecentric lenses are high-precision lenses designed to make full use of optical imaging characteristics and fully consider the influence of light in imaging. Currently, they are used in machine vision precision measurement and high-precision detection. The field has been widely used.