Telecentric Lenses

Overview

Object and Image Side Telecentricity.

This series of lenses are telecentric in both the object and image space, not just the object space as in the design of a normal telecentric lens. This design allows for telecentricity of less than 0.1% within the depth of field.

CCD and CMOS sensors continue to be developed with smaller and smaller pixels while increased electronic circuitry within the pixel further reduces the “fill factor.” To help focus light onto individual pixels, camera makers are using micro lens arrays in their designs. While these individual lenses, over each pixel, serve to collect light, they also pose a challenge to the optics designer. These micro lenses area most effective when the incoming rays are five degrees or less, of normal. The telecentric cone of light is a major benefit in these situations.

Low Distortion, High Accuracy

Double-Sided Telecentric lenses are less prone to optical aberrations and geometrical distortions. Image sizes will not vary across the field due to positioning of the sensor. Gauging applications will benefit from a double-sided telecentric lens compared to a simple object side only telecentric system. Our lenses are designed to work with CCD and CMOS sensors up to 28.7mm diagonal. We offer lenses with magnification from 0.03X to 2.0X as well as large format lenses with magnification from 0.239X to 0.478X.

Mounting Options

The back focal length is adjusted on the basis of C-mount or F-mount standard. A spacer kit with instructions to fine tune the back focus for a specific need is included with each lens. To see an example spec sheet, click here.

Advantages of Double-Sided Telecentric Lenses

• Telecentric both in the object and in the image space
• Less than 0.1% image distortion within the field depth at the field corners
• No image vignetting
• No parallax error
• No change of magnification within the depth of field
• MTF greater than 40% at 130 lines/mm
• Uniform illumination
• C or F mounts available
• Specially designed illumination accessories