STEMMER IMAGING

Advantages of telecentric lenses

With standard lenses an object appears to be smaller or bigger when it is closer or further away from the lens. Unlike common optics, telecentric lenses only accept incoming ray bundles that are parallel to the optical axis; therefore the object size remains unchanged. This is essential when you must measure objects that cannot be precisely positioned (e.g. on a conveyor belt).

Moreover, telecentric lenses eliminate any perspective error and are therefore perfect when thick objects must be measured.

Telecentric lenses also outperform standard lenses when it comes to distortion: An image is distorted when straight lines in the object space appear as curved lines in the image space. Distortion is measured as a percent deviation. Opto Engineering telecentric lenses feature incredibly low distortion, typically under 0.05 % and deliver extremely accurate geometrical information.

Special features of bi-telecentric

Bi-telecentric lenses are also telecentric on the detector side. This additionally guarantees:

• Increased Field Depth
• Even CCD illumination
• Constant magnification even when the CCD is not perfectly positioned

Bi-telecentric lenses are able to deliver incredibly accurate measurement on many different precision parts.

Opto Engineering bi-telecentric lenses are specifically designed for real industrial applications. The lenses have a fixed design with no adjustable focus or aperture mechanisms to withstand vibrations and ensure accurate and consistent performance.

Due to these qualities bi-telecentric lenses are the key component of any accurate measurement system based on machine vision technologies.

Characteristics of the Opto Engineering TC lenses

Compatible with high resolution / small pixel detectors like 5MP 2/3" detectors, these lenses feature very low distortion while their real bi- telecentricity makes them purely telecentric.

Models

• Object field of view 2.4 x 1.8 mm up to 239.8 x 179.9 mm
• Working distance 45.3 mm to 531 mm