27.11.2013

Telecentric lenses for everything involving color

vicotar® Telecentric Lenses T42B/0.26

Color inspections and inspections in the infrared range require lenses of a particularly high quality. This is because color fringing with distorted colors and blurred images reduces the accuracy and speed of an optical inspection system. Vision & Control has made an addition to its T42 series from the vicotar® range telecentric lenses in the form of the T42B/0.26 series, the lenses of which are designed to prevent this problem even arising in the first place.

This is absolutely essential in numerous different industries, especially where objects are inspected with colored light in order to cover all the relevant inspection characteristics. Examples include automatic optical inspections (AOI) of printed circuit boards and register control in printing presses for sheetfed and webfed printing and for the printing of flexible circuits. Characteristics are detected here in a great variety of colors. The lenses in the T42B/0.26 series are specially designed for the multispectral range and eliminate the need for any readjustments and software corrections.

This range of lenses was developed to ensure that in the spectral range of 470 to 850 nm the quality of the measurement is not influenced by lateral chromatic aberrations where cameras with a pixel pitch starting at 4 µm are used. This prevents the "skipping" of pixels between pixels of different colors. The series offers lenses with two different working distances, 145 mm and 187.5 mm, and two different aperture sizes - either NA' = 0.05 or NA' = 0.03. This corresponds to an effective F-number of 10 or 16.5. In addition to the long and short working distance, medium working distances or in-between sizes can also be supplied on request. The integrated fixed aperture makes the lenses absolutely ideal for industrial use in the series production of machines and, if requested, can also be modified for a larger depth of field. This enables different machine conditions and surrounding conditions to be taken into account, as well as the required depth of field and aperture of the optical system.

The object-sided und double-sided parallel light path (bilateral telecentricity) enables the best possible image quality to be achieved in terms of distortion and vignetting. The lenses can be used for sensors up to 2/3''. The series has been optimized for the visual and infrared spectral range. The vicotar® T42B/0.26 telecentric lenses are perfectly tailored to the extensive product range offered by Vision & Control, the vicosys® multi-camera systems, pictor® intelligent cameras, vicolux® illuminators and vicotar® lenses, plus: the lenses can be connected as C-mount lenses.