Collimated CSBACK


Collimated backlight by TPL Vision for measurement and inspection machine vision applications

Collimation effect seen on threaded part

Collimation effect seen in a plastic part

Collimation effect seen in a plastic part

TPL Vision’s collimated backlight, the CSBACK is the perfect illumination choice for the inspection or measurement of clear plastics and rounded parts. Collimated light by definition has parallel light rays, and therefore spreads minimally as it propagates, helping to create high-contrast images needed for precise edge detection and defect analysis.

Key application areas include the inspection of objects with rounded edges and clear parts, which may be challenging to inspect with traditional backlights due to the lack of contrast. A collimated light allows users to eliminate this effect by providing a narrower illumination angle that stops the light from wrapping around rounded parts. This also means that images of clear parts no longer appear “washed out”. The edges are more clearly defined, and details are seen with improved contrast, leading to high-quality images and increased accuracy. 

Typical applications

With traditional backlights, round parts will always have the issue of light wrapping around the edges of the component. However, the collimation effect can reduce this, because the light emitted from the surface of the collimated backlight is narrower (5% brightness at ±30°), creating much sharper edges. This makes the CSBACK ideal for the automotive, packaging and food & beverage industries, with common applications including the measurement of thread pitch, checking the placement of lids, and bottle neck inspection. The quality and consistency of illumination is crucial for inspection applications, because uneven lighting conditions can lead to inaccurate results and a loss of productivity.

Round threaded part being inspected, illuminated by a regular backlight

Round threaded part being inspected, illuminated by a collimated backlight

Plastic part (pharmaceutical industry) inspected with normal backlight

Plastic part (pharmaceutical industry) being inspected with collimated backlight

Using a collimated light source is also extremely effective on glass or clear plastic parts. Providing improved contrast, the CSBACK is perfect for the highly regulated pharmaceutical industry, helping with testing and bringing products to market at a faster pace with the use of automation. The CSBACK provides optimal illumination for measuring features like the fill levels of ampoules, particle size of granulated products, and the presence and angle of needles. Similarly, a collimated backlight is more effective at highlighting cracks or extruded details on clear plastics, and capable of creating better contrast for locating plastic parts in the food & beverages industry.

Technical details

The CSBACK can be used with regular C-mount lenses as well as telecentric lenses. The best method for illuminating highly precise measurement applications is to use a telecentric lens combined with a light, but this is often considered too expensive a solution for many applications. Introducing a collimated illumination to these applications enables users to switch to using normal C-mount lenses rather than telecentric lenses, bringing significant cost advantages and simplicity to the application. The collimated backlight also works with a telecentric lens, but careful setup is required as the working distance between the part being inspected and the light is critical.

Which light is right for my application?

TPL Vision has 2 backlight products available with the collimation effect, one for smaller fields of view and one for larger:

Minimum Size 50×50 200×200
Maximum Size 200×200 400×400
Increments 50mm 100mm
Thickness 21mm 45mm
Power Supply (current control integrated) 24VDC 24VDC
Mounting M4 threads on border T-slot on border, screw points in corners
Surface homogeneity * 90% 85%
Connector M12 4P M12 4P (T-power)
IP rating 40 40

* Surface homogeneity is at this level using a telecentric lens to cover the entire field. Using a standard optic, depending on the size of the light and the working distance, brightness might be reduced due to the light being at 5% of the brightness at ±30°.

Technical information

To view all the technical information, please click on the tabs below.

Setting up/lighting method

TPL Vision CSBACK lighting set up for machine vision projects

Reference builder

Reference Builder TPL Vision CSBACK


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