LED-based backlight systems are widely used in industrial machine-vision inspection machines to help outline the shape of parts, highlight their edges, or allow openings such as drilled holes to be imaged. But in many instances, end users need to change the product they are inspecting, so the LED lighting and diffuser on the system may need to be modified.
Products may differ in size and, accordingly, the small illumination source that worked well for a smaller product would need to be replaced by a larger illumination source to image a larger one. System integrators would much rather scale an illumination system up or down to work with their existing inspection systems.
Now, thanks to a novel illumination system developed by Microscan (Renton, WA, USA) engineers, they can do just that. The system—an enhancement to the company’s existing backlight technology—can not only be scaled up or down but also provides uniform and consistent illumination from edge to edge.
The simple concept, which saw Microscan rewarded with a US patent (7,976,184) in July 2011, allows the top diffuser plates of Microscan’s Edge-to-Edge Backlights to be interchangeable. The flexibility means users can now change the degree of diffusion for different applications without having to purchase a new LED light.
An additional benefit of Microscan’s concept is that system developers can substitute multiple diffusers with a single larger diffuser, to increase the uniformity of the light by eliminating the seams between them. Furthermore, the illumination source can be mounted to a back plate or a heat sink that is larger than the illumination source, allowing additional electronic circuitry or allowing for mounting the system to an additional structure.
-- Posted by Vision Systems Design