Another OLED niche: Assembly line inspection stations

Often when we write about OLED lighting, it is with a sense of a technology looking for a solution, or for a niche market. This time is no exception. Yes, long-running dreams of a broad OLED future have yet to be fulfilled. But wouldn’t the technology be perfectly suited for, say, machine vision?

Of course it would, according to Rochester, NY-based OLED vendor OLEDWorks — a stalwart not only in advancing the technology but also in trying to find markets for it. But don’t just take their word for it. Machine-vision lighting company CCS Inc. says so too, noting that OLEDs can improve upon the LEDs that CCS has long used.

Here comes the obligatory quick review: OLEDs (organic light-emitting diodes) are sheets of material, rather than the single points of LED, that light up in response to electricity.

OLEDs trump LEDs in thinness. But LED panel designers have made progress in that area. Plus, at last count LEDs continued to have the edge in efficiency, longevity, and cost. Thus, 34 years after Eastman Kodak scientists invented OLEDs in Rochester, OLED remains a long-simmering technology in terms of widespread adoption.

So with OLEDs still winning in thin, the OLED community is seeking environments where that attribute can really matter — for instance, in recreational vehicles; refrigerators; luxury cars; and even in aerospace.

Now, add machine vision to the list, not only because of the thin profile but also because the better light uniformity and low heat dissipation associated with OLEDs could make a difference, according to CCS senior general manager Toshiyuki Toyofuku. He also noted that lasers and ultraviolet (UV) LEDs can improve upon conventional LEDs.

Machine vision essentially refers to automated equipment, including robots that are outfitted with optical technologies they use to inspect goods such as products on an assembly line. They look for blemishes. The optical systems include lighting, cameras, sensors, and software. CCS makes the lighting that help inspection robots to see.

In a written question-and-answer with Toyofuku on the OLEDWorks blog, the CCS executive explained why OLEDs can outperform LEDs.

“We started CCS in 1993, and we have primarily offered LED lighting for inspection purposes,” he noted. “OLED lighting is one of our new types of lighting methods, as well as laser and other specialized types of LEDs like UV.”

Working with OLEDWorks, CCS launched a 3-mm-thick OLED panel for custom integration into product in early 2020.

“One advantage of OLEDs is that they are very thin and lightweight,” Toyofuku said. “Even our thinnest LED lights are about twice as thick. A compact design can be crucial for machine builders when they need to install a light in limited space or inside a machine.”

But it’s not just the thinness that excites CCS about OLEDs.

“The second benefit of OLEDs is the uniformity,” he continued. “High uniformity can increase the accuracy of the inspection by eliminating shadows and providing even illumination for the camera. When the uniformity is poor, some parts of the image may be too bright or dark, resulting in missed defects.”

Anything else?

“OLEDs also generate less heat than LEDs,” Toyofuku added. “Heat can cause various issues in machine vision. For example, it can damage the inspected object. Light will also lose brightness over time because of overheating. Therefore, it is important to reduce the amount of heat in the inspection as much as possible.”

CCS is part of Shiga, Japan-based Optex Group, a holding company for various outfits offering sensors, lighting, and industrial and automation electronics.

Like with other OLEDWorks blog reports, the interview does not identify actual end users. The account has more of a sense of hope than actual market momentum about it, although CCS is clearly using the technology on some customer sites.

CCS’ Toyofuku further pointed out a potential for bendable OLEDs, noting that “an inspection system could be installed on a production line even where there are turns.”

The OLED industry itself hopes that brisker sales lie just around the bend.

>>Looking for more on machine vision and industrial imaging technology and applications? Visit our sister publication Vision Systems Design.

MARK HALPER  is a contributing editor for LEDs Magazine, and an energy, technology, and business journalist ([email protected]).

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