Luminus has announced the Hospitality COB Series of LEDs designed for solid-state lighting (SSL) in restaurants, hotels, and similar spaces. The chip-on-board (COB) LEDs feature precise color control and fall below the black body locus (BBL) on a chromaticity or color space diagram. That chromaticity ensures that human eyes perceive warm skin tones and that people look good under the lighting.
Of course, the BBL is not necessarily a perfect definition of white light, but rather a reference based on how a black body radiator would map into a color space across a correlated color temperature (CCT) range. The BBL has proven useful as a reference for white-light chromaticity and indeed ANSI white-light color bins are centered along the BBL. You can refer to our seminal four-part series of articles on color science for a better understanding of the topic.
But LED manufacturers and even lighting manufacturers and designers have long utilized chromaticity points away from the BBL to achieve some goals relative to light perception and optimal light quality. Xicato announced below-the-BBL Vibrant light engines back in 2013 with the knowledge that the chromaticity would result in a lower CRI rating yet would improve the human perception of saturated colors. Indeed, Luminus itself first showed such a product at LightFair International 2014. And Lumileds has used the technique in its Crisp White LEDs.
Luminus said that the problem with the ANSI bins is that even in a 2-step SDCM (standard deviation of color matching) bin, half of the LEDs are above the BBL and half are below. Those LEDs that are above the BBL can cause the human eye to perceive a slight green tint. Luminus described the green tint as “extremely unattractive” on human skin.
Of course, packaged LEDs have come a long way from the timeframe when manufacturers first experimented with chromaticity below the BBL. Luminus said with a combination of chip and phosphor innovation, the Hospitality COB Series can deliver high color rendering scores along with the warm-tone benefits and eye comfort. The portfolio features CRI scores in the 90–95 range along with high R9 values and also high scores on the TM-30 metrics.
Indeed, the overall performance will likely expand the market for the LEDs beyond the hospitality target. “While this COB series was created for the hospitality industry, we’re finding that the 2-step color control, excellent color rendering, and attractive warm tones on human skin also appeal to lighting designers for retail shops and other public spaces,” said David Davito, senior global COB marketing director.
Luminus will offer the new LEDs in versions with a light-emitting surface (LES) ranging from 6–22 mm. Moreover, output flux will vary from 500–5000 lm. The LEDs will generally be used at the warm end of the CCT range. Luminus will offer 2700K-, 3000K-, 3500K-, and 4000K-CCT options.
LEDs Magazine chief editor MAURY WRIGHT is an electronics engineer turned technology journalist, who has focused specifically on the LED & Lighting industry for the past decade.
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