Osram is introducing the Soleriq S 13 with 10° binning for unprecedented color consistency
Since the intense use of LEDs in general lighting, white binning has become increasingly important. However, as the CIE 1931 2° color space which is used globally is slowly reaching its limits and is no longer capable of adequately mapping the perceptible color differences of white LEDs, it is high time to act. Based on scientific findings, Osram Opto Semiconductors has now found a solution to this problem, and has introduced “TEN°” binning, which provides unprecedented color consistency. The new white binning will be used in a series product – the third generation of the Soleriq S 13 – for the first time in the world.
In the usual CIE 1931 2° color space, two light-emitting diodes (LED) can exhibit noticeably different white tones despite the exact same color coordinates. The reason for this is the discrepancy between the CIE 1931 2° color space and the reality of color perception. In this color diagram it is assumed that the blue, green and red cones that are responsible for color perception in our eyes are evenly distributed. However, this is not the case in reality. The pigment density varies enormously over the field of view’s size; for example, there is a small area in the center where there are no blue cones at all. At a distance of 0,5 meters, the usual 2° color space only comprises a field of view with a diameter of 17 millimeters. Most applications in general illumination are rated at a field of view of 10° (about a diameter of 90 millimeters) and over, which is why distorted perceptions often occur. In white CoB LEDs, which are used as single light sources in wallwashers, spotlights and downlights, differences in color can be particularly unpleasant.
Although specialists have been aware of this problem for several decades and extensive research has been conducted, for LEDs they have only once tried to reduce the perceptible differences in color exclusively by ever smaller color bins; here, stricter standards were often set for LEDs than for conventional light sources. This trend went from complete ANSI boxes down to 5SDCM, 3SDCM and 1SDCM – and hence to binning sizes which presented a challenge to the production of light sources and the associated measurement technology. However, due to the shortcomings of the CIE 1931 2° color space, even the smallest color bin cannot prevent visible color differences.
Osram Opto Semiconductors has now changed this by applying the latest scientific findings on eye cones, as well as basic knowledge about the chromaticity chart with its important axes in terms of physics to the LEDs used in general illumination. When it comes to “TEN°” binning, major color differences can be avoided through different spectral shapes. To achieve this the company took the CIE 2015 10° color space, recently developed by the International Commission on Illumination, and implemented it as 10° binning for white LEDs. Compared to the 2° color space, this 10° color space is much closer to the color perception of the human eye. “TEN°” binning will by no means replace existing standards, but only add to them for now.
Osram Opto Semiconductors will use “TEN°” binning for the first time in the third generation of the Soleriq S 13, which will be available from March 2016. Thanks to this new feature, this LED will guarantee unprecedented color consistency. In addition, the new Soleriq LEDs continue to be compliant with current industry standards, and continue to be compatible with existing white groupings. This still enables customers to implement their specific products and applications without any problems. Whether and when the new white binning is transferred to other series products will depend on market acceptance.
For more information on the Soleriq S 13 and the entire product family please click here.