TEN° binning

What is TEN° binning?

Imagine you are illuminating a scene with three spotlights. The white light from these three spotlights may look a bit different. You are measuring the color coordinates and they are not only within 1SDCM but they are exactly the same still they look different! How can this happen?
This problem is caused by some inaccuracies in the CIE 1931 2° xy color diagram which everyone is using right now for LED white binning. It may happen, that LEDs with different spectral composition may be measured to have exactly the same color coordinates but the visual perception still shows color differences! This spectral differences can be caused by different wavelengths of the blue chip or the converter compositions.

How can we solve this problem and measure more accurately the visual impression of color differences? With the introduction of TENº binning we are also applying the recent CIE 170-2:2015 technical report to LED binning. This report is using the latest cone fundamentals from 2006 to create a fundamental chromaticity diagram with physiological axes to ensure that the visible color differences are also captured in the measurement and binning accordingly! The new color matching functions are now summarizing 85 years of research.

What exactly is the new OSRAM Opto Semiconductors TENº binning? The introduction of the new TENº binning is implementing three important and innovative steps to the white binning of LEDs to ensure that a 3SDCM binning really only shows up to 3UNIT real color differences and not more!

• The change from the CIE 1931 to the latest fundamental color matching functions ensures a correct measurement of the color coordinates in a color diagram with physiologically significant axes.

• The move from the 2° to the 10° field of view allows a much closer match of measurement and assessment of color differences in real general lighting applications. The 2° is roughly a 20mm disc at 0,5m. The 10° field of view is equivalent to a 90mm disc at 0,5m and therefore much closer to most real life situations.

• The move from the xy scale with the MacAdam ellipses to a u’v’ scale that transforms the ellipses into circles creates a unified color space where color differences in all directions are equally scaled. This makes life much easier to determine if the color differences measured are equivalent to the visual color differences in all directions.

How will the luminaire manufacturer benefit from the TENº binning? The following simulated production distribution of white LEDs demonstrates the risk with a 1SDCM binning and the solution with TENº binning.

(Simulation parameters: CCT=4000K; CRI=80; blue wavelength variation=15nm)

We are using two sets of LEDs. One is binned in a tight 1SDCM binning. The other one comes in the “TENº binning”.

The 1SDCM binning looks very narrow and suggests a very small color discrepancy. The TEN° binning is a standard 3SDCM binning in the 1931 2° color diagram fulfilling all industry standards.

As we learned, the 1931 2° color space is not able to measure color differences correctly and it may happen that LEDs with a very small color difference in the old color space still have a very large color difference in the 2015 10°.

If the LEDs are measured in the 2015 10° color space, the 1SDCM binning widens significantly and shows color differences even more than 3UNITs! The TEN° binned LEDs are safely within the 3UNITs boundary and don’t lead to this kind of unpleasant surprises.

Therefore the TEN° Binning is outperforming even a 1SDCM when it comes to color differences induced by a large variation of spectral differences!

The new TEN° Binning will completely comply with the existing 1931 2° standard 3SDCM binning and can fulfill all requirements of existing designs and standards. The new 2015° 10° 3UNIT feature is an addition to provide a better protection against unexpected large color differences!

• TEN° Binning complies fully with existing designs, specifications and standards
• Provides protection against unexpected large color discrepancy by using a more accurate color space
• Reduces the risk of strongly visible color differences between luminaires
• Introduces a new color space based on CIE 170-2:2015 using the latest fundamental color matching functions to create a chromaticity diagram with physiological axes
• Is ready to change the white binning of LEDs completely to a new color diagram
• Could help to reduce color differences between LEDs with different CRI values
• Could help to reduce color differences between LEDs from different types and converter mixes
• Could help to reduce color differences between LEDs from different manufacturers

Bartenbach GmbH:
„Forschungsarbeiten bei Bartenbach zeigten, dass in manchen Fällen die klassische photometrische Bewertung des Lichtspektrums mit dem visuellen Erscheinungsbild nicht übereinstimmt. Diese Differenz wurde auch in Lichtplanungsprojekten mit hohen Ansprüchen an die spektrale Lichtqualität sichtbar. Osram setzt mit einem neuen Weißbinning den richtigen Schritt, um die Qualität einer Beleuchtungsanlage mit LEDs zu erhöhen.“

NEL Neontechnik Elektroanlagen Leipzig GmbH, Dr. rer.nat. R. Hennig, Diplomphysiker, Bereichsleiter F/E/A:
„Ich kann mich hier nur der Meinung des Institutes Bartenbach anschließen. Als Wissenschaftler bin ich der Meinung TEN° binning ist ein vollkommen richtiger Schritt in die richtige Richtung und ist bereits lange erwartet und notwendig. Ich hoffe sehr, dass der General Lighting Markt diesen Ansatz entsprechend honoriert und sich daraus ein neuer Standard etabliert.“