Optical Basics LED Fundamentalsp

ColorimetryColorimetry

07-07-2011

Light and the Eye

The eye has incredible dynamic range

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Colorimetry

Colorimetry is the science that describes colors in terms of numbers.

Metamerism – different power spectra, same color coordinates

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Colorimetry

Roughly speaking the retina of the human eye has photoreceptors for red green and Roughly speaking, the retina of the human eye has photoreceptors for red, green, and blue.

Spectral distribution coefficients have been defined which allow us to compute color coordinates.coo d a es

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Color Coordinates

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CIE Chromaticity Diagram(u′, v′) chromaticity diagram, also

known as the CIE 1976

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Correlated Color Temperature (CCT)• Temperature of a blackbody radiator p y

closest in appearance.• Attempt to use a single number to

characterize a full spectrum.Pl ki l l f bl kb d• Plankian locus: colors of blackbody radiators

• Judd lines: perpendicular to Plankian locus in uv color spacein uv color space

• CCT: for colors on a Judd line, CCT is the temperature of the blackbody radiator at the intersection with the Plankian curve

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Color Rendering Index (CRI)

Fair

50-70 CRI

Better

70-80 CRI

Best

80-100 CRI

Source: Energy Star

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MacAdam Ellipse

Region in color space containing those colors which are indistinguishable to the average human eye from the color at the center of the ellipse.

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Example of OSRAM’s Binning Scheme0.45

3000K3500K

4000K 7

89

Planck

3-step MacAdams ellipses

0.404500K

5000K

6

5

4

Planck

5700K

6500KO

PQ

R S T U V W X

ANSI C78.377 quadrangles

0.35

HI

JK

LM

NO

78

q g

4000K

3000K

2500K

0.30 CD

EF

GH

45

67 4000K

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0.28

0.33

0.38

0.43

0.48

Disclaimer

All information contained in this document has been checked with the greatest care. OSRAM Opto Semiconductors GmbH can however, not be made liable for any damage that occurs in connection with the use of these contents.

OSRAM Opto Semiconductor GmbH makes no representations and warranties as to a possible interference with third parties' intellectual property rights in view of products originating from one of OSRAM Opto Semiconductor GmbH's partners, or in view of products being a combination of an OSRAM Opto Semiconductor GmbH's product and aproducts being a combination of an OSRAM Opto Semiconductor GmbH s product and a product of one of OSRAM Opto Semiconductor GmbH's partners. Furthermore, OSRAM Opto Semiconductors GmbH cannot be made liable for any damage that occurs in connection with the use of a product of one of OSRAM Opto Semiconductor GmbH's partners, or with the use of a combination of an OSRAM Opto Semiconductor GmbH's product and a product of one of OSRAM Opto Semiconductor GmbH's partners.

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DisclaimerThis document constitutes neither an offer to sell nor a solicitation to buy or subscribef iti A h ff ill b d l l th b i f th S itifor securities. Any such offer will be made solely on the basis of the SecuritiesProspectus yet to be approved by the German Financial Supervisory Authority(BaFin) and published thereafter. The information legally required to be provided toinvestors will be contained only in the Securities Prospectusinvestors will be contained only in the Securities Prospectus.The information contained herein is not for distribution, directly or indirectly, in orinto the United States of America (including its territories and possessions of anyState of the United States of America or the District of Columbia) and must not beState of the United States of America or the District of Columbia) and must not bedistributed to U.S. persons (as defined in Regulation S under the U.S. Securities Actof 1933, as amended ("Securities Act")) or publications with a general circulation inthe United States of America. This document is not an offer of securities for sale in theUnited States of America. The securities have not been and will not be registered underthe Securities Act and may not be offered or sold in the United States of Americaabsent registration or an exemption from registration under the Securities Act. TheIssuer does not intend to register any portion of the offering in the United States ofAmerica or to conduct a public offering of the securities in the United States of America.This document is not an offer of securities for sale in the United Kingdom, Canada,Japan or Australia

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Japan or Australia.

Thank you for your attention.Thank you for your attention.

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