Light and Color Methods of Achieving High CRI with LEDs ... and Color Methods of Achieving High CRI with LEDs ... emissions like those from SSL sources (red, ... or publications with

Light and Color

Methods of Achieving

High CRI with LEDs

November 2014

OSRAM High CRI LED Page 2

November 2014

Agenda

• Light and Color: Understanding the Basics

• Color Rendering Index for White Light Sources

• Methods for Creating White Light with LEDs

• New Techniques For Achieving High CRI


November 2014

…and to accent the rich color which abounds in nature, interior design, clothing and fabric, jewelry, etc., while giving product and lighting designers the new lighting resources to continue to evoke emotional responses to lit environments.

High Color Rendering from LEDs play an important role in satisfying the light quality needs of end users


November 2014

LIGHT COLOR AND QUALITY

Understanding the Basics


November 2014

Nature of Light: Illumination and Sensing


November 2014

IESNA Definition: A pictorial

representation of the radiant power

emitted by a light source at each

wavelength or band of wavelengths

in the visible region of the

electromagnetic spectrum (360 to

770 nanometers).

SPD plots for several common light

sources showing relative radiate

power as a function of wavelength.

– Gold: High Pressure Sodium

– Blue: CIE D65, model of “average

daylight” at 6504K

– Red: Incandescent (3000K)

– Green: LED (6000K)

Spectral Power Distribution (SPD)


November 2014

IESNA Definition: the absolute

temperature of a blackbody

whose chromaticity most

nearly resembles that of the

light source.

The correlated color temperature

(CCT) designation for a light

source gives a good indication

of the lamp's general

appearance, but does not give

information on its specific

spectral power distribution.

Therefore, two lamps may

appear to be the same color,

but their effects on object

colors can be quite different.

Correlated Color Temperature (CCT)


November 2014

COLOR RENDERING INDEX

For White Light Sources


November 2014

Color Rendering Index Ra

• The color rendering index describes how naturally a light source displays a set of

different test colors.

• Reference and test light sources are calculated at the same CCT, measuring shift in

chromaticity.

• Lamps that render color samples similarly will have a high CRI.

• The lower the CRI, the higher the luminous efficacy (lm/W) of an LED.

#1#2

#3 #4#5

#6

#8

#7

Color Rendering Index

A measure of the degree of color shift objects undergo when

illuminated by the light source as compared with the color of those

same objects when illuminated by a reference source.


November 2014

Reference Illuminants (Light Sources)

CRI measures the degree of color shift objects undergo when illuminated by the light

source as compared with the color of those same objects when illuminated by a

reference source of the same Correlated Color Temperature.

Black Body Radiator:

Color Temperatures in

the range of

2300K … < 5000K

Daylight Spectrum:

Color Temperatures

in the range of

5000K … 25000K


November 2014

Color Rendering Index Ra

• Additional six special test color samples

#1#2

#3 #4#5

#6

#8

#13

#11#10

#9

#14

#7

#12

Color Rendering Index


November 2014

CRI 50

8500K

Color Rendering Index (CRI)

Example

CRI 70

5000K

CRI 95

3500K


November 2014

Color Quality

Rating of Color Rendering Index

Definition of Color Rendering Classes for Color Quality


November 2014

Color Quality – Industry Ratings

Energy Star

• SSL Indoor Luminaires:

CCT: 2700, 3000, 3500, 4000/4100K and 5000K for commercial

CRI: Ra ≥80

• SSL Indoor Lamps:

CCT: 2700, 3000, 3500, 4000/4100K and 5000K

CRI: Ra ≥80, R9>0

Designlights Consortium (DLC)

• Based on lighting application

Application Minimum Light Output

Minimum

Luminaire

Efficacy

Allowable CCTs

(ANSI C78.377-

2008) Minimum CRI

Outdoor Pole/Arm-Mounted Area and Roadway Luminaires 1,000 lm 60 lm/W <5700K 50

Linear Panels (2x2 Troffers) 3,000 lm 60 lm/W <5000K 80

Four-foot Linear Replacement Lamps 2,200 lm 96 lm/W <5000K 80, R9>0


November 2014

Limitations of CRI

• Small number of color samples, which are unsaturated.

– Test color samples 9-12 are for saturated colors, but they do not contribute to the computation of general CRI.

• CRI does not reasonably characterize highly structured, narrowband spectral emissions like those from SSL sources (red, green, and blue components) which may increase or decrease saturation of certain colors.

• One number cannot tell you everything. Cannot fully characterize the multidimensional experience of color such as color appearance, color fidelity, chromatic discrimination, vividness and observer preferences.

• Mock-ups remain the recommended method of assessing lamp color rendering properties, particularly in color critical applications.


November 2014

Limitations of CRI

Example

• Same Chromaticity

• Same CCT

• Different CRI

• Different illumination

• lumens = 217

• CCT = 3231

• x = 0.4217 y = 0.3987

• D(uv) = 0.0002

• CRI=1

• lumens = 31.2

• CCT = 3223

• x = 0.4217 y = 0.3978

• D(uv) = -0.0002

• CRI=94


November 2014

New Metrics – Color Quality Scale (CQS) (CIE TC1-69)

• Developed at the National Institute of Standards and Technology (NIST) to define and better qualify LED lighting.

• CQS involves several facets of color quality, including: color rendering, chromatic discrimination, and observer preferences.

• Main differences from CRI:

– Takes into account subjective color saturation perception - Gives weight to an increase of saturation addressing perception

– Measures color fidelity with regard to color saturation preferences

– Moderate increase of saturation is often correlated with desired color perception.

• Identifies color fidelity but is only one number!


November 2014

New Metrics – CRI / Gaumut Area Index (GAI)

www.lrc.rpi.edu/programs/solidstate/assist/recommends/lightcolor.asp

• Developed by ASSIST program to give subjective assessments of vividness, naturalness and acceptability.

• CRI and CRI-like metrics only evaluate a single aspect: fidelity.

• Good color rendering by a light source requires an optimum amount of color saturation. Gamut area index (GAI) is a good indicator of saturation.

– This two-metric recommendation using CRI and GAI together can ensure good color rendering.

Results are representative of observers

of different geographical origins and for

sources of warm and cool CCTs,

different spectral makeup, and light level.


November 2014

LED Spectrum is Critical for Interior Design

Color Temperature (CCT) is not a

perfect measure of lighting quality

Color rendering index is another

imperfect lighting quality metric, with

its emotional impact dependent on the

interaction of the illuminated surfaces

Lighting spectrum, material textures and

optical property interactions influence

interior design results

Managing the LED color spectrum can

create varied emotions from “sterile /

clean to soft / warm”


November 2014

METHODS OF CREATING

White Light With LEDs


November 2014

New Innovative Approaches

How Do You Generate White Light?


November 2014

How Do LEDs Work?


November 2014

LED Phosphors


November 2014

• Entire white CCT-range (2700-6500K)

LED Phosphors

LCW.CCCRI95

2700-4000K

LCW.ECCRI82

2700-5000K

LCW.PCCRI70

4000-5000K

LUWCRI70

5500-6500K


November 2014

LED CCT Variations

CRI 95

CRI 70

CRI 80


November 2014

Traditional Light Sources

Fluorescent

CCT: 3000K

CRI: 85

High Pressure Sodium

CCT: 1800-2200K

CRI: ~20

Tungsten Halogen

3000K

CRI: ~95-100


November 2014

Lighting Technologies - The LED Advantage

LEDs are an energy-saving alternative to conventional incandescent bulbs

LEDs are point source emitters with precise optical control

No radiated heat, only conducted.

LEDs are available in all saturated and unsaturated colors

LEDs are “instant on-off” and can be precisely controlled

150 Im/W9 Im/W


November 2014

New Techniques

For Achieving High CRI


November 2014

• Typical CRI of 95

• R9 > 90

• R13 >90

• 2700-4000K

• Indoor Lighting

• Retail Lighting

Phosphor-based High CRI


November 2014

Phosphor-based High CRI

Warm white (3000K) LED with a typical CRI Ra = 95 and very good R9 and R13 values.


November 2014

With standard white LEDs it is not possible to realize LED luminaires

and lamps with both high efficiencies and high CRI.E

ffic

ien

cy o

n l

um

ina

ire

le

ve

l (l

m/W

)

The Efficiency and CRI Dilemma

*Luminaire efficiency considers thermal,

optical and electrical losses

Color Rendering and Luminaire Efficiency*

With the Brilliant Mix concept, high CRI and high efficiencies can be realized!

Brilliant Mix Solution


November 2014

• Mix of EQ White and Amber LEDs

• High efficacy and high CRI with Ra > 90

• Efficacies of >110 lm/W possible (2700K – 4000K) at LED level

Hybrid Approach - High CRI LEDs

Brilliant Mix Concept

“Brilliant Mix” - Mixing of EQ White and Amber/Red LEDs results in warm

white light...with a high CRI and a high luminous efficacy.


November 2014

• Mixing of EQ White and amber

LEDs enables warm

white light sources.

Brilliant Mix Concept

Combination of EQ White

and Amber LEDs results

in efficient light with a

high CRI



November 2014

Combination of Amber (617nm) and EQ White

Brilliant Mix Example



November 2014


Spectral Power Distribution


November 2014

Hybrid Approach - High CRI LEDs Brilliant Mix concept – R values (2700K)

CCT: 2700K


November 2014

OSLON SSL LED

Compact and symmetrical with high luminosity

Integrated silicone lens

Excellent thermal management


November 2014

New LED Concepts

Color tunable white

Highly efficient, high CRI, white color tuning


November 2014

Summary


November 2014

LED Source Measureables

+ +


November 2014

Summary

• CRI is the current way of describing a light’s ability to render color.

• New metrics are being developed.

• New research and development is ongoing to improve LED color rendering and efficacy.

• LED sources can truly compete today for color critical applications.

• OSRAM continues to lead the way in developing LEDs with superior high color rendering

for every lighting application.


November 2014

This document constitutes neither an offer to sell nor a solicitation to buy or subscribe for

securities. Any such offer will be made solely on the basis of the Securities Prospectus yet to

be approved by the German Financial Supervisory Authority (BaFin) and published thereafter.

The information legally required to be provided to investors will be contained only in the

Securities Prospectus. The information contained herein is not for distribution, directly or

indirectly, in or into the United States of America (including its territories and possessions of

any State of the United States of America or the District of Columbia) and must not be

distributed to U.S. persons (as defined in Regulation S under the U.S. Securities Act of 1933,

as amended ("Securities Act")) or publications with a general circulation in the United States of

America.

This document is not an offer of securities for sale in the United States of America. The

securities have not been and will not be registered under the Securities Act and may not be

offered or sold in the United States of America absent registration or an exemption from

registration under the Securities Act. The Issuer does not intend to register any portion of the

offering in the United States of America 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.

Disclaimer


November 2014

Thank you for your attention.

Documents

Light and Color Methods of Achieving High CRI with LEDs ... and Color Methods of Achieving High CRI with LEDs ... emissions like those from SSL sources (red, ... or publications with