Challenges of Meeting Aviation Requirements with LED Light Sources

Adam Willsey and Dave DeSalle Kopp Glass, Inc. – Pittsburgh, PA October 2011 Outline

• Background

• Aviation Specifications

• LED/Glass Results – , Green, , ,

• Conclusions Chromaticity • The CIE (Commission Internationale de l'Eclairage), in 1931, they developed the first standard for designating and matching . Chromaticity: Human Eye Response Chromaticity: Human Eye Response • Color coordinates x, y, and z are calculated from the tristimulus values X, Y, and Z.

X = K ∑ P(λ) X(λ) T(λ) ∆(λ) λ = 380nm to 780nm Y = K ∑ P(λ) Y(λ) T(λ) ∆(λ) Z = K ∑ P(λ )Z(λ) T(λ) ∆(λ)

• Where: P(λ)  light source power at wavelength X(λ), Y(λ), and Z(λ)  eye response at wavelength T(λ)  Filter Transmission at wavelength ∆(λ)  Wavelength difference K  a constant that divides out for x, y, and z

• Therefore: The coordinates of x, y are decimal percentages of the total color for red, green, and blue. Aviation Specifications FAA - Engineering Brief 67 D FAA - Engineering Brief 67D

2.1.1 Aviation Chromaticity Boundaries—All fixtures must meet the following chromaticity boundaries.

Boundary Equations:

White: Green: Green boundary: y = 0.643x + 0.150 Blue boundary: y = 0.768 – 1.306x Blue boundary: x = 0.320 White boundary: y = 0.600 Purple boundary: y = 0.757x + 0.050 Yellow boundary: y = 3.470 – 9.200x Yellow boundary: x = 0.440 Yellow: Blue: Green boundary: y = 0.727x + 0.054 Green boundary: y = 0.805 + 0.065 White boundary: y = 0.980 – x White boundary: y = 0.400 - x Red boundary: y = 0.387 Purple boundary: y = 1.668x – 0.222 Red: Yellow boundary: y = 0.320 White boundary: y = 0.980 - x Purple boundary: y = 0.290

FAA - Engineering Brief 67D

0.9 CIE - 1931 Boundary 0.8 Aviation Red

0.7 Aviation Yellow

Aviation Blue 0.6 Aviation White 0.5 Aviation Green 0.4 y - value EB 67 D - Red

0.3 EB 67 D - Yellow

0.2 EB 67 D - Blue EB 67 D - White 0.1 EB 67 D - Green 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 x - value White Light Sources

1.00

0.90 Cree XP-E - Neutral White 0.80

0.70 Cree XP-E - Cool White 0.60

0.50 Osram - Golden Dragon 0.40 Philips - 0.30 Luxeon

0.20 CIE Illuinant

Normalized Spectral Distribution A 0.10

0.00 380 480 580 680 780 Wavelength (nm) Incandescent vs. LED

Color Light Source x - value y-value (K)

Cree XP-E Neutral White 0.3749 0.3703 4100

Cree XP-E Cool White 0.2973 0.3089 7740

Osram - Golden Dragon 0.2899 0.2812 9350

Phillips - Luxeon 0.4075 0.4120 3620

CIE Illuminant A 0.4476 0.4074 2854 Incandescent vs. LED

0.6 CIE - 1931 Boundary Aviation White

0.5 Aviation White - EB 67 Draft Planckian Locus

0.4 Cree XP-E - Neutral White y - value Cree XP-E - Cool White Osram - Golden 0.3 Dragon White Philips - Luxeon

CIE Illuminant A

0.2 0.2 0.3 0.4 0.5 0.6 0.7 x - value Aviation Green 1

0.9

0.8 Green Glass 1 0.7

0.6 Green Glass 2

0.5 Cree XPE -

Distribution 0.4 Neutral White

0.3 CIE 0.2 Illuminant A Transmittance / Normalized Spectral Transmittance 0.1

0 380 430 480 530 580 630 680 730 780 Wavelength (nm) Aviation Green

0.9

0.8 CIE - 1931 Boundary

Aviation Green 0.7 Cree XP-E - Neutral White

0.6 Cree XP-E - Cool White y - value Osram Golden Dragon

0.5 Phillips Luxeon

CIE Illuminant A 0.4

EB 67D - Aviation Green 0.3 0 0.1 0.2 0.3 0.4 0.5 0.6 x - value Aviation Green

Tranmission Light Source Glass Color x-value y-value (%) Cree XP-E - Green 1 0.347 0.590 28.5 Neutral White Green 2 0.327 0.449 37.8

Cree XP-E - Green 1 0.312 0.587 30.2 Cool White Green 2 0.270 0.386 40.0

Osram - Golden Green 1 0.318 0.611 30.8 Dragon Green 2 0.279 0.399 40.1

Philips - Green 1 0.333 0.618 30.8 Luxeon Green 2 0.315 0.470 39.7

CIE Green 1 0.367 0.572 26.0 Illuminant A Green 2 0.368 0.483 35.4 Aviation Green

1

0.9

0.8 Green Glass 1

0.7

0.6 Green Glass 2

0.5

Philips - Luxeon

Distribution 0.4 Green - 525nm 0.3 Green LED - 0.2 510nm Transmittance / Normalized Spectral Transmittance 0.1

0 380 430 480 530 580 630 680 730 780 Wavelength (nm) Aviation Green

0.9 CIE - 1931 Boundary

0.8 Aviation Green

Cree XPE - Green - 0.7 517nm Phillips Luxeon - Green 527nm

0.6 Green LED - 500nm y - value Green LED - 505nm 0.5 Green LED - 510nm

0.4 CIE Illuminant A

EB 67D - Green 0.3 Aviation 0 0.1 0.2 0.3 0.4 0.5 0.6

x - value Aviation Green

Tranmission Light Source Glass Color x-value y-value (%)

Green LED Green 1 0.082 0.640 36.6 505nm Green 2 0.076 0.544 52.1

Green LED Green 1 0.110 0.724 40.5 515nm Green 2 0.100 0.678 52.5

Cree XP-E - Green 1 0.119 0.749 42.4 Green LED Green 2 0.108 0.719 53.0

Phillips - Green 1 0.204 0.738 42.0 Luxeon Green Green 2 0.203 0.726 50.0 Aviation Blue

1

0.9

0.8

0.7 Blue Blue ( CIE A )

0.6 Blue Glass ( LED ) 1 0.5

Distribution 0.4 Blue LED - 455nm

0.3 Blue LED - 475nm 0.2

Glass Transmittance / Normalized Spectral Glass Transmittance 0.1

0 380 430 480 530 580 630 680 730 780 Wavelength (nm) Aviation Blue

0.4

CIE - 1931 0.35 Boundary

0.3 Aviation Blue

0.25 Blue LED - 455nm 0.2 y - value Blue LED - 0.15 465nm

0.1 Blue LED - 475nm

0.05 EB 67 D - Aviation Blue 0 0 0.05 0.1 0.15 0.2 0.25 0.3 x - value Aviation Blue

Light Source Thickness (in) x-value y-value Transmission (%)

Blue 1 (CIE A) 0.1501 0.0268 48.37 Blue LED Blue 2 (LED) 0.1475 0.0318 78.67 455nm Blue 3 (LED) 0.1477 0.0317 74.72

Blue 1 (CIE A) 0.1382 0.0444 40.73 Blue LED Blue 2 (LED) 0.1338 0.0549 77.91 465nm Blue 3 (LED) 0.1341 0.0548 73.63

Blue 1 (CIE A) 0.1207 0.0815 32.8 Blue LED Blue 2 (LED) 0.1134 0.1043 76.28 475nm Blue 3 (LED) 0.1138 0.1044 71.87 Aviation Red 1

0.9

0.8

0.7 Red 1 0.6 Red 2 0.5 Red 3

Distribution 0.4 White LED 0.3 CIE Illuminant A 0.2

Glass Transmittance / Normalized Spectral Glass Transmittance 0.1

0 380 430 480 530 580 630 680 730 780 Wavelength (nm) Aviation Red

0.4 CIE - 1931 Boundary Aviation Red

0.35 Aviation Yellow

Cree XP-E - Neutral White Cree XP-E - Cool 0.3 White y - value Osram Golden - Dragon Philips - Luxeon 0.25 CIE Illuminant A

EB 67D - Aviation Red 0.2 0.55 0.6 0.65 0.7 0.75 0.8 x - value Aviation Red

Transmission Light Source Glass Color x-value y-value (%) Red 1 0.652 0.348 24 Cree XP-E - Red 2 0.668 0.332 19 Neutral White Red 3 0.698 0.302 10

Red 1 0.642 0.357 18 Cree XP-E - Cool Red 2 0.661 0.338 14 White Red 3 0.695 0.305 6

Red 1 0.643 0.357 18 Osram - Golden Red 2 0.662 0.338 13 Dragon Red 3 0.696 0.304 6

Red 1 0.648 0.352 24 Philips - Luxeon Red 2 0.666 0.334 18 Red 3 0.697 0.302 9

Red 1 0.664 0.336 31 CIE Illuminant A Red 2 0.678 0.325 25 Red 3 0.704 0.296 15 Aviation Yellow

1

0.9

0.8

0.7 Yellow 1

0.6 Yellow 2 0.5

0.4

Distribution Yellow 3

0.3 White LED 0.2

Glass Transmittance / Normalized Spectral Glass Transmittance 0.1 CIE Illuminant A 0 380 430 480 530 580 630 680 730 780 Wavelength (nm) Aviation Yellow

0.6 CIE - 1931 Boundary 0.55 Aviation Red

Aviation Yellow 0.5 Cree XP-E - 0.45 Neutral White Cree XP-E - Cool White y - value 0.4 Osram Golden - Dragon

0.35 Philips - Luxeon

CIE Illuminant A 0.3 EB 67D - Aviation Yellow 0.25 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 x - value Aviation Yellow Transmission Light Source Glass Color x-value y-value (%) Yellow 1 0.508 0.488 77 Cree XP-E - Yellow 2 0.582 0.417 47 Neutral White Yellow 3 0.606 0.394 39

Yellow 1 0.476 0.519 72 Cree XP-E - Cool Yellow 2 0.562 0.438 40 White Yellow 3 0.589 0.410 32

Yellow 1 0.473 0.522 73 Osram - Golden Yellow 2 0.560 0.439 40 Dragon Yellow 3 0.589 0.410 32

Yellow 1 0.499 0.496 81 Philips - Luxeon Yellow 2 0.573 0.427 49 Yellow 3 0.598 0.401 39

Yellow 1 0.545 0.452 78 CIE Illuminant A Yellow 2 0.606 0.394 52 Yellow 3 0.626 0.374 44 Aviation Red

1

0.9 Red 1 0.8

0.7 Red 2 0.6

0.5 Red 3

Distribution 0.4

0.3 Red LED - 610nm 0.2 Red LED - 0.1 Glass Transmittance / Normalized Spectral Glass Transmittance 645nm

0 380 430 480 530 580 630 680 730 780 Wavelength (nm) Aviation Red

0.4 CIE - 1931 Boundary Aviation Red

0.35 Aviation Yellow Red LED - 610nm 0.3 Red LED -

y - value 625nm Red LED - 645nm 0.25 CIE Illuminant A EB 67D - Aviation Red 0.2 0.55 0.6 0.65 0.7 0.75 0.8 x - value Aviation Red Transmission Light Source Glass Color x-value y-value (%) Red 1 0.662 0.338 82 Red LED Red 2 0.663 0.337 77 610nm Red 3 0.674 0.326 33

Red 1 0.697 0.303 85 Red LED Red 2 0.697 0.303 85 625nm Red 3 0.699 0.301 74

Red 1 0.721 0.279 86 Red LED Red 2 0.721 0.279 88 645nm Red 3 0.721 0.279 87

Red 1 0.648 0.352 24 Philips - Luxeon Red 2 0.666 0.334 18 Red 3 0.697 0.302 9

Red 1 0.664 0.336 31 CIE Illuminant A Red 2 0.678 0.325 25 Red 3 0.704 0.296 15 Aviation Yellow 1

0.9

0.8 Yellow 1 0.7 Yellow 2 0.6

0.5 Yellow 3

0.4 Distribution Yellow LED - 0.3 585nm

0.2 Yellow LED - 595nm

Glass Transmittance / Normalized Spectral Glass Transmittance 0.1

0 380 430 480 530 580 630 680 730 780 Wavelength (nm) Aviation Yellow

0.6 CIE - 1931 Boundary 0.55 Aviation Red

0.5 Aviation Yellow

0.45 Yellow LED - 585nm Yellow LED - y - value 0.4 590nm Yellow LED - 0.35 595nm CIE Illuminant A 0.3 EB 67D - Aviation Yellow 0.25 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 x - value Aviation Yellow Transmission Light Source Glass Color x-value y-value (%) Yellow 1 0.540 0.459 91 Yellow LED Yellow 2 0.544 0.455 80 585nm Yellow 3 0.551 0.448 71 Yellow 4 0.588 0.412 34

Yellow 1 0.567 0.432 91 Yellow LED Yellow 2 0.570 0.430 82 590nm Yellow 3 0.574 0.426 76 Yellow 4 0.601 0.399 46

Yellow 1 0.592 0.407 91 Yellow LED Yellow 2 0.594 0.406 83 595nm Yellow 3 0.596 0.403 79 Yellow 4 0.615 0.385 57

Yellow 1 0.545 0.452 78 Yellow 2 0.606 0.394 52 CIE Illuminant A Yellow 3 0.626 0.374 44 Yellow 4 0.664 0.336 31 Light Source Considerations

• White LED – – One LED in inventory – May be more difficult to meet specifications – Binning will be important

• Colored LED – Easy to meet color requirements – Higher transmission than with typical white light sources – Need to keep many different color types in stock Thank you! Questions?

Adam Willsey, [email protected] Dave DeSalle, [email protected]