GBU LED Lamps & Systems April 2010 Reflector Design Fortimo Spot Light Module.

GBU LED Lamps & SystemsApril 2010

Reflector DesignFortimo Spot Light Module

Confidential GBU LED Lamps & Systems, April 2010 2

Contents

• Reflectors for Accent Lighting

• Light mixing for Fortimo SLM

• Reflector design rules

• Optical interface

• Optical modeling using Ray Set files

• Examples of Reflectors for Fortimo Spot Light Module


Accent Lighting luminaires

• In accent lighting typically 3 beam widths are identified– Spot: 10 degree Full Width at Half Maximum– Medium: 24 degree Full Width at Half Maximum– Flood: 40 degree Full Width at Half Maximum

• The light source dimensions determine the limits of the possible beam width – Law of Etendue – for certain max reflector diameters

• With HID and Halogen smaller beams are possible due to the small source


Reflectors compact high intensity sourcesSource indoor guide Philips 2008

FWHM (°) 12 24 36 60

Pictures

Graphs

Light Output Ratio max.

0.67 0.65 0.60 0.60

Imax [kcd/klm] 15 2 1 0.75


Reflectors for Fortimo SLM versus DLMFortimo SLM Fortimo DLM

Light distribution Lambertian Lambertian

Light source uniformityNon uniform

(9 or 16 small sources)Uniform

Light mixing Required Not required

Light diffusing Required Not required

Front glassRequired

(Transparent or diffuse)Not required


Mixing the light

• Mixing the light is needed to reduce flux inhomogeneity and color variations between the individual LEDs

• Options– Segmenting and faceting of reflector wall – 3D faceting– Structured reflector surface (ie diffuse)

• Blurring / mixing widens the source:– Starting 12.8 mm of LED circle– After blurring 14 mm of source diameter

Confidential GBU LED Lamps & Systems, April 2010

76.0%

78.0%

80.0%

82.0%

84.0%

86.0%

88.0%

90.0%

92.0%

94.0%

96.0%

0 10 20 30 40 50 60 70 80

Effici

ency

of d

iffus

er

Vertical position of diffusing frontglass [mm]

Simulated effect of diffuse frontglass on reflector Type G (80x96mm, 15°)

1 degree diffuser 5 degree diffuser 10 degree diffuser 20 degree diffuser

7

Diffusing the light

• Diffusing the light is needed to fill the space between LEDs– Eliminates ring features in the beam

• Highest efficiency is achieved when placed at the top

84% 94% 94%

Specular reflector without diffuser

Specular reflector with diffuser


Rings in the far field

• A diffusion foil or structured front glass is needed to eliminate rings in the far field projection (if desired).

• Options:

1. Diffusion foil e.g. 5° diffusing foil of Luminit™

2. Structured glass

3. A transparent front glass with shading region at the outer edge• 1 and 2 slightly increase the beam width

Rings in far field Caused by direct rays

BeNeLux - OfficeBFi OPTiLAS B.V(Chr.Huygensweg 17-2408AJ)P.O. Box 222 2400 AE Alphen aan den RijnPhone: +31 (0)172-44 60 60Fax: +31 (0)172-44 34 14E-mail: [email protected] Schotel

http://www.bfioptilas.com/European+offices-3.htm

mailto:[email protected]


Accent factor / punch

9

0 5 10 15 20 25 30 350

1

2

3

4

5

6

7

8

9intensity plot, output=1008 lumen, refl.diam=70mm, height=80mm

polar angle [°]

beam

inte

nsity

[kcd

]

disk total

gauss total

direct light

Large quantity of direct light, large FWHM of direct light

• The shape of the light distribution determines the punch – Gaussian shape is acceptable for most applications

• Low height reflectors: more direct light, punch perception is reduced– FWHM ratio direct and reflected light should not be high

0 5 10 15 20 25 30 35 40 45 500

1

2

3

4

5

6

7

8

9intensity plot, output=1038 lumen, refl.diam=70mm, height=40mm

polar angle [°]

beam

inte

nsity

[kcd

]

disk total

gauss total

direct light

FWHM ratio direct/reflected light: 2.7 FWHM ratio direct/reflected light: 5.5


Reflector design parameters

Parameter Beam angle (FWHM)

Perception of punch

Peak intensity (CBCP)

Source diameter High Medium Medium

Reflector entrance diameter Low Low Low

Reflector exit diameter High Medium High

Reflector height Low High Low

Reflector wall diffusivity Medium Medium Medium

Diffusive front glass Medium Medium Medium


Typical reflector design limits

• Beam angle (FWHM) for certain reflector diameter is limited by law of Etendue, peak intensity is limited by reflector diameter and average source luminance

• Using Gaussian beam profile, an acceptable punch perception is achieved for the white shaded area

maximum peak intensity gaussian beam [k cd]

reflector exit diameter [mm]

refle

cto

r h

eig

ht

[mm

]

66

6

88

8

12

12

12

16

16

16

20

20

20

60 80 100 12020

30

40

50

60

70

80

90

100

110

120

Typical minimal beam width for 1100 lm module is ~15o FWHM

minimum FWHM gaussian beam [°]


refle

cto

r h

eig

ht

[mm

]

24

60 80 100 12020

30

40

50

60

70

80

90

100

110

120

(Source 1100 lm and 14mm)


Typical reflector design limits

• Beam angle (FWHM) for certain reflector diameter is limited by law of Etendue, peak intensity is limited by reflector diameter and average source luminance

• Using Gaussian beam profile, an acceptable punch perception is achieved for the white shaded area

Typical minimal beam width for 2000 lm module is ~20o FWHM

(Source 2000 lm and 20mm)

minimum FWHM gaussian beam [°]


refle

cto

r h

eig

ht

[mm

]

60 80 100 12020

30

40

50

60

70

80

90

100

110

120maximum peak intensity gaussian beam [k cd]


refle

cto

r h

eig

ht

[mm

]

66

6

88

8

12

12

12

16

16

16

20

20

20

60 80 100 12020

30

40

50

60

70

80

90

100

110

120


Light Output Ratio vs reflector dimensions

• The reflector Light Output Ratio (LOR) or efficiency decreases for higher reflectors due more reflections at the reflector wall.

• White shaded area depicts acceptable punch• No front glass taken into account

1100 lm 2000 lm


Typical reflector designs

• Table with typical reflector performances– Based on modeling, including mixing/diffusive impact, no front glass, Reflector R = 90%

module flux

source diameter

exit diameter height

beam FWHM CBCP

optical efficiency

intensity ratio

% lumens via reflector

direct light

FWHM

1% intensity diameter

[lm] [mm] [mm] [mm] [°] [k cd] [%] [peak/direct] [%] [°] [°]

20 17.8 4 96% 12 35% 103 10350 25.7 4 92% 12 72% 53 6280 27.5 4 91% 12 82% 35 66

20 9.8 8 98% 23 22% 121 12150 16.2 8 93% 23 60% 70 7080 18.2 8 92% 23 76% 47 47

20 5.0 16 99% 47 12% 136 12450 9.6 16 95% 47 45% 90 9080 11.5 16 93% 47 65% 64 64

20 3.6 23 99% 67 9% 143 9650 7.2 23 96% 67 37% 100 9680 9.0 23 94% 67 58% 74 74

20 14.5 8 98% 12 22% 121 121

50 24.0 8 93% 12 60% 70 7080 27.0 8 92% 12 76% 47 65

20 7.3 15 99% 23 12% 136 13650 14.0 15 95% 23 45% 90 9080 16.8 15 93% 23 65% 64 64

20 5.1 21 99% 33 9% 143 14150 10.4 21 96% 33 37% 100 10080 13.1 21 94% 33 58% 74 74

2000

120

120

20 100

70

reflector designssource reflector performance

1100 14

100

50

70Assumptions in calculations:Perfect lambertian sourceEtendue limited reflector designGaussian beamTwo lightpaths: direct light

via reflector, single reflection, R=90%optical diameters

Not included in calculations:Reflector designReflector rim diameterConvergent beam

Target FWM values: 2x7° 2x12° 2x20°


Reflector technologies

• Reflector technologies, price points, typical reflectivity• Final reflector efficiency (LOR) depends on reflector shapeTechnology Rough cost Tooling cost

Spinning / turning, post anodization Medium Medium

Stamping, post anodization Low Medium

Miro folding, pre anodized Medium, 1.5 Euro Low

Plastic molding, post anodization Low, < 1 Euro High

Glass, post anodization Medium High

Reflective layer Reflectivity Rough cost

Post anodizing chemical 75 – 85 % Medium

Post anodizing evaporation 80 – 90 % High

Pre anodized 90 – 98% High


Optical interface

16

Area for reflector mounting

Minimal distance of metallic reflector to electrical components is 1.2mm in open air, the cover ensures that this distance is met


Optical interface

• The surface available for reflector mounting is a ring with width:– 1100 lm: 7.3 mm– 2000 lm: 4.8 mm

Any 2000lm reflector will fit on the 1100lm module as well

y

x


Optical interface reflector attach

• Options for reflector attachment:– Mount to housing– Mount to heat sink– Glue to module– Using an additional bayonet on module

Option for reflector mounting with additional metal component


Ray Sets 1100/2000 modules for reflector design

• Available formats for customer use

• Measurement method– SIG 300, Radiant Imaging, flux measured is relative flux, including

color

Software Number of Rays comments

RS7 Measurement file No color info

Light Tools 100K, 500K, 10M rays Includes color info

Photopia 100K, 500K, 10M rays No color info

Lucid Shape 100K, 500K, 10M rays No color info

ASAP 100K, 500K, 10M rays No color info

Speos 100K, 500K, 10M rays No color info

Trace Pro 100K, 500K, 10M rays No color info

Zemax 100K, 500K, 10M rays No color info


Fortimo SLM 1100lm

• The coordinate system of the ray set is identical to the coordinate system of the CAD-file: ‘Fortimo_LED_SLM_1100_18W-8xx_wk10.stp. If you import both the ray set and the CAD-file to the same location they are aligned.

• To achieve this the following rotation and translation was performed:– Rotation about Z-axis: -1°– Translation along X-axis: 0.10mm– Translation along Y-axis: 0.01mm– Translation along Z-axis: -0.4mm (determined by defocus-analysis in

LightTools)• The origin of the coordinate system is now in the center of the module at the

height of the LED dies.• Part of the light is blocked by the module cover in the measurement. This part is

missing in the ray sets (see cross section).• The rays start on a cylinder above the LEDs, so no rays start inside the geometry

(radius = 9.4mm, 1.491mm < z < 1.5).

Alignment Image

Cross section of the CAD-model

Intensity polar plot1100 & 200 Lm SLM


Fortimo SLM 2000lm

• The coordinate system of the ray set is identical to the coordinate system of the CAD-file: Fortimo_LED_SLM_2000_33W-8xx_wk10.stp. If you import both the ray set and the CAD-file to the same location they are aligned.

• To achieve this the following translation was performed:– Translation along Y-axis: -0.1mm– Translation along Z-axis: -0.6mm (determined by defocus-analysis in

LightTools)• The origin of the coordinate system is now in the center of the module at the

height of the LED dies.• Part of the light is blocked by the module cover in the measurement. This part

is missing in the ray sets (see cross section).• The field of view of the SIG300 is too small for the module. Therefore, part of

the indirect light is missing in the ray sets (see alignment image).• The rays start on a cylinder above the LEDs, so no rays start inside the

geometry (radius = 11.9mm, 1.491mm < z < 1.5).

Alignment Image

Cross section of the CAD-model

Intensity polar plot


Prototype results 1100 lm module + SLS reflector 5° diffuser foil from LuminitTM

Lineair scaling

Log scaling

Δu’v’ <0.008 for values

larger than 5% of peak

intensity

Uniform spot, no ringsReflector efficiency: 86 – 90%Including POC foil: 82 – 85 %

Norm alised Lum inous intensity cross sections

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30

Angle (°)

Re

lati

ve

Lu

min

ou

s I

nte

ns

ity

(c

d)

vert. Cross

hor. Cross


Prototype results 1100 lm module + SLS reflector

20° diffuser foil from LuminitTM Lineair scaling

Log scaling

Uniform spot, no rings

Δu’v’ <0.008 for values

larger than 5% of peak

intensity


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30

Angle (°)

Re

lati

ve

Lu

min

ou

s I

nte

ns

ity

(c

d)

vert. Cross

hor. Cross


Prototype results 2000 lm module + SLS reflector 10° diffuser foil from LuminitTM

FWHM 26°

Visual appearance (log2 visualisation)Δu’v’ < 0.006 within 10% of peak intensityΔu’v’ < 0.008 within 5% of peak intensity

Reflector efficiency: 86 – 90%Including POC foil: 82 – 84 %


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30

Angle (°)

Re

lati

ve

Lu

min

ou

s I

nte

ns

ity

(c

d)

vert. Cross

hor. Cross


Reflector supplier Jordan

• Jordan developed three reflector types that fit both 1100 and 2000 lm modules with a click-fit onto the module

• Example beam profiles

luminous areadiameter height diameter

1.12991.010.101 1100 Spot 2 x 9 92.9% 6000 75 42 681.12991.010.101 2000 Spot 2 x 9 93.9% 5000 75 42 681.12992.010.101 1100 Medium 2 x 12 92.9% 3500 75 42 681.12992.010.101 2000 Medium 2 x 13 93.2% 2800 75 42 681.12993.010.101 1100 Flood 2 x 19 92.5% 1800 75 42 681.12993.010.101 2000 Flood 2 x 21 92.9% 1600 75 42 68

luminairereflector module beam

LOR(model) CBCP (cd/klm)Beam angle

1100 lm, 2 x 12.2O 2000 lm, 2 x 13.7O

Need diffusing exit window

http://www.jordan-reflektoren.de


Reflector supplier Alux-Luxar

• Alux Luxar is developing a series of reflectors– Both pre-anodized (Miro) and post anodized

• Example of Miro 8 based reflector for 1100 lm – Efficiency > 90%

http://www.alux-luxar.de

No diffuser

1o diffuser

5o diffuserEfficiency: -3%

-25 -15 -5 5 15 25 350

2000

4000

6000

8000

10000

12000

14000Intensity cross-section

no POC

POC1

POC5

Gauss, FWHM = 14.6 deg, CBCP = 9900 cd

angle (°)

Inte

nsi

ty (

cd)

Reflector in combination with 5o diffuser gives a Gaussian beam, FWHM < 15°.

/ 1100 lm


Contact addresses:


0%10%20%30%40%50%60%70%80%90%

100%

0° 10° 20° 30° 40° 50° 60° 70°

Max

imum

effi

cien

cy

Desired FWHM

Apperture diameter = 30 mm

Convergent beams - cross over reflector

• By combining the Fortimo SLM module and a convergent reflector, a system with an aperture can be designed

• The efficiency of the system is limited by the Law of Etendue

• Example for an aperture 30 mm and desired FWHM = 2x12o :– 2000 lm module with 20 mm efficiency: 11%– 1100 lm module with 14mm efficiency: 20%– With a hypothetical source of 6.5 mm:

efficiency: 100%1100 lm module

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GBU LED Lamps & Systems April 2010 Reflector Design Fortimo Spot Light Module.

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