Presented at the SPIE 2006 Annual Meeting
San Diego, CA
LED Luminaire
with Controlled Light Distribution
Donald J. Schertler, Stephen Chakmakjian,
Tasso R. M. Sales, G. Michael Morris
RPC Photonics, Inc.
www.RPCphotonics.com
8/30/2006
1
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Solid State Lighting
g Finding
greater use in commercial and residential
applications
4 High
Brightness
4 Small Size
4 Efficiency
g Light
Control
4 High
Brightness LEDs are Lambertian
4 Collimation tends to add structure to the light
4 Add a diffusion element
0
2
Ground glass, mixing rod, holographic diffuser
LED Luminaire with Controlled Light Distribution
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Controlled Light Distribution
g Engineered
Diffuser™ redistributes the
collimated LED light into any desired pattern
3
LED Luminaire with Controlled Light Distribution
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Collimator Design
g The
collimator has four surfaces that perfectly
collimate a point source at the origin
L
Paraboloid
H
Hyperbolic Lens
d
D
4
Sphere
LED Luminaire with Controlled Light Distribution
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Collimator Performance
g Example:
D = 5mm, H = 10mm, n = 1.5,
1mm2 LED
Spatial Distribution
5
Angular Distribution
LED Luminaire with Controlled Light Distribution
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Collimator Performance
g Example:
6
D = 5mm, n = 1.5, 1mm2 LED
H
L
d
FWHM
40mm
28.7mm
1.7mm
2.7°
20
20.6
2.3
4.4
10
15
3
6
5
11.2
3.7
8.5
LED Luminaire with Controlled Light Distribution
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Diffuser-Collimator Combinations
g The
Engineered Diffuser™ can be formed
directly on the collimator or as a separate
component placed above the collimator
7
LED Luminaire with Controlled Light Distribution
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Diffuser Fabrication – Laserwriting
Process
Bit map
I
Resist Coat
Substrate
Laser Intensity I
Intensity Conversion
x
Modulator
D/A
I(x,y)
Stage Control
(x,y)
Resist Profile after
Development
8
LED Luminaire with Controlled Light Distribution
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Engineered Diffusers™
• Refractive, microlens structure
• Each microlens is individually
designed
• Microlens parameters are
randomized to eliminate repetitive
artifacts and interference effects
• Control of scatter distribution and
intensity profiles
• Insensitive to wavelength
•Compatible with high volume
molding and replication processes
9
LED Luminaire with Controlled Light Distribution
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Engineered Diffuser™ Examples
Square
Rectangle
Annulus
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LED Luminaire with Controlled Light Distribution
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Luminaire Example
g OSRAM
Golden DRAGON® Green LED
4 Flux
of 35 lm at 500 mA
4 Efficiency of 20 lm/W
4 Lambertian emitter
11
LED Luminaire with Controlled Light Distribution
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Collimation Performance of the LED
LED Divergence from Collimator
700
Horizontal
Vertical
600
Relative Intensity
500
400
300
200
100
0
-20
-15
-10
-5
0
5
10
Scatter Angle
12
LED Luminaire with Controlled Light Distribution
15
20
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Flat-top Diffuser with Laser
Engineered Diffuser with Laser Illumination
4
3.5
Horizontal
Vertical
Relative Intensity
3
2.5
2
1.5
1
0.5
0
-30
-20
-10
0
10
Scatter Angle
13
LED Luminaire with Controlled Light Distribution
20
30
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Flat-top Diffuser with LED
Engineered Diffuser with Collimated LED Illumination
80
70
Horizontal
Vertical
Relative Intensity
60
50
40
30
20
10
0
-40
-30
-20
-10
0
10
20
Scatter Angle
14
LED Luminaire with Controlled Light Distribution
30
40
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Diffuser Engineered for the LED
Engineered Diffuser with Laser Illumination
5
4.5
Horizontal
Vertical
4
Relative Intensity
3.5
3
2.5
2
1.5
1
0.5
0
-45
-30
-15
0
15
Scatter Angle
15
LED Luminaire with Controlled Light Distribution
30
45
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Engineered Diffuser™ with LED
LED and Collimator with Engineered Diffuser
35
Horizontal
Vertical
30
Relative Intensity
25
20
15
10
5
0
-45
-30
-15
0
15
Scatter Angle
16
LED Luminaire with Controlled Light Distribution
30
45
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Luminaire Configurations
g One-
17
and two-dimensional arrays of LEDs
LED Luminaire with Controlled Light Distribution
Presented at the SPIE 2006 Annual Meeting
San Diego, CA
Summary
g High
brightness LED luminaire with
controlled light distribution.
g Custom scatter distributions – round, square,
rectangular, dipole, etc.
g Custom scatter profiles – flat top, Gaussian,
bowl-shaped, etc.
g Low profile lighting fixture
g Single, 1-D and 2-D LED arrays
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LED Luminaire with Controlled Light Distribution