We have been designing illumination systems with high
brightness light emitting diodes (HB LEDs) since the industry began with the
HP/Philips joint venture in the late 1990's. This joint venture has become
Lumileds over the years and is now one of several HB LED manufacturers.
The continuous progress in LED package flux (lumens) output has doubled every 24
months for the last 30 years is know as Haitz's Law, named after Dr. Roland
Haitz of HP/Agilent/Lumileds.
This output in flux per LED package doubling every 24 months
according to Haitz's Law has enable the HB LED to compete with the older
established illumination source technologies in the last six years. The HB
LED is already established in many industries such as automotive, transportation
traffic signals, displays, consumer electronics, entertainment, medical, dental,
architecture, industrial lighting, home illumination, precision metrology,
industrial processes, and the list goes on.
Over the past six years we have developed the techniques,
tools, processes, and expertise to design optical systems that utilize HB LEDs
in the illumination design consulting work we perform. We would like to
put this expertise and experience to work on your challenging illumination
design problems.
Illumination Design with High Brightness LEDs
What's the big deal? Why is it so difficult to accomplish the task?
The 500 pound gorilla of illumination design is called
étendue. Étendue is a product or multiplication of the area of the emitter
surface and the projected solid angle that the rays from the surface diverge
into and the units are mm^2-Steradians. This is a three dimensional
version of the Lagrange invariant from imaging or conventional lens design.
It is the conservation of energy law of illumination design. We like to
say that if you don't try to beat étendue at least twice a week then you are not
trying hard enough. Illumination designers always seem to be bumping their
creative brains into and up against this law frequently.
Current vintage HB LEDs emit light into a very large angle,
like the 180° hemisphere shown on the non-sequential ray trace above.
Remember illumination designers want to capture every photon of light from the
source as system efficiency or system throughput is typically a very important
design parameter in illumination designs.
A photon is a terrible thing to waste.
If we want to capture every photon that is emitted into this
hemisphere then we must have a large optical collection system near the source.
Large collection systems near the source are expensive and often are made
from injection molded polymers and glasses. A concave positive meniscus
lens is one choice and a reflective or refractive compound parabolic
concentrator or CPC is often used. A second choice is a fast aspheric lens
which typically does not collect the full hemisphere so photons are wasted, and
this is bad for through put efficiency. The next step after collection is
to get this collected light somewhat collimated or shaped and "optically
plumbed" down the optical axis to the illumination plane. Lets take a look
at the whole process.
How Can We Help You With Your HB LED Project?
We would like to discuss your challenging illumination design project needs.
Our illumination design consulting engineers have a wealth of experience and we
are interested in helping our clients solve their most challenging HB LED
illumination needs.
Contact us today with your basic requirements or current
HB LED challenges: 541-255-2165 or send us an email at
mpate (at) oscintl.com
Surface Texture Hemispherical
Bumps for LCD Backlight Application
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LED Fiber Tree for LED Digital Projector
Light Engine
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Twisted Light Pipe with Two
Luxeon LEDs |
Luxeon
Batwing HB LED Emitting
into Hemisphere |
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HB LED with Compound Parabolic Concentrator CPC Collection System |
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*NOTE: OSCI Inc designs standard and custom
round, square, and rectangular CPCs and TIR lens
for High Brightness LED light sources such as CREE, Lumileds, Luminous
Devices, OSRAM and other leading HB LED light sources. |
HB LED Links
Luminus Devices
Lumileds - Light from Silicon Valley
OSRAM Ostar®
Cree Inc
Nichia
Seoul
Semiconductor
Know of another HB LED links that should be here?
Please let us know at
info (at) oscintl.com
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We serve these LED Illumination Design
Industries:
- Automotive
- Medical
- Dental
- Displays—DLP, LCoS, LCD Backlight (LEDBLU)
- Transportation/Traffic
- Consumer Electronics
- Entertainment
- Architecture
- Industrial and Process Control
- Precision Metrology
- Machine Vision
Our
Illumination Design Process
We have been using, developing, teaching, and
refining this illumination design process over the past six years.
It consists of these seven steps. Each step has its own pitfalls
and challenges. When we follow these steps and synthesize them
with our experience and modern design tools we usually arrive at a great
solution for our clients.
- Source Model
- Collect Light from Source
- Optically plumbed down optical axis
- Illumination Plan - Angular and Spatial Properties
- Interaction with Device, Analyte, or Object
- Collect Light from Interaction
- Deliver to detector or display device
Our Illumination Design Tools:
- Zemax® and NSC Zemax
- FRED®
- ProSource
- Essential Macleod
- SolidWorks
- Mathematica
- Matlab
- MathCAD
- ASAP
- OSLO
- TracePro
- Code V
- LightTools®
LED Illumination System Measurement & Characterization
In addition to the design and development of HB LED illumination system we
also perform measurements on existing system to characterize their performance
properties to solve existing problems or in preparation for a new design or
illumination design enhancement.
- Source measurement, characterization, and modeling
- Source Imaging Goinometer
- Colorimetry
- Spatial Uniformity
- Angular Distribution
- Power Spectral Distribution
- Color Temperature
- Color Rendering Index
- Radiance/Irradiance
- Curing Dosage
- Temporal Radiometry/Photometry—Pulse Width Modulation
- Thermal Optic Performance Properties
LED Illumination Design Experience:
- Luxeon I, Luxeon III, Luxeon V, Luxeon K2, Luxeon Dental
- OSRAM Ostar® 2x2 and 2x3
- Cree MegaBright, XBright, SuperBlue
- And several others including custom designs
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