AB20-5 Datasheet, PDF (1/23 Pages) Lumileds Lighting Company – Secondary Optics Design Considerations for SuperFlux LEDs

application brief AB20 5
replaces AN1149 5
Secondary Optics Design
Considerations for SuperFlux LEDs
Secondary optics are those optics which exist outside of the LED package, such as reflector
cavities, Fresnel lenses, and pillow lenses. Secondary optics are used to create the desired
appearance and beam pattern of the LED signal lamp.
The following section details the optical characteristics and optical model creation for Lumileds
SuperFlux LEDs. In addition, simple techniques to aid in the design of collimating reflectors,
collimating lenses, and pillow lenses are discussed.
Table of Contents
Optical Characteristics of SuperFlux LEDs
2
LED Light Output
2
SuperFlux LED Radiation Patterns
2
Optical Modeling of SuperFlux LEDs
3
Point Source Optical Model
3
Detailed Optical Models
4
Secondary Optics
5
Pillow Lens Design
9
Design Case—Pillow Design for an LED CHMSL
9
Non symmetric Pillow Lenses
11
Selecting the Size of the Pillow Optic
11
Recommended Pillow Lens Prescriptions
12
Other Diverging Optics
13
Reflector Design
14
Design Case—Reflector for a CHMSL Application
14
Reflector Cavities with Linear Profiles
15
Reflector Cavities with Square and Rectangular Exit Apertures
15
Other Reflector Design Techniques
16
Collimating Lens Design
17
Fresnel Lens Design
18
Design Case—Collimator Lens
19
Other Lens Design Options
19
Appendix 5A
21