Abstract
Today's SSL illumination market shows a clear trend towards high flux packages with higher efficiency and higher Color Rendering Index, realized by means of multiple color chips and phosphors. Such light sources require the optics to provide both near- and far-field color mixing. This design problem is particularly challenging for collimated luminaries, since traditional diffusers cannot be employed without enlarging the exit aperture and reducing brightness. Furthermore, diffusers compromise the light output ratio (efficiency) of the lamps to which they are applied.
A solution, based on Khler integration, consisting of a spherical cap comprising spherical microlenses on both its interior and exterior sides was presented in 2012. The diameter of this so-called Shell-Mixer was 3 times that of the chiparray footprint. This work shows a new version of the Shell-Mixer, based on the Edge Ray Principle and conservation of etendue, where neither the overall shape of the optic nor the surfaces of the lenses are constrained to spheres or rotational Cartesian ovals. The new shell is freeform, only twice as large as the chip-array footprint and equals the original model in terms of color uniformity, brightness and efficiency.
A solution, based on Khler integration, consisting of a spherical cap comprising spherical microlenses on both its interior and exterior sides was presented in 2012. The diameter of this so-called Shell-Mixer was 3 times that of the chiparray footprint. This work shows a new version of the Shell-Mixer, based on the Edge Ray Principle and conservation of etendue, where neither the overall shape of the optic nor the surfaces of the lenses are constrained to spheres or rotational Cartesian ovals. The new shell is freeform, only twice as large as the chip-array footprint and equals the original model in terms of color uniformity, brightness and efficiency.
Original language | English |
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Title of host publication | Nonimaging optics: efficient design for illumination and solar concentration XII |
Publisher | SPIE |
Number of pages | 8 |
Volume | 9572 |
ISBN (Print) | 978-1-62841-738-8 |
Publication status | Published - 2015 |
Event | Efficient Design for Illumination and Solar Concentration XII - , United Kingdom Duration: 9 Aug 2015 → 10 Aug 2015 |
Conference
Conference | Efficient Design for Illumination and Solar Concentration XII |
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Country/Territory | United Kingdom |
Period | 9/08/15 → 10/08/15 |
Keywords
- LEDs
- Color Mixing;
- Freeform
- Kohler integration;
- Etendue
- Illumination