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Applied Optics

Applied Optics

APPLICATIONS-CENTERED RESEARCH IN OPTICS

  • Editor: Joseph N. Mait
  • Vol. 50, Iss. 24 — Aug. 20, 2011
  • pp: 4860–4867

Compact lens with circular spot profile for square die LEDs in multi-LED projectors

Thøger Kari, Jesper Gadegaard, Dennis Thykjaer Jørgensen, Thomas Søndergaard, Thomas Garm Pedersen, and Kjeld Pedersen  »View Author Affiliations


Applied Optics, Vol. 50, Issue 24, pp. 4860-4867 (2011)
http://dx.doi.org/10.1364/AO.50.004860


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Abstract

In the stage illumination industry, LED technology is promising both in terms of energy use and novel features, but it also has inherent issues. This paper presents a solution to the poor color homogeneity arising when multiple rectangular images formed from LED dies are combined into a circular spot profile. Using ray tracing, a nonrotationally symmetric collimating lens was optimized to round off such die images. The result is a high-output lens with an almost perfectly circular spot. In a simulated red green blue color mixing projector with seven LEDs, the lens reduced measurable color inhomogeneity by 24.1 % , with a 5.3% luminous gain, compared to the best rotationally symmetric benchmark lens.

© 2011 Optical Society of America

OCIS Codes
(220.2740) Optical design and fabrication : Geometric optical design
(220.3620) Optical design and fabrication : Lens system design
(230.3670) Optical devices : Light-emitting diodes
(330.1730) Vision, color, and visual optics : Colorimetry
(220.4298) Optical design and fabrication : Nonimaging optics

ToC Category:
Optical Design and Fabrication

History
Original Manuscript: April 13, 2011
Revised Manuscript: July 6, 2011
Manuscript Accepted: July 7, 2011
Published: August 19, 2011

Citation
Thøger Kari, Jesper Gadegaard, Dennis Thykjaer Jørgensen, Thomas Søndergaard, Thomas Garm Pedersen, and Kjeld Pedersen, "Compact lens with circular spot profile for square die LEDs in multi-LED projectors," Appl. Opt. 50, 4860-4867 (2011)
http://www.opticsinfobase.org/ao/abstract.cfm?URI=ao-50-24-4860


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References

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