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Applied Optics

Applied 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)

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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

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

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)

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