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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 20, Iss. 22 — Oct. 22, 2012
  • pp: 24418–24428

New freeform lenses for white LEDs with high color spatial uniformity

Shuiming Li, Kai Wang, Fei Chen, and Sheng Liu  »View Author Affiliations

Optics Express, Vol. 20, Issue 22, pp. 24418-24428 (2012)

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A novel freeform lens structure made up of two surfaces is proposed and optimized to enhance the color spatial uniformity (CSU) of white light-emitting diodes (LEDs). Compared with our previous method, an improved design method by optimizing the light energy mapping relationship is proposed to eliminate the dark area, which appears in the illumination pattern due to a deep batwing luminous intensity distribution. Moreover, experiments with a significant evaluation function are performed and demonstrate that the CSU in terms of color difference ( Δu'v' ) can be enhanced as high as 92%. In addition, this novel lens can further improve the CSU of white LEDs with conformal coating. High-quality illumination pattern without yellow rings and dark areas can be realized based on this novel freeform lens with little light loss.

© 2012 OSA

OCIS Codes
(220.3630) Optical design and fabrication : Lenses
(230.3670) Optical devices : Light-emitting diodes
(330.1710) Vision, color, and visual optics : Color, measurement
(220.4298) Optical design and fabrication : Nonimaging optics

ToC Category:
Optical Design and Fabrication

Original Manuscript: August 28, 2012
Revised Manuscript: October 2, 2012
Manuscript Accepted: October 2, 2012
Published: October 11, 2012

Shuiming Li, Kai Wang, Fei Chen, and Sheng Liu, "New freeform lenses for white LEDs with high color spatial uniformity," Opt. Express 20, 24418-24428 (2012)

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