• Acta Photonica Sinica
  • Vol. 43, Issue 8, 822003 (2014)
MENG Xiang-xiang1、2、*, LIU Wei-qi1, FENG Rui1, WEI Zhong-lun1, ZHOU Min3, and YANG Jian-ming1、2
Author Affiliations
  • 1[in Chinese]
  • 2[in Chinese]
  • 3[in Chinese]
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    DOI: 10.3788/gzxb20144308.0822003 Cite this Article
    MENG Xiang-xiang, LIU Wei-qi, FENG Rui, WEI Zhong-lun, ZHOU Min, YANG Jian-ming. Design of LED Collimator for Uniform Illumination with Double Freeform Surfaces[J]. Acta Photonica Sinica, 2014, 43(8): 822003 Copy Citation Text show less

    Abstract

    A LED collimator with double freeform surfaces was designed for uniform illumination in both near field and far field.The collimator includes refractive part and reflective part,and each part has double freeform surfaces.Based on Malus Law,the constant optical path length equations that realize the rays collimating were derived.Then associating with tangent-plane iterative method,the date both up freeform surface and down freeform surface simultaneously could be calculated.The simulations show that,84.55% of the energy is collected in ±2° for 1 mm×1 mm size white LED after considering the Fresnel loss,reflective surfaces loss and material absorbing.The uniformity in near field is 94.59%, and the uniformity in far field is 89.01%.The uniformity in near field and the optical efficiency in ± 4° are above 90% and 83.5% respectively,while the LED chip sizes are under 2 mm×2 mm.It is illustrated that the LED collimator can realize uniform illumination in both near field and far field with high light efficiency and the tolerance meet the requirements of alignment.
    MENG Xiang-xiang, LIU Wei-qi, FENG Rui, WEI Zhong-lun, ZHOU Min, YANG Jian-ming. Design of LED Collimator for Uniform Illumination with Double Freeform Surfaces[J]. Acta Photonica Sinica, 2014, 43(8): 822003
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