標題: Illuminance and Starting Distance of the Far Field of LED-Array Luminaire Operated at Short Working Distance
作者: Sun, Ching-Cherng
Lin, Yi-Syuan
Yang, Tsung-Hsun
Lin, Shih-Kang
Lee, Xuan-Hao
Wu, Chi-Shou
Yu, Yeh-Wei
電子物理學系
Department of Electrophysics
關鍵字: LED array;optical design;short working distance;far field
公開日期: 1-May-2020
摘要: A luminaire with a light-emitting diode (LED) array can provide hotspot illumination in a short range. Therefore, a design of a luminaire with the largest central illuminance (LCI) and a high uniformity is warranted. In this paper, we present a study of illuminance variation with respect to the distance of an illumination target of a luminaire with LED array. The emission property of the luminous intensity is characterized by the cosine power law or the divergent angle of full width at half maximum (FWHM). A real LED module is designed to create the simulation for different luminaire types. The occurrence of the LCI and the far-field region are observed. Our results demonstrate that the LCI distance remains shorter than the starting distance of the far field (SDFF). To simplify the simulation, we propose the replacement of the real LED module with a point or flat-extended source. Such light sources must be equipped with the specific cosine power factor corresponding to the divergent angle of the FWHM of the LED module. These light sources are acceptable for describing illumination characteristics, including the SDFF. Our results may facilitate the design of LED-array luminaires operated at short working distances, such as reading lighting or illumination in microscopes.
URI: http://dx.doi.org/10.3390/cryst10050360
http://hdl.handle.net/11536/154935
ISSN: 2073-4352
DOI: 10.3390/cryst10050360
期刊: CRYSTALS
Volume: 10
Issue: 5
起始頁: 0
結束頁: 0
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