This paper proposes a freeform surface lens design based on the Fresnel model to achieve a compact structure and good collimation. A simulation indicates the lens enjoys an efficiency as high as 88.43% within a half view angle of 2° for 1 × 1 mm2 size LED. This paper makes a comparison of three types of lens, among which the Fresnel freeform lens achieves the best performance when the LED size is smaller than 2.5 × 2.5 mm2. The influence of the LED size and the manufacturing tolerances are discussed.
Get full access to this article
View all access options for this article.
References
1.
PimputkarSSpeckJSDenBaarsSPNakamuraS. Prospects for LED lighting. Nature Photonics2009; 3(4): 180–182.
2.
WuSHuoYXuM. Applications of LED light sources in lighting. Light Sources and Illumination2008;(3, 30–32.
