摘要(英) |
In this paper, an LED light source is used to design a vehicle low-beam headlamp that complies with the Economic Commission of Europe, Regulation no.112 (ECE R112) vehicle safety testing standards. The light source used in the design of this paper, through the requirements of the illuminance values in various regions of the European regulations, calculates the luminous flux on the side of 25 meters to be 101.5425 lm, so the white light LED LW-W5SN with a luminous flux of 146 lm is selected as the light source of the car lamp. The compound reflector uses two kinds of reflectors. The first reflector is an elliptical reflector. The distance between the two focal points of the elliptical reflector is 50 mm, and the efficiency of light entering the elliptical reflector is 97.71%. The second type of mirror is a parabolic mirror, the focal length of which is selected to be 50 mm and the diameter is 200 mm. The focus of the parabolic mirror is the same as the second focus of the elliptical mirror, so the light exits from the second focus of the elliptical mirror to the parabolic mirror. After reflection, a collimated light is formed, and a toric lens with a height of 100 mm and a width of 185 mm is added in front of the parabolic reflector to make the light path rectangular distribution. In order to meet the European light distribution of the left and right, the left light pattern is a rectangular distribution, but the illumination requirement is much smaller than that of the right half. The right light pattern has the same rectangular distribution as the left light pattern. Above the rectangle, there is a triangular light design with an elevation angle of 15. Finally, after the ring lens, place an optical element on the left and right, a filter with a 45% transmittance on the left, and reduce its illuminance; place an array of 15 prisms on the right, each prism thickness is 2 mm, the distance between each slice is 2 mm, The top angle of each piece of prism is decreasing from right to left, which can meet the European standard light type and illuminance requirements, and the total luminous flux on the side can be 101.3 lm, and the total efficiency is 69.38%. In order to improve the efficiency of the low beam light, the 45% transmittance filter is removed and replaced with 18 piece prism array, each prism thickness is 2 mm, each prism spacing is 1.2 mm, each prism apex angle is fixed at 18.33, the total luminous flux measured on the side is 124.2 lm, and the total efficiency is 85.07%. |
參考文獻 |
1. G. Lindae, “Improvements of Low-Beam Pattern by use of Polyellipsoid Headlamps(PES),” SAE Transactions 94(2), 216-227 (1985).
2. H. Zerhau-Dreihoefer, U. Haack, T. Weber, and D. Wendt, “Light source modeling for automotive lighting devices,” Proc. SPIE 4775, 58–66 (2002).
3. W. J. Cassarly, D. R. Jenkins, and H. Mönch, “Accurate illumination system predictions using measured spatial luminance distributions,” Proc. SPIE 4775, 78–85 (2002)
4. A. Cvetkovic, O. Dross, J. Chaves, P. Benitez, J. C. Minano, and R. Mohedano, “Etendue-preserving mixing and projection optics for high-luminance LEDs, applied to automotive headlamps,” Opt. Express 14, 13014–13020 (2006).
5. J. J. Chen, K. L. Huang, and P. C. Lin, “Computer modeling of a fiber-and-light-emitting-diode-based vehicle headlamp,” Opt. Eng. 49, 073002 (2010).
6. F. Chen, K. Wang, Z. Qin, D. Wu, X. Luo, and S. Liu, “Design method of high-efficient LED headlamp lens,” Opt. Express 18, 20926–20938 (2010).
7. X. Zhu, Q. Zhu, H. Wu, and C. Chen, “Optical design of LED-based automotive headlamps,” Opt. Laser Technol. 45, 262–266 (2013).
8. A. Ge, W. Wang, Z. Du, P. Qiu, J. Wang, and J. Cai, “High-energy-efficiency optical system for an LED-based headlamp architecture,” Appl. Opt. 52, 8318–8323 (2013).
9. A. Ge, Z. Du, W. Wang, P. Qiu, J. Wang, J. Cai, and X. Song, “A composite optical system for a LED-based headlamp low beam module,” Light. Res. Technol. 45, 752–757 (2013).
10. C. C. Hsieh, Y. H. Li, and C. C. Hung, “Modular design of the LED vehicle projector headlamp system,” Appl. Opt. 52, 5221–5229 (2013).
11. H. Wang, X. Wang, Y. Li, and P. Ge, “Design of a newly projected light-emitting diode low-beam headlamp based on microlenses,” Appl. Opt. 54, 1794-1801 (2015).
12. H. Wu, X. Zhang, and P. Ge, “Modular design of a high-efficiency LED headlamp system based on freeform reflectors,” Optics & Laser Technology 72, 79-85 (2015).
13. 陳建安,「汽車之近光燈白光LED照明設計」,國立中央大學光電科學與工程研究所,碩士論文,民國107年12月。
14. United Nations Economic Commission for Europe, vehicle regulations Reg.112 Rev.2., http://www.unece.org/trans/main/wp29/wp29regs101-120.html (2018).
15. Osram, http://www.osram-os.com.
16. D. Malacara, Optical Shop Testing, 2nd ed. (Wiley, 1992)
17. W. S. Sun, C. L. Tien, W. C. Lo, and P. Y. Chu, “Optical design of an LED motorcycle headlamp with compound reflectors and a toric lens,” Appl. Opt. 54, E102–E108 (2015). |