Design method of a light emitting diode front fog lamp based on a freeform reflector

Wu, Heng; Zhang, Xianmin; Ge, Peng

doi:10.1016/j.optlastec.2015.04.002

Cited by 11 publications

(5 citation statements)

References 21 publications

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“…To evaluate the transmit-ability on the lens, the light control efficiency (LCE) is defined as the ratio between the energy projected to the illuminated areas and the total energy emitted from the LED source, which is denoted as: [12] η ϕ ϕ = ( ) 9 target source where the ϕ target and ϕ source are the luminous flux on the target plane and the total luminous flux from the LED source, respectively. In our optics system, the LCE can be up to 76%, and it only needs a LED source and lens, which saves the cost and the space.…”

Section: Simulation Resultsmentioning

confidence: 99%

“…But multiple pairs of LEDs and TIR lenses are needed for the full fog lamp, which requires much space. Wu did well on the front fog lamp based on a freeform reflector [12], but feedback method was necessary because of the non-integrability on the reflective surface [13,14]. During every feedback calculation, Wu set 30 sampling points and matched them to set up a new mapping, then re-calculated the more accurate surface.…”

Section: Introductionmentioning

confidence: 99%

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Design of an optical lens combined with a total internal reflection (TIR) freeform surface for a LED front fog lamp

Wang

2017

Optics & Laser Technology

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Section: Simulation Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Design of an optical lens combined with a total internal reflection (TIR) freeform surface for a LED front fog lamp

Wang

2017

Optics & Laser Technology

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“…The resulting asymmetric LED FFL type could satisfy the regulations for FFLs in ECE R19 Revision 7. 17 Wu et al 18 designed a new type of freeform surface for the FFL of a vehicle. The main FFL design was finally obtained by adjusting the structure of the reflecting surface and the LEDs.…”

Section: Introductionmentioning

confidence: 99%

Design of a high-efficiency system with combined reflectors for a light-emitting diode front fog lamp

Yang

Liu

et al. 2020

Lighting Research & Technology

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This paper provides a design method for a light-emitting diode front fog lamp system based on a freeform surface and an improved quadric surface. First, a light-receiving reflector is used to converge the light-emitting diode beam to form an equivalent lighting point. Then, the relationship between the point and the light pattern on the work surface is calculated, and the freeform surface is constructed based on Snell’s law and non-imaging optical theory. Finally, two compensated reflectors are added at both ends of the freeform surface to reflect the unutilized light to achieve the compensation effect. By application of combined reflectors, the light pattern at the work surface 25 m away can satisfy the requirement of ECE R19 Revision 7. Also, this system has the advantages of small size and high efficiency because lens or prism groups are avoided. And the utilization of a compensated surface also increases light efficiency. Finally, a prototype model is tested, which also meets the regulatory requirements.

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“…To avoid deriving and solving the complicated MA equation, a ray-mapping method is commonly used. [5][6][7][8][9][10][11][12][13][14] The ray-mapping method can simplify the problem greatly by breaking the design process into two separate steps: computing a ray map between the incident and target irradiance or intensity distribution; calculating the freeform surface point by point based on Snell's law to meet the ray map. But the ray-mapping method usually suffers the problem of finding a raymapping relationship that satisfies the integrability condition for a smooth continuous surface.…”

Section: Introductionmentioning

confidence: 99%

Designing double freeform surfaces for point source and extended sources using a construction, iteration and optimization process

Lai

2018

Lighting Research & Technology

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In this paper, a construction-iteration-optimization method is developed to design a double freeform surface lens for point sources as well as extended sources to achieve uniform illuminance. In the construction process, the initial double freeform surfaces are first calculated by the variable separation method with preset source-target ray mapping to obtain the maximum utilization ratio with Fresnel loss. Then, the double freeform surfaces are fitted into a fourth-order XY polynomial surface considering both the coordinates and surface normals of the data points, which ensures the smoothness of freeform surfaces. To reduce the relative standard deviation of the illuminance distribution, an iteration process is required to reconstruct the two freeform surfaces by turns, and this process can be repeated several times to further decrease the deviation of the rays. The system after the construction-iteration process can be taken as a good starting point for further optimization with optical design software. Although the construction-iteration-optimization process is for a point source at first, with the advantage of multi-parameter representation of freeform surfaces we can further optimize the parameters for an extended source by replacing the point source. Simulation results for illuminance uniformity are demonstrated to verify the effectiveness of this method. The energy utilization ratios are above 86.5% and 82.3% with Fresnel loss, while the relative standard deviations of the illuminance distribution are less than 0.036 and 0.063 for a point source and an extended source, respectively.

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Design method of a light emitting diode front fog lamp based on a freeform reflector

Cited by 11 publications

References 21 publications

Design of an optical lens combined with a total internal reflection (TIR) freeform surface for a LED front fog lamp

Design of an optical lens combined with a total internal reflection (TIR) freeform surface for a LED front fog lamp

Design of a high-efficiency system with combined reflectors for a light-emitting diode front fog lamp

Designing double freeform surfaces for point source and extended sources using a construction, iteration and optimization process

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