A Fresnel freeform surface collimating lens for LEDs

Zhu, Liangliang; Ge, Aiming; Ge, Zhenyi; Hao, Rujiang; Chen, J; Tao, Xiaoming

doi:10.1177/1477153517712780

Cited by 6 publications

(3 citation statements)

References 7 publications

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“…To make a decision on the acceptable level of accuracy and to identify the reason for any differences, a convergence analysis of the simulation calculation results in relation to the laboratory measurement results that have a direct impact on the photometric characteristics of luminaires should be conducted. A luminous intensity distribution is a basic luminaire parameter that is subject to calculations and that is assumed at the initial stage of each optical system design [21]. The LID itself contains the accurate information about the luminous intensity distribution of the luminaire in each direction of the space.…”

Section: Methods For Modelling Geometric-photometric Features Of Ligh...mentioning

confidence: 99%

Bulletin of the Polish Academy of Sciences: Technical Sciences

Żagan,

Zalewski,

Słomiński

et al. 2020

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This paper presents modern methods for designing optical systems for luminaires in the context of long years of light sources development. It shows that the development of technology for producing increasingly precise optical systems has led to an evolution in the construction of luminaires with increased efficacy and utilizing more efficiently the features of a specific family of light sources. Methods for designing and modelling optical systems with the use of mathematical curves as well as advanced the free-forming method are described. The paper also shows methods for modelling light sources features, especially luminance ones, designed to make precise simulation calculations required in any luminaire design process. Knowledge of luminance distributions of light sources and precise luminance distributions of optical systems for luminaires raises the design process to a very high level, enabling positive modern light source features, such as high luminance and their small dimensions, to be used consciously while minimizing negative ones, such as discomfort glare, caused by luminaires. The paper presents the results of simulation calculations and laboratory measurements for a selected case of luminaire equipped with a discharge lamp of maximum luminance exceeding 30 million cd/m 2 .

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Section: Methods For Modelling Geometric-photometric Features Of Ligh...mentioning

confidence: 99%

Bulletin of the Polish Academy of Sciences: Technical Sciences

Żagan,

Zalewski,

Słomiński

et al. 2020

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show abstract

“…As we all know, the FFL of a vehicle plays an important role in improving visibility under severe weather conditions such as fog, snow, rain or dust. Conventional FFLs generally use high intensity discharge light sources, 6 but they have the obvious disadvantages of a short life and low efficiency, which means they cannot meet the requirements of energy saving and environmental protection. As a new type of light source, LEDs have the advantages of a small size and a long life, which can greatly improve the quality and effectiveness of vehicle lighting.…”

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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“…At that time, in the field of lighting technology, floodlighting and measuring technology [3][4][5], we were facing an actual revolution. The methods of design and analysis of optical systems were also changing [6][7][8][9]. The construction and specificity of light distribution in the light sources themselves in general applications has also changed considerably [10].…”

Section: Introductionmentioning

confidence: 99%

Bulletin of the Polish Academy of Sciences: Technical Sciences

Słomiński¹

2019

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Designing, optimizing and analyzing optical systems as part of the implementation process into production of modern luminaires require using advanced simulation and computational methods. The progressive miniaturization of LED (light emitting diode) chips and growth in maximum luminance values, achieving up to 10 8 cd/m 2 , require constructing very accurate geometries of reflector and lens systems producing complex luminous intensity distributions while reducing discomfort glare levels. Currently, the design process cannot function without advanced simulation methods. Today's simulation methods in the lighting technology offer very good results as far as relatively large conventional light sources such as halogen lamps, metal halide lamps and high pressure sodium lamps are concerned. Unfortunately, they often fail in the case of chip-on-board LED light sources whose luminous surface dimensions are increasingly often contained inside a cube of the side length below 1mm. With the high sensitivity of such small chips and lenses with dimensions ranging from a just a few to between 10 and 20 mm, which is presented in this paper, modern luminance distribution measurement methods, luminance modelling and ray tracing methods should be used to minimize any errors arising from incorrectly projecting the design in the final physical model. Also, very importantly, focus should be directed towards reducing a chance of making a mistake while collimating the position of the light source inside the optical system. The paper presents a novel simulation calculation method enriched with an analysis of optical system sensitivity to a light source position. The results of simulation calculations are compared with the results of laboratory measurements for corresponding systems.

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A Fresnel freeform surface collimating lens for LEDs

Cited by 6 publications

References 7 publications

Bulletin of the Polish Academy of Sciences: Technical Sciences

Bulletin of the Polish Academy of Sciences: Technical Sciences

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

Bulletin of the Polish Academy of Sciences: Technical Sciences

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