scholarly journals Luminous Efficacy of LED White Light Sources

2016 ◽  
Vol 16 (06) ◽  
pp. 64-74
Author(s):  
V Pavlov ◽  
V Pyasetskiy ◽  
A Horohorov ◽  
A Shirankov



2021 ◽  
Vol 13 (2) ◽  
pp. 40
Author(s):  
Jacek Kusznier

The text presents differences between the mechanism of seeing and recording images and potential sources of errors in color reproduction in recorded images. The measurements show that despite the relatively high values of indices (Ra, Rf i Rg) not all tested lamps are suitable for use on a photo set, as indicated by the value of TLCI index. The lighting requirements on a film set prioritize the quality of color reproduction, even at the expense of reducing the Luminous efficacy of a source (LES ) value. Full Text: PDF ReferencesL.T. Sharpe, A. Jagla, W. Jägle, "A luminous efficiency function, V*(λ), for daylight adaptation", J. Vision 5(11), 948 (2012) DirectLink K. Mangold, J.A. Shaw, M. Vollmer, The physics of near-infrared photography, Eur. J. Phys. 34 (2013), pp. 51-71 CrossRef Simunovic M. P., On Seeing Yellow The Case for, and Against, Short-Wavelength Light-Absorbing Intraocular Lenses, Archives of Ophthalmology, vol. 130, no. 7, pp. 919-926, 2012 CrossRef M. Gilewski, The ecological hazard of artificial lighting in greenhouses, Phot. Lett. Pol., vol. 11 Issue: 3, pp. 87-89, 2019. CrossRef M. Gilewski, The role of light in the plants world, Phot. Lett. Pol., vol. 11, no. 4, pp. 115-117, 2019 CrossRef I. Fryc and E. Czech Spectral correction of the measurement CCD array, Optical Engineering 41(10), pp.2402-2406 (2002). CrossRef L. Bellia, U. Blaszczak, F. Fragliasso, L. Gryko, Matching CIE illuminants to measured spectral power distributions: A method to evaluate non-visual potential of daylight in two European cities, Solar Energy, Volume 208, 2020, Pages 830-858 CrossRef J. Kusznier and W. Wojtkowski, Impact of climatic conditions on PV panels operation in a photovoltaic power plant, IEEE, 2019 15th Selected Issues of Electrical Engineering and Electronics (WZEE), Zakopane, Poland, pp. 1-6, 2019 CrossRef J. Kusznier and W. Wojtkowski, Impact of climatic conditions and solar exposure on the aging of PV panels, IEEE, 2019 15th Selected Issues of Electrical Engineering and Electronics (WZEE), Zakopane, Poland, pp. 1-6, 2019 CrossRef J. Fan, Y. Li, I. Fryc, C. Qian, X. Fan and G. Zhang, Machine-Learning Assisted Prediction of Spectral Power Distribution for Full-Spectrum White Light-Emitting Diode, in IEEE Photonics Journal, vol. 12, no. 1, pp. 1-18, Feb. 2020, Art no. 8200218, CrossRef M. Gilewski, L. Gryko, A. Zajac, Digital controlling system to the set of high power LEDs, Proc. of SPIE, 8902, 89021D, 2013 CrossRef J. Kusznier, W. Wojtkowski, Spectral properties of smart LED lamps, Phot. Lett. Pol., vol. 12, no. 1, pp. 16-18, 2020. CrossRef J. Kusznier, Changes in the Spectral Power Distribution of Light Sources for Smart Lighting, IEEE, 14th WZEE, pp. 1-5, 2018 CrossRef H. F. Ivey, Color and Efficiency of Luminescent Light Sources, J. Opt. Soc. Am. 53, 1185-1198 (1963) CrossRef F. Zhang, H. Xu, Z. Wang, Optimizing spectral compositions of multichannel LED light sources by IES color fidelity index and luminous efficacy of radiation, Appl. Opt. 56, 1962-1971 (2017) CrossRef T. W. Murphy Jr., Maximum spectral luminous efficacy of white light, Journal of Applied Physics 111, 104909 (2012) CrossRef Po-Chieh Hung and Jeffrey Y. Tsao, Maximum White Luminous Efficacy of Radiation Versus Color Rendering Index and Color Temperature: Exact Results and a Useful Analytic Expression, J. Display Technol. 9, 405-412 (2013) CrossRef V. M. Lisitsyn, V. S. Lukash, S. A. Stepanov, and Ju Yangyang , White LEDs with limit luminous efficacy, AIP Conference Proc 1698, 060008 (2016) CrossRef J. Kowalska, I. Fryc, Colour rendition quality of typical fluorescent lamps determined by CIE Colour Fidelity Index and Colour Rendering Index, Przeglad Elektrotechniczny R. 95(7), pp. 94-97, 2019 CrossRef I. Fryc, J. Fryc, A. Wasowski, "Rozważania o jakości oddawania barw źródeł światła, wyrażanej wskaźnikiem Ra (CRI), uwzględniające fizjologię widzenia oraz zagadnienia techniczno-prawne", Przeglad Elektrotechniczny R. 92(2), 218 (2016) CrossRef TECH 3353, Development of a "standard" television camera model implemented in the TLCI-2012, Source: FTV-LED, EBU, Geneva November 2012 DirectLink TECH 3354, Comparison of CIE colour metrics for use in the television lighting consistency index (TLCI-2012), Source: FTV-LED, EBU, Geneva November 2012 DirectLink TECH 3355, Method for the assessment of the colorimetric properties of luminaires the television lighting consistency index (TLCI-2012) and the television luminaire matching factor (TLMF-2013), Source: FTV-LED Geneva March 2017 DirectLink J. Kusznier, Mixing colours inside the optical fibre elements, Przeglad Elektrotechniczny, R 84(8), pp 182-185, 2008 DirectLink



2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Snjezana Soltic ◽  
Andrew N. Chalmers

The purpose of this investigation is to quantify the influence of the peak wavelength shifts in commercially available LEDs on the characteristics of the mixed-LED white-light sources. For this purpose, a tetrachromatic spectrum was optimized and then subjected to deviations in the peak wavelengths. A total of 882 combinations of peak wavelength values were evaluated, and the results are reported in terms of correlated colour temperature, colour-rendering properties, and radiant luminous efficacy. The results show that there can be significant changes in the characteristics of the source under these conditions. Such changes are highly likely to present problems when dealing with applications where an effective and accurate white-light source is important.



Nano Letters ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2397-2405
Author(s):  
Jin Xiang ◽  
Mincheng Panmai ◽  
Shuwen Bai ◽  
Yuhao Ren ◽  
Guang-Can Li ◽  
...  


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Prashant Pradhan ◽  
Juan Carlos Alonso ◽  
Monserrat Bizarro

ZnO and Al doped ZnO films were produced by spray pyrolysis. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis spectroscopy, and photoluminescence. Their photocatalytic activity was evaluated by the decomposition of the methyl orange dye using different light sources: ultraviolet light, artificial white light, and direct sunlight. The films were also tested under darkness for comparison. The ZnO films were able to degrade the test pollutant under UV and sunlight in more than a 60% after 180 min of irradiation and a scarce degradation was obtained using white light. However, the Al doped ZnO films presented a very high degradation rate not only under UV and sunlight (100% degradation), but also under white light (90% degradation after the same irradiation time). An unexpected high degradation was also obtained in the dark, which indicates that a nonphotonic process is taking place parallel to the photocatalytic process. This can be due to the extra electrons—provided by the aluminum atoms—that migrate to the surface and produce radicals favoring the decomposition process even in the dark. The high activity achieved by the ZnO: Al films under natural conditions can be potentially applied to water treatment processes.



2012 ◽  
Vol 111 (10) ◽  
pp. 104909 ◽  
Author(s):  
Thomas W. Murphy


2014 ◽  
Vol 3 (5-6) ◽  
Author(s):  
Roland Lachmayer ◽  
Alexander Wolf ◽  
Gerolf Kloppenburg

AbstractFor many lighting applications, light-emitting diodes (LEDs) are replacing traditional light sources providing the possibility for smart and efficient systems as well as a reduction in the product weight. A next step in this development is the integration of laser-based light sources to increase luminance and to further scale down the optics possibly leading to a reduction of necessary resources. This article reviews the possibilities and challenges arising from the use of laser diodes especially compared to current high-power LED systems in terms of efficiency, color-rendering properties, and thermal management.



2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Andrew Chalmers ◽  
Snjezana Soltic

This paper is concerned with designing light source spectra for optimum luminous efficacy and colour rendering. We demonstrate that it is possible to design light sources that can provide both good colour rendering and high luminous efficacy by combining the outputs of a number of narrowband spectral constituents. Also, the achievable results depend on the numbers and wavelengths of the different spectral bands utilized in the mixture. Practical realization of these concepts has been demonstrated in this pilot study which combines a number of simulations with tests using real LEDs (light emitting diodes). Such sources are capable of providing highly efficient lighting systems with good energy conservation potential. Further research is underway to investigate the practicalities of our proposals in relation to large-scale light source production.



2021 ◽  
Author(s):  
James Raring ◽  
Changmin Lee ◽  
Mohamed Sufyan Islim ◽  
Sovan Das ◽  
Adrian Sparks ◽  
...  


2018 ◽  
Vol 66 (3) ◽  
pp. 271-280 ◽  
Author(s):  
Snjezana Soltic ◽  
Andrew N. Chalmers
Keyword(s):  


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