TM-30–15 and CIE-CRI-Ra: Investigation of Сolour Rendering of White PC LEDs

2018 ◽  
pp. 81-87
Author(s):  
Karin Bieske ◽  
Ulla Maria Hartwig ◽  
Christoph Schierz ◽  
Alexander Wilm ◽  
Carolin Horst
Keyword(s):  
Light Sources ◽  
Halogen Lamp ◽  
Fluorescent Lamp ◽  
Colour Difference ◽  
Led Light ◽  
Colour Saturation ◽  
Colour Rendering ◽  
Test Scenarios ◽  
Tungsten Halogen Lamp

The colour rendering properties of 21 phosphor converted LED light sources (pc LED) with different Rf and Rg values as in the Fidelity Index and Gamut Index of the TM­30–15 have been investigated. Scenarios illuminated by pc LEDs, a fluorescent lamp (FL) and a tungsten halogen lamp (THL) were presented to 34 subjects. An assortment of coloured objects was arranged identically in two adjoining booths and participants rated the test scenarios in comparison with the reference illuminant (THL). For colour quality, both indexes are reflected in the observer’s ratings. The Fidelity Index strongly correlates with the colour difference and colour shift perceived; the Gamut Index with the subjects’ ratings of the colour saturation. Participants found the best match with the fluorescent lamp (Rf = 80/ Rg = 100) to be the pc LEDs with Rf = 75/ Rg = 105 and Rf = 80/ Rg = 105.

A Comparison of Fluorescent and Nonfluorescent Light Sources for Phototherapy

PEDIATRICS ◽  
1980 ◽  
Vol 65 (4) ◽  
pp. 795-798 ◽  
Author(s):  
Joseph B. Warshaw ◽  
Jeryl Gagliardi ◽  
Anil Patel
Keyword(s):  
Serum Bilirubin ◽  
Newborn Infants ◽  
Radiant Flux ◽  
Light Sources ◽  
Halogen Lamp ◽  
The Mean ◽  
Additional Support ◽  
The Relationship ◽  
Tungsten Halogen Lamp ◽  
Practical Measure

We have compared fluorescent and nonfluorescent light sources for phototherapy for newborn infants with hyperbilirubinemia. Phototherapy was provided by a tungsten halogen lamp and conventional fluorescent lights with identical radiant flux of 6 µW/sq cm. For 22 infants treated with the nonfluorescent lamp the mean duration of phototherapy was 33.77 hours and the mean reduction of bilirubin was 3.84 mg/100 ml/day. This did not differ significantly from infants treated with conventional fluorescent lights. The nonfluorescent light can be utilized for infants in incubators or on radiant warmers. These results provide additional support for the relationship between radiant flux as a practical measure of phototherapy dose and the clinical response of a reduction in serum bilirubin.

scholarly journals The light color quality of LED operating at winter temperatures

2019 ◽  
Vol 11 (4) ◽  
pp. 112 ◽  
Author(s):  
Przemysław Tabaka ◽  
Pawel Rozga
Keyword(s):  
Solid State ◽  
Operating Temperature ◽  
Solid State Lighting ◽  
Light Sources ◽  
Led Light ◽  
Fluorescent Lamps ◽  
Color Rendering ◽  
Incandescent Lamps ◽  
Colour Rendering

The paper presents the results of calculations of colorimetric parameters of LED sources operating at a temperature range from -25oC to 25oC. The chromaticity coordinates and color rendition quality parameters were calculated on the basis of registered spectral distributions of radiation. For individual LED chromaticity shift is illustrated at CIE 1931 x,y diagram with 3 step and 7 step MacAdam ellipses. Full Text: PDF ReferencesJ. P. Freyssinier, D. Frering, J. Taylor, N. Narendran, and P. Rizzo, Reducing lighting energy use in retail display windows. Sixth International Conference on Solid State Lighting, Proceedings of SPIE 6337, 63371L (2006). CrossRef Aman, M. M., et al., 2013. Analysis of the performance of domestic lighting lamps, Energy Policy, CrossRef E. Elijošiute, J. Balciukevičiute, G. Denafas, Life cycle assessment of; compact fluorescent and incandescent lamps: Comparative analysis. Environ Res. Eng. Manag. 61 (3), pp. 65-72, (2012), CrossRef D. Czyzewski, LED substitutes of conventional incandescent lamps Przeglad Elektrotechniczny R. 88, No. 11 (2012), CrossRef P. Tabaka, P. Rozga, Assessment of methods of marking LED sources with the power of equivalent light bulb, ulletin of the Polish Academy of Sciences. Technical Sciences, Vol. 65, No. 6, (2017) CrossRef I. Fryc, P. Jakubowski, K. Kołacz, Analysis of optical radiation parameters of compact discharge HID lamps and LED COB modules used for illuminating shop windows, Przeglad Elektrotechniczny,R. 93, No 11, (2017); pp. 186-189, CrossRef T. Kawabata, Y. Ohno; Optical measurements of OLED panels for lighting applications, pp 1176-1186 Jun 2013, Journal of Modern Optics, Vol. 60, 2013 Issue 14 CrossRef W. Żagan, Conditions necessary to replacing the conventional lamps by energy-saving lamps, Przeglad Elektrotechniczny R. 85, No. 5, pp. 100-104, (2009). DirectLink P. Tabaka; Influence of Ambient Temperature on Colour Properties of Low-Pressure Fluorescent Lamps, Light & Engineering, Vol. 23; No. 2; (2015). DirectLink W. R. Ryckaert, et al., Linear LED tubes versus fluorescent lamps: An evaluation. Energy Build. 49, pp. 429-436. CrossRef M. Zalesinska, J. Zablocka, K. Wandachowicz, Evaluation of Selected Parameters of Non-Directional Household Lamps, Conference: 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4), CrossRef I. Fryc; Measurement techniques of optical LEDs properties performed with compliance conformity with CIE 127:2007 standard, Przeglad Elektrotechniczny R. 85, No. 11, pp. 317-319, (2009) DirectLink IESNA, IES Approved Method: Measuring Lumen Maintenance of LED Light Sources. IES LM-80-08', IES Subcommittee on Solid-State Lighting of the IES Testing Procedures Committee (2018). DirectLink D. B. Judd, Estimation of chromaticity differences and nearest color temperature on the standard 1931 ICI colorimetric coordinate system. J. Opt. Soc. America 26 (11), 421, (1936) CrossRef CIE 177:2007 Colour Rendering of White LED Light Sources DirectLink CIE 13.3-1995 Method of Measuring and Specifying Colour. DirectLink CIE 224:2017 Colour Fidelity Index for accurate scientific use DirectLink CIE 15:2004 Colorimetry. DirectLink D. Mozysrska, M. Wyrwas, I. Fryc, The determination of the LEDs colorimetric parameters, in the range of their operating temperature, Przeglad Elektrotechniczny, R. 93, No. 4a, pp. 232-234, (2012). DirectLink J. Kowalska, Analysis of parameters describing the quality of the color rendering of light sources according to the IES TM-30-15 and the CIE 013.3-1995, Przeglad Elektrotechniczny, R. 93, No. 6; pp. 50-54, (2017) 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, No. 7; (2019), pp. 94-97 CrossRef J. Kowalska, Ambiguity and limitations in determining the quality of the color rendering of light sources by index Ra (CIE CRI), Przeglad Elektrotechniczny, R. 93 No. 5, pp. 74-78, (2017) CrossRef I. Fryc, J. Fryc, A. Wasowski, Considerations about determining color rendering of light sources, Przeglad Elektrotechniczny, R. 92 No. 2, pp. 218-223, (2016) CrossRef I. Fryc, LED's spectral power distribution under different condition of operating temperature and driving current, Przeglad Elektrotechniczny, R. 86, No. 10, pp. 187-189, (2010). DirectLink A. David, P. Fini, K. Houser et al., Development of the IES method for evaluating the color rendition of light sources, Optics Express; Vol. 23; Issue 12, pp. 15888-15906, (2015). CrossRef K. Houser, M. Mossman, K. Smet et al, Tutorial, Color Rendering and Its Applications in Lighting, LEUKOS; Vol. 12, Issue 1-2; pp. 7-26; (2016). CrossRef

scholarly journals The effect of led light sources with varied spectral composition on the in vitro rooting bility of garden strawberry (Fragaria × ananassa)

2019 ◽  
Vol 180 (1) ◽  
pp. 33-37 ◽  
Author(s):  
I. A. Byadovsky
Keyword(s):  
Red Light ◽  
Spectral Composition ◽  
Light Flux ◽  
Light Sources ◽  
Fragaria Ananassa ◽  
Fluorescent Lamp ◽  
Led Light ◽  
Rooting Ability ◽  
Strawberry Cultivars

Consideration is given to the possibility of using LED light sources with different ratios of red (650 - 660 nm), orange (600 - 610 nm) and blue (440 - 450 nm) light in the light flux in the rooting stage of garden strawberry (Fragaria×ananassa(Duch. ex Weston) Duch. ex Rozier) grownin vitro. The study covered a sizable diversity of strawberry cultivars (selected from thein vitrocollection): ‘Borovitskaya’, ‘Vityaz’, ‘Zenga Zengana’, ‘Khoney’, ‘Tsaritsa’, ‘Kubata’, ‘Dukat’, ‘Marmalada’, ‘Valenta’, ‘Rusich’, ‘Krasavitsa Zagorya’, ‘Neznakomka’ and ‘Roksana’, thus ensuring quite diversified results. It was established that the use of LED sources with an increased content of red light in the light flux increased the rooting percentage (1.15-1.25 times) and the number of roots per one microcutting (1.29-1.77 times) inin vitroculture, as compared with fluorescent lamp lighting. It was observed that with different spectral compositions of light the rooting ability of microcuttings was cultivar-specific.

Museum lighting with LEDs: Evaluation of lighting damage to contemporary photographic materials

2018 ◽  
Vol 51 (3) ◽  
pp. 417-431 ◽  
Author(s):  
H-W Luo ◽  
C-J Chou ◽  
H-S Chen ◽  
MR Luo
Keyword(s):  
Colour Change ◽  
Light Sources ◽  
Halogen Lamp ◽  
Light Fastness ◽  
Colour Difference ◽  
Damage Potential ◽  
White Leds ◽  
Short And Long Term ◽  
Physical And Chemical

It is possible to assess the damage to artworks by measuring different physical and chemical parameters. One of the most important parameters is colour difference, which is a consequence of chemical changes in the material. CIE 157:2004 ‘Control of Damage to Museum Objects by Optical Radiation’ classifies museum collections into four groups, according to different levels of light fastness. However, these classes were developed from research using traditional light sources. Even though LED technology is becoming more popular, there is no advanced evaluation of colour fading or a colour change test for contemporary artworks. This study established that the CIE 157:2004 method, based on threshold effective radiant exposure, can be applied to an actual ageing test of ultraviolet-blocked light sources including two types of white LEDs and one traditional halogen lamp. The results also present a colour fading model that can be used in museum LED lighting to predict the colour difference in contemporary photographic materials for short- and long-term exhibition. This study also provides a revised light dosage classification of modern photographic materials for museums. Moreover, the verification studies can be used as a conceptual reference for assessing the damage potential of other art materials under the tunable multi-LED system of the future.

Design of Solar-Powered LED Road Lighting System

2019 ◽  
pp. 75-85
Author(s):  
Canan Perdahci ◽  
Hamdi Ozkan
Keyword(s):  
High Pressure ◽  
Renewable Energy Sources ◽  
Junction Temperature ◽  
Mercury Vapour ◽  
Light Sources ◽  
Street Lighting ◽  
Led Light ◽  
Road Lighting ◽  
Lighting Systems ◽  
High Pressure Sodium Lamp

Turkey is rich in terms of renewable energy sources and, therefore, is now encouraging the use of sustainable clean lighting systems in road applications. High pressure sodium lamp is the most widely used type in main roads, but other types of lamps such as mercury vapour lamps or metal halide lamps can be utilized for street lighting. Since it enables energy and money saving, LED light technology has replaced high pressure sodium lamps nowadays. Once solar power system (PV) is integrated with LED lamp for street lighting, the amount of saving and local impact might be enriched. LEDs used as light sources in road lighting luminaires with rising lumen values, decreasing junction temperature, higher colour rendering efficiency, longer lifetime have become more efficient than many light sources with the latest developments. Since the structure of the luminaires in which the LED light sources are used differs from that of the conventional light sources, the optical, thermal and electrical design of the LED luminaires must be considered differently. Thus, this study concentrates upon design considerations and the operating principle of solarpowered LED road lighting luminaire in details. Also, a simple solar panel system was designed and the economical values obtained at the end of 20 years were compared when using the ongrid system and the off-grid system.

scholarly journals Analysis on High-Power Seaport LED Luminaire with Uniform Light Distribution Based on Optimized Lens and Heatsink

2021 ◽  
Vol 11 (9) ◽  
pp. 4035
Author(s):  
Jinsheon Kim ◽  
Jeungmo Kang ◽  
Woojin Jang
Keyword(s):  
Light Source ◽  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Light Distribution ◽  
Light Sources ◽  
Led Light ◽  
High Power Led ◽  
Distribution Requirement ◽  
Lighting Application

In the case of light-emitting diode (LED) seaport luminaires, they should be designed in consideration of glare, average illuminance, and overall uniformity. Although it is possible to implement light distribution through auxiliary devices such as reflectors, it means increasing the weight and size of the luminaire, which reduces the feasibility. Considering the special environment of seaport luminaires, which are installed at a height of 30 m or more, it is necessary to reduce the weight of the device, facilitate replacement, and secure a light source with a long life. In this paper, an optimized lens design was investigated to provide uniform light distribution to meet the requirement in the seaport lighting application. Four types of lens were designed and fabricated to verify the uniform light distribution requirement for the seaport lighting application. Using numerical analysis, we optimized the lens that provides the required minimum overall uniformity for the seaport lighting application. A theoretical analysis for the heatsink structure and shape were conducted to reduce the heat from the high-power LED light sources up to 250 W. As a result of these analyses on the heat dissipation characteristics of the high-power LED light source used in the LED seaport luminaire, the heatsink with hexagonal-shape fins shows the best heat dissipation effect. Finally, a prototype LED seaport luminaire with an optimized lens and heat sink was fabricated and tested in a real seaport environment. The light distribution characteristics of this prototype LED seaport luminaire were compared with a commercial high-pressure sodium luminaire and metal halide luminaire.

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