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Proceedings Paper

Quadrichromatic white solid state lamp with digital feedback
Author(s): Arturas Zukauskas; Rimantas Vaicekauskas; Felikas Ivanauskas; Genadij Kurilcik; Zenius Bliznikas; Kestutis Breive; Jevgenij Krupic; Andrius Rupsys; Algirdas Novickovas; Pranciskus Vitta; Alvydas Navickas; Vytautas Raskauskas; Michael S. Shur; Remis Gaska
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Paper Abstract

White light with high color rendering indices can be produced by additive color mixing of emissions from several light-emitting diodes (LEDs) having different primary colors. White Versatile Solid-State Lamps (VSSLs) with variable color temperature, constant-chromaticity dimming, and efficiency/color-rendering trade-off can be developed using pulse-width modulation (PWM) driving technique. However, such lamps exhibit chromaticity shifts caused by different temperature and aging coefficients of the optical output for primary LEDs of different colors. To overcome this drawback, we developed a polychromatic white solid-state lamp with an internal digital feedback. The lamp features a quadrichromatic (red-amber-green-blue) design based on commercially available high-power LEDs. The design is optimized to achieve high values of the general color rendering index (69 to 79 points) in the color-temperature range of 2856 to 6504 K. A computer-controlled driving circuit contains a pulse-width modulator and a photodiode-based meter. The software performs periodical measurement of the radiant flux from primary LEDs of each color and adjusts the widths of the driving pulses. These VSSLs with feedback found application in phototherapy of seasonal affective disorder (SAD).

Paper Details

Date Published: 26 January 2004
PDF: 14 pages
Proc. SPIE 5187, Third International Conference on Solid State Lighting, (26 January 2004); doi: 10.1117/12.514079
Show Author Affiliations
Arturas Zukauskas, Vilnius Univ. (Lithuania)
Rimantas Vaicekauskas, Vilnius Univ. (Lithuania)
Felikas Ivanauskas, Vilnius Univ. (Lithuania)
Genadij Kurilcik, Vilnius Univ. (Lithuania)
Zenius Bliznikas, Vilnius Univ. (Lithuania)
Kestutis Breive, Vilnius Univ. (Lithuania)
Jevgenij Krupic, Vilnius Univ. (Lithuania)
Andrius Rupsys, Vilnius Univ. (Lithuania)
Algirdas Novickovas, Vilnius Univ. (Lithuania)
Pranciskus Vitta, Vilnius Univ. (Lithuania)
Alvydas Navickas, Vilnius Univ. (Lithuania)
Vytautas Raskauskas, Vilnius Univ. (Lithuania)
Michael S. Shur, Rensselaer Polytechnic Institute (United States)
Remis Gaska, Sensor Electronic Technology, Inc. (United States)

Published in SPIE Proceedings Vol. 5187:
Third International Conference on Solid State Lighting
Ian T. Ferguson; Nadarajah Narendran; Steven P. DenBaars; John C. Carrano, Editor(s)

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