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Proceedings Paper

White LEDs for solid state lighting
Author(s): Isamu Niki; Yukio Narukawa; Daisuke Morita; Shin-ya Sonobe; Tomotsugu Mitani; Hiroto Tamaki; Yoshinori Murazaki; Motokazu Yamada; Takashi Mukai
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Paper Abstract

We show recent results of GaN based LEDs, the high efficiency blue LED, the high efficacy white LED, the high color rendering LED, the warm white LED, and the high output power 365-nm UV LED. The output power and the external efficiency of the high efficiency blue LED at 20 mA were 19.3 mW and 35.8%, respectively. Moreover, the lifetime of the molded this lamp was improved. For the high efficacy white LED using this high efficiency blue LED, the correlated color temperature (CCT) and the luminous efficacy (ηL) at 20 mA were 5470 K and 61.4 lm/W, respectively. This luminous efficacy is close to that of a fluorescent lamp. When the high color rendering LED using new red phosphor and shorter-YAG was operated at 20 mA, the CCT, ηL and the general color rendering index (Ra) were 4670 K, 28.3 lm/W and 87.7, respectively. In particular, the red color reproduction was improved. For the warm white, the CCT, ηL and Ra at 20 mA were 2830 K, 18.9 lm/W and 87.5, respectively. It can be used as a replacement for incandescent bulbs. When the high output power 365-nm UV LED was operated at a forward bias direct current (DC) of 500 mA, Po and ηex were 210 mW and 12.4%, respectively.

Paper Details

Date Published: 26 January 2004
PDF: 9 pages
Proc. SPIE 5187, Third International Conference on Solid State Lighting, (26 January 2004); doi: 10.1117/12.514069
Show Author Affiliations
Isamu Niki, Nichia Corp. (Japan)
Yukio Narukawa, Nichia Corp. (Japan)
Daisuke Morita, Nichia Corp. (Japan)
Shin-ya Sonobe, Nichia Corp. (Japan)
Tomotsugu Mitani, Nichia Corp. (Japan)
Hiroto Tamaki, Nichia Corp. (Japan)
Yoshinori Murazaki, Nichia Corp. (Japan)
Motokazu Yamada, Nichia Corp. (Japan)
Takashi Mukai, Nichia Corp. (Japan)


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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