
Proceedings Paper
Converter film technology for homogeneous white lightFormat | Member Price | Non-Member Price |
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Paper Abstract
An important issue for white ultra high power LEDs is the
generation of a homogeneous light with high efficiency and a
good color rendering index. Different from hot light sources
LEDs do not emit the whole range of visible wavelengths. Only
a certain wavelength with a limited full width at half maximum
is emitted. Therefore a combination of wavelengths must be
used to satisfy the human eye for white light. The CIE
chromaticity diagram (Fig. 1) shows, that several combinations
of wavelengths let the brain realize white light. Already the
combination of two wavelengths (e.g. cyan and red or blue and
yellow) let us think, that the source is white, if this wavelengths
hit our receptors. This is completely different, if the light is
illuminating an object. The reflection spectra of this object,
which is crucial for our color feeling about this object, can not
be stimulated in the whole range. For example a red stop sign,
which is absorbing all wavelength excepting red, will absorb
the blue and yellow light from our "white" light source and due
to the missing red, the sign seems to be dark grey or black.
Paper Details
Date Published: 26 September 2007
PDF: 10 pages
Proc. SPIE 6797, Manufacturing LEDs for Lighting and Displays, 67970L (26 September 2007); doi: 10.1117/12.759437
Published in SPIE Proceedings Vol. 6797:
Manufacturing LEDs for Lighting and Displays
Thomas P. Pearsall, Editor(s)
PDF: 10 pages
Proc. SPIE 6797, Manufacturing LEDs for Lighting and Displays, 67970L (26 September 2007); doi: 10.1117/12.759437
Show Author Affiliations
Rafael C. Jordan, Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration (Germany)
Jörg Bauer, Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration (Germany)
Jörg Bauer, Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration (Germany)
Hermann Oppermann, Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration (Germany)
Published in SPIE Proceedings Vol. 6797:
Manufacturing LEDs for Lighting and Displays
Thomas P. Pearsall, Editor(s)
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