Proceedings Article | 7 September 2016
KEYWORDS: Light emitting diodes, Light sources, Light sources and illumination, Radium, Optical inspection, Agriculture, Semiconductors, Facility engineering, Light, Lithium
Light emitting diode (LED) has been recognized as an applicable light source for indoor and outdoor lighting, city
beautifying, landscape facilities, and municipal engineering etc. Conventional LED has superior characteristics such as
long life time, low power consumption, high contrast, and wide viewing angle. Recently, LED with high color-rendering
index and special spectral characteristics has received more and more attention. This paper is intended to report a solar
spectrum simulated by multichip LED light source. The typical solar spectrum of 5500k released by CIE was simulated
as a reference. Four types of LEDs with different spectral power distributions would be used in the LED light source,
which included a 430nm LED, a 480nm LED, a 500nm LED and a white LED. In order to obtain better simulation
results, the white LED was achieved by a 450nm LED chip with the mixture of phosphor. The phosphor combination
was prepared by mixing green phosphor, yellow phosphor and red phosphor in a certain proportion. The multichip LED
light source could provide a high fidelity spectral match with the typical solar spectrum of 5500k by adjusting injection
current to each device. The luminous flux, CIE chromaticity coordinate x, y, CCT, and Ra were 104.7 lm, 0.3337, 0.3681,
5460K, and 88.6, respectively. Because of high color-rendering index and highly match to the solar spectrum, the
multichip LED light source is a competitive candidate for applications where special spectral is required, such as
colorimetric measurements, visual inspection, gemstone identification and agriculture.
