Open AccessColor temperature tunable white light emitting diodes packaged with an omni-directional reflector
Author(s) -
Jung-Chieh Su,
Chun-Lin Lu
Publication year - 2009
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.17.021408
Subject(s) - color rendering index , optics , color temperature , materials science , optoelectronics , light emitting diode , reflector (photography) , phosphor , diode , white light , high color , distributed bragg reflector , light source , wavelength , physics , computer science , image processing , color image , artificial intelligence , image (mathematics)
This study proposed a correlated color temperature (CCT) tunable phosphor-converted white light emitting diode (LED) with an omni-directional reflector (ODR). Applying current to each individual InGaN based ultraviolet, purple and blue source LED chip of the white LED package, we can achieve the CCT tunability. The optimum color properties of the resulting white light are (0.3347, 0.3384), 5398 K, 81, 3137-8746 K for color coordinates, CCT, color rendering index (CRI) and CCT tuning range, respectively. Roughening the ODR substrate, we solve the non-uniformity color distribution caused by the reflectance of the ODR and positioning of source LED chips.