Color temperature tunable white light emitting diodes packaged with an omni-directional reflector.
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.
Su
Jung-Chieh
JC
Department of Electronic Engineering, Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan. jsu@mail.ntust.edu.tw
Lu
Chun-Lin
CL