Improving the optical performance of multi-chip LEDs by using patterned phosphor configurations.

In order to improve the color uniformity of multi-chip LEDs, a patterned phosphor configuration has been proposed by using pulsing spray process. The patterned phosphor has detached yellow and red phosphor regions matching every single LED chip. Optical performances of different phosphor parameters are experimentally investigated. The results show that the yellow central coating (YCC) configuration produces outstanding performance not only in chromatic uniformity but also in luminous. In comparison with the conventional phosphor coating, the YCC patterned phosphor LED can improve the luminous flux by 20.6%, and decrease the difference of the correlated color temperature (CCT) distribution from 1362K to 489K. We believe that the patterned phosphor configuration can be used for improving optical properties of multi-chip LEDs.