Light-emitting diodes on curved ceramic substrate with primary optics for modification of luminous intensity

Unlike the conventional light-emitting diode (LED) luminaire with a planar substrate and only the forward emission, the proposed LED luminaire with a curved ceramic substrate can perform both the forward and the backward emissions and inherits the merits of good heat-dissipation and low cost from the ceramic substrate. Assembled with the proper primary optics, an illustrated LED bulb has been designed, fabricated and measured. The measured luminous intensity of the LED bulb has shown the backward emission and designed distribution with the beam-angle of 133 deg. To broaden the application areas, such a LED bulb on a curved substrate has been modularized as a streetlight. The measured results of the proposed streetlight have shown that the beam angle of the luminous intensity and the luminaire efficiency are 132 deg and 86%, respectively. Meanwhile, its luminous characteristics also fit the Chinese standard for lighting design of urban roads.