Optical characterization and manufacturing of an optical plate for increasing light efficiency of LED systems

The use of an optical plate to enhance light efficiency of LED systems was suggested. The optical plate technology indicates that polymeric optical plates having optical patterns on themselves are placed on LED systems. We designed and manufactured an optical plate that enhance light efficiency, and verified its optical characteristics in this study. The shape and the size of the spherical lens patterns were designed based on the lens formula including the refraction indices of air and PMMA, thickness of the optical component and the optical distance. To manufacture the optical plate having the designed spherical lens patterns, a metal mold was machined by ultra-fine punching machining technology. Using the ultra-fine punching machining system, spherical lens patterns with 0.45 mm in height, 1.15 mm in diameter were successfully machined on the top of a mold of 90 * 60 mm2 size. Using the machined mold and transparent PMMA, an optical plate with the spherical lens patterns was molded by injection molding technology. The optical plate was placed on the LED system, and the luminance was measured with and without the optical plate, and as a result the average and the maximum intensity increased by 1.4 times and 1.3 times respectively.