| Summary: | 碩士 === 國立交通大學 === 工學院精密與自動化工程學程 === 101 === The common LED lamps presented in the commercial retailers generally emitter the ray in the 180 degree range. The light distribution is produced from that LEDs with planar emitting characteristic are placed inside a semi-sphere cover. This distributional angle that is less than 180 degree can not meet the standard of an omni-directional lamp of Energy Star specification .In order to improve the light distribution of the previous mentioned LED lamps, this thesis proposed using a secondary optics lens, total internal reflection (TIR) lens, to change LED light distribution. Throughout the technique of TIR lens, light can be guided forward specific directions that can meet Energy Star specification. This thesis began with the current state of development of the LED lamp. Then we searched relative lens patents about large angle applications. Compared with these patents, we proposed a specific TIR lens profile different from the searched patents. Based the TIR lens profile, we revised the TIR lens profile by optics simulation analysis until the light distribution met the standard of omni-directional lamp. The designed model was sent to a CNC factory to manufacture a plastic mock-up sample. We assembled the mock-up lens and the other parts for a LED lamp. The LED lamp was measured by a goniophotometer device. The measured result of the far-filed light distribution is approximate to the standard of omni-directional lamp. The active beam angle reaches 280 degree. The lumen between 135 and 180 degree is more than 6 percent of the total lumen. The measured points between 135 and -135 degree are more than half that satisfy the required uniformity of the standard of omni-directional lamp. The others are slight out of the range of standard. The difference between simulation result and measured one is close. Compared with the LED lamp presented in commercial retailers, the LED lamp designed in the thesis has the advantage of larger beam angle that can light the area below a LED lamp.
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