| Title |
Study of the Optical System Design for Omni-Directional LED Bulb Satisfying Energy Star’s Light Bulbs Specification) |
| Authors |
Jae-Hyeon Jang ; Kwang-Il Park ; Jong-Tae Kim ; Young Moon Yu |
| DOI |
http://dx.doi.org/10.5207/JIEIE.2017.31.8.058 |
| Keywords |
LED ; Bulb ; Diffuser ; Energy Star ; Cover Shape |
| Abstract |
In this paper, Omni-directional LED bulb satisfying Energy Star’s Light Distribution Standard has been studied by optimal optical system design. The LightTools S/W was used for the optical design. The prototype of bulb was manufactured according to the optimized design and evaluated its optical properties.The COB (Chip on board) type LED package was used as light source. Firstly, the shape of bulb covers based on the spherical, elliptical and cylindrical shape were analyzed by simulating light distribution. The optimal shape of the bulb cover suitable for the light distribution standard was tested and determined by adjusting the height and curvature of each shape. Secondly, three kinds of bulb cover materials with 90%, 66%, and 52% of transmittance were prepared and measured for each scattering distribution characteristics, respectively. Thirdly, the measured scattering distribution data of each cover material was applied to the optimal bulb cover shape, the light distribution simulation of Omni-directional lamp was executed, and then the results were compared to the Energy Star light distribution standard. It was found that the optimal bulb cover shape with a high concentration of diffusing agent of 52% of transmittance satisfied the requirement of Energy Star standard. aBased on the simulation and analysis results, a prototype of Omni-directional LED bulb with the optimal shape and the cover material of 52% of transmittance was manufactured and measured the optical uniformity and back light distribution. Finally it was proved that the prototype satisfied the requirement of Energy Star light distribution standard. |