| dc.description.abstract | White LED is getting popular in the market due to its enhanced optical efficiency which highlighted features like energy-efficiency, environmental friendliness, long lifetime, and low maintenance, it has been booming by gradually replaced traditional light bulb. However, LED has higher luminous intensity comparing with traditional light bulb, LED has some shortcomings. for example, higher luminance and glare caused eye discomfort, in order to improve higher luminance and glare, it requests second optics such as reflector and lens. Nevertheless, the non-uniformity of illumination and focus still need to be improved.
In this study, present three pieces of high power LED module as light sources for desk lamp as a research model. Investigation on the use of second optical lens to enhance the efficiency and uniformity of lighting needs. Simultaneously, in the workable of injection molding process plastics(polycarbonate), added a hBN powder for cooling capacity study.
Part of the optical performance, we utilizing simulated (optics simulation software) and second optical lens fallow by reading condition: the height to desk 400 mm and illumination area 600×400 mm, to design lenses achieve the parameter in both of uniformity and sufficient intensity. The optics simulation software shows, 90 ° × 60 ° of non-symmetric lens have sufficient intensity and light uniformity. Compared with the non-optical lens, average light intensity from 304.0 lux increased to 514.1 lux, light uniformity increased from 58.36% to 78.21%. Compared with the lens prototype, average light intensity from 304.0 lux increased to 389.3 lux, light uniformity increased from 55.71% to 81.16%. Clearly indicated the non-symmetric lens used in LED can effectively improve intensity and light uniformity.
Finally, hBN and PC materials have been successfully fabricated a hBN /PC composite. In the thermal performance testing, compared to pure PC material, the temperature drop from the 60.6 ℃ to 53.7 ℃.This thermal conductivity hBN /PC composite can be used on injection molding process for complex shapes and thermal module.
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