Precision Grinding and Micro Hot Embossing of the Microgroove Lens Array for Light Transmitting and Uniforming

doi:10.3901/JME.2017.12.190

Abstract

Abstract: The thin wall LED lighting needs the screen-printed micro array light guide plate (LGP), but the ink micro-dots array on the surface age easily and the microstructure is difficultly optimized. Therefore, the spatial microgroove lens array with Gauss distribution is designed on LGP surface, and the numerical control micro-grinding technology is adopted to fabricate it for replacing the commercial screen-printed 2D micro circular array. The light transmission efficiency and uniformity of LGP is simulated by using the micro optical principle to optimize the shape, size and distribution of micro lens array. Then, micro lens array is precisely ground on the surface of PMMA LGP, and the light transmission efficiency and uniformity are tested. Finally, the rapid micro hot embossing process is developed by using the micro-ground die core. The micro-optic analyses show that the microgroove lens array increase light transmission efficiency by 6% and 15% compared with the micro square lens array and micro hemisphere lens array, respectively. Further, the variable interval Gauss distribution of microgroove lens array improves the light transmission efficiency by 32% and its uniformity by 73%, compared with the equal interval distribution, respectively. The experimental results show that the micro-grinding technology is able to control the surface quality and shape accuracy of the microgroove lens; the micro-ground LED LGP enhances the light transmission efficiency by 7% and its uniformity by 9% compared with the screen printed LGP. Furthermore, using the 3 s rapid micro hot embossing can fabricate microgroove lens array with variable interval and depth, leading to an increase 26% in illumination and an increase 49% in uniformity. As a result, the space-optimized microgroove lens array can produce higher micro-optics application value than the 2D micro circular array.

Key words: LED illumination, light guide plate, micro hot embossing, micro lens array, micro optics, micro-grinding

CLC Number:

TG580
TB858

HU Manfeng, XIE Jin, LIU Jinan, SI Xianhai. Precision Grinding and Micro Hot Embossing of the Microgroove Lens Array for Light Transmitting and Uniforming[J]. Journal of Mechanical Engineering, 2017, 53(23): 190-196.

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