레이저 가공 산란패턴의 유형에 따른 도광판의 휘도 및 균일도 향상에 관한 연구

Abstract

The researched on a light guide panel have been conducted consistently by industrial manufacturers until now, but the systemic approach on development of the light guide panel was not provided due to the development for the sake of mass production. Since the performance of the light guide panel are highly sensitive to allowable tolerance in fabrication process, restriction on the rigorous study of the dependency on various variables was given. As an alternative to improvement of the performance of the light guide panel, luminance variation by the control of distribution of inner scatterers was proposed, where the scatterers were implemented in the light guide panel by using three-dimensional laser processing system. In this study, the most critical relationship between luminance and the inner scatterers' pattern was analyzed according to the designed patterns. The luminance by the scatterers' pattern in the light guide panel was not uniform and mainly concentrated on the part of light entrance. To overcome this problem, the scatterer's patterns, which was fabricated with a CO2 laser during short processing time, were designed for improving luminance and uniformity. The increase of processing depth in the light guide panel during the fabrication was proposed, which would result in enhancement of light extraction efficiency at end of the light guide panel. In this study, performance of the light guide panel was simulated with changing inter distance between scatterers and processing depth. From the results, designed patterns was implemented and the luminance and uniformity was measured. The core technology in the fabrication was to guarantee the uniform brightness. From the simulation results, it is conformed that adjustment of processing depth was necessary to induce uniform light extraction. The results obtained from simulated light guide panel having corrected processing depths were used for the fabrication. The measured average luminance and uniformity was improved by 8 times and 2.5 times than that of the light guide panel having inner scatterer patterns. The detailed control of processing conditions offered 15 times and 5 times at the same time. The utilization of optimized processing conditions such as the processing depth and the inter-distances in the scatterer pattern for product manufacture could provide short processing time and maximized luminance. Reduction of time consuming in designing scatterer pattern is possible and overall duration from design to evaluation of fabricated product could shorten effectively. In addition, the use of simulated conditions in the implementation could decrease loss in light intensity and improve the performance of the light extraction.