Design and Fabrication of a Light Emitting Diode-Based Diffuser Sheet-less Light Guide Plate for Lighting Applications

This paper presents the design and fabrication of a light emitting diode-based light guide plate to realize the diffuser sheet-less applications for an indoor lighting. The diffuser sheet has been used for distributing the luminous intensity in uniform over the target n area, but it leads to light loss and production cost. Here, a diffuser sheet-less LGP with high luminous efficiency and high spatial uniformity was designed by a Monte-Carlo ray tracing method and fabricated by an ultraprecision machining. Simulation results showed that the U-groove LGP has great potential to get rid of the diffuser sheet: efficiency of 70.5% (lm/lm) and uniform luminous intensity distribution of 145 at a viewing angle (C = 0) and 120 at a viewing angle (C = 90), respectively From the measurement results, it agreed with the simulation results. Thus, it was confirmed that the proposed LGP shows a good performance in terms of efficiency and a wide luminous intensity distribution, and a possibility to substitute for a diffuser-based illumination system.