The Illumination Uniformity Study of Diffuser Plates for Reflective LED Desk Lighting

This paper presents the illumination uniformity study on the reading area for a well-designed reflective LED desk light lamp by placing diffuser plate with optical simulation technique. The investigation for the performance of intensity and uniformity was performed and discussed by changing various types of diffuser plate with and without microstructures to reflect and spread light, including pyramid, sphere and cylinder. Due to the development of microstructures on diffuser plate, the light intensity distribution was uniformed on the reading area. In addition, the diffusion and spreading effect from a rough surface with round-corner shape microstructures was better than that with tapering corner microstructures. The illumination uniformity was strongly influenced by the shape of microstructure on reflective diffuser plate. The optimal design with cylinder-shape microstructure and without gaps between each element had better performance in this study; the illumination uniformity was increased from 8 % to 57 % and the enhancement was 86 %.