Optical model of optical volume diffusion plate - BSDF measurement of polycarbonate plate doped with silicon dioxide micro particle

High-efficiency diffusers play important roles in modern optical industry. The applications include back-light of television, uniform lighting, glare suppression, lighting decoration, and so on. In this paper, we develop optical volume diffusion plate using polycarbonate (PC) plate doped with silicon dioxide (SiO2) micro particle. The scattering distribution of diffusers is an important factor in the lighting design. Commercial detectors often measure the bidirectional scattering distribution function (BSDF) by a scanning and time-consuming method. We have proposed screen imaging synthesis (SIS) system in 2012, and it can easily measure the bidirectional transmittance distribution function (BTDF). In this paper, the optimized formula is presented to correct the vignetting effect and scattering effect caused by the screen. A quasi-Lambertian screen is made to enhance precision. Finally, we combine the SIS system with the rotation controller, and a semi-automatic measuring machine is built. The SIS generation can measure BSDF of the samples precisely and easily. In order to reduce glare problems and design a luminaire with uniform light distribution, we usually use diffusers to modulate the luminaire.