Polarization-Preserving Light Guide Plate for a Linearly Polarized Backlight
Abbreviated Journal Title
J. Disp. Technol.
Light guide plate; liquid crystal display (LCD); LCD BACKLIGHT; DISPLAYS; CONVERTER; DESIGN; Engineering, Electrical & Electronic; Optics; Physics, Applied
We analyze the polarization-preserving property of two conventional edge-lit light guide plates (LGPs) based on scattering dots and refractive microgrooves and find that these two structures almost completely depolarize the incident linearly polarized light. We then propose a new edge-lit LGP based on total internal reflection (TIR). Simulation results show that such a TIR-based LGP can largely preserve the polarization state of the incident linearly polarized light. The polarization efficiency is 77.2%. By incorporating a linearly polarized LED to our proposed LGP, the overall optical gain is 1.54 compared with the backlight system with an unpolarized LED. At on-axis, the luminance is higher. Because the output light is concentrated near the surface normal direction, no additional brightness enhancement film is needed. This polarization-preserving LGP enables a polarized or partially polarized LED backlight to be used, which in turn greatly enhances the optical efficiency of a LCD.
Journal of Display Technology
"Polarization-Preserving Light Guide Plate for a Linearly Polarized Backlight" (2014). Faculty Bibliography 2010s. 5742.