Directional light-guide devices with continuously variable spatial frequency sub-micron grating structures for autostereoscopic display applications

摘要

Autostereoscopic displays are a promising three dimensional display technology for its convenience and compatibility with current display systems which has attracted considerable attention. We describe in detail an autostereoscopic display system with full-parallax using a directional light-guide device with continuously variable spatial frequency sub-micron grating structures. The optimization process of parameters of the multi-direction light-guide is given. A method of implementing sub-micron grating pixels (SMGPs) based on an ultraviolet continuously variable spatial frequency photolithography process has been proposed. The process aims to provide low cost fabrication of variable spatial frequency grating pixels with high efficiency. We fabricate 2 inch backlight plate with nine viewing directions, and the pitch of each diffractive pixel varies between 441 ran and 578 nm. The properties of SMGPs are investigated by the measurement of diffraction efficiency dependence on viewing angle under a collimated 650 nm LED light source at an incidence angle of 60°. The variation of diffraction efficiency with regards to viewing angle is weak. The measured diffraction efficiency is around 6%, which is in good agreement with the simulated value.