Light-efficient augmented reality 3D display using highly transparent retro-reflective screen

Abstract

We propose and demonstrate a light efficient 3D display using a highly transparent desktop-size augmented reality screen. The display consists of a specially designed transparent retro-reflective screen and a pair of low power pico-projectors positioned close to the viewer’s eyes to provide stereo views. The transfer screen is an optically clear sheet partially patterned with retro-reflective microspheres for high optical gain. The retro-reflective material buried in the screen reflect incident light back towards the projectors with narrow scattering angle and facilitates the viewer to perceive a very bright content. The tabletop prototype mainly consists of an in-house fabricated large AR screen (60x40cm2) and a pair of laser scanning 30 lumen pico-projectors. The display is tested for different viewing configurations, different display parameters such as retro-reflective coefficient, eye-box size, polarization maintainability, stereo crosstalk and brightness. The AR prototype display provides 75% optical transparency, exceptional brightness (up to 1000 cd/m2 when viewed through beam-splitters and 350 cd/m2 with bare eyes) and negligible crosstalk in 3D mode (<5% and <1% when viewed through beam-splitters and polarizers respectively) for the working distance of up to 2 meters.