Open AccessDoubling the optical efficiency of VR systems with a directional backlight and a diffractive deflection film
Author(s) -
Junyu Zou,
Tao Zhan,
EnLin Hsiang,
Xinpeng Du,
Xiaoming Yu,
Kun Li,
ShinTson Wu
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.430920
Subject(s) - backlight , optics , collimated light , fresnel lens , diffraction efficiency , materials science , diffraction , deflection (physics) , computer science , liquid crystal display , lens (geology) , optoelectronics , physics , laser
We demonstrate an approach to double the optical efficiency of virtual reality (VR) systems based on a directional backlight and a diffractive deflection film (DDF). The directional backlight consists of a commercial collimated light-emitting diode (LED) array and a two-layer privacy film, while the DDF is a three-domain Pancharatnam-Berry (PB) phase lens. Such a PB phase lens was fabricated by the zone exposure and spin-coating method. The focal length of each domain is designed according to the imaging optics of the VR system. Our approach works well in both Fresnel and "pancake" VR systems. We also build the corresponding models in LightTools, and the simulation results are in good agreement with experiment. In experiment, we achieved a 2.25x optical efficiency enhancement for both systems, which agrees with the simulation results (2.48x for Fresnel and 2.44x for "pancake" systems) well. Potential application for high efficiency VR displays is foreseeable.