Wide Field Of View Hoe-Based Waveguides System For Ar Display

Augmented reality (AR) systems are of huge interest for last decade since they are predicted to be the next generation of mobile devices for consumers. One of the key parameters in terms of AR systems properties is the field of view. The best performance in this regard is shown by DOE/HOE-based planar-waveguides systems since they can provide the widest field of view among other approaches even with the simplest architecture. However it is still not wide enough for consumers, so more complex architectures are created. In this work, a novel approach for reaching wide field of view is proposed. It is based on the eyebox magnification in two directions by two different waveguides systems. The first system provides magnification along the axis with wider field of view and consists of waveguides inclined along the field of view central beam with HOE-based 1D gratings, providing the TIR diffraction in both +1 and -1 orders. The TIR condition in this case is reached more easily because of inclination, so the wider angular spectrum can be transferred. The second system provides magnification along the axis with narrower field of view and consists of conventional HOE-based periscope system with in-coupling and out-coupling zones. The system working principle, HOEs specifications, main advantages, challenges and solutions are discussed. The proposed system allow 60-degrees diagonal field of view for the white (RGB) color.