Investigation of expanding the field of view in the near-eye display

The field of view (FOV) has always been a key indicator to measure the quality of the near-eye display (NED) system. How to expand the field of view of the system without reducing other system metrics has always been a key issue in the development of near-eye display systems. In recent years, with the booming development of process technology there have been various schemes for expanding the display field of view of near-eye display systems, including grating partitioning, grating layering, using curved or free-form surfaces optical structure, and others. Each method of expanding the field of view has its applicable conditions, for example grating partitioning and grating layering are suitable for use in a waveguide display system using a grating as a coupled input and output. While the free-form surface component as a light guiding structure not only can be used for the coupled input and output component of the waveguide display system, but also can directly replace the slab waveguide as the main optical path of the near-eye display system. This talk will systematically analyze the technical principles and features of the above methods, and prospect for the future development of each method. In addition, some near-eye display systems with large fields of view will be presented as examples to more fully demonstrate the technical principle and features. Furthermore, analysis and outlook across the NED system is included.