Optical see-through augmented reality displays with wide field of view and hard-edge occlusion by using paired conical reflectors

Optical see-through head-mounted displays are actively developed in recent years. An appropriate method for mutual occlusion is essential to provide a decent user experience in many application scenarios of augmented reality. However, existing mutual occlusion methods fail to work well with a large field of view (FOV). In this Letter, we propose a double-parabolic-mirror structure that renders hard-edge occlusion within a wide FOV. The parabolic mirror increases the numerical aperture of the system significantly, and the usage of paired parabolic mirrors eliminates most optical aberrations. A liquid crystal on silicon device is introduced as the spatial light modulator for imaging a bright see-through view and rendering sharp occlusion patterns. A loop structure is built to eliminate vertical parallax. The system is designed to obtain a maximum monocular FOV of H114^◦ × V95^◦ with hard-edge occlusion, and a FOV of H83.5^◦ × V53.1^◦ is demonstrated with our bench-top prototype.