See-through aerial imaging display with eyebox control optical system

We propose what we believe to be a novel non-mechanical eyebox (EB) control optical system for aerial imaging by retro-reflection (AIRR) integrated with virtual reality (VR) head-mounted display (HMD) optics, eliminating the need for the user to wear an HMD. This technology enhances the user's positional freedom. To demonstrate the concept, we employ a Pancharatnam Berry phase diffraction grating (PBP-DG) as a one-dimensional (1D) EB position-shifting device and fabricate a demonstrator. Experimental results confirm that the demonstrator successfully shifts the EB approximately 8 mm in the horizontal direction using a PBP-DG located 30 mm away from the VR HMD optics. Furthermore, we confirm that the virtual image distance can be varied depending on the distance between the display and the VR HMD optics.