Extending eyebox with tunable viewpoints for see-through near-eye display

Area of Science:

• Optics and Photonics
• Display Technology
• Human-Computer Interaction

Background:

• Maxwellian displays offer always-in-focus imaging, crucial for alleviating the vergence-accommodation conflict (VAC) in near-eye displays (NEDs).
• A significant limitation of traditional Maxwellian displays is their small eyebox, restricting their practical applications.
• Expanding the eyebox is essential for improving user experience and enabling wider adoption of NEDs.

Purpose of the Study:

• To propose and demonstrate a novel Maxwellian see-through NED with an extended eyebox.
• To address the limitations of conventional Maxwellian displays by enhancing the eyebox size and adaptability.
• To maintain always-in-focus imaging while improving the field of view and eye relief.

Main Methods:

• Utilized a multiplexed holographic optical element (HOE) for viewpoint multiplication.
• Incorporated polarization gratings (PGs) to redirect multiple viewpoints.
• Implemented a mechanical tuning mechanism for PGs to adjust viewpoint positions relative to the eye pupil.

Main Results:

• Achieved an always-in-focus display system with a 12 mm horizontal eyebox.
• Demonstrated a 32.7° diagonal field of view (FOV) and 16.5 mm eye relief (ERF).
• Confirmed tunable viewpoints capable of matching the actual eye pupil size.

Conclusions:

• The proposed Maxwellian see-through NED effectively extends the eyebox using HOEs and PGs.
• The system offers competitive performance regarding eyebox size, adaptability, and focus cues over a large depth range.
• This approach presents a viable solution for enhancing the usability of Maxwellian NEDs for augmented reality applications.