Pupil-Adaptive Retina Projection Augment Reality Displays With Switchable Ultra-Dense Viewpoints

Area of Science:

• Optics and Photonics
• Augmented Reality Displays
• Liquid Crystal Devices

Background:

• Retina projection displays (RPDs) in augmented reality (AR) offer a long depth of field (DOF) to address vergence-accommodation conflict (VAC).
• Existing fixed multi-viewpoint RPDs suffer from image overlap or discontinuity due to eye rotation and ambient light variations.

Purpose of the Study:

• To develop an RPD AR system with switchable ultra-dense viewpoints to overcome limitations of fixed systems.
• To eliminate image discontinuity and improve visual clarity in AR applications.

Main Methods:

• Utilized a photo-alignment liquid crystal Dammann grating (p-LCDG) to create switchable ultra-dense viewpoints.
• Implemented a light selector for precise control over viewpoint illumination.
• Integrated eye tracking technology for seamless viewpoint switching.

Main Results:

• Achieved 49 switchable viewpoints with high rotation precision (1.28°/viewpoint) over a 36 mm² range.
• Demonstrated viewpoint spacing (0.532 mm) smaller than the minimum pupil radius (≈1 mm).
• Effectively eliminated image missing or discontinuity through controlled viewpoint selection.

Conclusions:

• The proposed RPD AR system with switchable ultra-dense viewpoints effectively resolves image discontinuity issues.
• This technology enables high-performance RPDs for advanced augmented reality applications.
• The p-LCDG based approach offers precise control and a seamless visual experience.