Flat Lens AR/VR Glasses Polarization Design for Higher Transparency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional near-eye displays face challenges in achieving a small form factor, large field-of-view, and large eye box while maintaining transparency and efficiency, particularly due to the use of circular polarizers that attenuate non-uniformly polarized light, leading to tint and reduced light transmission.
Innovation Solution
The use of an anisotropic material, such as a waveplate, to convert non-uniformly polarized light from a waveguide into circularly-polarized light without a linear polarizer, combined with Pancharatnam-Berry Phase (PBP) lenses, to enhance transparency and efficiency by minimizing light attenuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional circular polarizers are used to polarize light in near-eye displays, then the desired polarization effect is achieved, but light transmission is attenuated non-uniformly causing tint and reduced efficiency
Solution Approach 1:
The patent changes the polarization method from conventional linear polarizers to geometric phase elements (metasurfaces) that manipulate light phase. This parameter change in the polarization mechanism eliminates non-uniform attenuation and tint while maintaining efficient light transmission through the waveguide display system.
Solution Approach 2:
The patent replaces the mechanical/optical system of linear polarizers with a geometric phase-based metasurface system. This substitution uses phase modulation rather than amplitude filtering, eliminating the harmful tint effect while preserving light transmission efficiency.
2Illumination intensity
If conventional VR magnifier optics are used to achieve large field-of-view, then FOV is improved, but the form factor becomes large and weight increases
Solution Approach 1:
The patent extracts and removes the bulky magnifier optics from the display system by implementing the imaging function directly within the waveguide using geometric phase elements. This extraction eliminates unnecessary components, reducing both weight and form factor while maintaining large field-of-view capability.
Solution Approach 2:
The geometric phase elements in the waveguide perform multiple functions simultaneously: they provide field-of-view expansion, focus light, and enable compact integration. This multi-functionality replaces multiple separate optical components, reducing overall system weight and size.
3Illumination intensity
If conventional VR magnifier optics are used to achieve large field-of-view, then FOV is improved, but the form factor becomes large
Solution Approach 1:
The patent extracts and removes the bulky magnifier optics from the display system by implementing the imaging function directly within the waveguide using geometric phase elements. This extraction eliminates unnecessary components, reducing both weight and form factor while maintaining large field-of-view capability.
Solution Approach 2:
The geometric phase elements are nested within the waveguide structure, with the waveguide serving as both the light transmission medium and the imaging element. This nesting eliminates the need for separate external optics, dramatically reducing the overall display volume while maintaining large field-of-view.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
An artificial-reality display uses an anisotropic material to circularly-polarize light exiting a waveguide so that the artificial-reality display is relatively transparent.