Transparent Eye Illumination Layer for Compact AR Glint Tracking

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Solution Overview

Problem

Existing augmented reality (AR) technologies face challenges in providing a comfortable and natural-feeling presentation of virtual image elements amidst real-world imagery, and there is a demand to reduce the size of display systems, including components like polarizing beam splitters.

Innovation Solution

A head-mounted display system with a frame, image projector, waveguide, coupling and out-coupling optical elements, and a camera is designed to project and capture light to and from the eye, enabling augmented reality image content display while imaging the environment, using components like cholesteric liquid crystal diffraction gratings and polarization selective elements to enhance image projection and capture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If polarizing beam splitters are used in display systems to direct polarized light, then image projection capability is improved, but system size increases

Engineering Contradiction:

Improveimage projection capabilityVSAvoidsystem size

Core Design Contradiction:

Illumination intensityVSVolume of moving object

Solution Approach 1:

The patent extracts the polarizing beam splitter component from the display system and replaces it with a waveguide-based optical system. This removal of the bulky beam splitter while maintaining the light directing function through waveguide total internal reflection directly resolves the contradiction between image projection capability and system size.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical polarizing beam splitter system with an optical waveguide system that uses total internal reflection and diffractive optical elements. This substitution eliminates the need for large mechanical components while achieving the same light manipulation functions, thereby reducing system size while maintaining projection capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If virtual image elements are presented without transparency to real-world visual input, then virtual image clarity is improved, but natural feeling and comfort deteriorate

Engineering Contradiction:

Improvevirtual image clarityVSAvoidnatural feeling and comfort

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The waveguide system serves multiple functions simultaneously: it guides virtual image light to the user's eye while also allowing real-world visual input to pass through transparently. This multi-functionality enables both clear virtual images and natural real-world viewing to coexist, resolving the contradiction between image clarity and comfort.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The waveguide acts as an intermediary optical element that separates and manages different light paths - directing virtual image light through total internal reflection while allowing real-world light to pass through transparently. This intermediary structure enables both functions to operate simultaneously without interfering with each other, achieving both clarity and natural feeling.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Volume of moving object

If the display system size is reduced, then portability and wearability are improved, but image projection quality may deteriorate

Engineering Contradiction:

Improvesystem sizeVSAvoidimage projection quality

Core Design Contradiction:

Volume of moving objectVSIllumination intensity

Solution Approach 1:

The patent employs thin film waveguide structures and diffractive optical elements that can be integrated into compact head-mounted display form factors. These thin optical components maintain effective light manipulation and image projection quality while enabling significant size reduction for portability and wearability.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The waveguide system redirects light propagation into different spatial dimensions through total internal reflection and diffractive elements, allowing compact optical path folding. This dimensional manipulation enables maintaining image projection quality in a reduced physical footprint, resolving the contradiction between size and quality.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system provides a more realistic and comfortable AR experience by aligning accommodation and vergence, reducing system size, and improving image projection and capture efficiency.

Implementation Method 1

at least one waveguide... configured such that light is coupled into said waveguide and guided therein

Methodology Applied

Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

cholesteric liquid crystal diffraction gratings

Methodology Applied

Scientific EffectDiffraction: Diffraction

Implementation Method 3

polarization selective elements to enhance image projection and capture

Methodology Applied

Scientific EffectPolarization: Polarisation

Data Source

PatentUS20260072280A1System for providing illumination of the eye

Publication Date: 2026.03.12 MAGIC LEAP INC

AI summary

A thin transparent layer can be integrated in a head mounted display device and disposed in front of the eye of a wearer. The thin transparent layer may be configured to output light such that light is directed onto the eye to create reflections therefrom that can be used, for example, for glint based tracking. The thin transparent layer can be configured to reduced obstructions in the field of the view of the user.