AR Waveguide Zero-Order Recycling for Thin, Wide-View Displays

Solution Overview

Problem

Existing waveguides in augmented reality devices face challenges in achieving high light transmission efficiency while maintaining a thin thickness and wide viewing angle, with current input-coupling methods either limiting the viewing angle or reducing light transmission efficiency.

Innovation Solution

A waveguide design incorporating an input-coupling element that diffracts and reflects zero-order diffraction light multiple times within the waveguide body, utilizing reflective elements to enhance light propagation and reduce loss, and optionally employing multiple layers with varying lattice characteristics to optimize light input and output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If freeform reflection or multimirror reflection is used to input light into the waveguide, then the waveguide structure is simple and light transmission efficiency is high, but the viewing angle is limited and the waveguide cannot be made thin

Engineering Contradiction:

Improvelight transmission efficiencyVSAvoidwaveguide thickness

Core Design Contradiction:

Loss of energyVSLength of moving object

Solution Approach 1:

The input-coupling element is divided into multiple regions with different lattice structures (first lattice structure for first-order diffraction, second lattice structure for zero-order diffraction). This segmentation allows different portions of light to be directed through different paths, enabling both thin waveguide design and wide viewing angle while maintaining high light transmission efficiency.

Inventive Principle:

Principle #1Segmentation

2Loss of energy

If freeform reflection or multimirror reflection is used to input light into the waveguide, then the waveguide structure is simple and light transmission efficiency is high, but the viewing angle is limited

Engineering Contradiction:

Improvelight transmission efficiencyVSAvoidviewing angle

Core Design Contradiction:

Loss of energyVSAdaptability or versatility

Solution Approach 1:

The input-coupling element is divided into multiple regions with different lattice structures (first lattice structure for first-order diffraction, second lattice structure for zero-order diffraction). This segmentation allows different portions of light to be directed through different paths, enabling both thin waveguide design and wide viewing angle while maintaining high light transmission efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent utilizes the zero-order diffraction path in addition to the first-order diffraction path, adding another dimension to light input. This allows light to enter the waveguide through multiple mechanisms simultaneously, expanding the viewing angle while maintaining high light transmission efficiency.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Length of moving object

If an input-coupling diffractive element is used to input light into the waveguide, then the waveguide can be made thin, but only first-order diffracted light is used which causes low light transmission efficiency

Engineering Contradiction:

Improvewaveguide thicknessVSAvoidlight transmission efficiency

Core Design Contradiction:

Length of moving objectVSLoss of energy

Solution Approach 1:

The input-coupling element is divided into multiple regions with different lattice structures (first lattice structure for first-order diffraction, second lattice structure for zero-order diffraction). This segmentation allows different portions of light to be directed through different paths, enabling both thin waveguide design and wide viewing angle while maintaining high light transmission efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent utilizes the zero-order diffraction path in addition to the first-order diffraction path, adding another dimension to light input. This allows light to enter the waveguide through multiple mechanisms simultaneously, expanding the viewing angle while maintaining high light transmission efficiency.

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 design reduces light loss and enhances system efficiency, allowing for a thinner, lighter augmented reality device with improved viewing angles and image quality.

Implementation Method 1

an input-coupling element inputting one portion of the light into the waveguide body

Methodology Applied

Scientific EffectDiffraction: Diffraction

Implementation Method 2

a reflective element disposed at the second side of the waveguide body and again inputting another portion of the light into the waveguide body

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS12372708B2Waveguide and augmented reality device employing the same

Publication Date: 2025.07.29 SAMSUNG ELECTRONICS CO LTD

AI summary

A waveguide and an augmented reality (AR) device employing the waveguide are disclosed. The waveguide includes a waveguide body, an input-coupling element inputting a light into the waveguide body, a reflective element disposed at one side of the waveguide body and again inputting a light that is not input into the waveguide body or is transmitted through the waveguide body into the waveguide body, and an output-coupling element outputting a light propagating inside the waveguide body to an outside.