Wavelength-Selective Waveguide Architectures for AR Crosstalk Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing virtual and augmented reality systems face challenges in providing comfortable, natural-feeling, and rich presentations of virtual image elements amidst real-world imagery, due to issues like image quality degradation, crosstalk, and color balance problems caused by incoupling and outcoupling optical elements.

Innovation Solution

The implementation of waveguides that incouple and outcouple light with low levels of crosstalk, using architectures that selectively output light of different wavelengths, color filters to limit interacting wavelengths, and multiple waveguides for each range of wavelengths, to enhance image clarity and color accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If incoupling and outcoupling optical elements are used to present virtual image elements, then virtual reality or augmented reality experiences can be achieved, but image quality degradation, crosstalk, and color balance problems occur

Engineering Contradiction:
Improvevirtual reality/augmented reality experience capabilityVSAvoidimage quality
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent divides the optical system into multiple separate waveguides, each dedicated to a specific wavelength range. This segmentation prevents crosstalk between different wavelengths and eliminates the need for complex incoupling/outcoupling elements that cause image quality degradation. Each waveguide independently guides its designated wavelength range from the light source directly to the user's eye.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces wavelength-selective filters as intermediary components that selectively transmit specific wavelength ranges to their corresponding waveguides. These filters act as mediators between the broadband light source and the wavelength-specific waveguides, ensuring that each waveguide receives only its designated wavelengths without interference from other wavelength ranges.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Quantity of substance

If multiple wavelengths of light are outputted through the same waveguide, then color richness is improved, but crosstalk and ghosting increase

Engineering Contradiction:
Improvecolor richnessVSAvoidcrosstalk and ghosting
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent segments the single waveguide into multiple separate waveguides, each dedicated to a specific wavelength range. This physical separation eliminates crosstalk and ghosting effects that occur when multiple wavelengths share the same waveguide, while still maintaining color richness by combining the output from multiple wavelength-specific waveguides.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent assigns different local qualities (wavelength ranges) to different waveguides. Each waveguide is optimized for its specific wavelength range, allowing for better control and management of light properties. This local specialization prevents the harmful interactions that occur when diverse wavelengths are forced through a single waveguide.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If wavelength selective filters are used to limit interacting wavelengths, then color accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvecolor accuracyVSAvoidoptical system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple wavelength-selective filters with their corresponding waveguides into an integrated optical system. Rather than treating filters and waveguides as separate complex components, the design merges them into a unified structure where each filter-waveguide pair operates as a cohesive unit, simplifying the overall system architecture while maintaining high color accuracy.

Inventive Principle:
Principle #5Merging (Combining)

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

This approach reduces ghosting and improves image clarity, increases perceived color quality, and allows for precise control over the proportions of different wavelengths of light, resulting in higher color accuracy and a wider range of colors displayed.

Implementation Method 1

a first waveguide configured to guide light of a first range of wavelengths from a light source to an eye of the user... a second waveguide configured to guide light of a second range of wavelengths from the light source to the eye of the user

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

The display device includes a first dichroic filter configured to transmit a first range of wavelengths and reflect a second range of wavelengths

Methodology Applied
Scientific EffectDichroic filtering: Dichroic Filter

Implementation Method 3

The display device includes an optical element configured to couple light from the light source into the waveguide

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3968085B1Architectures and methods for outputting different wavelength light out of wave guides
Publication Date: 2025.05.14 MAGIC LEAP INC
  • EP3968085B1 patent drawingFigure 1
  • EP3968085B1 patent drawingFigure 2
  • EP3968085B1 patent drawingFigure 3~4

AI summary

Architectures are provided for selectively outputting light for forming images, the light having different wavelengths and being outputted with low levels of crosstalk. In some embodiments, light is incoupled into a waveguide and deflected to propagate in different directions, depending on wavelength. The incoupled light then outcoupled by outcoupling optical elements that outcouple light based on the direction of propagation of the light. In some other embodiments, color filters are between a waveguide and outcoupling elements. The color filters limit the wavelengths of light that interact with and are outcoupled by the outcoupling elements. In yet other embodiments, a different waveguide is provided for each range of wavelengths to be outputted. Incoupling optical elements selectively incouple light of the appropriate range of wavelengths into a corresponding waveguide, from which the light is outcoupled.