Waveguide Combiner Camera Layout for AR Registration Accuracy

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Solution Overview

Problem

Existing virtual reality (VR), mixed reality (MR), and augmented reality (AR) display systems face challenges in accurately registering virtual objects with real-world objects due to uncertainties in display angle and position, leading to errors in projected boresight and parallax, particularly in applications where mechanical registration is not feasible or desirable.

Innovation Solution

The use of optical waveguide combiners with multiple cameras optically coupled to the output coupler, allowing for electronic self-calibration and registration of virtual objects with real objects through image stitching and fiducial alignment, eliminating the need for mechanical registration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If mechanical registration is used to align virtual objects with real objects, then registration accuracy is improved, but device complexity and mechanical constraints increase

Engineering Contradiction:
Improveregistration accuracyVSAvoidmechanical registration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical registration systems with an optical-capture-based electronic alignment system. Multiple cameras capture images of real objects, and virtual objects are aligned with these captured images through computational methods, eliminating the need for mechanical registration components and their associated complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system creates captured images (copies) of real objects using multiple cameras, and then aligns virtual objects with these image copies. This allows registration to be performed in the digital/image domain rather than requiring direct mechanical alignment in physical space

Inventive Principle:
Principle #26Copying

2Measurement precision

If mechanical registration is used to ensure alignment, then registration accuracy is improved, but ease of operation deteriorates due to mechanical constraints

Engineering Contradiction:
Improveregistration accuracyVSAvoidoperational flexibility
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

By replacing mechanical registration with electronic image-based alignment, the system removes physical constraints and mechanical linkages that limited operational flexibility. The cameras and computational system can adapt to various positions and configurations without mechanical coupling

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If multiple cameras with overlapping fields of view are used, then device complexity increases, but registration accuracy and field of view coverage are improved

Engineering Contradiction:
Improveregistration accuracyVSAvoidcamera system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system divides the overall field of view into multiple overlapping regions, each captured by a separate camera. This segmentation allows each camera to focus on a specific area with high precision, while the overlap regions provide common reference points for accurate registration across the entire scene

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent combines images from multiple cameras through image stitching and merging processes. The overlapping fields of view are integrated to create a comprehensive aligned view, where the combination of multiple perspectives improves overall registration accuracy despite increased system complexity

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

Enables accurate registration of virtual objects with real objects, improving the precision of AR and VR displays by electronically correcting misalignments and ensuring proper alignment without mechanical constraints.

Implementation Method 1

an optical waveguide combiner comprising a waveguide optical substrate, an optical input coupler on, in or adjacent the waveguide optical substrate; and an optical output coupler on or in the waveguide optical substrate

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

The output coupler comprises optical diffractive elements

Methodology Applied
Scientific EffectDiffraction: Diffraction

Data Source

PatentEP4445207B1Optical waveguide combiner systems and methods
Publication Date: 2026.01.28 SNAP INC
  • EP4445207B1 patent drawingFigure 1
  • EP4445207B1 patent drawingFigure 2
  • EP4445207B1 patent drawingFigure 3

AI summary

An optical display system has an optical waveguide combiner and one or more cameras, cameras is optically coupled to the optical waveguide combiner and have a field of view of at least one real object and at least one virtual object displayable by the optical display system. The cameras, which may be for example wafer level waveguide cameras, may be disposed outside the usable field of view of an output coupler. The cameras may be self-calibrated electronically using images captured by the cameras of one or more virtual objects displayable by the optical display system. AR/VR/MR registration of devices and/or displayed virtual objects with real objects may be implemented using the images captured by the cameras of the displayed virtual objects and real world objects. Real object distance and/or spatial location relative to the optical waveguide combiners may be determined or estimated from the captured images.