Near-Eye Display Optical Path Sharing for Binocular Image Alignment

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Solution Overview

Problem

Binocular near-eye display devices face misalignment issues due to deformation of optical components, leading to misaligned virtual images projected to the left and right eyes, which can occur during device placement or use.

Innovation Solution

The implementation of a common optical path for both image light and alignment light in each optical system, allowing for calibration to align virtual images by compensating for deformations through shared optical path distortions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate optical paths are used for left-eye and right-eye image projection, then independent image rendering is achieved, but misalignment occurs due to optical component deformation

Engineering Contradiction:
Improveimage alignment accuracyVSAvoidoptical system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the calibration light path with the image projection path by using the same optical components (beam splitter, holographic optical element, lens) for both functions. This allows the calibration process to automatically compensate for optical deformations affecting both paths equally, resolving the alignment accuracy issue without adding separate calibration hardware for each eye.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system uses itself for calibration by projecting calibration patterns through its own optical path and capturing them with its own imaging components. The computed alignment transformations are then applied to correct the image projection, allowing the system to self-calibrate without external intervention or separate calibration devices.

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If rigid optical components are used, then manufacturing precision is improved, but adaptability to head movement and deformation is reduced

Engineering Contradiction:
Improveoptical component precisionVSAvoidaccommodation of head movement
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic calibration by continuously or periodically updating alignment transformations based on real-time detection of calibration patterns. This allows the system to adapt to changing optical conditions caused by head movement or component deformation, maintaining alignment accuracy despite the use of rigid optical components.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system employs feedback through the calibration process: calibration patterns are projected, captured by imaging components, processed to determine alignment transformations, and then used to correct subsequent image projections. This closed-loop feedback mechanism compensates for optical deformations and maintains alignment accuracy.

Inventive Principle:
Principle #23Feedback

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

Ensures accurate alignment of virtual images projected to the left and right eyes by compensating for deformations in the optical systems, maintaining proper stereoscopic presentation.

Implementation Method 1

a projection beam path between the image source and the light-deflecting optical component and an alignment beam path between the alignment optical component and the light-deflecting component share a common optical path

Methodology Applied
Scientific EffectCommon optical path sharing:

Implementation Method 2

a light-deflecting optical component positioned in a field of view of a user eye, an image source configured to emit imaging light

Methodology Applied
Scientific EffectLight deflection:

Data Source

PatentEP3443406B1Binocular image alignment for near-eye display
Publication Date: 2025.12.17 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3443406B1 patent drawingFigure 1
  • EP3443406B1 patent drawingFigure 2A~2B
  • EP3443406B1 patent drawingFigure 3~4

AI summary

A near-eye display device comprises a left-eye optical system and a right-eye optical system. Each of the left-eye optical system and the right-eye optical system comprises a light-deflecting optical component positioned in a field of view of a user eye, an image source configured to emit imaging light, and an alignment optical component, wherein projection beam path between the image source and the light-deflecting optical component and an alignment beam path between the alignment optical component and the light-deflecting component share a common optical path.