Wearable Head-Up Display Hinge and Optical Alignment

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Solution Overview

Problem

Conventional wearable head-up displays are bulky and rigid, making them inconvenient for folding and storage, which is a limitation for both military and non-military applications.

Innovation Solution

A compact wearable head-up display design featuring a microdisplay, collimation optics, and a combiner assembly with a hingeable frame that allows for easy folding and storage, incorporating a locking mechanism for safety and power-saving features, and optionally using a prism, diffraction grating, or mirror array for efficient light direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional wearable head-up displays are used, then image projection functionality is achieved, but the device becomes bulky and rigid, preventing folding and convenient storage

Engineering Contradiction:
Improvefolding capabilityVSAvoiddevice size
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The device is divided into separate segments including a frame, arms, and image projection means that can be hingeably connected. This segmentation allows the device to be folded into a compact form while maintaining the necessary functional components for image projection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The device incorporates hinge joints that enable dynamic transformation between unfolded (operational) and folded (storage) states. This dynamic structure allows the device to adapt its form factor based on usage requirements, transitioning from a rigid operational state to a compact storage state.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the device is made compact for portability, then folding capability is improved, but safety control and power saving become more difficult to implement

Engineering Contradiction:
ImproveportabilityVSAvoidsafety control
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system incorporates sensors that detect the hinge position and provide feedback to the control circuitry. This feedback mechanism enables the system to automatically control the light source based on whether the device is in unfolded or folded position, ensuring safety protocols are maintained while enabling compact folding for portability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The device uses its own structural state (hinge position) to automatically control its operation. When folded, the device automatically deactivates the light source through integrated sensors and control circuits, eliminating the need for separate safety monitoring systems and enabling compact design without compromising safety.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If optical projection components are included, then head-up display functionality is achieved, but the device size increases and folding becomes difficult

Engineering Contradiction:
Improvedisplay functionalityVSAvoidcomponent count
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple optical components (light source, imaging device, collimation optics) into an integrated image projection means assembly. This merging reduces the overall component count and simplifies the device structure while maintaining full head-up display functionality, enabling the device to be compact and foldable.

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 convenient folding and storage while maintaining image quality and safety protocols, allowing for comfortable and aesthetically favorable wear with reduced component count and improved portability.

Implementation Method 1

The combiner assembly may comprise an output waveguide

Methodology Applied
Scientific EffectTotal Internal Reflection: Total Internal Reflection

Implementation Method 2

The combiner assembly may comprise a prism

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

The combiner assembly may comprise a diffraction grating

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 4

The combiner assembly may comprise a mirror array

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 5

a collimation optic, positioned in the arm, the collimation optic being arranged to receive the image-bearing light and output collimated light

Methodology Applied
Scientific EffectCollimation: Lens

Data Source

PatentEP3729185B1Wearable devices
Publication Date: 2024.01.17 SNAP INC
  • EP3729185B1 patent drawingFigure 1~2
  • EP3729185B1 patent drawingFigure 3
  • EP3729185B1 patent drawingFigure 4

AI summary

A wearable head-up display which allows for convenient and safe stowage when not in use. A hinge component is positioned within the optical path from an image projector to a display component which ensures optical alignment for projection. A detection means is provided to signal when the wearable device is in a folded position in order to deactivate the projector.