Prescriptive See-Through Eyepiece with Optical Combiner

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Solution Overview

Problem

Conventional near-to-eye displays interfere with prescription corrective glasses, offering uncomfortable and less-than-desirable options for users who do not wear contact lenses, as they fail to effectively integrate corrective eye prescriptions without adding weight or compromising industrial design.

Innovation Solution

A prescriptive see-through eyepiece is designed with a meniscus lens body and a partially reflective optical combiner, which provides corrective lensing for both image light and external scene light, using a combination of concave and convex curvatures to ensure equal prescriptive correction, allowing for a range of diopter corrections from -8 to +8, and fabricated using various techniques such as casting, over-casting, and injection molding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional near-to-eye displays are used, then the display can be worn close to the user's eyes, but it physically interferes with conventional prescription corrective glasses and creates uncomfortable configurations

Engineering Contradiction:
Improvecomfort of wearingVSAvoidcompatibility with prescription glasses
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent merges the prescription corrective lens functionality with the near-to-eye display optic by integrating a prescription-specific meniscus lens body with an optical combiner. This combination allows the display to provide both corrective lensing for the user's prescription and the necessary display functionality in a single integrated optic, eliminating the need to wear separate prescription glasses with the display.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated optic performs multiple functions simultaneously: it acts as both a prescription corrective lens and a near-to-eye display optic. The meniscus lens body provides prescriptive lensing while the optical combiner enables the display functionality, making the single component universal for both correction and display purposes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If prescription corrective lenses are integrated into the display, then corrective lensing can be provided, but the device complexity increases

Engineering Contradiction:
Improveprescription correction capabilityVSAvoidoptical structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple optical functions into a single integrated component rather than using separate lenses and optics. By merging the prescription corrective lens and the display optic into one unified structure, the design reduces overall system complexity while maintaining prescription correction capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single integrated optic performs both prescription correction and display functions, eliminating the need for multiple separate components. This multi-functionality approach reduces device complexity by consolidating what would otherwise require separate lenses and optical elements.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If multiple separate lenses are used for correction and display, then prescriptive correction can be achieved, but the weight and industrial design are compromised

Engineering Contradiction:
Improveprescription correctionVSAvoideyepiece weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The patent merges the corrective lens and display optic into a single integrated component, eliminating the need for multiple separate lenses. This consolidation significantly reduces the total weight of the eyepiece while maintaining full prescription correction capability, making the device more comfortable for extended wear.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of manufacture

If conventional combiners are used without lensing, then the combining functionality is achieved, but the field of view and focus control are limited

Engineering Contradiction:
Improvecombining functionalityVSAvoidfield of view control
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent merges the field of view control lensing with the display optic by integrating a meniscus lens body that provides both prescriptive correction and field of view management. This combination allows the system to maintain combining functionality while adding sophisticated field of view and focus control capabilities.

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

The solution enables a comfortable and effective integration of corrective prescriptions into near-to-eye displays, maintaining industrial design aesthetics while providing appropriate lensing for both virtual and real-world images, suitable for a wide range of prescriptions and amenable to high-volume manufacturing.

Implementation Method 1

A prescriptive see-through eyepiece is designed with a meniscus lens body and a partially reflective optical combiner, which provides corrective lensing for both image light and external scene light

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

a partially reflective optical combiner, which provides corrective lensing for both image light and external scene light

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3368940B1Free space optical combiner with prescription integration
Publication Date: 2021.12.15 GOOGLE LLC
  • EP3368940B1 patent drawingFigure 1
  • EP3368940B1 patent drawingFigure 2A~2B
  • EP3368940B1 patent drawingFigure 3

AI summary

A prescriptive see-through eyepiece includes a meniscus lens body and an optical combiner. The meniscus lens body has an external scene side with a convex curvature and an eye-ward side with a concave curvature. The optical combiner is disposed within the meniscus lens body to combine image light incident through the eye-ward side with external scene light incident through the external scene side into a combined image. The optical combiner is partially reflective and imparts substantially no lensing power to the external scene light passing through. The optical combiner along with the concave curvature of the eye-ward side are configured to impart prescriptive lensing to the image light while the convex curvature of the external scene side and the concave curvature of the eye-ward side are configured to impart the prescriptive lensing to the external scene light.