Variable Focus Lens Membrane for Compact Multifocal Displays

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Solution Overview

Problem

Existing mixed reality and augmented reality display devices face challenges in efficiently presenting virtual image information across multiple focal planes due to bulky and complex variable focus assemblies that complicate calibration and resource intensity.

Innovation Solution

A head-mounted display device incorporates a variable focus lens assembly with a rigid refractive component, a shaper ring, and a flexible lens membrane, where an actuator module adjusts the optical power by moving the shaper ring relative to the refractive component, altering the curvature of the flexible lens membrane, and includes actuators such as rotary motors, stepper motors, and shape memory alloy wires to control focus adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional variable focus assemblies are used to present virtual image information in multiple focal planes, then the display device can achieve multi-focal plane capability, but the assembly becomes bulky and complex

Engineering Contradiction:

Improvemulti-focal plane capabilityVSAvoidassembly complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent employs a flexible lens membrane instead of traditional rigid lens elements. This flexible membrane can be dynamically deformed by an actuator to change the focal plane, enabling multi-focal plane capability while significantly reducing the overall assembly size and complexity compared to traditional rigid lens-based variable focus systems.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The system uses a dynamically deformable flexible lens membrane that can be actuated to change its shape and focal properties in real-time. This dynamic approach replaces static, bulky mechanical focus adjustment mechanisms with a lightweight, electronically controlled flexible element that adapts its optical properties as needed.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

Engineering Contradiction:

Improvemulti-focal plane capabilityVSAvoidcalibration complexity

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The flexible lens membrane system inherently provides self-aligning properties due to its flexible nature and the way it deforms under actuation. The membrane's flexibility allows it to automatically adapt to slight misalignments and maintain proper optical alignment across different focal planes, reducing the need for complex calibration procedures compared to rigid lens systems.

Inventive Principle:

Principle #25Self-service

3Adaptability or versatility

Engineering Contradiction:

Improvemulti-focal plane capabilityVSAvoidresource intensity

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The flexible lens membrane is a lightweight, low-inertia component that requires minimal actuation force compared to traditional rigid lens systems. This reduces the energy consumption of the actuator and overall system while maintaining the ability to switch between multiple focal planes efficiently.

Inventive Principle:

Principle #30Flexible shells and thin films

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 compact and efficient adjustment of focal planes, enhancing the user experience by simplifying calibration and reducing resource intensity in mixed reality and augmented reality systems.

Implementation Method 1

a flexible lens membrane between the shaper ring and the rigid refractive component. The flexible lens membrane covers the aperture

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

A volume of fluid is disposed within the chamber. The rigid refractive component and the flexible lens membrane define a chamber between the flexible lens membrane and the refractive component

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS20250271675A1Variable focus assemblies

Publication Date: 2025.08.28 MAGIC LEAP INC

AI summary

An example head-mounted display device includes a light projector, an optical assembly arranged to direct light from a light projector to a user, and an actuator module. The optical assembly includes a variable focus lens assembly including a rigid refractive component, a shaper ring defining an aperture, and a flexible lens membrane between the shaper ring and the rigid refractive component and covering the aperture. The refractive component, the shaper ring, and the lens membrane are arranged along an axis. The refractive component and the lens membrane define a chamber containing a volume of fluid. The actuator module is configured to adjust an optical power of the variable focus lens by moving the shaper ring relative to the refractive component along the axis, such that a curvature of the lens membrane in the aperture is modified.