Deformable Membrane Optical Device for Compact Variable Focal Length

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Solution Overview

Problem

Existing variable focal length optical devices are bulky due to the presence of a remote pump and have complex, expensive fluidic circuits that slow down response time.

Innovation Solution

A variable focal length optical device with a deformable membrane featuring a stiffening structure comprising ribs or layers that define deformable regions, allowing for fluid pressure-induced deformation of the membrane to adjust focal length, while maintaining a simple and efficient design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a remote pump and complex fluidic circuit are used to vary focal length, then the device can achieve variable focal length adjustment, but the device becomes bulky and response time is slowed

Engineering Contradiction:
Improvevariable focal length adjustmentVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the remote pump and complex fluidic circuit from the system. Instead, it uses a simple membrane structure with integrated stiffening ribs that can be directly actuated by localized forces, thereby achieving focal length variation without the bulky and complex fluidic infrastructure

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention employs a deformable membrane as the core component for focal length adjustment. The membrane, equipped with stiffening ribs, can be locally deformed to change the curvature and focal length of optical elements, providing a compact and responsive alternative to pump-based fluidic systems

Inventive Principle:
Principle #30Flexible shells and thin films

2Adaptability or versatility

If a complex fluidic circuit is used to deform the membrane, then focal length can be adjusted, but manufacturing cost increases and response time is penalized

Engineering Contradiction:
Improvefocal length adjustmentVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The membrane is segmented into multiple deformable regions by the stiffening ribs, allowing independent control of different optical zones. This segmentation is achieved through a simple rib structure that can be integrated into the membrane manufacturing process, avoiding the need for complex fluidic circuits while enabling precise focal length adjustment

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The use of a thin, flexible membrane with integrated stiffening ribs provides a manufacturable and cost-effective solution. The membrane structure can be fabricated using standard thin-film techniques, eliminating the need for expensive and complex fluidic circuit integration

Inventive Principle:
Principle #30Flexible shells and thin films

3Device complexity

If a deformable membrane with stiffening structure is used, then device size is reduced and response time is improved, but manufacturing complexity may increase

Engineering Contradiction:
Improvedevice complexityVSAvoidmanufacturing complexity
Core Design Contradiction:
Device complexityVSEase of manufacture

Solution Approach 1:

The stiffening structure is merged directly into the membrane as an integrated component rather than a separate assembly. The ribs are formed as part of the membrane structure itself, allowing simultaneous fabrication in a single manufacturing process and simplifying assembly while maintaining the compact design

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 results in a compact, cost-effective optical device with improved response time and efficient focal length adjustment, enabling flexible optical system configurations.

Implementation Method 1

applying an electrical actuating voltage to the actuating device and deforming the membrane in each deformable region delimited by a cavity in the stiffening structure

Methodology Applied
Scientific EffectElectrical actuation:

Implementation Method 2

deforming a membrane under the effect of a variation in fluid pressure

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Data Source

PatentEP3123212B1Optical device with a deformable membrane
Publication Date: 2020.06.24 WEBSTER CAPITAL LLC
  • EP3123212B1 patent drawingFigure 1~2
  • EP3123212B1 patent drawingFigure 3~4C
  • EP3123212B1 patent drawingFigure 4D~5

AI summary

The invention relates to a variable-focus optical device (100) comprising: a deformable membrane (1); a mounting (2) to which a peripheral anchoring zone (1c) of said membrane (1) is connected; a recess filled with a constant volume of a fluid (3), said recess being defined by the membrane (1), a bottom (20) opposite the membrane (1) and a wall (21) of the mounting (2) extending between the bottom (20) and the membrane (1); a device (4) for actuating a region (1a) of the membrane (1) located between the peripheral anchoring area (1c) and a central portion (1b) of the membrane (1), configured such as to bend by the application of an electric actuation voltage in order to move a portion of the volume of fluid (3), characterized in that the membrane (1) comprises a rigidifying structure (10) comprising cavities which delimit, in the central portion (1b) of said membrane, at least two deformable regions (1d) each constituting a dioptre of an elementary optical system, each elementary optical system comprising said deformable region (1d) with respect to the membrane, the fluid (3) and the bottom (20) of the recess.