Single-Actuator Fluid-Filled Lens Assembly for Near-Eye Displays

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Near-Eye-Display (NED) devices are bulky due to multiple electrical, mechanical, and optical components, which deter users from wearing them for extended periods.

Innovation Solution

An optical assembly utilizing a single actuator to control multiple variable fluid-filled lenses, reducing the need for multiple actuators, reservoirs, and supporting electronics, thereby minimizing weight, complexity, and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple actuators are used to control multiple variable optical lenses, then the optical functionality is improved, but the weight and device complexity increase

Engineering Contradiction:
Improveoptical functionalityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple actuator functions into a single actuator that controls multiple variable optical lenses simultaneously. This merging approach reduces the total number of actuators from multiple to one, thereby reducing device complexity while maintaining the ability to adjust optical power across all lenses. The single actuator integrates the control functionality that would otherwise require separate actuators for each lens.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single actuator is designed with multi-functionality to control multiple different optical lenses (including both real image and virtual image lenses) across different optical domains. This universal actuator can adjust the optical power of various lens types, eliminating the need for specialized actuators for each lens and reducing overall system complexity.

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

2Measurement precision

If multiple actuators and supporting electronics are used, then the control precision is improved, but the weight and power consumption increase

Engineering Contradiction:
Improvecontrol precisionVSAvoidweight
Core Design Contradiction:
Measurement precisionVSWeight of moving object

Solution Approach 1:

The patent merges multiple actuators and their supporting electronics into a single actuator system, directly reducing the total weight of the NED device. By consolidating the actuation mechanism, the device eliminates redundant components that would add weight, while the single actuator maintains sufficient control precision for adjusting multiple lenses.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts and eliminates redundant actuators and supporting electronics from the system, keeping only the essential single actuator needed to control all variable optical lenses. This extraction of unnecessary components reduces weight while preserving the core functionality and control precision required for optical adjustment.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If multiple actuators are used, then the optical control versatility is improved, but the power consumption increases

Engineering Contradiction:
Improveoptical control versatilityVSAvoidpower consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent combines multiple power-consuming actuator systems into a single actuator, reducing the total power consumption of the device. The single actuator shares the power load across multiple lens controls, eliminating redundant power consumption associated with multiple separate actuator systems while maintaining optical control versatility.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The universal single actuator performs multiple optical control functions that would otherwise require separate actuators, reducing overall power consumption. By designing the actuator to handle diverse lens types and optical domains, the system eliminates the need for multiple specialized actuators, each consuming power independently.

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

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 provides weight, power, and cost savings while enabling configuration of virtual object focal planes and maintaining a non-magnified view of the physical world.

Implementation Method 1

As fluid is pumped into a lens, the flexible element becomes convex and the power of the lens becomes positive. As fluid is pumped out of a lens, the flexible element becomes concave and the power of the lens becomes negative.

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP3732513B1Optical assembly including a single actuator and multiple fluid-filled optical lenses for a near-eye display device
Publication Date: 2025.09.10 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3732513B1 patent drawingFigure 1
  • EP3732513B1 patent drawingFigure 2A
  • EP3732513B1 patent drawingFigure 2B

AI summary

A near-eye display device (100) includes a pair of fluid-filled lenses (200A-B). The optical power of an inner lens (200B) of the pair of lenses (200A-B) can be set to position a focal plane for a virtual object (206) from infinity to a predefined distance. The optical power of an outer lens (200A) of the pair of lenses (200A-B) is set to cancel out the optical power of the inner lens (200B). A single actuator (212) coupled to a reservoir (208) pumps fluid into or out of the lenses (200A-B) to change their optical power. When the actuator (212) is activated, fluid flows into one of the lenses in a pair (200A-B) and out of the other lens in the pair (200A-B). The amount of fluid in each lens in a pair of lenses (200A-B) is thereby maintained to cancel out the optical power of the other lens. A single actuator (212) can also be utilized to modify the power of two or more pairs of lenses (200A-D).