Near-Eye Display Modulation Stack for Multi-Focal 3D Rendering

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Solution Overview

Problem

Existing near-eye display systems are hindered by expensive, slow, and fragile mechanical components, as well as large and costly beam splitters, making them unsuitable for size and cost-constrained applications.

Innovation Solution

A near-eye display system utilizing a modulation stack with digital light path length modulators, which adjust light path lengths based on polarization to create multiple focal planes without mechanical movement, enabling efficient and compact 3D image rendering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If mechanical movement mechanisms (gears or liquid lenses) are used to render multiple focal planes, then the display can provide three-dimensional imaging, but the system becomes expensive, slow, and fragile

Engineering Contradiction:
Improvemulti-focal plane capabilityVSAvoidsystem fragility
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent replaces mechanical movement mechanisms (gears, liquid lenses) with a modulation stack consisting of digital light path length modulators. These modulators use optical modulation rather than mechanical movement to achieve multi-focal plane rendering, eliminating the fragility, cost, and speed limitations of mechanical systems while maintaining the ability to provide three-dimensional imaging with multiple focal lengths

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If multiple mirrors and lenses are used to display multiple focal lengths, then the display can achieve multi-focal functionality, but the system becomes large and expensive

Engineering Contradiction:
Improvemulti-focal length displayVSAvoidsystem size
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent transitions from using multiple physical mirrors and lenses arranged in space to a stacked modular configuration where multiple digital light path length modulators are arranged in layers. This vertical stacking approach reduces the horizontal footprint and overall system size while maintaining multi-focal length capability through digital control of each modulator layer

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Speed

If liquid lenses are used to adjust focal length, then the display can dynamically change focus, but the system becomes expensive and slow

Engineering Contradiction:
Improvefocal adjustment speedVSAvoidsystem cost
Core Design Contradiction:
SpeedVSEase of manufacture

Solution Approach 1:

The patent replaces liquid lens mechanisms with digital light path length modulators that use optical modulation and digital control signals to achieve rapid focal length changes. This substitution eliminates the slow response and high cost associated with liquid lenses while enabling fast, programmable focal adjustment through electronic control of the modulation stack

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

This solution provides a high-quality 3D display that meets human visual requirements, preventing user discomfort and offering improved performance over existing technologies by eliminating the need for expensive and fragile mechanical components.

Implementation Method 1

A digital light path length modulator can be used to create two focal planes. In one embodiment, using a modulation stack with a plurality of digital light path length modulators, the number of focal planes can be increased

Methodology Applied
Scientific EffectPolarization: Polarisation

Data Source

PatentEP3497508B1A near-eye display system including a modulation stack
Publication Date: 2025.04.16 AVEGANT CORP
  • EP3497508B1 patent drawingFigure 1
  • EP3497508B1 patent drawingFigure 2A
  • EP3497508B1 patent drawingFigure 2B

AI summary

A near-eye display system comprising a image source, a modulation stack, and an imaging assembly. The modulation stack, in one embodiment, comprises one or more digital light path length modulators.