Flat Gratings High Index Materials Head-Mounted Displays

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Solution Overview

Problem

Conventional 3D display systems often fail to provide a realistic and comfortable perception of depth due to mismatch between accommodation and vergence, leading to discomfort and poor depth perception for many users.

Innovation Solution

A head-mounted display device incorporating optical elements with grating structures, where a first optical element with protrusions of a first material and a second material disposed between them, is used to project images corresponding to multiple depth planes, aligning with the user's accommodated state, thereby enhancing depth cues and comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional 3D display systems are used, then images can be projected, but depth perception is poor and user comfort is reduced due to accommodation-vergence mismatch

Engineering Contradiction:
Improvedepth perception qualityVSAvoiduser comfort
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the optical parameters of the display system by introducing multiple optical elements with different focal lengths and transmission characteristics. Each optical element is configured to transmit light corresponding to a different depth plane, allowing the system to adjust the optical parameters dynamically to match the user's accommodated state, thereby resolving the accommodation-vergence mismatch and improving both depth perception quality and user comfort

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If multiple depth planes are projected, then depth information is provided, but the system complexity increases

Engineering Contradiction:
Improvedepth plane representationVSAvoidoptical element configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the optical system into multiple discrete optical elements, where each element is responsible for a specific depth plane. This segmentation allows the complex function of representing multiple depth planes to be divided into simpler, manageable units, each with specific focal lengths and transmission characteristics, making the overall system more versatile while keeping individual components relatively simple

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each optical element in the patent is designed to perform multiple functions: it transmits light for a specific depth plane while also contributing to the overall focusing and transmission characteristics of the display system. This multi-functionality reduces the need for separate dedicated components for each depth plane, thereby managing system complexity while maintaining high adaptability

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 a more believable and comfortable simulation of depth by aligning image presentations with the user's accommodated state, improving depth perception and reducing user discomfort in 3D displays.

Implementation Method 1

The first optical element defines a grating at along a periphery of the first optical element. The grating includes a plurality of protrusions extending from a base portion of the first optical element.

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 2

eyepieces can be constructed using thin layers of one or more highly refractive materials

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP4018231B1Flat spectral response gratings using high index materials
Publication Date: 2024.09.11 MAGIC LEAP INC
  • EP4018231B1 patent drawingFigure 1
  • EP4018231B1 patent drawingFigure 2A~2B
  • EP4018231B1 patent drawingFigure 3A~3C

AI summary

An example head-mounted display device includes a plurality of optical elements in optical communication. The optical elements are configured to project an image in a field of view of a user wearing the head-mounted display device. A first optical element is configured to receive light from a second optical element. The first optical element defines a grating at along a periphery of the first optical element. The grating includes a plurality of protrusions extending from a base portion of the first optical element. The protrusions include a first material having a first optical dispersion profile for visible wavelengths of light. The grating also includes a second material disposed between at least some of the plurality of protrusions along the base portion of the first optical element. The second material has a second optical dispersion profile for visible wavelengths of light.