Head-Mounted Display Imaging Device Using Segmented Optical Channels

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Solution Overview

Problem

Existing imaging devices for data glasses face challenges in achieving a compact design with uniform brightness distribution for a given eyebox and field angles, as they require large prismatic approaches and complex optical surfaces that are difficult to manufacture with high optical quality.

Innovation Solution

The imaging device divides the initial image into multiple partial images, each transmitted through separate imaging channels with image-forming reflection and refraction surfaces on a shared spectacle lens, allowing for a compact design and uniform brightness distribution by overlapping image areas from different channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a large prismatic approach is used to achieve a large eyebox and desired field angles, then the optical imaging quality is improved, but the device size and complexity increase

Engineering Contradiction:
Improveoptical imaging qualityVSAvoidprismatic attachment size
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The imaging device is divided into multiple imaging channels, each handling a specific portion of the overall field of view. Each imaging channel has its own imaging element and optical path, allowing the system to achieve large eyebox and field angles without requiring a single large prismatic attachment. The segmentation of the image into multiple sections enables each channel to use smaller, more manageable optical components.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If large imaging surfaces are used to achieve a large eyebox, then the optical imaging quality is improved, but the device size increases

Engineering Contradiction:
Improveoptical imaging qualityVSAvoidprismatic attachment size
Core Design Contradiction:
Manufacturing precisionVSArea of stationary object

Solution Approach 1:

The total imaging task is segmented across multiple imaging channels, each with its own imaging element and optical path. This allows the system to achieve large eyebox coverage without requiring each individual component to be large. The segmented approach distributes the optical requirements across multiple smaller surfaces.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-plane imaging approach to a multi-dimensional arrangement with multiple imaging channels stacked or arranged in space. This dimensional change allows the system to achieve large effective imaging area without increasing the footprint of individual optical surfaces, as multiple channels share the same physical space in different orientations.

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

3Volume of moving object

If multiple imaging channels are used to reduce lens diameters, then the device compactness is improved, but the device complexity increases

Engineering Contradiction:
Improvedevice compactnessVSAvoidimaging channel configuration
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

Multiple imaging channels are merged into a single integrated optical system that shares common components such as the spectacle lens and optical path elements. The imaging elements from multiple channels are combined to form a complete virtual image, allowing compactness while managing complexity through shared infrastructure rather than completely separate systems.

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

This solution enables a compact and efficient imaging device that fills the eyebox completely with uniform brightness, reducing the complexity and manufacturing challenges of large optical surfaces while maintaining high optical quality.

Implementation Method 1

each comprising at least one image-forming reflection surface and/or at least one image-forming refraction surface

Methodology Applied
Scientific EffectImage-forming reflection: Reflection

Implementation Method 2

each comprising at least one image-forming reflection surface and/or at least one image-forming refraction surface

Methodology Applied
Scientific EffectImage-forming refraction: Refraction

Implementation Method 3

a spectacle lens common to all imaging channels, via which the imaging channels are directed in the direction of an observer's eye

Methodology Applied
Scientific EffectOptical transmission: Lens

Data Source

PatentEP3631562B1Imaging device, head-mounted display, and method for generating an image from an original image in a head-mounted display
Publication Date: 2024.09.04 TOOZ TECH GMBH
  • EP3631562B1 patent drawingFigure 1
  • EP3631562B1 patent drawingFigure 2
  • EP3631562B1 patent drawingFigure 3

AI summary

The invention relates to an imaging device for a head-mounted display for generating a virtual image from an original image split into at least two original subimages. The imaging device comprises: an imager element arrangement (1) comprising a number of imager elements (11 to 16) on which a corresponding number of original subimages is displayed; a number of imaging channels corresponding to the number of imager elements (11 to 16), which each have at least one image-forming reflection surface (271 to 276) and/or at least one image-forming refraction surface (251 to 256, 291 to 296), each of the imaging channels being associated with one of the imager elements (11 to 16) and transmitting one of the original subimages; and an ophthalmic lens (5) common to all of the imaging channels, used to deflect the imaging channels towards an observer's eye. The image-forming reflection surfaces (271 to 276) and/or refraction surfaces (251 to 256, 291 to 296) of the imaging channels are surfaces of a prism (3) arranged on the ophthalmic lens (5).