Projection Device for Head Mounted Displays Using Dual Beam Divergence

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Solution Overview

Problem

Current data glasses technologies face challenges in efficiently displaying high-resolution images across different visual fields of the eye, leading to resource inefficiencies and increased component requirements, while also limiting the field of view and eyebox size.

Innovation Solution

A projection device for data glasses that uses an image generation unit to create two light beams with different beam divergences and perceptible image sharpness, and a deflection element, such as a hologram, to display sharp image information in the central field of vision and blurred information in the peripheral field, reducing the number of components and enhancing the field of view.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If high-resolution images are displayed across all visual fields, then image quality is improved, but resource consumption and component requirements increase

Engineering Contradiction:
Improveimage sharpnessVSAvoidresource consumption
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent applies local quality by displaying high-resolution sharp images only in the central field of vision where the eye can perceive them, while displaying blurred images in the peripheral field of vision. This matches the visual acuity distribution of the human eye, providing high image quality where needed while reducing resource consumption in areas where high quality is not perceivable.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If multiple light beams are used to cover different visual fields, then field of view is improved, but device complexity increases

Engineering Contradiction:
Improvefield of viewVSAvoidcomponent requirements
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges multiple light beams carrying different image information into a single optical path using a beam combiner. This allows multiple images (sharp central field image and blurred peripheral field image) to be combined and displayed through a single optical outlet, reducing device complexity while maintaining an expanded field of view.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The projection device uses a single optical system that serves multiple functions: it displays both the sharp central field image and the blurred peripheral field image, and can switch between different image sources (first image information from first light beam, second image information from second light beam). This multi-functionality reduces the need for separate dedicated systems for each visual field.

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

3Manufacturing precision

If image sharpness is increased in peripheral field, then perceived quality is improved, but energy consumption increases

Engineering Contradiction:
Improveperceptible image sharpnessVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The system recognizes that the human eye has different visual acuity in different regions, with high acuity in the central field and low acuity in the peripheral field. Therefore, it displays high-sharpness images only in the central field where they can be perceived, and blurred images in the peripheral field where high sharpness would not be noticed, thereby saving energy.

Inventive Principle:
Principle #3Local quality

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 approach allows for a resource-saving system with reduced components, improved functionality, and a larger field of view, ensuring high image sharpness only where it can be perceived, thereby increasing efficiency and reducing manufacturing costs.

Implementation Method 1

at least one deflection element that is designed to display the first image information using the first light beam within a first field of vision of an eye and to display the second image information using the second light beam within a second field of vision of the eye

Methodology Applied
Scientific EffectLight deflection: Reflection

Implementation Method 2

the first light beam and the second light beam differ from one another with regard to beam divergence and the first image information and the second image information differ from one another with regard to perceptible image sharpness

Methodology Applied
Scientific EffectBeam divergence: Diffraction

Data Source

PatentEP3411747B1Projection device for head mounted displays, method of presenting images using a head mounted display and controller
Publication Date: 2023.05.10 ROBERT BOSCH GMBH
  • EP3411747B1 patent drawingFigure 1
  • EP3411747B1 patent drawingFigure 2
  • EP3411747B1 patent drawingFigure 3~4

AI summary

The invention relates to a projection device (1002) for smart glasses (1000). The projection device (1002) comprises an image generation unit (1004) for generating at least one first light beam (1010) representing first image information and a second light beam (1012) representing second image information. The first light beam (1010) and the second light beam (1012) differ from one another with regard to a beam divergence. Furthermore, the first image information and the second image information differ from one another with regard to a perceivable image sharpness. In addition, the projection device (1002) comprises at least one deflection element (1008) which is designed to present the first image information using the first light beam (1010) within a first visual field (1014) of an eye (1016) and to present the second image information using the second light beam (1012) within a second visual field (1018) of the eye (1016) located outside of the first visual field (1014).