Vehicle HUD Virtual Image Depth Control for 3D Visual Comfort

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Solution Overview

Problem

Current head-up display systems in vehicles primarily project two-dimensional images at a fixed distance, causing eye strain and fatigue due to frequent focal adjustments, and are not suitable for displaying complex information effectively, especially lacking in 3D display functionality which is essential for improved visual comfort and safety.

Innovation Solution

A display system comprising a display device and an image transmission device that forms multiple virtual images through different optical paths, with adjustable imaging positions, using polymer dispersed liquid crystal layers and light conversion elements to achieve 2D and 3D display modes, reducing eye fatigue and enhancing visual comfort by projecting images at varying distances and angles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a fixed-distance 2D image is projected, then the display structure is simple, but eye strain and fatigue occur due to frequent focal adjustments

Engineering Contradiction:
Improvedisplay structureVSAvoideye strain and fatigue
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent transitions from 2D fixed-distance display to 3D light field display by introducing multiple virtual images at different depths along the optical axis. This dimensional change allows the driver's eyes to focus at different distances, reducing focal adjustment fatigue while maintaining a relatively simple overall display structure.

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

Solution Approach 2:

The system dynamically adjusts the focal depth by controlling different liquid crystal layers to create multiple virtual images at varying distances. This dynamic capability enables the display to adapt to different viewing conditions and reduce eye strain without significantly increasing structural complexity.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If multiple virtual images at different depths are formed, then visual comfort and 3D effect are improved, but the device complexity increases

Engineering Contradiction:
Improvevisual comfortVSAvoidoptical system complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The optical system is segmented into multiple functional layers, with each liquid crystal layer responsible for forming virtual images at specific depths. This segmentation allows independent control of each layer, simplifying the overall system architecture while achieving complex 3D light field display effects.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The liquid crystal layers serve multiple functions: they act as both the display medium and the optical element for depth control. By integrating these functions into a single component, the patent reduces the need for additional optical elements, thereby managing device complexity while achieving improved visual comfort.

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

3Adaptability or versatility

If polymer dispersed liquid crystal layers are used for 3D display, then 3D imaging capability is achieved, but manufacturing complexity increases

Engineering Contradiction:
Improve3D display capabilityVSAvoidmanufacturing process
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent uses polymer dispersed liquid crystal (PDLC) material that combines liquid crystal molecules dispersed in a polymer matrix. This composite material structure enables 3D light field display capabilities while maintaining compatibility with existing liquid crystal manufacturing processes, thereby balancing manufacturing ease with advanced functionality.

Inventive Principle:
Principle #40Composite materials

4Object-affected harmful factors

If imaging position is made variable, then driving safety and information clarity are improved, but control system complexity increases

Engineering Contradiction:
Improvedriving safetyVSAvoidcontrol system complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The system automatically adjusts the imaging position and focal depth based on driver behavior patterns and road conditions without requiring manual intervention. This self-service capability improves driving safety by providing optimal display information while managing control complexity through automated algorithms.

Inventive Principle:
Principle #25Self-service

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 system effectively reduces eye fatigue and improves visual comfort by allowing adjustable imaging positions and flexible display modes, including 3D imaging, which enhances driving safety by providing clear and comfortable information display without requiring frequent focal adjustments.

Implementation Method 1

at least two polymer dispersed liquid crystal layers of the plurality of polymer dispersed liquid crystal layers are capable of being controlled to be in a diffusion state to form the at least two sub-virtual images

Methodology Applied
Scientific EffectLight diffusion: Scattering

Implementation Method 2

the light conversion element is configured to receive the light of the first image and convert the light of the first image into first polarized light... the light conversion element is configured to receive the light of the second image and convert the light of the second image into second polarized light... a polarization direction of the first polarized light and a polarization direction of the second polarized light are different

Methodology Applied
Scientific EffectPolarization: Polarisation

Data Source

PatentEP3647117B1Display system and vehicle
Publication Date: 2024.09.04 BOE TECHNOLOGY GROUP CO LTD
  • EP3647117B1 patent drawingFigure 1~2
  • EP3647117B1 patent drawingFigure 3~4A
  • EP3647117B1 patent drawingFigure 4B~5

AI summary

A display system and a display method therefor, and a vehicle. The display system comprises: a display device (10) and an image transmission device (11). The display device (10) is configured to display a plurality of images; the image transmission device (11) is configured to transmit, over different paths, light of at least two images among the plurality of images, and to form at least two virtual images respectively corresponding to the at least two images among the plurality of images, the imaging position of at least one of the at least two virtual images being variable.