Head-Up Display Eye Box Adjustment and Virtual Image Stabilization

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Solution Overview

Problem

Existing head-up displays in vehicles face challenges in maintaining the alignment of virtual images with the environment when the driver's eye position changes, leading to displacement of the virtual image and reduced visibility of superimposed information.

Innovation Solution

The system includes adjustment means to modify the light beam direction and a compensation system that keeps the observation point aligned with a fixed point relative to the display, ensuring that the virtual image remains superimposed on environmental elements during eye position adjustments, using a combination of screen control modules, mirror movement, and optical systems to maintain image alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the combiner is rotated around a horizontal axis to move the eye box to adapt to driver's eye positions, then the adaptability to different eye positions is improved, but the position of the virtual image displaces relative to the space facing the driver

Engineering Contradiction:
Improveadaptability to different eye positionsVSAvoidposition accuracy of virtual image
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system separates the eye box adjustment function from the virtual image positioning function. The combiner rotation handles eye box adaptation while the projection system independently compensates for virtual image position shifts, dividing the correction task into distinct operational segments

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The projection system acts as an intermediary between the combiner rotation and the final virtual image position. It receives the rotated light beam and actively compensates for position displacement through controlled adjustment, mediating the conflict between eye box adaptation and image stability

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a mirror on the display is rotated around a horizontal axis to move the eyepiece to the driver's eye level, then the ease of operation for different drivers is improved, but the position of the virtual image shifts relative to the space facing the driver

Engineering Contradiction:
Improveease of operation for different driversVSAvoidposition accuracy of virtual image
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The system divides the adjustment functions into separate components: the mirror rotation handles eyepiece positioning for different drivers while the projection system independently manages virtual image position compensation, allowing each component to optimize its specific function without interfering with the other

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The projection system serves as an intermediary that receives light from the rotated mirror and actively corrects the resulting virtual image position shift, mediating between the mechanical adjustment for driver comfort and the optical requirement for stable image positioning

Inventive Principle:
Principle #24Intermediary (Mediator)

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 allows the virtual image to remain visually superimposed on environmental elements, such as traffic lanes, even as the driver's eye position changes, enhancing the visibility and effectiveness of augmented reality features in the head-up display.

Implementation Method 1

an optical projection system, adapted to project the light beam exiting the screen towards a partially transparent blade so as to form, by reflection by said blade, a virtual image of the screen

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

adjustment means to modify a direction presented by the light beam exiting the screen

Methodology Applied
Scientific EffectLight propagation: Light

Data Source

PatentEP3701314B1Head-up display
Publication Date: 2021.09.08 VALEO COMFORT & DRIVING ASSISTANCE
  • EP3701314B1 patent drawingFigure 1~2
  • EP3701314B1 patent drawingFigure 3~4
  • EP3701314B1 patent drawingFigure 5

AI summary

The invention concerns a head-up display (10) comprising: - a screen suitable for generating an image to be displayed, and - an optical projection system, for forming, by reflection on a partially transparent panel (2), a virtual image (IMV) of the screen visible at maximum brightness from an observation point (O). According to the invention, the display further comprises: - adjustment means for modifying a direction presented by a light beam exiting the screen, and - a compensation system configured to keep the following aligned when said direction is modified: - said observation point, - a given point (P') of the virtual image, and - a point (B) that is fixed relative to the display, situated on an opposite side to said observation point with respect to the virtual image.