Optical Distortion Element for Multi-Vehicle HUD Windshields

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Solution Overview

Problem

Existing head-up displays are limited by the size of their eyebox and require individual optical elements for each vehicle variant, leading to high logistics and storage costs, as well as complex fine-tuning for unforeseen image errors.

Innovation Solution

A method for designing an optical distortion element that compensates for average windshield curvatures across different vehicle types, using a universal optical distortion element combined with electronic image distortion, which is adaptable to specific vehicle types through software adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If individual optical elements are manufactured for each vehicle variant, then image compensation accuracy is improved, but logistics and storage costs increase

Engineering Contradiction:
Improveimage compensation accuracyVSAvoidlogistics and storage costs
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent applies universality by designing a single optical distortion element that can be used across multiple vehicle variants. Instead of manufacturing separate optical elements for each vehicle type, the invention creates one universal element that compensates for average windshield curvatures across different vehicle types, thereby reducing logistics and storage costs while maintaining acceptable image quality.

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

Solution Approach 2:

The patent applies parameter changes by using electronic image distortion to adjust image parameters (distortion parameters) based on the specific vehicle type and windshield curvature. Rather than changing the physical optical element for each vehicle variant, the system modifies the digital image parameters to compensate for different curvatures, enabling a single optical element to serve multiple configurations.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If subsequent fine-tuning of optical elements is performed, then image errors are corrected, but complexity of calibration increases

Engineering Contradiction:
Improveimage error correctionVSAvoidcalibration complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical/optical fine-tuning process with electronic image processing. Instead of physically adjusting or recalibrating optical elements for each vehicle variant, the system uses electronic distortion parameters to correct image errors. This substitution of mechanical calibration with electronic processing significantly reduces calibration complexity while maintaining image accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent applies preliminary action by pre-calculating and storing distortion parameters for different vehicle types before deployment. Rather than performing complex fine-tuning during installation, the system has already determined the appropriate distortion parameters for various vehicle configurations, allowing for quick and simple parameter selection during setup without requiring complex real-time calibration.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If a universal optical distortion element is used, then production costs are reduced, but adaptability to specific vehicle types decreases

Engineering Contradiction:
Improveproduction costVSAvoidadaptability to vehicle types
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent introduces an intermediary - the electronic image distortion system - that bridges the universal optical distortion element and specific vehicle types. The universal optical element provides the base image, and the electronic intermediary adjusts the image parameters to adapt to different vehicle types and windshield curvatures. This intermediary layer maintains production simplicity while achieving vehicle-specific adaptability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent uses parameter changes to maintain adaptability with a universal optical element. By modifying the digital image parameters (distortion parameters) based on the specific vehicle type and windshield curvature measurements, the system enables a single optical element to adapt to multiple vehicle configurations without requiring physical customization, thus maintaining both low production costs and high adaptability.

Inventive Principle:
Principle #35Parameter changes

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

Enables cost-effective production and reduces the need for individual calibration by using a single optical distortion element for multiple vehicle types, ensuring manageable image resolution and adaptability through electronic image processing.

Implementation Method 1

determining a compensation curvature for an optical distortion element with which a distortion is compensated that corresponds to an average curvature determined from the measured curvatures

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

The mirror unit is a partially reflective, translucent screen. The viewer therefore sees the content displayed by the image generator as a virtual image

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3807697B1Method of design of a distortion element for an apparatus for generating a virtual image
Publication Date: 2025.09.03 CONTINENTAL AUTOMOTIVE TECHNOLOGIES GMBH
  • EP3807697B1 patent drawingFigure 1
  • EP3807697B1 patent drawingFigure 2~3
  • EP3807697B1 patent drawingFigure 4

AI summary

The invention relates to an apparatus for generating a virtual image. The device comprises an imaging unit (1) for generating an image and an optical waveguide for expanding an exit pupil and an optical unit (2). The optical unit (2) is designed to project an image generated by the imaging unit (1) onto a curved mirror unit (3, 31), wherein the optical unit (2) has an optical distortion element (71), the distortion of which is independent of an embodiment of the curved mirror unit (3, 31). The device also has an image signal distortion unit (72) which is set up to control the imaging unit (1) in such a way that the image generated by the imaging unit (1) is statically distorted according to the configuration of the curved mirror unit (3, 31).