Vehicle HUD Distortion Correction via Driver Line of Sight Detection

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Solution Overview

Problem

Existing head-up display (HUD) systems for vehicles face challenges in presenting virtual images without distortion across varying windshield shapes, leading to increased manufacturing costs and complexity due to the need for individual adjustment and distortion correction parameters.

Innovation Solution

A projection type display device that includes a light source, light modulation element, projection unit, sight line detection unit, measurement data acquisition unit, correction data generation unit, and image data correction unit, which detects the driver's line of sight and acquires measurement data on the windshield shape to generate and apply correction data for minimizing distortion in projected images.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If distortion correction parameters are calculated and stored for each viewpoint position, then virtual image distortion is reduced, but manufacturing cost and operational complexity increase

Engineering Contradiction:

Improvevirtual image distortion correctionVSAvoiddistortion correction parameter management

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system automatically detects the driver's viewpoint position using image analysis and retrieves the corresponding distortion correction parameter from storage, eliminating the need for manual parameter selection or complex adjustment operations by service personnel

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

Distortion correction parameters for multiple viewpoint positions are pre-calculated and stored in the storage unit before vehicle operation, allowing rapid automatic selection during use without requiring real-time calculation or manual intervention

Inventive Principle:

Principle #10Preliminary action

2Area of stationary object

If projection range and visual recognition range are increased, then image coverage is improved, but distortion correction becomes more difficult

Engineering Contradiction:

Improveprojection rangeVSAvoiddistortion correction accuracy

Core Design Contradiction:

Area of stationary objectVSManufacturing precision

Solution Approach 1:

The wide projection range is divided into multiple viewpoint positions, with specific distortion correction parameters calculated for each position. The system then automatically selects the appropriate parameter segment based on detected driver viewpoint, maintaining high correction accuracy across the entire extended range

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different distortion correction parameters are applied for different viewpoint positions within the projection range. Each local region (viewpoint position) has its own optimized correction parameters, allowing accurate distortion correction throughout the entire wide projection area

Inventive Principle:

Principle #3Local quality

3Manufacturing precision

If optical system is adjusted to reduce virtual image distortion, then image quality improves, but number of components and management complexity increase

Engineering Contradiction:

Improvevirtual image distortionVSAvoidoptical system components

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical/optical adjustment systems with a digital image processing approach. Distortion correction is achieved by processing image data with correction parameters rather than physically adjusting optical components, reducing the number of optical elements and their management complexity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

Instead of changing physical optical parameters through component adjustment, the system changes digital image parameters by applying distortion correction parameters to the image data. This software-based parameter change achieves the same effect with simpler hardware

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

This solution allows for the presentation of virtual images with reduced distortion across any windshield shape, simplifying the adjustment process and reducing manufacturing costs by optimizing distortion correction for each vehicle without the need for extensive parameter calculation.

Implementation Method 1

a light modulation element that spatially modulates light emitted from the light source on the basis of image data

Methodology Applied

Scientific EffectLight modulation:

Implementation Method 2

a projection unit that projects image light that is spatially modulated by the light modulation element onto a windshield of a vehicle

Methodology Applied

Scientific EffectLight projection:

Data Source

PatentUS10768416B2Projection type display device, projection display method, and projection display program

Publication Date: 2020.09.08 FUJIFILM CORP

AI summary

An HUD includes a projection unit that projects image light that is spatially modulated on the basis of image data onto a windshield, a sight line detection unit that detects a line of sight of a driver of a vehicle, and a system controller that acquires measurement data on shape of a region including a point that intersects the line of sight of the driver in a projectable range of the image light in the windshield, generates correction data for correcting distortion of an image based on the image light projected onto the region on the basis of the acquired measurement data and the direction of the line of sight of the driver, and corrects the image data using the generated correction data.