Thermal Sensor Face Detection for Head-Up Display Positioning

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Solution Overview

Problem

Existing head-up display systems in vehicles have a limited angle of view, making it difficult for drivers to perceive the projected image, especially when adjusted for comfort positions, and require illumination, which is not always necessary or desirable.

Innovation Solution

A device using a thermal sensor to create a matrix of heat points to detect the face position without illumination, processing this data to determine adjustment information for optimizing the display height, and an optical system with movable components to adjust the image projection accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a camera-based system with illumination is used to detect face position, then the detection accuracy is improved, but the device complexity and energy consumption increase

Engineering Contradiction:
Improveface position detection accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential information needed for face position detection - the thermal signature - rather than capturing and processing full optical images. The thermal sensor array captures thermal radiation patterns that directly indicate face position, eliminating the need for complex image processing algorithms and illumination systems while maintaining detection accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the optical-mechanical detection system (camera with illumination) with a thermal detection system. Instead of using visible or infrared cameras that require light sources and complex image processing, the system uses thermal sensors to detect thermal radiation, substituting a simpler physical measurement approach for the more complex optical system.

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

2Reliability

If infrared illumination is used to enable camera-based detection, then the detection capability is improved, but the energy consumption increases

Engineering Contradiction:
Improvedetection capabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The thermal sensor system is self-service in that it detects thermal radiation that naturally emanates from the driver's face without requiring any external energy input for illumination. The system passively captures thermal energy already present in the environment, eliminating the need for active illumination sources and their associated energy consumption.

Inventive Principle:
Principle #25Self-service

3Device complexity

If the display image position is fixed, then the device complexity is reduced, but the adaptability to different driver positions deteriorates

Engineering Contradiction:
Improvedisplay system complexityVSAvoidadaptability to driver position
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The system implements feedback by continuously monitoring the driver's face position through thermal detection and using this information to dynamically adjust the display image position. The thermal sensor data provides real-time feedback about driver location, which the control system uses to automatically reposition the heads-up display, creating a closed-loop adaptive system.

Inventive Principle:
Principle #23Feedback

4Measurement precision

If a high-resolution image matrix is used for face detection, then the measurement precision is improved, but the processing time and computational requirements increase

Engineering Contradiction:
Improveface position precisionVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts only the critical thermal signature information from the scene using a relatively small sensor array, rather than capturing and processing high-resolution optical images. The thermal data provides sufficient precision for face position detection with minimal processing requirements, as it focuses only on the relevant thermal patterns rather than full image analysis.

Inventive Principle:
Principle #2Taking out (Extraction)

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 accurate positioning of the head-up display without illuminating the driver, improving visibility and reducing the complexity of the detection system compared to conventional image processing methods.

Implementation Method 1

a thermal sensor (4) configured to determine the heat emitted from a target zone (6), likely to be occupied by the individual (2), in the form of a matrix of points (10)

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP3019907B1Method and device for detecting the position of the face of a person, in particular of a motor vehicle driver, and display including such a device
Publication Date: 2018.09.19 VALEO COMFORT & DRIVING ASSISTANCE
  • EP3019907B1 patent drawingFigure 1~3
  • EP3019907B1 patent drawingFigure 4~6

AI summary

The invention relates to a device (1) for detecting the position of the face (2) of a person, in particular of a motor vehicle driver, wherein said device includes: a thermal sensor (4) configured for determining the heat generated from a target area (6) likely to be occupied by a person, in the form of a dot (10) matrix (8), each dot (10) in said matrix (8) representing the heat generated by a portion of said target area (6), processing means for analyzing a value acquired through a physical quantity for the dots (10) of said matrix (8) in order to detect at least one piece of adjustment information that is representative of the position of said face (2) within said target area (6). The invention also relates to a corresponding detection method and display, in particular a head-up display, provided with said device.