Head-Up Display Optical Elements for Rain and Dirt Detection

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Solution Overview

Problem

Conventional rain sensors on vehicles have limited detection areas, are visually intrusive, and often fail to detect rain or dirt in the driver's field of vision, leading to inefficient and unreliable windshield cleaning and potential driver annoyance.

Innovation Solution

Integrating a camera with a focusing element and image sensor into the head-up display system, utilizing the optical elements to detect rain and dirt on a large area of the windshield, allowing for reliable detection and integration with existing head-up display electronics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a conventional rain sensor is mounted in the upper area of the windshield, then the sensor area is relatively small (approx. 2.5 cm²), but the sensor can detect rain in its field of vision

Engineering Contradiction:
Improvesensor areaVSAvoiddetection reliability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The head-up display optical system is repurposed to serve dual functions: displaying information to the driver and capturing images for rain/dirt detection. The existing optical elements (windshield, mirrors, lenses) are used for both their original display function and for imaging the windshield surface, eliminating the need for a separate dedicated sensor system and enabling a much larger effective sensor area.

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

Solution Approach 2:

The patent combines the rain/dirt detection camera system with the head-up display optical path. The camera is integrated into the existing display structure, sharing optical elements and mounting space. This merging allows the system to achieve a large sensor area (covering the entire driver field of vision area) while maintaining compact integration within the vehicle's existing architecture.

Inventive Principle:
Principle #5Merging (Combining)

2Area of stationary object

If a rain sensor is mounted in the upper area of the windshield, then the sensor area is relatively small, but the installation is simple

Engineering Contradiction:
Improvesensor areaVSAvoidsystem complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The head-up display optical system is repurposed to serve dual functions: displaying information to the driver and capturing images for rain/dirt detection. The existing optical elements (windshield, mirrors, lenses) are used for both their original display function and for imaging the windshield surface, eliminating the need for a separate dedicated sensor system and enabling a much larger effective sensor area.

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

Solution Approach 2:

The patent combines the rain/dirt detection camera system with the head-up display optical path. The camera is integrated into the existing display structure, sharing optical elements and mounting space. This merging allows the system to achieve a large sensor area (covering the entire driver field of vision area) while maintaining compact integration within the vehicle's existing architecture.

Inventive Principle:
Principle #5Merging (Combining)

3Area of stationary object

If a conventional rain sensor is used, then the sensor is visible from the outside, but the installation space is limited

Engineering Contradiction:
Improvesensor areaVSAvoiddesign ease
Core Design Contradiction:
Area of stationary objectVSEase of manufacture

Solution Approach 1:

The patent combines the rain/dirt detection camera system with the head-up display optical path. The camera is integrated into the existing display structure, sharing optical elements and mounting space. This merging allows the system to achieve a large sensor area (covering the entire driver field of vision area) while maintaining compact integration within the vehicle's existing architecture.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The head-up display optical system acts as an intermediary that enables the camera to capture images of the windshield surface without the camera itself being visible from the outside. The optical elements (mirrors, lenses) mediate between the camera sensor and the windshield, allowing indirect imaging while keeping the camera hidden within the vehicle interior.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Area of stationary object

If the sensor monitors a window section not in the driver's field of vision, then the sensor area is small, but the detection is simple

Engineering Contradiction:
Improvesensor areaVSAvoiddetection precision
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The head-up display optical system is repurposed to serve dual functions: displaying information to the driver and capturing images for rain/dirt detection. The existing optical elements (windshield, mirrors, lenses) are used for both their original display function and for imaging the windshield surface, eliminating the need for a separate dedicated sensor system and enabling a much larger effective sensor area.

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

Solution Approach 2:

The camera system is configured to specifically image the area of the windshield in the driver's field of vision, which is the most critical area for detection. The optical elements are positioned and oriented to focus on this specific region, ensuring high detection precision where it matters most while still utilizing the entire optical path for imaging.

Inventive Principle:
Principle #3Local quality

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 fast and reliable detection of rain and dirt directly in the driver's field of vision, reducing visibility and installation issues, while also supporting driver identification and fatigue detection, with potential for additional functions like ambient light sensing and communication interfaces.

Implementation Method 1

An essential idea of the invention consists in introducing an additional camera, comprising a focusing element and an image sensor, statically or dynamically into the beam path of a head-up display. For example, a lens or an objective can be used as the focusing element.

Methodology Applied
Scientific EffectOptical focusing: Focusing

Implementation Method 2

Head-up displays are used to project information in the driver's eye... the projection beam path of the head-up display into the driver's eye

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

The camera can be introduced into the optical system of the head-up display via a beam splitter

Methodology Applied
Scientific EffectBeam splitting: Reflection

Data Source

PatentEP2504732B1Use of the optical elements of a head-up display for the camera-based rain and dirt sensor system, driver identification or fatigue detection
Publication Date: 2013.12.25 CONTI TEMIC MICROELECTRONIC GMBH
  • EP2504732B1 patent drawingFigure 1~2

AI summary

The invention relates to a vehicle having an apparatus for producing a head-up display, wherein a camera comprising an image sensor (6) and a focusing element (8) is statically or dynamically introduced into the beam path of the head-up display via an optical or mechanical element (5). The focusing element (8) is arranged in such a manner that a region (7) of the outside of the windscreen (3) is imaged on the image sensor (6) in a focused manner. The vehicle may have, in particular, at least one of the following assistance functions on the basis of evaluation of the data from the image sensor: driver recognition, fatigue detection, rain/dirt detection.