Windshield HUD Calibration for Ghost-Free Reflective Coatings
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Solution Overview
Problem
Head-up displays (HUDs) in vehicles with laminated windshields featuring electrically conductive coatings create unwanted secondary images due to additional reflective interfaces, leading to blurry and color-inaccurate projections.
Innovation Solution
A head-up display system with a composite screen and calibration means that includes a projector, sensors, and a control unit to generate a corrective image, compensating for deviations caused by reflective properties of the laminated glass, ensuring sharp and accurate projections by electronically pre-distorting the image.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If an electrically conductive coating is applied to the windshield to improve thermal comfort and reduce IR heating, then thermal comfort is improved, but additional unwanted secondary images (layer reflections) are created that degrade image quality
Solution Approach 1:
The patent converts the harmful layer reflection from the conductive coating into a beneficial element by generating a corrective image that, when superimposed with the primary and secondary reflections, creates a sharp and color-accurate virtual image. The conductive coating's reflective property is accepted and compensated for rather than eliminated.
Solution Approach 2:
The system performs preliminary anti-action by pre-calculating and pre-distorting the corrective image before display. The calibration process detects the reflective properties of the composite screen and determines the necessary compensation in advance, so that when the corrective image is generated, it automatically compensates for the layer reflection effect.
2Object-generated harmful factors
If the windshield uses a wedge-shaped thermoplastic film to superimpose primary and secondary reflections and reduce ghost images, then ghost image visibility is reduced, but the manufacturing complexity and precision requirements increase
Solution Approach 1:
The patent replaces the mechanical/wedge-based solution with an electronic/digital solution. Instead of relying on the physical wedge angle of the thermoplastic film to superimpose reflections, the system uses electronic image processing to generate a corrective image that compensates for reflections, thereby eliminating the need for precise mechanical wedge angle control.
Solution Approach 2:
The system changes the approach from modifying physical parameters (wedge angle, film thickness) to modifying digital parameters (image distortion, color balance). The calibration process measures the actual reflective properties and adjusts the corrective image parameters accordingly, providing flexibility without mechanical complexity.
3Manufacturing precision
If calibration means with sensing means are added to detect reflective properties and generate corrective images, then image accuracy is improved, but device complexity increases
Solution Approach 1:
The calibration means serves multiple functions: it detects the reflective properties of the composite screen, determines the necessary compensation parameters, and generates the corrective image. This multi-functionality reduces the need for separate dedicated components for each function, thereby limiting the increase in overall system complexity.
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
The system provides clear, sharp, and color-accurate virtual images by superimposing reflections, minimizing disruptive ghost images, and enhancing thermal comfort with IR-reflective coatings.
Implementation Method 1
These coatings can act as IR-reflective coatings to reduce the heating of the vehicle interior
Implementation Method 2
The calibration means have sensing means for detecting the reflective properties of the composite screen
Implementation Method 3
images are projected onto the windshield, reflected there, and perceived by the driver as a virtual image
Data Source
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AI summary
The present invention relates to a head-up display system (11) for representing image information for an observer, comprising an image encoder (4) for emitting a first image, a projection area comprising a portion of a composite pane (10) for deflecting a projection of an image, wherein calibration means (7, 8, 9) are provided for setting a deviation between a first image and the projection of the first image and have capturing means (7) for capturing a reflection property of the composite pane, and the image encoder (4) is provided for generating a correction image depending on the deviation.