Capacitive Sensor Windshield for Rain Detection
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Solution Overview
Problem
Existing windshield rain sensors, such as light sensors and stray-field capacitors, require significant space, obstruct driver vision, and are prone to errors in detecting rain intensity and presence.
Innovation Solution
A composite pane with a capacitive sensor featuring transparent, electrically conductive coatings forming electrodes that are capacitively coupled, integrated into the windshield, allowing for space-saving and reliable detection of moisture, including rain, using an electronic sensor unit that calculates signal correlations to trigger the windshield wiper system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If light sensors are used for rain detection, then rain presence can be detected, but significant space is required and driver vision is obstructed
Solution Approach 1:
The patent merges the sensor functionality directly into the windshield glass structure by integrating transparent conductive coatings (ITO layers) onto the glass surfaces. This eliminates separate sensor housings and components, allowing the sensor to be embedded within the existing windshield assembly, thereby reducing space requirements while maintaining detection reliability.
Solution Approach 2:
The patent employs thin transparent conductive film coatings applied to the windshield glass surfaces as capacitor electrodes. These thin films enable the sensor functionality to be integrated into the glass structure itself, minimizing space occupation and avoiding obstruction of driver vision while maintaining effective rain detection capability.
2Measurement precision
If stray-field capacitors with multiple electrodes are used, then rain detection capability is improved, but driver through-vision is restricted and application becomes laborious
Solution Approach 1:
The patent combines the capacitor electrodes directly with the transparent conductive coatings that are already part of the windshield structure. By using the same ITO layers as both structural and sensing elements, the system achieves precise rain detection without requiring separate electrode applications, thereby simplifying the manufacturing process and improving ease of application.
3Ease of operation
If transparent conductive coatings are used for capacitor electrodes, then driver vision is not obstructed and integration is simplified, but reliable rain intensity detection must be achieved
Solution Approach 1:
The patent segments the transparent conductive coating into multiple distinct capacitor electrodes (first capacitor electrode, second capacitor electrode, third capacitor electrode) with specific geometric arrangements. This segmentation enables the system to detect not only rain presence but also rain intensity by measuring capacitance changes between different electrode pairs, while maintaining visual transparency and ease of integration.
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 solution provides a compact, reliable, and effective rain detection system that does not obstruct driver vision, accurately detecting rain presence and intensity, ensuring quick and reliable activation of the windshield wiper system.
Implementation Method 1
a capacitive sensor for detecting moisture having at least one capacitor that is connected to an electronic sensor unit, which is provided for detecting a change in capacitance of the capacitor
Implementation Method 2
Between the reference electrode and at least one counter electrode, an electrical field is generated, which extends into a dielectric space outside the windshield
Implementation Method 3
an electrical field is generated, which extends into a dielectric space outside the windshield
Data Source
AI summary
A composite pane for separating an interior space from an external environment, includes an inner pane, an outer pane with an inner surface, and an intermediate layer that areally joins the inner surface of the outer pane to an outer surface of the inner pane, a capacitive sensor for detecting moisture having at least one capacitor that is connected to an electronic sensor unit, which is provided for detecting a change in capacitance of the capacitor, wherein the capacitor has at least two electrodes formed from a transparent, electrically conductive coating, which are capacitively coupled.