Capacitive Sensor Integration in Automotive Glazing

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Solution Overview

Problem

Existing automobile glazing systems face challenges in integrating and controlling electrically powered functional assemblies, such as lighting and optical property modifiers, due to the need for accessible control means that do not disrupt the glazing's aesthetic and optical properties, while minimizing parasitic signal interference from other electronic components.

Innovation Solution

The implementation of capacitive sensors with conductive layers applied to a support inserted between the glass sheets of the glazing, which are designed to operate with multiple electrodes and signal processing to discriminate against parasitic influences, ensuring reliable and sensitive control while maintaining transparency and minimal visual impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If capacitive sensors with conductive layers are applied directly to the glass sheets of the glazing, then the control means are integrated into the glazing and aesthetically pleasing, but the control elements occupy a large surface area and significantly disrupt the visual appearance

Engineering Contradiction:
Improveintegration of control means into glazingVSAvoidsurface area occupied by control elements
Core Design Contradiction:
Ease of operationVSArea of stationary object

Solution Approach 1:

The patent divides the control system into separate functional modules: capacitive sensors, processing units, and power supplies are distributed across multiple glass sheets rather than consolidated on a single sheet. This segmentation reduces the surface area required for each control element while maintaining full functionality, allowing transparent conductive layers to be applied only where needed on specific sheets.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent utilizes the third dimension by applying transparent conductive layers to the inner surfaces of glass sheets, embedding control elements within the glazing structure itself rather than placing them on the outer surface. This dimensional relocation allows control elements to be hidden within the transparent layers, maintaining aesthetic appearance while providing full control functionality.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Illumination intensity

If transparent conductive layers are applied to control the functional assemblies, then the visual appearance and light transmission are maintained, but parasitic signals from other electronic components interfere with sensor operation

Engineering Contradiction:
Improvelight transmission through glazingVSAvoidparasitic signal interference
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces intermediary shielding layers and grounding structures between the capacitive sensors and other electronic components. These intermediary elements act as barriers that block parasitic electromagnetic signals while allowing the transparent conductive layers to maintain their light transmission properties. The shielding layers are strategically positioned to intercept interference before it reaches the sensitive sensor regions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies different properties to different regions of the glazing: transparent conductive layers are applied only in specific local areas where control elements are needed, rather than covering entire sheets. This localized application minimizes the total conductive material present, reducing parasitic signals while maintaining control functionality. The conductive layers are concentrated in discrete zones rather than distributed uniformly.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If the control means are placed on external surfaces such as dashboard or door trim, then accessibility is improved, but the integration into the glazing is lost and aesthetic appeal is reduced

Engineering Contradiction:
Improveaccessibility of control elementsVSAvoidintegration complexity of control system
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent designs the glass sheets to serve multiple functions simultaneously: they provide structural support, maintain optical clarity, and host integrated control elements through transparent conductive layers. The same glass sheets that form the glazing also contain the control interfaces, eliminating the need for separate external control components and reducing overall system complexity while maintaining accessibility.

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

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 discreet, reliable, and efficient control of electrically powered assemblies within the glazing, minimizing interference and maintaining high light transmission and optical quality, while facilitating easier assembly and location of control elements.

Implementation Method 1

The sensors used for these commands are of the capacitive type and consist of conductive layers applied to this support

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3079903B1Automotive glazing
Publication Date: 2021.03.03 AGC GLASS EUROPE SA
  • EP3079903B1 patent drawingFigure 1~2
  • EP3079903B1 patent drawingFigure 3~4
  • EP3079903B1 patent drawingFigure 5~6

AI summary

The invention pertains to a motor vehicle glazing comprising two sheets of glass, outer and inner, brought together by means of one or more inserted thermoplastic sheets, at least one electrically powered functional assembly being inserted between the sheets of the glazing, a capacitive sensor controlling the power supply of the functional assembly by means of a unit for processing the signals emitted by the sensor, the sensor also being inserted into the glazing on a transparent substrate coated with an equally transparent conductive layer, a layer in which the sensor is formed.