Heatable Composite Glazing With Capacitive Touch Rejection

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Solution Overview

Problem

Existing heatable composite windows with capacitive switching areas are either expensive to integrate or obstruct the view, and they often trigger unintended switching signals from external factors like rain or windscreen wipers.

Innovation Solution

A heatable composite pane with a capacitive switching area that incorporates a substrate, a cover pane, and intermediate layers, featuring an electrically conductive layer for heating and capacitive sensing, where the capacitive switching area is designed to be minimally invasive and only triggers signals when touched from the inside, using a specific geometry and sensor electronics to differentiate internal from external touches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a capacitive switching area is integrated into the heated composite window, then touch sensing functionality is achieved, but the view through the window is obstructed and external factors like rain or wipers may trigger unintended switching signals

Engineering Contradiction:
Improvetouch sensing functionalityVSAvoidunintended switching signals from external factors
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by creating distinct zones within the capacitive switching area: a contact area for intentional touch input and a surrounding ambient area that serves as a reference. The sensor electronics evaluate the relationship between capacitance changes in these different zones to distinguish between intentional touches and external factors like rain or wipers, thereby resolving the contradiction between providing touch sensing and avoiding false triggers.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If a capacitive switching area with contact area and supply area is integrated into the heated composite window, then touch sensing functionality is achieved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvetouch sensing functionalityVSAvoidintegration cost and complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent merges multiple functions into the heated composite window structure: the heating wires and current collectors provide thermal functionality, while the carrier film with electrically conductive layer provides both the heating path and the capacitive switching area. By integrating the capacitive switching components into the existing heating structure rather than adding separate systems, the patent achieves touch sensing functionality while minimizing manufacturing complexity and cost.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If the capacitive switching area uses a carrier film with electrically conductive layer, then touch sensing is enabled, but the view through the window is obstructed

Engineering Contradiction:
Improvetouch sensing functionalityVSAvoidview clarity through window
Core Design Contradiction:
Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent uses a thin carrier film with an electrically conductive layer to create the capacitive switching area. This thin-film structure enables touch sensing functionality while minimizing obstruction of the view through the window, as the thin film and conductive layer are sufficiently transparent to allow light transmission. The flexible nature of the thin film also allows it to be integrated into the curved or flat surfaces of the window without compromising optical properties.

Inventive Principle:
Principle #30Flexible shells and thin films

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 allows for the integration of a capacitive switching area into heatable composite windows that is cost-effective, minimally obstructive, and reliably avoids external triggering of switching signals, ensuring precise control and safety, particularly in vehicle applications.

Implementation Method 1

wherein one end of each heating wire is electrically connected to each of the collectors, so that when an electrical voltage is applied to the collectors a heating current can flow through the heating wire, thereby heating the heating wire

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

When an object approaches the switching zone, the capacitance of the surface electrode to ground or the capacitance of the capacitor formed by the two coupled electrodes changes. The change in capacitance is measured by a circuit arrangement or sensor electronics

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3372052B1Heatable compound glazing with capacitive switching range
Publication Date: 2020.09.09 SAINT GOBAIN VITRAGE SA
  • EP3372052B1 patent drawingFigure 1A~1B
  • EP3372052B1 patent drawingFigure 1C~1D
  • EP3372052B1 patent drawingFigure 2A

AI summary

The invention relates to a pane assembly (101), comprising: a heatable composite pane (100) having a capacitive switching region (10), comprising: a substrate (1) and a cover pane (4) and at least a first intermediate layer (3), which is arranged between the substrate (1) and the cover pane (4), wherein a carrier film (5) having an electrically conductive layer (6) is arranged between the substrate (1) and the first intermediate layer (3) or between the cover pane (4) and the first intermediate layer (3) at least in some sections, at least one region of the electrically conductive layer (6) forms a capacitive switching region (10), the capacitive switching region (10) has a contact region (11), a supply line region (12), and a connection region (13), the supply line region (12) electrically connects the contact region (11) to the connection region (13) and the connection region (13) can be electrically connected to sensor electronics (14) and at least one heating wire (21) and at least two bus conductors (22) are arranged between the substrate (1) and the cover pane (4), and each end of the heating wire (21) is connected to one of the bus conductors (22) in an electrically conductive manner such that a heating current can flow through the heating wire (21) when a voltage is applied to the bus conductors (22), whereby the heating wire (21) can be heated, and capacitive sensor electronics (14), which are connected in an electrically conductive manner to the connection region (13) by means of a first input and to the heating wire (21) or the bus conductors (22) by means of a second input.