Capacitive Switching Area in Low-E Window Pane
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Solution Overview
Problem
Conventional window panes with low-E coatings and capacitive switching areas face challenges in integrating capacitive switching areas inexpensively and achieving improved signal quality, while also managing thermal radiation and emissivity effectively.
Innovation Solution
A disk arrangement with a low-E coating on the inside surface of a pane, featuring capacitive switching areas electrically separated by coating-free lines, and connected to capacitive sensor electronics, which enhances signal-to-noise ratio and thermal comfort by reducing thermal radiation emission and absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a capacitive switching area is integrated into a window pane with low-E coating, then the functionality of touch or proximity sensing is achieved, but the signal quality and noise ratio deteriorate due to interference from the surrounding low-E coating areas
Solution Approach 1:
The low-E coating is divided into multiple electrically isolated regions using coating-free separating lines. The capacitive switching area is segmented from the surrounding low-E coating areas, allowing independent electrical control and reducing capacitive coupling interference. This segmentation enables the switching area to function as a distinct capacitive sensor while minimizing noise from adjacent coated regions.
Solution Approach 2:
Different regions of the pane surface are assigned different electrical properties: the capacitive switching area has specific electrode patterns optimized for sensing, while surrounding areas have the low-E coating removed or modified to reduce interference. This local differentiation allows the switching area to maintain high signal quality while the overall pane retains thermal radiation control in non-switching regions.
2Measurement precision
If coating-free separating lines are introduced to electrically isolate capacitive switching areas, then signal quality is improved, but manufacturing complexity increases
Solution Approach 1:
The coating-free separating lines are created using laser structuring or sputtering processes that directly modify the coating material without mechanical contact. This replaces traditional mechanical masking and etching methods, reducing the number of manufacturing steps and tooling requirements while achieving precise electrical isolation.
Solution Approach 2:
The same low-E coating deposition and laser structuring processes used for creating the coating-free separating lines are also employed for creating the capacitive electrode patterns themselves. This multi-functionality reduces manufacturing complexity by using a unified process flow for both thermal control and capacitive sensing features.
3Reliability
If the low-E coating is removed in separating lines to electrically isolate capacitive areas, then electrical separation is achieved, but thermal radiation control is reduced in those areas
Solution Approach 1:
The width of the coating-free separating lines is optimized to be sufficiently narrow to minimize their impact on overall thermal radiation control while being wide enough to provide adequate electrical isolation. By transitioning the separating lines to a minimal dimension, the trade-off between electrical isolation and thermal performance is resolved in favor of both requirements.
Solution Approach 2:
The low-E coating is removed only in the minimal necessary areas to create electrical isolation, rather than removing it from entire regions. This partial action maintains thermal radiation control in most areas while achieving the necessary electrical separation for capacitive switching 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
The solution improves the integration and signal quality of capacitive switching areas in window panes, providing enhanced thermal comfort and reduced thermal radiation emission, making it suitable for vehicle and building glazing applications.
Implementation Method 1
Such a low-E coating reflects a significant portion of solar radiation, especially in the infrared range, which leads to reduced heating, for example of the vehicle interior, in summer
Implementation Method 2
The coating also reduces the emission of long-wave heat radiation from a heated pane into the vehicle interior when the coating is applied to the surface of a pane facing the vehicle interior
Implementation Method 3
If an object approaches the switching range, 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 via a circuit arrangement or sensor electronics and a switching signal is triggered when a threshold value is exceeded
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 1E
AI summary
The present invention relates to a pane arrangement (101), comprising: - a pane (1) with an inner surface (IV) and an outer surface (III), - a low-E coating (6) which is arranged at least partially on the inner surface (IV) of the pane (1), - at least one coating-free first partition line (7) which is formed in the low-E coating (6) and by which at least one capacitive switching region (10) is electrically isolated from a surrounding region (15) of the low-E coating (6), wherein the surrounding region (15) surrounds the capacitive switching region (10) at least in sections, in particular completely, and wherein the capacitive switching region (10) has a contact region (11), a supply line region (12) and a first connection region (13), wherein the supply line region (12) electrically connects the contact region (11) to the first connection region (13), - at least one coating-free second partition line (8) which is formed in the low-E coating (6) and by which the surrounding region (15) is electrically isolated from an outer region (31) of the low-E coating (6), wherein the outer region (31) at least partially, in particular completely, surrounds the surrounding region (15), - a capacitive sensor electronics system (14) which is electrically connected to the first connection region (13) of the capacitive switching region (10) and to the surrounding region (15) by means of a second connection region (16).