Transparent Window Heating Coating with Gradient Conductive Transition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Heatable transparent window coatings face challenges in achieving sufficient heating power with low feed voltage while maintaining good electrical properties and optical transparency, especially in large window dimensions or long current paths, due to high surface resistance.
Innovation Solution
The transitional region between bus bars and the heating area has varying electrical and optical properties, with highly conductive but less transparent structures near the bus bars gradually becoming more transparent and less conductive towards the central viewing area, using opaque conductive regions and transparent non-conductive regions, and incorporating conductor paths that decrease in width and density towards the heating area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the surface resistance of the heating coating is reduced by increasing the thickness of conductive layers, then the heating power is improved, but the transmission of visible light is reduced
Solution Approach 1:
The patent applies local quality by creating a transitional region with different properties from the central viewing area. The transitional region has lower surface resistance (higher conductivity) to enable effective heating, while the central viewing area maintains higher transparency. This is achieved through a gradient structure where conductive material density varies spatially, allowing each region to optimize for its specific function—heating near the edges and visibility in the center.
Solution Approach 2:
The heating window is segmented into distinct functional zones: a central viewing area (A) optimized for transparency and transitional regions (B) optimized for heating conductivity. This segmentation allows the system to achieve both high visible light transmission in the viewing area and sufficient heating power in the transitional regions without compromising either function.
2Power
If the surface resistance is reduced to achieve adequate heating power with low voltage, then the heating effectiveness is improved, but the transparency of the window is reduced
Solution Approach 1:
Different regions of the window are assigned different quality characteristics: the transitional regions have low surface resistance for effective heating with 12-14V supply, while the central viewing area maintains high transparency. The transitional regions act as buffer zones that handle the electrical heating function without interfering with the optical properties of the central area.
Solution Approach 2:
The patent resolves the contradiction by adding a spatial dimension to the solution. Instead of uniformly reducing surface resistance across the entire window, the conductivity is varied across the surface area, creating a two-dimensional gradient from high conductivity at the edges to low conductivity in the center. This allows the system to achieve adequate heating power while preserving central transparency.
3Reliability
If additional conductor or grid elements are added to reduce surface resistance in transitional regions, then the electrical conductivity is improved, but the visibility in the viewing area is compromised
Solution Approach 1:
The window is divided into functional segments where conductor elements are strategically placed only in transitional regions (B) and not in the central viewing area (A). This segmentation ensures that electrical conductivity is enhanced where needed for heating while visibility is preserved in the critical viewing zone.
Solution Approach 2:
Conductive elements are applied locally in the transitional regions rather than uniformly across the entire window. The transitional regions serve as buffer zones with enhanced conductivity for effective heating, while the central viewing area maintains its optical properties. This local application of conductive material resolves the conflict between electrical performance and visual clarity.
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 design achieves reduced effective surface resistance and increased transparency towards the center of the window, providing effective heating power with low voltage while maintaining a visually appealing appearance and ensuring good conductivity.
Implementation Method 1
a current flows between them over a heating area formed by the coating
Implementation Method 2
the effective surface resistance of which is lower than the surface resistance of the coating
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A transparent window (1) has an electrically heatable coating, which extends over a substantial part of the area of the window (1), in particular over its viewing area (A). In addition, the coating is electrically connected to at least two mutually opposite low-impedance bus bars in such a way that, after an electrical feed voltage has been applied to the bus bars, a current flows between them over a heating area (21) formed by the coating. In this arrangement, there is between the bus bars and the heating area (21) at least one at least partially light-transmitting transitional region (15), the effective surface resistance of which is lower than the surface resistance of the coating. In order to obtain a transitional region (15) having the visual appearance of a band filter, it is proposed that the surface resistance in the at least one transitional region (15) increases in the direction from the assigned bus bar to the heating area (21).