Heated Glazing Busbar Layout for Faster Windshield Defogging

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing glazing technologies for vehicles and other applications are not effective in achieving rapid defogging or defrosting, particularly in critical viewing regions such as windshields and camera areas, as they require complex manufacturing processes and do not optimize heat distribution efficiently.

Innovation Solution

The glazing design incorporates a configuration of conductors and busbars with strategically placed gaps and varying conductor densities to create resistors with different power densities, allowing for increased heat generation in required regions, and a method of manufacturing that embeds conductors in interlayer material without the need for transfer sheets, enabling faster defogging or defrosting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If uniform conductor distribution is used across the entire glazing, then manufacturing is simple, but heat distribution is not optimized for critical regions

Engineering Contradiction:
Improveheat distributionVSAvoidconductor configuration
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent applies local quality by varying the conductor density in different regions of the glazing. Specifically, the conductor density is increased in critical regions such as the upper portion and corners of the windshield to generate more heat where needed for defogging and defrosting, while maintaining lower density in non-critical areas. This creates region-specific thermal characteristics without requiring a completely different manufacturing approach.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The glazing surface is segmented into multiple regions with different conductor densities. The patent divides the windshield into critical regions (upper portion, corners) and non-critical regions, assigning different conductor configurations to each segment. This segmentation allows independent optimization of heat generation in each region to meet specific functional requirements.

Inventive Principle:
Principle #1Segmentation

2Productivity

If complex conductor configurations are used to optimize heat distribution, then defogging performance improves, but manufacturing complexity increases

Engineering Contradiction:
Improvedefogging speedVSAvoidmanufacturing process
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-defining specific conductor configurations and patterns during the design and manufacturing phase. The conductor layouts for different regions (higher density in upper portions and corners, lower density in central and lower areas) are predetermined and integrated into the glazing manufacturing process, eliminating the need for complex post-manufacturing adjustments or installations.

Inventive Principle:
Principle #10Preliminary action

3Speed

If high power density is applied across the entire glazing, then defrosting is faster, but energy consumption increases

Engineering Contradiction:
Improvedefrosting speedVSAvoidenergy consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The patent applies local quality by concentrating high power density only in critical regions where defogging and defrosting are most needed, such as the upper portion and corners of the windshield. Non-critical regions operate at lower power densities. This localized approach achieves effective defrosting performance while minimizing overall energy consumption compared to uniform high-power application across the entire glazing surface.

Inventive Principle:
Principle #3Local quality

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 configuration results in faster defogging or defrosting in critical regions, enabling earlier readiness of cameras and Advanced Driver Assistance Systems, while simplifying the manufacturing process and optimizing heat distribution for efficient defrosting.

Implementation Method 1

heated electrical conductors are known for demisting and defrosting

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP4091408B1Glazing, method of manufacturing said glazing and use of said glazing
Publication Date: 2023.12.20 PILKINGTON GRP LTD
  • EP4091408B1 patent drawingFigure 1~2
  • EP4091408B1 patent drawingFigure 3~4
  • EP4091408B1 patent drawingFigure 5~6

AI summary

The invention concerns a glazing (10) comprising first and second busbars (1, 2) for connection to an electrical supply; a third busbar (3) positioned between first and second busbars (1, 2); a plurality of conductors (5) electrically connected to the first busbar (1); wherein a first group of conductors (5) extends from the first busbar (1) to the third busbar (3) to form a first resistor (R1); a second group of conductors (5) extends from a side of the third busbar (3) facing the second busbar (2) and is electrically connected to the second busbar (2) to form a second resistor (R2); wherein fewer conductors (5) extend from the side of the third busbar (3) facing the second busbar (2) than extend from a side of the third busbar (3) facing the first busbar (1); further comprising at least one gap (6) on one side of the third busbar (3) opposite a conductor (5) on the other side and an information acquisition area (7) arranged between the third busbar (3) and the second busbar (2) wherein the at least one gap (6) is positioned outside the information acquisition area (7).