Segmented Switchable Glazing Busbar Layout for Uniform Sun Visors

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Solution Overview

Problem

Conventional electrically controllable sun visors in vehicles face challenges with homogeneous switching behavior and reduced service life due to inhomogeneities in surface electrodes, especially in smaller sizes, leading to increased power consumption and component failure.

Innovation Solution

A composite pane with a segment-like switchable functional element where the surface electrodes are divided by insulation lines, allowing for longer busbars that exceed the segment width, ensuring robustness and independent control of segments, thereby minimizing the risk of failure and improving switching behavior.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of stationary object

If the size of the functional element is reduced to enable smaller segments, then the vehicle's weight is reduced and space is freed up, but the area available for electrical contacting decreases leading to inhomogeneous switching behavior and increased component failure

Engineering Contradiction:
Improvevehicle weightVSAvoidelectrical contact reliability
Core Design Contradiction:
Weight of stationary objectVSReliability

Solution Approach 1:

The bus bar is segmented into multiple contact zones along its length, with each zone corresponding to a specific segment of the functional element. This allows the bus bar to provide extended electrical contact area while accommodating the reduced size of individual segments, ensuring homogeneous voltage distribution across all segments without increasing overall vehicle weight.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bus bar is designed with non-uniform electrical contact properties along its length, creating locally optimized contact zones. Each contact zone has specific electrical characteristics tailored to the requirements of its corresponding functional element segment, ensuring reliable switching behavior even as segment size decreases.

Inventive Principle:
Principle #3Local quality

2Device complexity

If conventional bus bars are used with small segments, then the device complexity is low, but inhomogeneities in surface electrodes lead to increased power consumption and component failure

Engineering Contradiction:
Improveelectrical contacting structureVSAvoidpower consumption
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The bus bar is divided into multiple contact zones that correspond to individual segments of the functional element. This segmentation allows for optimized electrical contact at each zone, ensuring homogeneous voltage distribution and preventing local inhomogeneities that would cause increased power consumption and component failure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrical contact parameters of the bus bar are varied along its length to match the specific requirements of each functional element segment. This includes adjusting contact area, contact pressure, and electrical conductivity locally to achieve uniform switching behavior and minimize power losses.

Inventive Principle:
Principle #35Parameter changes

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 enables reliable and long-lasting electrical contacting with improved voltage distribution and reduced risk of overheating, resulting in a more robust and efficient electrically controllable sun visor system.

Implementation Method 1

The surface electrodes are electrically connected to bus bars, via which the functional element can be connected to an external voltage source

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

If a voltage is applied to the surface electrodes, the liquid crystals align in a common direction, increasing the light transmission through the active layer

Methodology Applied
Scientific EffectElectro-optic effect: Electro-Optic Effects

Data Source

PatentEP3870440B1Laminated glazing with segmented functional element with electrically driven optical properties
Publication Date: 2024.07.31 SAINT GOBAIN SEKURIT FRANCE
  • EP3870440B1 patent drawingFigure 1a~1b
  • EP3870440B1 patent drawingFigure 2a~2b
  • EP3870440B1 patent drawingFigure 2c~3

AI summary

The invention relates to a composite pane having an electrically controllable functional element that can be switched in segments, the composite pane at least comprising a first pane (1) and a second pane (2), which are connected to one another by means of an intermediate layer (3), and a functional element (5), which has a plurality of lateral edges (4.1, 4.2, 4.3, 4.4) and is embedded in the intermediate layer (3), wherein: the functional element (5) comprises a first flat electrode (12) and a second flat electrode (13) arranged one over the other in a planar manner, between which an active layer (11) is arranged in a planar manner; the first flat electrode (12) is divided into a plurality of segments (17) by means of at least one separating line (16); a group of first busbars (18) electrically contacts the first flat electrode (12), and each segment (17) of the first flat electrode (12) is electrically contacted by one busbar from the group of the first busbars (18); at least one second busbar (19) electrically contacts the second flat electrode (13); the length of at least one first busbar (18), along the segment (17) associated with said first busbar, exceeds the width of the segment (17); first busbars (18) that contact segments (17) adjacent to one another are arranged on opposite lateral edges (4.2, 4.2) of the functional element (5); the first busbars (18) adjacent to one another on a common lateral edge (4.2, 4.4) are electrically isolated from one another by separating lines (16).