Multi-zone electrochromic devices with independent bus bar control

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Solution Overview

Problem

Large-sized electrochromic devices often exhibit non-uniform coloration due to leakage currents, leading to visible color differences across the device, especially when bus bars are far apart, resulting in slower color change and aesthetic issues.

Innovation Solution

The implementation of multiple, independently controllable electrochromic zones sharing a common continuous bus bar, allowing for optimized control of coloration across the device, with each zone potentially having different surface areas or shapes, and the use of additional interior bus bars between opposing side bus bars to enhance control and uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a single continuous bus bar configuration is used in large electrochromic devices, then the device structure is simpler and manufacturing is easier, but leakage currents cause non-uniform coloration and slower color change

Engineering Contradiction:
Improvedevice structure simplicityVSAvoidcoloration uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent divides the electrochromic device into multiple independently controllable zones by segmenting the bus bar connections. Each zone has its own electrode connections, allowing independent control of coloration in different regions. This segmentation eliminates the non-uniform coloration problem caused by leakage currents in large devices while maintaining manufacturing feasibility through modular design.

Inventive Principle:
Principle #1Segmentation

2Area of stationary object

If bus bars are placed far apart to cover large device areas, then the device size is increased, but color change speed decreases and coloration uniformity deteriorates

Engineering Contradiction:
Improvedevice areaVSAvoidcolor change speed
Core Design Contradiction:
Area of stationary objectVSProductivity

Solution Approach 1:

The patent segments the large electrochromic device into multiple zones with separate electrode connections. Each zone can be controlled independently, allowing faster color change in each segment while covering a large total area. The segmentation reduces the effective distance for ion transport in each zone, improving color change speed without sacrificing device area.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic control of multiple zones through independent electrical connections. Each zone can be activated or deactivated independently, allowing the system to optimize color change speed by applying voltage to specific zones as needed. This dynamic control enables large devices to achieve uniform and fast coloration across the entire area.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If multiple independently controllable zones are implemented, then coloration uniformity and control precision are improved, but device complexity increases

Engineering Contradiction:
Improvecoloration uniformityVSAvoidzone control complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent divides the device into segments with independent control, improving coloration uniformity. The segmentation is achieved through separate electrode connections for each zone, allowing precise control of coloration in each region while maintaining a relatively simple overall structure that does not excessively increase device complexity.

Inventive Principle:
Principle #1Segmentation

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 solution enables uniform coloration and faster color change across large electrochromic devices, improving aesthetic appeal and functionality by allowing independent control of each zone, thereby reducing the impact of leakage currents and enhancing solar control and daylight harvesting.

Implementation Method 1

Electrochromic devices include electrochromic materials that are known to change their optical properties, such as coloration, in response to the application of an electrical potential, thereby making the device more or less transparent

Methodology Applied
Scientific EffectElectrochromism: Electrochromism

Implementation Method 2

When an electric potential is applied across the layered structure of the electrochromic device, such as by connecting the respective conductive layers to a low voltage electrical source, ions, such as Li+ ions stored in the counter electrode layer, flow from the counter electrode layer, through the ion conductor layer and to the electrochromic layer

Methodology Applied
Scientific EffectIon transport: Ion Exchange

Implementation Method 3

In addition, electrons flow from the counter electrode layer, around an external circuit including a low voltage electrical source, to the electrochromic layer so as to maintain charge neutrality in the counter electrode layer and the electrochromic layer

Methodology Applied
Scientific EffectElectron flow: Conduction (electrical)

Data Source

PatentEP2820473B1Multi-zone electrochromic devices
Publication Date: 2019.10.23 SAGE ELECTROCHROMICS INC
  • EP2820473B1 patent drawingFigure 1A
  • EP2820473B1 patent drawingFigure 1B
  • EP2820473B1 patent drawingFigure 2

AI summary

In one aspect of the present invention is a substrate comprising multiple, independently controllable electrochromic zones (200A, 200B), wherein each of the electrochromic zones share a common, continuous bus bar (242). In one embodiment, of the electrochromic zones are not completely isolated from each other. In another embodiment, each of the electrochromic zones have the same surface area. In another embodiment, each of the electrochromic zones have a different surface area.