Curved Liquid Crystal Window Bonding via Low-Temperature Lamination

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Solution Overview

Problem

Existing technologies face challenges in creating dimmable liquid crystal (LC) assemblies suitable for use in safety-critical environments like vehicle windows, requiring materials and manufacturing processes that ensure impact resistance, fragmentation prevention, and optical clarity while allowing for variable light transmittance.

Innovation Solution

The development of dimmable LC assemblies that incorporate flexible materials, polyvinyl butyral (PVB) layers, and ultraviolet (UV) blocking layers, along with advanced manufacturing techniques such as laminating in a vacuum environment to reduce temperature and pressure, enabling the creation of curved LC assemblies that conform to complex surfaces while maintaining optical clarity and safety standards.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If traditional lamination processes are used with high temperature and pressure, then bonding strength is improved, but the liquid crystal cell components (spacers, LC material) are damaged or deformed

Engineering Contradiction:
Improvebonding strengthVSAvoidintegrity of LC cell components
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent changes the temperature and pressure parameters of the lamination process from traditional high values to lower values (temperature below the LC material's clearing point, pressure below 100 psi) to prevent damage to spacers and LC material while still achieving adequate bonding through extended processing time and vacuum environment

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies adhesive materials to the bonding surfaces before lamination and allows them to set or partially cure in advance, creating preliminary bonds that hold components in place during the low-temperature lamination process, preventing displacement without requiring high pressure

Inventive Principle:
Principle #10Preliminary action

2Productivity

If UV curing adhesive is used, then bonding speed and strength are improved, but UV blocking layers prevent adequate UV transmission for curing

Engineering Contradiction:
Improvebonding speedVSAvoidUV blocking by polarizer layers
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts or removes the UV blocking property from the adhesive system by selecting adhesive materials that do not require UV curing, such as heat-activated or moisture-curing adhesives, allowing the UV blocking polarizer layers to remain in place without interfering with the bonding process

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary curing mechanism (heat activation or moisture curing) that operates through the UV blocking layers, allowing adhesive bonding to proceed without direct UV transmission while maintaining bonding effectiveness

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the LC assembly is made flexible for impact resistance, then safety is improved, but optical clarity and structural rigidity are compromised

Engineering Contradiction:
Improveimpact resistanceVSAvoidoptical clarity
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The patent uses composite material structures combining flexible substrates (such as flexible polymer films) with rigid protective layers and optically clear adhesive materials, achieving both impact resistance through flexibility and optical clarity through the transparent composite structure

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent employs flexible thin film substrates and cover layers that can deform under impact to absorb energy while maintaining optical transparency, allowing the assembly to be flexible for safety yet optically clear for visibility

Inventive Principle:
Principle #30Flexible shells and thin films

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 proposed solution allows for the creation of dimmable LC assemblies that are impact-resistant, prevent fragmentation, and maintain optical clarity, making them suitable for use in vehicle windows and other safety-critical applications while enabling variable light transmittance for enhanced user comfort and safety.

Implementation Method 1

an LC assembly that is electrically controllable to vary the light transmittance of the LC assembly

Methodology Applied
Scientific EffectLiquid crystal electro-optic effect: Electro-Optic Effects

Implementation Method 2

the temperature and/or pressure is lowered by performing lamination in a vacuum environment

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP4109171B1Liquid crystal window bonding and sealing
Publication Date: 2025.05.21 WICUE USA INC
  • EP4109171B1 patent drawingFigure 1~2C
  • EP4109171B1 patent drawingFigure 3A~3C
  • EP4109171B1 patent drawingFigure 4

AI summary

Described herein are liquid crystal (LC) assemblies that are dimmable and techniques for manufacturing LC assemblies. In one example, an LC assembly comprises: a first curved glass panel, a second curved glass panel, and a liquid crystal panel having a first outer surface and a second outer surface, a layer of a liquid adhesive attaching the first curved glass panel and the first outer surface of the liquid crystal panel, and a film adhesive attaching the second curved glass panel and the second outer surface of the liquid crystal panel.