Light Control Element Using Glass Film and Resin Composite

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Solution Overview

Problem

Existing light control elements, particularly those with a light control layer sandwiched between two glass sheets, are heavy and cumbersome, while lighter alternatives with a light control film sandwiched between resin films face issues with surface flaws and durability over time.

Innovation Solution

A light control element comprising a glass film, a light control layer, and a pressure-sensitive adhesive layer, where the light control layer is sandwiched between the glass film and a resin film, allowing for flexibility and easy bonding to glass surfaces, with specific thickness and modulus of elasticity ranges for each component to ensure reliability and weight reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a light control layer is sandwiched between two glass sheets, then reliability and surface durability are improved, but weight and construction complexity increase significantly

Engineering Contradiction:
Improvesurface durabilityVSAvoidweight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent replaces one glass sheet with a thin resin film (30-150 μm thickness) that provides sufficient protection while dramatically reducing weight. The resin film serves as a flexible protective shell that maintains surface durability without the weight penalty of glass, directly resolving the contradiction between reliability and weight.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent creates a composite structure combining glass film (50-180 μm), light control layer, and resin film (30-150 μm) with specific modulus of elasticity ranges (glass: 5-20 GPa, resin: 2-10 GPa). This composite material approach optimizes the balance between durability, flexibility, and weight by selecting materials with complementary properties.

Inventive Principle:
Principle #40Composite materials

2Weight of moving object

If a light control film with resin films is used instead of glass sheets, then weight is reduced, but surface flaws and time-dependent deterioration occur

Engineering Contradiction:
ImproveweightVSAvoidsurface durability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent uses a thin resin film (30-150 μm) as a flexible protective shell that reduces weight while maintaining sufficient surface protection. The specific thickness range and modulus of elasticity (2-10 GPa) are optimized to prevent surface flaws and deterioration while keeping the structure lightweight.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The composite structure of glass film + light control layer + resin film creates a synergistic system where the glass provides rigidity and the resin provides flexibility and weight reduction, together achieving both light weight and high reliability.

Inventive Principle:
Principle #40Composite materials

3Strength

If thick glass sheets are used for the light control element, then strength and durability are improved, but flexibility and ease of bonding are reduced

Engineering Contradiction:
ImprovestrengthVSAvoidflexibility
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent employs thin films (glass: 50-180 μm, resin: 30-150 μm) instead of thick glass sheets, enabling the light control element to be bent to a radius of 20-80 mm. This thin-film approach maintains sufficient strength while achieving the required flexibility for bonding to curved or irregular surfaces.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent optimizes the thickness parameters of glass film (50-180 μm) and resin film (30-150 μm) to achieve a balance between strength and flexibility. By controlling these dimensional parameters within specific ranges, the element gains both adequate strength and the flexibility needed for easy bonding.

Inventive Principle:
Principle #35Parameter changes

4Weight of moving object

If thin glass or resin films are used, then weight and flexibility are improved, but impact resistance and scratch resistance are reduced

Engineering Contradiction:
ImproveweightVSAvoidimpact resistance
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent creates a composite sandwich structure where thin glass film (50-180 μm) and thin resin film (30-150 μm) work together with the light control layer to provide impact and scratch resistance. The combination of materials with different mechanical properties compensates for the reduced thickness, achieving both weight reduction and maintained strength.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The thin resin film (30-150 μm) acts as a flexible protective shell that, while thin, provides sufficient impact and scratch resistance when combined with the glass film and light control layer. The specific thickness and modulus of elasticity are optimized to prevent surface damage while maintaining flexibility.

Inventive Principle:
Principle #30Flexible shells and thin films

Data Source

PatentEP3779577B1Dimming element including glass film
Publication Date: 2024.10.23 NITTO DENKO CORP
  • EP3779577B1 patent drawingFigure 1~2
  • EP3779577B1 patent drawingFigure 3~4

AI summary

The present invention provides a light control element which has a light weight and high reliability and can easily be bonded to a glass surface or the like. The light control element of the present invention includes a glass film, a light control layer, a resin film, and a pressure-sensitive adhesive layer in the stated order, wherein the light control element has a bending radius of from 20 mm to 100 mm, and wherein the glass film has a thickness of from 50 µm to 200 µm.