Liquid-Crystal Light-Adjusting Member Near-Infrared Reflectance

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Solution Overview

Problem

Existing liquid crystal light adjusting elements with indium tin composite oxide (ITO) exhibit poor near-infrared ray reflectance properties, leading to inadequate heat shielding when exposed to sunlight, and adding an IR reflective layer increases thickness and production costs.

Innovation Solution

A liquid crystal light adjusting member with a light transmitting electrically conductive layer comprising a first inorganic oxide layer, a metal layer, and a second inorganic oxide layer, where the second oxide layer is semicrystalline, providing high near-infrared reflectance without the need for an IR reflective layer, thereby reducing thickness and production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an IR reflective layer is bonded to the surface of a substrate to improve heat shielding properties, then the near infrared ray reflectance is improved, but the thickness of the liquid crystal light adjusting element is increased and the production cost is increased

Engineering Contradiction:
Improveheat shielding propertiesVSAvoidthickness
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent combines the IR reflective layer and the light transmitting electrically conductive layer into a single integrated layer. This merged layer simultaneously provides both heat shielding properties and electrical conductivity, eliminating the need for separate layers and thus reducing overall thickness while maintaining improved heat shielding performance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs a composite material structure where the IR reflective layer is formed by combining metal particles (for IR reflection) with transparent resin (for light transmission and structural integrity). This composite approach enables the layer to achieve both heat shielding and optical transparency functions within a thin profile, avoiding the thickness increase that would result from adding separate functional layers.

Inventive Principle:
Principle #40Composite materials

2Reliability

If an IR reflective layer is bonded to the surface of a substrate to improve heat shielding properties, then the near infrared ray reflectance is improved, but the production cost is increased

Engineering Contradiction:
Improveheat shielding propertiesVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the IR reflective layer and the light transmitting electrically conductive layer into a single layer that performs both functions. This reduces the total number of layers that need to be manufactured and assembled, thereby simplifying the production process and reducing production costs while maintaining improved heat shielding properties.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a multi-functional layer that simultaneously provides IR reflection, light transmission, and electrical conductivity. This universal layer eliminates the need for multiple separate layers, reducing manufacturing complexity and production costs while achieving the desired heat shielding performance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 achieves excellent near-infrared ray reflectance, efficiently shielding heat rays from sunlight while maintaining a reduced thickness and lower production costs for the liquid crystal light adjusting element.

Implementation Method 1

the metal layer having a high reflectance in a near infrared ray region

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

the refractive indices of the layers can be different even with the same thickness and material

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3438733B1Liquid-crystal light-adjusting member and liquid-crystal light-adjusting element
Publication Date: 2023.07.19 NITTO DENKO CORP
  • EP3438733B1 patent drawingFigure 1
  • EP3438733B1 patent drawingFigure 2A~2B
  • EP3438733B1 patent drawingFigure 3

AI summary

A liquid crystal light adjusting member sequentially includes a transparent substrate, a light transmitting electrically conductive layer, and a liquid crystal light adjusting layer. The light transmitting electrically conductive layer sequentially includes a first inorganic oxide layer, a metal layer, and a second inorganic oxide layer.