Depolarizing Fiber in Automotive Display Adhesive Layers

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Solution Overview

Problem

Existing liquid crystal display apparatuses face issues with visibility due to linear polarization, which is exacerbated by the use of sunglasses with polarization functions, and current depolarization plates with porous particles suffer from high haze and reduced transparency.

Innovation Solution

Incorporating depolarizing fibers with specific properties into both the adhesive and base material layers of the display apparatus, which eliminates linear polarization and enhances visibility without compromising transparency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a depolarization plate with porous particles is used to eliminate linear polarization, then the polarization is reduced, but the haze increases and transparency decreases

Engineering Contradiction:
Improvelinear polarizationVSAvoidtransparency
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The patent changes the key parameter from porous particle size (a few micrometers) to ultrafine fiber diameter (0.1-100 μm, preferably 1-10 μm). This parameter change allows the depolarizing material to scatter polarized light effectively while minimizing haze and maintaining high transparency, directly resolving the contradiction between polarization elimination and transparency preservation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system consisting of ultrafine fibers dispersed in a transparent resin matrix. This composite structure combines the depolarizing effect of the fibers with the transparency of the resin, achieving both polarization elimination and high transparency simultaneously, thereby resolving the contradiction between these two properties

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If porous particles with a few micrometers diameter are used for depolarization, then polarization elimination is achieved, but the depolarization plate becomes unsuitable for high transparency display apparatus

Engineering Contradiction:
ImprovepolarizationVSAvoidsuitability for high transparency display
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent fundamentally changes the size parameter from micrometer-scale porous particles to ultrafine fiber dimensions (0.1-100 μm). This parameter transformation enables the material to maintain high transparency while effectively eliminating polarization, making it suitable for high transparency display apparatus and resolving the reliability issue

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 effectively suppresses the generation of linear polarization, improves image clarity, and maintains high transparency, thereby enhancing the visibility of displayed images even when viewed through polarized sunglasses.

Implementation Method 1

a liquid crystal panel has a configuration, in which liquid crystal is filled into a gap between two glass plates, and a polarization plate is arranged on an outside of one of the glass plates, and accordingly, a displayed image displayed on the liquid crystal panel is linearly polarized in terms of principle

Methodology Applied
Scientific EffectPolarization elimination: Polarisation

Implementation Method 2

a haze (opacity) of the depolarization plate is increased by the fact that the porous particles become a diffusion source of incident visible light

Methodology Applied
Scientific EffectLight scattering: Scattering

Data Source

PatentEP2816396B1Display apparatus, automotive display apparatus, and method for manufacturing display apparatus
Publication Date: 2018.05.02 NISSAN MOTOR CO LTD
  • EP2816396B1 patent drawingFigure 1(a)~1(i)
  • EP2816396B1 patent drawingFigure 2(a)~2(f)
  • EP2816396B1 patent drawingFigure 3~4

AI summary

A display apparatus includes: a liquid crystal panel (31); a touch panel (31) placed on the liquid crystal panel (31); a base material layer (37, 40) stacked on the touch panel (34); and an adhesive layer (36, 39) interposed between the touch panel (34) and the base material layer (37, 40). Fiber having properties to solve polarization is contained in at least one of the base material layer (37, 40) and the adhesive layer (36, 39).