Thin Polarizer Durability via Transparent Resin Layer

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Thin polarizers used in liquid crystal display devices are prone to damage and light leakage due to their mechanical weakness and lack of durability, especially when exposed to heat, as they lack protective films on both sides.

Innovation Solution

A method involving a laminate with a carrier film and a thin polarizer, where the carrier film is peeled off and replaced with a transparent resin layer to enhance durability, and a pressure-sensitive adhesive layer is applied for improved adhesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If a thin polarizer is used to reduce the thickness of the polarizing film, then the overall thickness of the display device is reduced, but the mechanical strength and durability of the polarizer deteriorate, causing damage and light leakage

Engineering Contradiction:

Improvethickness of polarizing filmVSAvoidmechanical strength of polarizer

Core Design Contradiction:

Length of stationary objectVSStrength

Solution Approach 1:

The patent applies composite materials by combining the thin polarizer with a protective film to form a laminated structure. The protective film has specific mechanical properties (tensile strength ≥ 20 MPa, elongation at break ≥ 100%) that compensate for the weakness of the thin polarizer, while maintaining overall thinness. This composite structure resolves the contradiction by providing both reduced thickness and enhanced strength.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent uses a flexible protective film with specific mechanical properties (tensile strength ≥ 20 MPa, elongation at break ≥ 100%) that can withstand the stresses of handling and application without cracking the thin polarizer. The protective film acts as a flexible shell that protects the fragile thin polarizer while allowing the overall structure to remain thin and adaptable.

Inventive Principle:

Principle #30Flexible shells and thin films

2Ease of manufacture

If the carrier film is peeled off from the thin polarizer, then the polarizer can be used in its final application, but the shock from peeling causes surface removal or cracking of the polarizer

Engineering Contradiction:

Improveease of carrier film removalVSAvoidintegrity of polarizer during peeling

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies beforehand cushioning by providing a protective film on the polarizer before the carrier film is peeled off. This protective film acts as a cushion that absorbs the shock and stress of the peeling process, preventing surface removal and cracking of the thin polarizer. The protective film is designed with appropriate adhesion properties to stay attached during peeling while allowing easy removal of the carrier film.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Length of stationary object

If no protective film is provided on the carrier film side to maintain thinness, then the polarizing film thickness is reduced, but the polarizer becomes vulnerable to damage and light leakage in heated environments

Engineering Contradiction:

Improvethickness of polarizing filmVSAvoidsusceptibility to heat and mechanical damage

Core Design Contradiction:

Length of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent uses composite materials by creating a laminated structure where the protective film is specifically designed with thermal and mechanical properties that protect the thin polarizer from heat-induced damage and mechanical stress. The protective film has high tensile strength and elongation at break, providing durability while maintaining the thin overall structure of the polarizing film.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent applies parameter changes by carefully controlling the thickness and mechanical properties of the protective film to achieve optimal protection. The protective film is designed with specific parameters (tensile strength ≥ 20 MPa, elongation at break ≥ 100%) that provide sufficient protection against heat and mechanical damage while keeping the overall film thin. The adhesion strength between layers is also optimized to prevent delamination under thermal stress.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10088705B2Method for producing polarizing film

Publication Date: 2018.10.02 NITTO DENKO CORP

AI summary

A method for producing a polarizing film includes (1) preparing a laminate (a) which includes a carrier film and a polarizer with a thickness of 10 μm or less formed on one surface of the carrier film and contains a polyvinyl alcohol-based resin; (2) peeling off the carrier film from the laminate (a); and (3) applying a liquid material to a side of the laminate (a) from which the carrier film has been peeled off and then solidifying or curing the liquid material to form a transparent resin layer with a thickness of 0.2 μm or more, wherein the liquid material contains a resin component or a curable component capable of forming a resin layer. This production method enables the achievement of a polarizing film which is able to have satisfactory durability in a heated environment even in cases where a thin polarizer is used therefor.