Optical Element Manufacturing with Reflection-Suppressing Support

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Solution Overview

Problem

The existing methods for manufacturing optical elements with liquid crystal layers suffer from unevenness in the alignment pattern due to reflection of light from the support surface, leading to suboptimal optical properties.

Innovation Solution

A method involving a support with a reflection-suppressing portion to minimize light reflection during the exposure process, using photo-alignable materials and polarized light interference patterns to form an optically-anisotropic layer with reduced in-plane unevenness, and a peeling step to transfer the optically-anisotropic layer for various applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the alignment film is irradiated with coherent light to form an alignment pattern, then the liquid crystal molecules can be aligned in the desired pattern, but light reflection from the support surface causes unevenness in the alignment pattern

Engineering Contradiction:

Improvealignment pattern uniformityVSAvoidlight reflection

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies an anti-reflection coating on the support surface to convert the harmful light reflection into a beneficial reduction of reflected light. The anti-reflection coating has a refractive index between that of air and the support material, reducing the reflection coefficient and preventing interference patterns that would otherwise cause alignment unevenness.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The anti-reflection coating acts as an intermediary layer between air and the support surface. This intermediate layer with graded refractive index reduces the abrupt impedance mismatch, thereby minimizing light reflection and the resulting interference effects during alignment film irradiation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If a reflection suppressing portion is added to the support, then light reflection is reduced, but the device complexity increases

Engineering Contradiction:

Improvealignment pattern uniformityVSAvoidsupport structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent modifies the optical parameters of the support surface by applying an anti-reflection coating with specific refractive index properties. This parameter change reduces the reflection coefficient without fundamentally altering the support structure, thereby maintaining simplicity while improving alignment uniformity.

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 method effectively reduces in-plane unevenness in the liquid crystal alignment, resulting in improved optical properties and desired diffraction capabilities for the optical elements.

Implementation Method 1

a photochemical reaction occurs in the alignment film by irradiating a surface opposite to a surface where the alignment film is formed with the polarized light in the exposure step

Methodology Applied

Scientific EffectPhotochemical reaction: Photo-oxidation

Implementation Method 2

the support includes a reflection suppressing portion that suppresses reflection of light in a wavelength range of at least a part of a light absorption band where a photochemical reaction occurs in the alignment film

Methodology Applied

Scientific EffectLight reflection suppression: Anti-Reflective Coating

Implementation Method 3

forming an optically-anisotropic layer on the alignment film... using a liquid crystal composition including a liquid crystal compound

Methodology Applied

Scientific EffectLiquid crystal alignment: Liquid Crystals

Data Source

PatentUS11815706B2Method of manufacturing optical element and optical element

Publication Date: 2023.11.14 FUJIFILM CORP

AI summary

Provided are a method of manufacturing an optical element in which an optically-anisotropic layer having a small amount of in-plane unevenness can be prepared, and an optical element. The method of manufacturing an optical element is a method of manufacturing an optical element, the optical element including an optically-anisotropic layer that is formed using a liquid crystal composition including a liquid crystal compound, an alignment film that aligns the liquid crystal compound, and a support, the method including: an alignment film forming step of forming the alignment film on one surface of the support; and an optically-anisotropic layer forming step of forming the optically-anisotropic layer on the alignment film, in which the alignment film includes a photo-alignable material, the alignment film forming step includes an exposure step of exposing different in-plane positions of the alignment film to light components having different polarization directions, and the support includes a reflection suppressing portion that suppresses reflection of light in a wavelength range of at least a part of a light absorption band where a photochemical reaction occurs in the alignment film by irradiating a surface opposite to a surface where the alignment film is formed with the polarized light in the exposure step.