PDLC Display Dichroic Dye Alignment via Electric Field
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Solution Overview
Problem
Conventional polymer dispersed liquid crystal (PDLC) display devices face issues with dichroic dyes not being arranged in a regular direction within the polymer, leading to adverse effects on visibility and ultraviolet ray hardening characteristics due to random distribution and absorption.
Innovation Solution
A method involving the application of an electric field to a mixture solution of liquid crystals, photopolymerizable material, and dichroic dyes before ultraviolet irradiation to align dichroic dyes parallel to the electric field, ensuring they remain aligned within the polymer after hardening, while maintaining liquid crystal electric characteristics through the use of liquid crystalline polymers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If dichroic dyes are mixed in the PDLC layer, then improved contrast is achieved, but the dichroic dyes may be randomly distributed and adversely affect visibility
Solution Approach 1:
An electric field is applied to the mixture solution before the photopolymerization reaction occurs, causing the dichroic dyes to arrange themselves in a line along the electric field direction. This preliminary arrangement ensures that when the polymerization hardens the mixture, the dichroic dyes maintain their aligned configuration rather than being randomly distributed.
Solution Approach 2:
The patent changes the physical state and arrangement parameters of dichroic dyes by applying an electric field during the mixture solution phase. The electric field causes the dichroic dyes to transition from a random distribution to an aligned configuration parallel to the field direction, which is then preserved after photopolymerization.
2Illumination intensity
If dichroic dyes are arranged in a line by applying electric field before photopolymerization, then visibility is improved, but liquid crystals may lose their electric characteristic in the mixture solution
Solution Approach 1:
The patent modifies the composition parameters of the mixture solution by adding liquid crystalline polymers. These polymers change the overall characteristics of the mixture to maintain the electric responsiveness of liquid crystals while allowing dichroic dyes to arrange under an electric field. The liquid crystalline polymers help preserve the electric characteristics necessary for dichroic dye alignment.
3Manufacturing precision
If dichroic dyes exist in the polymer during ultraviolet hardening, then uniform dispersion is achieved, but the dichroic dyes continuously absorb ultraviolet rays and deteriorate hardening characteristics
Solution Approach 1:
The patent applies an electric field to arrange dichroic dyes in a line before the ultraviolet photopolymerization process. This preliminary arrangement reduces the random distribution of dichroic dyes that would otherwise cause continuous ultraviolet absorption. By pre-aligning the dichroic dyes, the ultraviolet rays can more effectively penetrate and harden the polymer.
Solution Approach 2:
The patent converts the harmful effect of dichroic dyes absorbing ultraviolet rays into a beneficial outcome by arranging them in parallel alignment. This ordered configuration allows ultraviolet rays to penetrate more effectively through the mixture solution, improving hardening characteristics while the dichroic dyes maintain their functional properties.
4Manufacturing precision
If electric field is applied to mixture solution before hardening, then dichroic dyes may be arranged, but they remain randomly arranged after hardening
Solution Approach 1:
The electric field is applied to the mixture solution during the liquid phase, before photopolymerization occurs. This timing is critical because the mixture solution allows the dichroic dyes to move and align along the electric field lines. Once aligned, the photopolymerization process locks this configuration in place, ensuring stability after hardening.
Solution Approach 2:
The patent utilizes the phase transition from liquid mixture solution to solid polymer through photopolymerization. During the liquid phase, dichroic dyes can move and align under the electric field. The phase transition to solid polymer then freezes this aligned configuration, maintaining stability and preventing random redistribution.
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
Improves visibility and ultraviolet ray penetration during hardening, reducing performance deterioration and enhancing the hardening characteristics of the polymer by maintaining dichroic dye alignment and reducing random absorption.
Implementation Method 1
applying an electric field between the first electrode and the second electrode... the dichroic dyes in the mixture solution may be arranged in parallel to the electric field when the electric field is applied
Implementation Method 2
irradiating the mixture solution with ultraviolet rays while the electric field is being applied so as to form a PDLC layer... hardening the mixture solution by using ultraviolet rays
Implementation Method 3
the dichroic dyes may be arranged according to the movement of the liquid crystals... the liquid crystals may be first arranged in a line by applying an electric field and then the dichroic dyes are arranged in a line by the movement of the liquid crystals
Data Source
AI summary
Example embodiments relate to a method of manufacturing a polymer dispersed liquid crystal (PDLC) display device including dichroic dye. The method may include filling a mixture solution including liquid crystals, a photopolymerizable material, dichroic dyes, and liquid crystalline polymers in a space between a first electrode and a second electrode that face each other; applying an electric field between the first electrode and the second electrode; and arranging the dichroic dyes in the mixture solution.