Twist-Oriented Light Modulator for Wide Transmittance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light modulating devices using guest-host liquid crystal systems face limitations in widening the transmittance variable range due to low solubility of dichroic dyes and high amounts of chiral dopants, leading to liquid crystal defects and visibility issues.
Innovation Solution
A light modulating device with a twist orientation configuration, utilizing a specific d/p ratio of the liquid crystal layer thickness to pitch, maintained by a partition wall spacer, and incorporating a pressure-sensitive adhesive layer to enhance bonding and orientation, without liquid crystal alignment films on one substrate, allowing for wide transmittance variation without defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the amount of dichroic dye is increased to widen the transmittance variable range, then the transmittance ratio improves, but the solubility limitation is reached and liquid crystal defects occur
Solution Approach 1:
The patent changes the chemical composition parameters by introducing a chiral dopant with specific molecular structure (containing chiral center and aromatic ring) and controlling its concentration within 0.1-5 wt%, thereby modifying the liquid crystal system's optical properties to achieve wide transmittance ratio without exceeding solubility limits
Solution Approach 2:
The patent creates a composite liquid crystal system combining host liquid crystal molecules with chiral dopant guest molecules, where the chiral dopant forms a cholesteric phase that provides both optical modulation and structural stability, preventing liquid crystal defects while enabling wide transmittance variation
2Quantity of substance
If a large amount of chiral dopant is added to widen the transmittance variable range, then the transmittance ratio improves, but liquid crystal defects and visibility deterioration occur
Solution Approach 1:
The patent optimizes the chiral dopant concentration parameter within the specific range of 0.1-5 wt% and controls the cell gap thickness parameter within 5-50 μm, achieving the optimal balance for wide transmittance ratio while maintaining excellent visibility and preventing liquid crystal defects
Solution Approach 2:
The patent applies a moderate amount of chiral dopant (0.1-5 wt%) rather than excessive amounts, which is sufficient to achieve the desired optical modulation effect while avoiding the harmful side effects of over-concentration such as liquid crystal defects and visibility deterioration
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 device achieves a wide transmittance variable range with improved visibility and reduced defects by optimizing the d/p ratio and using a pressure-sensitive adhesive layer for enhanced substrate bonding, ensuring excellent optical properties and adhesive force.
Implementation Method 1
a device using a guest-host liquid crystal system changes light absorptivity of a liquid crystal layer by mixing a dichroic dye with respect to host molecules in the liquid crystal layer as guest molecules and changing the arrangement of the host molecules and guest molecules by a voltage applied to liquid crystals
Implementation Method 2
mixing a dichroic dye with respect to host molecules in the liquid crystal layer
Implementation Method 3
the liquid crystal layer is configured to implement a twist orientation
Data Source
Figure 1
Figure 2
Figure 3
AI summary
In the present application, it is possible to provide a light modulating device which has a wide transmittance variable range and does not cause problems such as liquid crystal defects or visibility deterioration, while implementing low transmittance in a black mode, and its use.