Liquid Crystal Display Temperature Control for Impurity Removal
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Solution Overview
Problem
Existing liquid crystal display technologies face challenges in effectively removing ionic impurities from the display region, leading to reduced transmittance and display quality, as they often rely on heating the liquid crystal layer to weaken adsorption forces, which can cause unnecessary deterioration of the liquid crystal material and fail to monitor impurity concentration timing effectively.
Innovation Solution
A method is introduced to control the temperature of the liquid crystal layer between 60°C and the nematic-isotropic phase transition temperature minus 20°C, using a transmittance measuring device to detect a 10% change in transmittance and then adjusting the cooling device to raise the temperature, while employing a trapping electrode to enhance impurity removal through electric fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the liquid crystal layer is heated to raise temperature to weaken adsorption force of ionic impurities, then ionic impurities can be swept out more effectively, but the liquid crystal material deteriorates faster
Solution Approach 1:
The patent changes the temperature parameter dynamically based on impurity concentration levels. When ionic impurity concentration exceeds a threshold (detected via transmittance change), the temperature is raised to 60-80°C to enhance impurity removal. When impurity concentration is below the threshold, the temperature is reduced to 20-40°C to minimize deterioration, thus optimizing both display quality and lifespan
Solution Approach 2:
The patent implements periodic temperature adjustment cycles based on monitored impurity concentration. The system alternates between high-temperature phases (for impurity removal when needed) and low-temperature phases (for preservation when impurity levels are acceptable), creating a rhythmic operational pattern that balances performance and durability
2Reliability
If the liquid crystal layer is heated continuously to maintain high temperature, then ionic impurities are continuously removed, but energy consumption increases and unnecessary deterioration occurs
Solution Approach 1:
The patent employs a feedback mechanism where the transmittance measuring device continuously monitors ionic impurity concentration and provides real-time information to the temperature control system. Based on this feedback, the temperature is adjusted dynamically - raised only when impurity concentration exceeds the threshold and reduced when it is acceptable - thereby eliminating continuous heating and reducing energy consumption while maintaining display quality
Solution Approach 2:
The system performs self-diagnosis and self-adjustment by autonomously monitoring its own impurity concentration levels through transmittance measurement and automatically adjusting temperature accordingly, without requiring external intervention or continuous high-energy input
3Loss of time
If transmittance measuring device is used to detect impurity concentration changes, then heating can be applied at appropriate timing, but device complexity increases
Solution Approach 1:
The patent uses transmittance (optical property) as an intermediary parameter to indirectly measure ionic impurity concentration. Instead of directly detecting impurities, the system measures light transmittance through the liquid crystal layer, which changes in response to impurity concentration. This intermediary approach enables timing-based temperature control without requiring complex direct impurity sensing equipment
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
This approach efficiently sweeps ionic impurities out of the display region, maintaining display quality by minimizing unnecessary heat exposure and effectively managing impurity concentration, thus prolonging the lifespan of the liquid crystal layer.
Implementation Method 1
raising temperatures of the liquid crystal layer to be equal to or more than a nematic-isotropic phase transition temperature Tni
Implementation Method 2
sweeps ionic impurities out of the display region by using an electric field generated with a trapping electrode provided outside the display region
Implementation Method 3
transmittance measuring device configured to measure a transmittance of the liquid crystal panel
Data Source
AI summary
A projection-type display device includes a liquid crystal device, a transmittance measuring device configured to measure a transmittance of a liquid crystal panel, and a cooling device. After a result of measurement of the transmittance by the transmittance measuring device changes by 10% relative to a default value, a control unit controls the cooling device to raise temperatures of a liquid crystal layer to be not less than 60° C. and not more than a nematic-isotropic phase transition temperature Tni-20° C. This makes it possible to efficiently sweep impurities from a display region to the outside of the display region without heating the liquid crystal layer more than necessary. In addition, a liquid crystal volume ratio V1/V2 of a liquid crystal device for blue among a plurality of liquid crystal devices is greater than that of the other liquid crystal panels, where V1 is a volume of liquid crystal at the inner side of a seal material, and V2 is a volume of the liquid crystal layer in the display region.