Blue-Phase LCD Comb-Electrode Drive for Hysteresis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display devices using polymer stabilized blue-phase liquid crystals suffer from hysteresis and delayed fall time due to high viscosity and lattice distortion, leading to unsharp images and burn-in issues.
Innovation Solution
A liquid crystal display device with a structure that includes a first and second substrate with comb-like electrodes, a blue-phase liquid crystal layer, and a drive circuit that sequentially applies electric fields in parallel and perpendicular directions to the substrates to modulate the liquid crystal layer, ensuring synchronized voltage application to the electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If polymer stabilized blue-phase liquid crystal with high permittivity anisotropy is used to reduce drive voltage, then drive voltage is reduced, but impurity ion imbalance occurs causing unsharp moving images and burn-in
Solution Approach 1:
The patent applies periodic alternating voltage to the liquid crystal layer. By switching the voltage polarity between positive and negative states, the periodic action prevents impurity ions from accumulating in one direction, thereby reducing ion imbalance while maintaining the benefits of high permittivity anisotropy liquid crystal for low drive voltage operation.
Solution Approach 2:
The patent introduces a preliminary voltage application step before normal display operation. This preliminary action involves applying a specific voltage to pre-position impurity ions or prevent their accumulation, thereby preventing burn-in and unsharp images before they occur during normal operation.
2Speed
If blue-phase liquid crystal is used to achieve high-speed response, then response speed is improved, but hysteresis occurs between applied voltage and transmittance
Solution Approach 1:
The patent employs periodic voltage reversal to counteract hysteresis effects. By alternately applying positive and negative voltages, the system resets the liquid crystal state periodically, eliminating the cumulative hysteresis that would otherwise cause instability in the voltage-transmittance relationship while preserving fast response characteristics.
3Stability of the object's composition
If high viscosity liquid crystal is used to maintain lattice structure, then optical isotropy is maintained, but fall time becomes longer than rise time
Solution Approach 1:
The patent uses periodic voltage reversal to address the asymmetric response time. During the voltage reversal cycle, the high viscosity liquid crystal is given time to return to its isotropic state, and the alternating polarity prevents permanent orientation changes, thereby reducing fall time while maintaining lattice structure stability during normal operation.
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 compensates for hysteresis and delay in fall time, improving image sharpness and reducing the risk of burn-in by controlling the electric field direction and voltage application, resulting in enhanced response times and dynamic range.
Implementation Method 1
a liquid crystal display device driving the blue-phase liquid crystal layer by an electric field developed between the first electrode and the second electrode
Implementation Method 2
The polymer stabilized blue-phase liquid crystal exhibits optical isotropy when no voltage is applied thereto and exhibits a characteristic that the optical anisotropy thereof changes when an electric field is applied thereto
Data Source
AI summary
Provided is a liquid crystal display device, including: a first substrate including a first electrode and a second electrode each including a plurality of linear electrodes and formed so as to be comb-like; a second substrate; a blue-phase liquid crystal layer; first drain lines and second drain lines extending in Y direction and provided side by side in X direction; gate lines extending in the X direction; a first thin film transistor for supplying a drain signal from one of the first drain lines to the first electrode; a second thin film transistor for supplying a drain signal from one of the second drain lines to the second electrode, which is plate-like and formed on the blue-phase liquid crystal layer side of the second substrate so as to cover at least a region in which pixels are formed.