Liquid Crystal Display Device Slit Electrode Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-definition liquid crystal display devices for VR face challenges in maintaining transmittance due to pixel downsizing, domain generation, and decreased holding capacitance, which leads to flickering and limited liquid crystal material options for high response speed.
Innovation Solution
A liquid crystal display device structure featuring a scan line and video signal line with specific tilting angles, a three-layer electrode structure for holding capacitance, and slits in the common electrode to minimize domain formation and maintain transmittance, allowing for the use of high-speed liquid crystal materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pixel size is reduced for high definition display, then display resolution is improved, but light transmittance decreases
Solution Approach 1:
The common electrode is divided into multiple segments with slits formed therein, allowing light to pass through the slits while maintaining the electrode's electrical function. This segmentation enables the electrode to occupy less area, increasing the effective light transmission area in downsized pixels.
Solution Approach 2:
The slit structure creates local variations in the common electrode, with specific regions (slits) optimized for light transmission while other regions maintain electrical conductivity. This local quality differentiation allows simultaneous optimization of both light transmittance and electrical function in high-definition pixels.
2Measurement precision
If pixel size is reduced for high definition display, then display resolution is improved, but holding capacitance decreases
Solution Approach 1:
Multiple electrode layers (first electrode, second electrode, third electrode) are combined to form a composite electrode structure. This merging of multiple electrodes creates sufficient holding capacitance area even when individual pixel size is reduced, as the cumulative capacitance from multiple electrode interfaces compensates for the smaller pixel area.
Solution Approach 2:
The electrode structure extends into the vertical dimension with multiple layers (first electrode, second electrode, third electrode) separated by insulating films. This dimensional expansion allows holding capacitance to be increased by utilizing vertical stacking rather than relying solely on horizontal pixel area, thus maintaining capacitance in downsized pixels.
3Speed
If liquid crystal material is changed for high response speed, then response speed is improved, but domain generation increases
Solution Approach 1:
The harmful domain formation is extracted and eliminated by introducing slits in the common electrode. These slits modify the electric field distribution, preventing the reverse rotation of liquid crystal molecules that causes domain generation, thus allowing use of fast-response liquid crystal materials without domain issues.
Solution Approach 2:
The electric field distribution parameter is changed by introducing slits in the common electrode. This parameter change modifies how the electric field acts on liquid crystal molecules, preventing the conditions that lead to domain formation while maintaining high response speed characteristics.
4Reliability
If common electrode area is increased for holding capacitance, then holding capacitance is improved, but light transmittance decreases
Solution Approach 1:
The common electrode is segmented into multiple parts with slits, creating a structure where conductive regions provide holding capacitance while slit regions allow light transmission. This segmentation enables the electrode to fulfill both electrical and optical functions simultaneously without compromising either performance.
Solution Approach 2:
The common electrode is implemented as a thin film structure with slits, allowing it to be transparent in slit regions while maintaining electrical continuity through the conductive material. This thin film approach with integrated slits enables sufficient capacitance with minimal optical obstruction.
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 solution enhances transmittance and stability, prevents flickering, and expands the range of liquid crystal material options for high-definition displays, ensuring natural image quality and high response speed.
Implementation Method 1
A liquid crystal display device has a TFT substrate, a counter substrate opposing to the TFT substrate, and a liquid crystal layer sandwiched between the TFT substrate and the counter substrate. The TFT substrate has plural pixels arranged in matrix form; each of the pixels has a pixel electrode and a thin film transistor (TFT). A transmittance of light in each of the pixel is controlled by liquid crystal molecules; thus, images are formed.
Implementation Method 2
Another problem is a decrease in holding capacitance. The holding capacitance is formed between the pixel electrode and the common electrode; when the pixel becomes smaller, the pixel electrode becomes smaller; as a result, the holding capacitance decreases. If the holding capacitance becomes smaller, the flickers in the display occur.
Implementation Method 3
In addition, in the liquid crystal display device, the domain is generated due to a reverse rotation of the liquid crystal molecules in certain places; the light doesn't transmit the boundary between the domain and the normal region, thus, the a generation of the domain further decreases the transmittance of the pixel.
Data Source
AI summary
The purpose of the invention is to avoid the domain in high definition liquid crystal display devices. The representative structure is as follows. Scan lines extending in a first direction, video signal lines extending in a second direction, a pixel is formed in an area surrounded by the video signal lines and the scan lines, the pixel includes: a thin film transistor, a flattening film that covers the thin film transistor, a first electrode formed on the flattening film, a second electrode formed over the first electrode via an insulating film, and a contact hole that is formed in the flattening film to connect the first electrode and the thin film transistor; the second electrode is formed in common in plural pixels, and has a slit between the video signal lines; wherein the slit is formed continuously in a plurality of pixels arranged in the second direction.