Liquid Crystal Display Common Electrode Charge Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display devices face degradation due to electric charges from static electricity or moisture, leading to issues like flicker and burn-in when a common potential is applied to the counter substrate, which can also cause pseudo-vertical electric fields and display quality degradation.
Innovation Solution
A liquid crystal display device design where the common electrode and conductive light shielding layer on the counter substrate are electrically coupled via a protection circuit, allowing for the management of electric charges and preventing abnormal potentials that could affect display quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a common potential is applied to the counter substrate to remove electric charges, then the reliability is improved, but the display quality deteriorates due to pseudo-vertical electric fields causing flicker and burn-in
Solution Approach 1:
The patent divides the electrical connection between the common electrode and light shielding layer into two distinct modes: a first connection mode during normal display operation and a second connection mode for charge removal. This segmentation allows the system to optimize for different functional requirements at different times, avoiding the harmful pseudo-vertical electric fields during display while enabling effective charge management when needed.
Solution Approach 2:
The patent implements periodic switching between connection modes based on operational requirements. The switching circuit changes the electrical connection state between the common electrode and light shielding layer according to predetermined conditions, enabling the system to alternate between charge removal mode and normal display mode, thus preventing continuous exposure to harmful electric fields while maintaining reliability.
2Reliability
If the conductive light shielding layer is electrically coupled to the common electrode, then the electric charge management is improved, but the device complexity increases due to additional switching circuits
Solution Approach 1:
The switching circuit is designed to perform multiple functions: it controls the electrical connection between the common electrode and light shielding layer, manages electric charges, and adapts to different operational modes. By making the switching circuit multi-functional, the patent reduces the need for separate dedicated circuits for each function, thereby managing device complexity while maintaining comprehensive charge management capability.
Solution Approach 2:
The switching circuit automatically determines and switches between connection modes based on predetermined conditions without requiring external control. This self-service mechanism simplifies the overall system architecture by eliminating the need for complex external control circuits, as the switching circuit independently manages the electrical connection states based on its internal logic and detected conditions.
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 configuration effectively suppresses abnormal display issues such as unevenness, flicker, and burn-in by ensuring the conductive light shielding layer's potential is managed, improving overall display quality and reducing the impact of static electricity and moisture.
Implementation Method 1
a liquid crystal layer held between the first substrate and the second substrate, and a circular seal material arranged so as to surround the liquid crystal layer, in which the liquid crystal layer is driven by an electric field produced between the pixel electrode and the common electrode
Implementation Method 2
a counter substrate that includes a conductive light shielding layer and faces the pixel substrate
Implementation Method 3
the common electrode and the light shielding layer are electrically coupled to each other via a protection circuit
Implementation Method 4
the common electrode and the light shielding layer are electrically coupled to each other via a protection circuit, in which the potential of the light shielding layer is controlled to a predetermined potential by the drive circuit
Data Source
AI summary
A liquid crystal display device includes a pixel substrate, a counter substrate, and a liquid crystal layer. The pixel substrate includes a pixel electrode and a common electrode. The counter substrate has a conductive light shielding layer and faces the pixel substrate. The liquid crystal layer is sealed in between the pixel substrate and the counter substrate. The common electrode and the light shielding layer are electrically coupled to each other via a protection circuit.