Liquid Crystal Display Shielding and Trap Electrodes for Ion Management
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Solution Overview
Problem
Liquid crystal display devices face issues with ion accumulation due to impurities and water entering from outside, leading to reduced brightness and black unevenness, as existing shielding electrodes are ineffective in preventing ion collection within the display area.
Innovation Solution
The implementation of a liquid crystal display device design featuring a shielding electrode and a trap electrode with different voltages, where the shielding electrode blocks ions and the trap electrode collects them, effectively preventing ion accumulation in the display area by positioning them in non-overlapping layers and using a conductive line to connect the driving circuit to the shielding electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a shielding electrode is provided between the counter-substrate and polarizer, then ions in the non-display area can be held to some extent, but ions still collect in the display area causing black unevenness
Solution Approach 1:
The patent divides the single shielding electrode into multiple segmented electrodes (first shielding electrode and second shielding electrode) positioned at different locations. The first shielding electrode is positioned to hold ions in one region of the non-display area, while the second shielding electrode holds ions in another region, collectively preventing ion migration into the display area more effectively than a single electrode could achieve.
Solution Approach 2:
The patent introduces a trap electrode as an intermediary component between the shielding electrode and the display area. This trap electrode actively captures and holds ions in the non-display area, serving as a mediator that prevents ions from migrating into the display area, thereby enhancing the shielding effect without directly blocking the entire ion path.
2Device complexity
If scanning lines extend outside the display area, then driving circuit can be provided on active-element substrate, but ions collect in the vicinity of scanning lines outside display area
Solution Approach 1:
The patent positions shielding electrodes and trap electrodes in advance within the non-display area, before ions can migrate from the scanning line regions. These electrodes are pre-configured to create electric fields that actively prevent ion accumulation near scanning lines, addressing the ion collection problem proactively rather than reactively.
Solution Approach 2:
The patent utilizes the electric fields naturally generated by the scanning lines and driving circuit, which originally cause ion collection, and converts them into beneficial effects. By strategically positioning shielding and trap electrodes, the same electric fields are harnessed to actively guide and hold ions in the non-display area, transforming the harmful ion collection effect into a controlled ion management mechanism.
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 blocks and collects ions in the non-display area, preventing them from entering the display area and maintaining image quality by reducing ion-induced brightness reduction and black unevenness.
Implementation Method 1
a shielding electrode and a trap electrode are provided in a non-display area. At least part of the trap electrode is provided in a different position from that of the shielding electrode as seen in plan view. The shielding electrode blocks ions
Implementation Method 2
the trap electrode collects them, effectively preventing ion accumulation in the display area by positioning them in non-overlapping layers
Data Source
AI summary
According to one embodiment, a liquid crystal display device includes an active-element substrate. The active-element substrate includes a display area, a non-display area, an image signal line, an active element including a scanning line and connected to the image signal line, a driving circuit, a common electrode, a first electrode electrically connected to the common electrode and provided in the non-display area, and a second electrode the voltage of which is lower than that of the common electrode, and which is provided in the non-display area. At least part of the second electrode is provided in a different position from that of the first electrode as seen in plan view. The scanning line is provided below the first electrode.