Stripe Common Electrode Design for Low-Leakage High-Resolution Displays

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Solution Overview

Problem

Existing liquid crystal display devices face issues with wiring delay due to parasitic capacitance, light leakage, and reduced contrast, particularly in high-resolution displays with narrow pixel areas, which affect power consumption and viewing angle.

Innovation Solution

The display device incorporates a common electrode with stripe regions intersecting with signal lines, reducing parasitic capacitance and light leakage, and includes a large-capacitance capacitor with a high dielectric constant insulating film, enhancing aperture ratio and contrast.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the pixel area is reduced for high-resolution displays, then the resolution is improved, but the parasitic capacitance increases causing wiring delay

Engineering Contradiction:

Improvedisplay resolutionVSAvoidwiring delay

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts the common electrode from the traditional planar structure and reconfigures it as stripe-shaped regions. This extraction and reconfiguration reduces the overlapping area between the common electrode and signal lines, thereby reducing parasitic capacitance and wiring delay while maintaining high display resolution

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The common electrode is segmented into multiple stripe-shaped regions that extend in the row direction. This segmentation reduces the continuous overlapping area with signal lines, decreasing parasitic capacitance and improving signal transmission speed in high-resolution displays

Inventive Principle:

Principle #1Segmentation

2Illumination intensity

If the aperture ratio is increased, then the light transmission is improved, but the contrast ratio deteriorates due to light leakage

Engineering Contradiction:

Improveaperture ratioVSAvoidlight leakage

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The common electrode is divided into stripe-shaped regions that create distinct electric field zones. This segmentation allows for better control of liquid crystal alignment at pixel boundaries, reducing light leakage while maintaining high aperture ratio for improved light transmission

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The stripe-shaped common electrode creates localized electric field distributions that improve liquid crystal alignment specifically at critical boundary regions. This local quality enhancement reduces light leakage without compromising the overall aperture ratio

Inventive Principle:

Principle #3Local quality

3Adaptability or versatility

If the viewing angle is widened, then the display coverage is improved, but the image contrast deteriorates

Engineering Contradiction:

Improveviewing angleVSAvoidimage contrast

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The stripe-shaped common electrode segments the electric field distribution to improve liquid crystal alignment consistency across different viewing angles. This segmentation maintains contrast ratio while enabling wider viewing angle coverage

Inventive Principle:

Principle #1Segmentation

4Reliability

If the capacitor area is increased, then the capacitance value is improved, but the aperture ratio deteriorates

Engineering Contradiction:

Improvecapacitance valueVSAvoidaperture ratio

Core Design Contradiction:

ReliabilityVSArea of moving object

Solution Approach 1:

The stripe-shaped common electrode serves dual functions: it acts as the common electrode for liquid crystal control and simultaneously functions as one electrode of the storage capacitor. This multi-functionality eliminates the need for separate capacitor structures, maintaining high aperture ratio while providing sufficient capacitance value

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 design reduces wiring delay, minimizes light leakage, improves contrast, and lowers power consumption while maintaining a high aperture ratio and wide viewing angle, especially in high-resolution displays.

Implementation Method 1

a capacitor including the pixel electrode, the common electrode, and a nitride insulating film provided between the pixel electrode and the common electrode

Methodology Applied

Scientific EffectDielectric: Dielectric

Data Source

PatentUS20250264764A1Display device

Publication Date: 2025.08.21 SEMICON ENERGY LAB CO LTD

AI summary

A display device with less light leakage and excellent contrast is provided. A display device having a high aperture ratio and including a large-capacitance capacitor is provided. A display device in which wiring delay due to parasitic capacitance is reduced is provided. A display device includes a transistor over a substrate, a pixel electrode connected to the transistor, a signal line electrically connected to the transistor, a scan line electrically connected to the transistor and intersecting with the signal line, and a common electrode overlapping with the pixel electrode and the signal line with an insulating film provided therebetween. The common electrode includes stripe regions extending in a direction intersecting with the signal line.