Display Device Common Electrode Segmentation for Uniform Luminance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The resistance of the common electrode in light-emitting displays leads to non-uniform voltage application, affecting luminance uniformity and increasing power consumption.

Innovation Solution

Incorporating low-resistance metal wires for common voltage transmission and connecting the common electrode to these wires, with connection wires made of the same material as the pixel electrode or conductive layer, to maintain uniform voltage distribution and facilitate resistance measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the common electrode is used to transmit common voltage to light-emitting elements, then the display device can be simplified without separate light sources, but voltage drop occurs due to resistance leading to non-uniform luminance

Engineering Contradiction:

Improvedisplay device structureVSAvoidluminance uniformity

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The common electrode is divided into multiple segments (first common electrode, second common electrode, third common electrode) positioned at different locations. Each segment connects to separate common voltage transmission lines, distributing the voltage transmission paths to reduce overall resistance and voltage drop, thereby improving luminance uniformity across the display.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Common voltage transmission lines are introduced as intermediary conductors between the common voltage source and the segmented common electrode. These transmission lines provide low-resistance pathways, mediating the voltage transmission to minimize voltage drop across the common electrode and ensure uniform voltage distribution to all light-emitting elements.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If low-resistance metal wires are used for common voltage transmission, then voltage drop is reduced, but contact resistance between common electrode and wires becomes a measurement challenge

Engineering Contradiction:

Improvevoltage uniformityVSAvoidcontact resistance

Core Design Contradiction:

Manufacturing precisionVSDifficulty of detecting and measuring

Solution Approach 1:

Test pads are introduced as intermediary measurement points between the common voltage transmission lines and external measurement equipment. These pads provide accessible contact points that allow indirect measurement of contact resistance at the interface between the common electrode and transmission lines, making the measurement process feasible despite the low resistance of the metal wires.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The measurement approach is substituted from direct physical contact measurement to electrical measurement through the test pads. By using electrical measurement methods through the pad structure, contact resistance can be detected and measured without requiring direct mechanical or physical access to the wire-electrode interface.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If the common electrode spans the entire display area, then voltage distribution is simplified, but resistance increases causing power consumption to increase

Engineering Contradiction:

Improvevoltage transmission systemVSAvoidpower consumption

Core Design Contradiction:

Device complexityVSUse of energy by stationary object

Solution Approach 1:

The common electrode is segmented into multiple separate electrodes positioned at different locations across the display area. Each segment connects to common voltage transmission lines, creating multiple parallel voltage transmission paths. This segmentation reduces the resistance of individual paths and allows for more efficient power distribution, reducing overall power consumption while maintaining a relatively simple voltage transmission system architecture.

Inventive Principle:

Principle #1Segmentation

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

Improves voltage drop at the common electrode, ensures uniform luminance, and allows for contact failure detection and repair, thereby enhancing display quality and reducing power consumption.

Implementation Method 1

a common voltage transmission line which is disposed in the non-display area and transmits a common voltage, a common voltage line disposed in the display area and connected with the common voltage transmission line

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

Due to the resistance of the common electrode and a consequent voltage drop, the level of the common voltage applied to the light-emitting elements may not be uniform

Methodology Applied

Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentUS12446424B2Display device

Publication Date: 2025.10.14 SAMSUNG DISPLAY CO LTD

AI summary

A display device includes a substrate including a display area and a non-display area surrounding the display area, a common voltage transmission line which is disposed in the non-display area and transmits a common voltage, a common voltage line disposed in the display area and connected with the common voltage transmission line, a common electrode disposed in the display area and the non-display area and connected with the common voltage line, a first pad disposed in the non-display area and connected with the common electrode, and a second pad disposed in the non-display area and connected with the common voltage transmission line.