Display Device Dummy Subpixels Suppress Bright Lines

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In display devices with charge transfer layers formed over the entire surface, bright lines appear at the end portions due to higher luminance emission, which is undesirable.

Innovation Solution

Incorporating a non-display region with dummy subpixels and a charge transfer layer that matches the display region's layer, preventing positive holes from accumulating and emitting light with unintended luminance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a charge transfer layer is formed over the entire surface of the display region, then the charge transfer function is improved, but bright lines appear at the end portions due to excessive luminance

Engineering Contradiction:

Improvecharge transfer functionVSAvoidluminance at end portions

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The patent divides the display region into two segments: a first display region where the charge transfer layer is formed, and a second display region (end portions) where the charge transfer layer is not formed. This segmentation allows the charge transfer function to be maintained in the first region while preventing excessive luminance and bright lines in the second region.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different structural configurations to different regions of the display. The charge transfer layer is selectively formed only in the first display region, creating a local quality difference that optimizes charge transfer where needed while avoiding the bright line problem in the end portions (second display region).

Inventive Principle:

Principle #3Local quality

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 suppresses the occurrence of bright lines by ensuring that positive holes are accumulated and directed within the non-display region, maintaining intended luminance levels.

Implementation Method 1

a charge transfer layer which is one layer provided between a lower electrode and a light-emitting layer

Methodology Applied

Scientific EffectCharge transport: Conduction (electrical)

Implementation Method 2

a light-emitting element including the lower electrode, the charge transfer layer, a light-emitting layer, and the upper electrode

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS20240407242A1Display device and method for manufacturing display device

Publication Date: 2024.12.05 SHARP DISPLAY TECHNOLOGY CORP

AI summary

A display device includes a substrate; a display region located on the substrate and provided with a plurality of pixels each including a plurality of subpixels; a non-display region located on the substrate, including a plurality of dummy subpixels provided along an end portion of the display region, and continued from the display region; a plurality of lower electrodes; a charge transfer layer; and an upper electrode. The plurality of subpixels provided in the display region each include a light-emitting element including the lower electrode, the charge transfer layer, a light-emitting layer, and the upper electrode in that order from the substrate side, and the plurality of dummy subpixels provided in the non-display region each include a non-emitting charge transfer element including the lower electrode, the charge transfer layer, and the upper electrode in that order from the substrate side.