Pixel Carrier Blocking Structure to Prevent Display Crosstalk

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Solution Overview

Problem

The formation of a common hole transport layer or electron transport layer across multiple pixels in self-luminous display devices leads to optical crosstalk, where carriers from one pixel inadvertently illuminate adjacent pixels, degrading display quality.

Innovation Solution

A display device design featuring island-shaped lower electrodes and a common first carrier transport layer with a carrier blocking section between adjacent pixels, preventing carrier transport between adjacent light-emitting elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a common carrier transport layer is formed across multiple pixels, then manufacturing steps are reduced and manufacturing costs decrease, but optical crosstalk occurs between adjacent pixels

Engineering Contradiction:

Improvemanufacturing stepsVSAvoidoptical crosstalk

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The common carrier transport layer is segmented into island-shaped regions corresponding to each pixel, with carrier blocking sections formed between adjacent pixels. This segmentation prevents carrier diffusion to adjacent pixels while maintaining the common layer structure, thereby eliminating optical crosstalk without significantly increasing manufacturing complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The carrier transport layer exhibits different properties in different regions: it has high carrier transport capability within each pixel area and carrier blocking capability between pixels. This local differentiation allows the layer to simultaneously enable efficient carrier transport to the light-emitting layer while preventing crosstalk to adjacent pixels

Inventive Principle:

Principle #3Local quality

2Reliability

If a common carrier transport layer is formed across multiple pixels, then foreign matter penetration is prevented and device reliability improves, but optical crosstalk occurs between adjacent pixels

Engineering Contradiction:

Improveprotection from foreign mattersVSAvoidoptical crosstalk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The continuous common carrier transport layer is divided into discrete island-shaped sections with carrier blocking sections between them. This segmentation maintains the protective function against foreign matter penetration while preventing carrier diffusion to adjacent pixels, thereby eliminating optical crosstalk while preserving reliability

Inventive Principle:

Principle #1Segmentation

3Object-affected harmful factors

If island-shaped electrodes and carrier blocking sections are implemented, then optical crosstalk is prevented, but device structure becomes more complex

Engineering Contradiction:

Improveoptical crosstalkVSAvoidstructure

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The carrier blocking function is merged into the common carrier transport layer itself through the formation of carrier blocking sections, rather than requiring separate blocking structures. This integration prevents optical crosstalk while minimizing structural complexity and maintaining manufacturing efficiency

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS12495665B2Display device having carrier blocking section between pixels

Publication Date: 2025.12.09 SHARP KK

AI summary

A display device includes a hole transport layer common to a plurality of light-emitting elements between a light-emitting layer and an anode electrode below thereof in the light-emitting element in each pixel. The hole transport layer includes a hole transport section that transports positive holes to the light-emitting layer, and an adjacent pixel hole blocking section that is formed in a portion between the light-emitting elements in adjacent pixels and blocks transportation of positive holes between the light-emitting elements in adjacent pixels.