OLED Pixel Structure with Center Subpixel for Leakage Current Management

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Solution Overview

Problem

Current OLED display devices face issues of low transmittance, low luminous efficiency, and high power consumption due to leakage between adjacent anodes in standard RGB or Delta pixel arrangements, which worsen with higher Pixel Per Inch (PPI) densities.

Innovation Solution

A pixel structure comprising a center sub-pixel surrounded by first, second, and third sub-pixels, where the minimum distance between the center sub-pixel and surrounding sub-pixels within a pixel unit is smaller than the distance between adjacent pixel units, allowing leakage current to flow to the center sub-pixel for light emission, thereby improving transmittance and luminous efficiency while reducing power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If standard RGB or Delta pixel arrangement is used, then device complexity is reduced and manufacturing is simplified, but transmittance decreases, luminous efficiency decreases, and power consumption increases

Engineering Contradiction:

Improvepixel arrangement simplicityVSAvoidpower consumption

Core Design Contradiction:

Ease of manufactureVSLoss of energy

Solution Approach 1:

The pixel structure is segmented into multiple sub-pixels (first, second, third, and center sub-pixels) with different functions. The center sub-pixel specifically captures leakage current from surrounding sub-pixels, separating the light emission function from the charge collection function, thereby reducing energy loss while maintaining manufacturing simplicity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The leakage current that was previously causing energy loss and color crosstalk is converted into a beneficial resource by directing it to the center sub-pixel for light emission. This transforms the harmful leakage effect into useful luminous output, improving luminous efficiency and reducing power consumption

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Device complexity

If standard RGB or Delta pixel arrangement is used, then device complexity is reduced, but transmittance decreases and luminous efficiency decreases

Engineering Contradiction:

Improvepixel structure complexityVSAvoidluminous efficiency

Core Design Contradiction:

Device complexityVSIllumination intensity

Solution Approach 1:

The patent introduces a new spatial dimension by placing a center sub-pixel within the region surrounded by other sub-pixels, creating a nested pixel configuration. This dimensional change allows the center sub-pixel to capture leakage current that would otherwise be lost, thereby improving luminous efficiency without significantly increasing overall device complexity

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The center sub-pixel serves multiple functions: it acts as a light-emitting element, a charge collection node for leakage current, and a means to reduce color crosstalk. This multi-functionality improves luminous efficiency and transmittance while adding minimal structural complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Manufacturing precision

If higher PPI density is used, then display resolution is improved, but leakage between adjacent anodes increases

Engineering Contradiction:

Improvepixel densityVSAvoidleakage current

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The center sub-pixel acts as an intermediary element that intercepts and redirects leakage current before it can cause harmful effects like color crosstalk or energy loss. This intermediary structure effectively manages the increased leakage problem associated with higher PPI densities

Inventive Principle:

Principle #24Intermediary (Mediator)

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 enhances transmittance and luminous efficiency by up to 75% and reduces power consumption, as demonstrated in a 0.71-inch full high definition Micro OLED display device, while also mitigating color crosstalk issues.

Implementation Method 1

drain a leakage current between at least one of the first sub-pixel, the second sub-pixel, and the third sub-pixel in the at least one pixel unit and the center sub-pixel to the center sub-pixel

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

driving the center sub-pixel to emit light

Methodology Applied

Scientific EffectLight emission: Electroluminescence

Data Source

PatentUS11832491B2Pixel structure with different distance between adjacent subpixels and pixels, display substrate and driving method therefor, and display device

Publication Date: 2023.11.28 HEFEI BOE OPTOELECTRONIC TECH CO LTD

AI summary

A pixel structure, a display substrate and a driving method therefor, and a display device. The pixel structure includes a plurality of pixel units; each pixel unit comprises a first sub-pixel, a second sub-pixel, a third sub-pixel, and a central sub-pixel; the central sub-pixel is located in an area enclosed by the first sub-pixel, the second sub-pixel, and the third sub-pixel; the minimum distance from the central sub-pixel to at least one of the first sub-pixel, the second sub-pixel, and the third sub-pixel in a same pixel unit is less than the distance between two adjacent pixel units.