Light Emitting Element Shared Cathode Resolution

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Solution Overview

Problem

The existing light emitting elements have limited resolution due to the minimum size constraint of light emitting units, which is determined by the combined size of anode and cathode electrodes, making it difficult to further reduce the size and increase the number of units.

Innovation Solution

The light emitting units are divided into sets, sharing a common electron transport layer and cathode electrode, with a conductive pattern in the periphery to reduce resistance and a light blocking hood to prevent optical crosstalk, allowing for smaller unit sizes and increased density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If each light emitting unit has separate anode and cathode electrodes, then the structure is simple and easy to manufacture, but the minimum size of light emitting unit is constrained by the combined size of both electrodes, limiting resolution improvement

Engineering Contradiction:
ImproveresolutionVSAvoidstructure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges the cathode electrodes of multiple light emitting units into a shared common cathode electrode. Specifically, multiple light emitting units are arranged in sets where units in the same set share a common cathode electrode, reducing the number of discrete electrode structures while maintaining individual unit functionality. This merging approach directly reduces the minimum size constraint and improves resolution.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent segments the electrode structure by separating the anode and cathode functions. Each light emitting unit retains its own anode electrode for independent control, while the cathode is segmented into shared common cathodes for groups of units. This segmentation allows independent addressing of units while reducing overall electrode count and size constraints.

Inventive Principle:
Principle #1Segmentation

2Area of moving object

If light emitting units are reduced in size to increase density, then resolution improves, but the combined size of anode and cathode electrodes prevents further size reduction

Engineering Contradiction:
Improvelight emitting unit sizeVSAvoidresolution
Core Design Contradiction:
Area of moving objectVSManufacturing precision

Solution Approach 1:

By combining multiple cathode electrodes into shared common cathodes, the patent eliminates redundant electrode structures. Light emitting units within the same set share the common cathode, allowing the anode electrode to be positioned closer to the light emitting layer without requiring separate cathode structures for each unit. This directly enables further size reduction of individual light emitting units.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent reorganizes the electrode layout by introducing a shared dimension for cathode electrodes. Instead of each unit having its own cathode in the same plane, multiple units share a common cathode structure that extends across multiple units, effectively utilizing the dimensional space more efficiently and allowing tighter packing of units.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Device complexity

If multiple light emitting units share a common electron transport layer and cathode electrode, then the number of electrodes is reduced and size is minimized, but current distribution uniformity may be affected

Engineering Contradiction:
Improvenumber of electrodesVSAvoidcurrent distribution uniformity
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies local quality by providing separate conductive patterns in the electron transport layer for each light emitting unit, even though they share a common cathode. These localized conductive patterns ensure that each unit receives appropriate current distribution while maintaining the shared cathode structure. This local differentiation maintains current uniformity despite the shared global cathode structure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The conductive patterns in the electron transport layer act as intermediaries between the shared common cathode and the individual anode electrodes. These intermediary conductive structures distribute current uniformly from the shared cathode to each light emitting unit, ensuring reliable current distribution while maintaining the benefits of the shared electrode architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3451393B1Light-emitting element and method for preparing same
Publication Date: 2021.04.07 BOE TECHNOLOGY GROUP CO LTD
  • EP3451393B1 patent drawingFigure 1~2
  • EP3451393B1 patent drawingFigure 3~4
  • EP3451393B1 patent drawingFigure 5~6

AI summary

The present invention discloses a light emitting element and a fabrication method thereof. The light emitting element includes: an anode electrode, a hole transport layer, a light emitting layer, an electron transport layer and a cathode electrode, all of the light emitting units are divided into a plurality of light emitting sets, each light emitting set includes at least two light emitting units and the light emitting units in a same light emitting set share a same electron transport layer and a same cathode electrode. In the technical solutions of the present invention, all of the light emitting units in a same light emitting set share a same electron transport layer and a same cathode electrode, thus effectively reducing the number of the cathode electrodes. In this case, there is no need to provide a cathode electrode in areas corresponding to a part of the light emitting units, and the part of the light emitting units can have a minimum size approximately equal to the size of the anode electrode. As compared with the prior art, sizes of a part of the light emitting units in the light emitting element can be effectively reduced in the technical solutions of the present invention, which allows the number of light emitting units that can be provided in the light emitting element to be increased, and further facilitates improving resolution of the light emitting element.