Segmented OLED Cathode Layout for Higher Light Transmittance

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Solution Overview

Problem

As the area of each cathode increases in organic devices, the electrical resistance decreases, but the transmittance of light also decreases, posing a challenge in achieving high light transmission and functionality in display areas.

Innovation Solution

The organic device is designed with a second display area having a lower occupancy of the second electrode, where the electrode lines are arranged in a specific direction, allowing for increased transmittance by minimizing electrode connections and optimizing the arrangement of organic layers, thereby enhancing light detection and display capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the area of each cathode is increased to decrease electrical resistance, then the electrical resistance decreases, but the transmittance of light decreases

Engineering Contradiction:
Improveelectrical resistanceVSAvoidtransmittance of light
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The second electrode is divided into multiple electrode lines arranged in the first direction, with adjacent electrode lines not connected to each other. This segmentation reduces the overall electrode area while maintaining electrical functionality, thereby improving light transmittance without significantly increasing electrical resistance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrode sections are arranged to overlap the organic layers in the second direction, creating different local configurations. Some electrode sections have different shapes to optimize both electrical connection and light transmission properties in different regions of the device.

Inventive Principle:
Principle #3Local quality

2Reliability

If the occupancy of the second electrode is increased to improve electrical conductivity, then the electrical conductivity improves, but the transmittance of light decreases

Engineering Contradiction:
Improveelectrical conductivityVSAvoidtransmittance of light
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The second electrode is segmented into multiple discrete electrode lines rather than forming a continuous layer. This allows the electrode to provide sufficient conductivity through multiple parallel paths while minimizing the total area occupied, thus maintaining high light transmittance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrode lines are arranged in the first direction while electrode sections extend in the second direction to overlap organic layers. This multi-directional arrangement optimizes both conductivity (through length in first direction) and transmittance (by controlling area in both directions).

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

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 design increases the transmittance of light in the second display area, improving the functionality of sensors and reducing constructive interference, thus enhancing the overall performance of the organic device.

Implementation Method 1

an organic EL display device has become a focus of attention

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

A method of depositing the material of pixels on a substrate by vapor deposition is known

Methodology Applied
Scientific EffectVapor deposition: Physical Vapour Deposition

Data Source

PatentEP4020585B1Organic device, group of masks and manufacturing method for organic device
Publication Date: 2026.01.28 DAI NIPPON PRINTING CO LTD
  • EP4020585B1 patent drawingFigure 1
  • EP4020585B1 patent drawingFigure 2
  • EP4020585B1 patent drawingFigure 3

AI summary

An organic device may include a substrate, first electrodes on the substrate, organic layers on the first electrodes, and a second electrode on the organic layers. When viewed in a direction normal to the substrate, the organic device may include a first display area that includes the second electrode at a first occupancy, and a second display area that includes the second electrode at a second occupancy lower than the first occupancy. In the second display area, the organic layers may be arranged in intersecting first and second directions, and the second electrode may include electrode lines arranged in the first direction. Each electrode line may include electrode sections arranged in the second direction and overlapping the organic layers. Any adjacent two electrode sections in the second direction may be connected. The electrode sections may include first and second electrode sections respectively having different first and second shapes.