OLED Device with Vertically Stacked Segments for AC Driving

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Solution Overview

Problem

Existing OLED devices face inefficiencies in large area light sources due to high driving voltage and flickering issues, especially when AC driving is required, and they lack efficient methods for color mixing without additional diffusers.

Innovation Solution

The OLED device comprises serially connected organic light emitting diode segments with vertically stacked diodes having opposing conducting directions, sharing a common electrode for electrical connection, allowing for AC driving and color mixing without additional diffusers, and minimizing losses by using a single cathode interlayer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If OLED devices are segmented into small strips connected in series to increase efficiency, then the efficiency of the light source is improved, but the device complexity increases due to multiple connections and electrodes

Engineering Contradiction:
ImproveefficiencyVSAvoiddevice complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent merges the electrode structures of adjacent OLED segments by making the common electrode of one segment continuous with the segment electrode of the neighboring segment. This integration eliminates the need for separate connection electrodes and reduces the number of discrete components, thereby simplifying the device structure while preserving the efficiency benefits of segmentation

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The common electrode of each OLED segment serves dual functions: it acts as the common electrode for that specific segment and simultaneously serves as the segment electrode for the adjacent segment. This multi-functionality reduces the total number of electrodes required and simplifies the overall device architecture

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If anti-parallel connection of different OLED devices is implemented to permit AC driving and reduce flickering, then the quality of light emission is improved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveflickering reductionVSAvoidmanufacturing difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent combines multiple OLED segments with different conducting directions into a single integrated device structure. By making electrodes continuous across segment boundaries and stacking segments vertically, the invention achieves anti-parallel connection functionality without requiring separate devices to be manually connected, thereby simplifying manufacturing

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from a planar arrangement of segments to a vertical stacking configuration. This dimensional change allows multiple segments with opposing conducting directions to be integrated in the vertical dimension, enabling AC driving capability while maintaining a compact and manufacturable structure

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

3Stability of the object's composition

If additional diffusers are added to achieve color mixing in large area OLED devices, then the uniformity of light emission is improved, but the device complexity and production costs increase

Engineering Contradiction:
ImproveuniformityVSAvoidproduction costs
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent employs OLED segments with different conducting directions that emit light in complementary color ranges. Through the anti-parallel connection and vertical stacking configuration, these segments work together to produce a combined light output that achieves color mixing and uniformity intrinsically, without requiring additional diffusing elements

Inventive Principle:
Principle #25Self-service

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 efficiency, reduces flickering, and enables uniform light emission over large areas with reduced production costs, as it allows for AC driving and color mixing without additional diffusers, while maintaining high efficiency and scalability.

Implementation Method 1

Organic light emitting devices (OLEDs) are light emitting devices that use organic electroluminescent materials excited by electric current to emit light

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP2404483B1Organic light emitting diode device comprising a sequence of serially connected organic light emitting diode segments
Publication Date: 2019.08.28 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP2404483B1 patent drawingFigure 1
  • EP2404483B1 patent drawingFigure 2
  • EP2404483B1 patent drawingFigure 3a~3b

AI summary

The invention relates to an organic light emitting diode segment (100) comprising two organic light emitting diodes (102; 104), wherein the organic light emitting diodes are vertically stacked with their conducting directions pointing in opposed directions, wherein in the stack the organic light emitting diodes (102; 104) are electrically connected to each other by a common shared electrode (112).