Flexible OLED Display Touch Sensing Integration

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Solution Overview

Problem

The integration of a touch screen panel with flexible organic light-emitting display devices results in increased thickness, manufacturing costs, and reduced flexibility due to the use of add-on type touch screen panels with glass substrates, which complicates the manufacturing process and degrades the device's flexibility.

Innovation Solution

A method of manufacturing a flexible organic light-emitting display device that integrates the touch sensing unit within the upper flexible substrate assembly, eliminating the need for a separate touch substrate by forming the first and second electrode patterns on the color filter layer, thereby reducing thickness, simplifying the manufacturing process, and enhancing flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an add-on type touch screen panel with glass substrate is attached to the organic light-emitting display device, then touch sensing functionality is achieved, but the thickness of the device increases

Engineering Contradiction:
Improvetouch sensing functionalityVSAvoiddevice thickness
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent merges the touch screen panel with the color filter substrate by integrating the touch sensing electrode patterns directly onto the color filter layer. This consolidation eliminates the need for a separate add-on touch screen panel and its glass substrate, thereby reducing overall device thickness while maintaining touch sensing functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The color filter substrate is given multiple functions: it serves both as the color filter layer for the display and as the substrate for the touch sensing electrode patterns. This multi-functionality approach eliminates the need for separate dedicated touch screen components, reducing thickness without compromising touch sensing capability.

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

2Reliability

If an add-on type touch screen panel with glass substrate is used, then touch sensing functionality is achieved, but the manufacturing cost increases

Engineering Contradiction:
Improvetouch sensing functionalityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By combining the touch sensing electrode patterns with the color filter layer manufacturing process, the patent eliminates the need for separate touch screen panel production and assembly. This integration reduces the number of manufacturing steps, material layers, and assembly operations, thereby lowering manufacturing costs while maintaining touch sensing functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The color filter substrate performs dual functions as both the color filter and touch sensing substrate. This multi-functionality reduces the total component count and material requirements, simplifying the manufacturing process and reducing costs associated with producing and assembling separate touch screen panels.

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

3Reliability

If an add-on type touch screen panel with glass substrate is attached, then touch sensing functionality is achieved, but the manufacturing process becomes more complex

Engineering Contradiction:
Improvetouch sensing functionalityVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the touch sensing electrode pattern formation with the color filter layer fabrication process. This integration reduces the total number of manufacturing steps, eliminates intermediate assembly operations, and simplifies the overall manufacturing process while ensuring proper alignment and functionality of the touch sensing elements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The color filter substrate serves multiple purposes including color filtering and touch sensing substrate functions. This multi-functionality reduces the number of separate components and assembly steps required, thereby simplifying the manufacturing process and reducing process complexity.

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

4Reliability

If an add-on type touch screen panel with glass substrate is used, then touch sensing functionality is achieved, but the flexibility of the device deteriorates

Engineering Contradiction:
Improvetouch sensing functionalityVSAvoidflexibility
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

By integrating the touch sensing electrode patterns directly onto the color filter layer, the patent eliminates the need for a separate glass substrate in the touch screen panel. This merger removes the rigid glass layer that compromises flexibility, allowing the flexible display device to maintain its bendable characteristics while retaining touch sensing functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The color filter substrate performs both color filtering and touch sensing substrate functions. This multi-functionality eliminates the need for a separate rigid glass substrate, enabling the device to maintain flexibility while providing effective touch sensing capability through the integrated electrode patterns.

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

Data Source

PatentEP2939230B1Flexible organic light-emitting display device and method for manufacturing the same
Publication Date: 2021.03.03 LG DISPLAY CO LTD
  • EP2939230B1 patent drawingFigure 1~2a
  • EP2939230B1 patent drawingFigure 2b~2d
  • EP2939230B1 patent drawingFigure 3a~4a

AI summary

A flexible organic light-emitting display device and a method of manufacturing the flexible organic light-emitting display device are provided. The flexible organic light-emitting display device comprises a lower flexible substrate assembly and an upper flexible substrate assembly that are bonded by a bonding layer. The lower flexible substrate assembly includes a first flexible substrate, a thin film transistor formed on the first flexible substrate, a white organic light-emitting element formed on the thin film transistor, and an encapsulation layer formed on the white organic light-emitting element. The upper flexible substrate assembly comprises a second flexible substrate, an interlayer and a touch sensing unit formed on the interlayer layer. The interlayer may be at least one of a color filter layer, a transparent resin layer, an insulating film layer and a second flexible substrate.