OLED Touch Sensing Layer Using Piezoelectric Pressure Member
Solution Overview
Problem
Existing organic light emitting display devices with integrated touch panels face challenges in sensing force touch due to increased thickness caused by mechanical elements, which affects user interface efficiency and device design.
Innovation Solution
An organic light emitting display device with a thin thickness that integrates a touch panel, featuring a touch sensing layer with a first and second touch electrode layer and a pressure reaction member, where the pressure reaction member can be made of piezoelectric or piezoresistive materials, allowing for sensing of touch position and force without the need for additional mechanical elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a mechanical element is disposed between the OLED means and a mounting structure to sense force touch, then force touch sensing capability is improved, but device thickness increases
Solution Approach 1:
The patent replaces the mechanical element-based force touch sensing system with an electrical field-based sensing system. The touch sensing layer uses transparent conductive oxide layers and signal processing circuits to detect touch forces through changes in electrical capacitance or resistance, eliminating the need for mechanical components and thereby reducing device thickness while maintaining sensing capability.
Solution Approach 2:
The patent introduces a touch sensing layer as an intermediary between the OLED display layer and the cover glass. This sensing layer, comprising transparent conductive oxide layers, acts as a mediator that can detect touch forces through electrical field changes without requiring direct mechanical contact or additional mechanical structures, thus preserving the slim form factor.
2Adaptability or versatility
If mechanical elements are added to the OLED device for touch sensing, then touch sensing function is improved, but device complexity increases
Solution Approach 1:
The touch sensing layer is designed to perform multiple functions: it serves as both the touch sensing element and part of the display structure. The transparent conductive oxide layers can function as both electrodes for touch sensing and as conductive layers integrated with the OLED structure, reducing the need for separate components and simplifying the overall device architecture.
Solution Approach 2:
The patent merges the touch sensing function with the existing OLED display structure by integrating the touch sensing layer directly onto the OLED means. The transparent conductive oxide layers are combined with the display's electrode structures, creating a unified multi-functional layer that reduces component count and structural complexity.
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
Enables efficient sensing of touch position and force with a reduced device thickness, enhancing user interface capabilities and maintaining a slim form factor.
Implementation Method 1
The pressure reaction member may include a piezoelectric material or a piezoresistive material
Implementation Method 2
The pressure reaction member may include a piezoelectric material or a piezoresistive material
Data Source
AI summary
Disclosed is an organic light emitting display device including an encapsulation layer covering a pixel array layer provided on a substrate and a cover window coupled to a touch sensing layer. The touch sensing layer may include a first touch electrode layer provided on the encapsulation layer, a second touch electrode layer provided on the first touch electrode layer, and a pressure reaction member provided between the first touch electrode layer and the second touch electrode layer. Electrical characteristic of the pressure reaction member may be changed according to force applied to the pressure reaction member.