OLED Cathode Multiplexing for Force Touch Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional force touch display devices increase in thickness due to the addition of separate pressure sensing and touch layers, which contradicts the trend of thinning in display technology, affecting competitiveness.
Innovation Solution
A force touch display device incorporating an organic light emitting diode (OLED) layer with a strain layer and a touch function layer, where the cathode includes a pressure detecting pattern, and the touch function layer comprises induction and drive electrode chains, allowing for touch and pressure detection without increasing the device thickness by multiplexing the cathode as pressure induction electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate pressure sensing layer and touch layer are added to achieve force touch functionality, then force touch capability is improved, but device thickness increases
Solution Approach 1:
The patent merges the pressure sensing layer and touch layer into a single integrated layer structure. The pressure sensing layer includes both first electrode chains and second electrode chains that serve dual purposes: detecting pressure through capacitance changes and detecting touch through their interaction with touch electrodes, thereby eliminating the need for separate layers and reducing device thickness.
Solution Approach 2:
The pressure sensing layer is designed with multi-functionality, where the first electrode chains serve both as pressure sensing elements (detecting capacitance changes due to pressure) and as touch sensing elements (interacting with touch electrodes to detect touch events). This universal design allows a single layer to perform multiple functions that traditionally required separate layers.
2Measurement precision
If conventional force touch structure with separate layers is used, then pressure detection accuracy is improved, but device complexity increases
Solution Approach 1:
The patent combines pressure detection and touch detection functions into a single pressure sensing layer with integrated electrode chains. This merging reduces the number of discrete layers and components, simplifying the overall device structure while maintaining the capability to detect both pressure and touch events through the same integrated system.
Solution Approach 2:
The first electrode chains in the pressure sensing layer are designed to serve dual functions: detecting pressure through capacitance changes and detecting touch through interaction with touch electrodes. This multi-functional design reduces device complexity by eliminating redundant components while preserving measurement precision for both pressure and touch detection.
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 force touch functionality without thickness increase, enhancing competitiveness by integrating touch and pressure detection within the existing OLED structure, maintaining the thin form factor while providing varied user experiences.
Implementation Method 1
When it operates, holes from the anode and electrons from the cathode are emitted to the organic light emitting layer, a combination of these electrons and holes generates pairs of excitatory electron-holes, and the pairs of excitatory electron-holes are transferred from excited state to ground state to achieve light emission.
Implementation Method 2
The touch function layer comprises a touch substrate layer disposed on the strain layer, a plurality of induction electrode chains paralleling one another at intervals and disposed on the touch substrate layer, and a plurality of drive electrode chains paralleling one another at intervals disposed on the touch substrate layer, wherein the induction electrode chains insulatively intersect the drive electrode chains
Implementation Method 3
a strain layer disposed on the OLED layer... when force touch is performed, touch detection is performed by the touch function layer, and pressure detection is performed by cooperation of the cathode and the touch function layer
Data Source
AI summary
The present invention provides a force touch display device and a force touch control method. The force touch display device includes a substrate, an organic light emitting diode (OLED) layer disposed on the substrate, a strain layer disposed on the OLED layer, and a touch function layer disposed on the strain layer; wherein the OLED layer comprises an anode disposed on the substrate, a light emission layer disposed on the anode, and a cathode disposed on the light emission layer and comprising a pressure detecting pattern; wherein when force touch is performed, touch detection is performed by the touch function layer, and pressure detection is performed by cooperation of the cathode and the touch function layer. By multiplexing the cathode of the OLED as a pressure induction electrodes, the force touch can be achieved without increase of a thickness of a product to improve competitivity.