Touch Substrate With Interlaced Electrodes For Flexible AMOLED
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional capacitive touch screens in flexible AMOLED displays face reduced sensitivity and accuracy due to large parasitic capacitance between touch electrodes and cathodes, leading to small capacitance changes that are difficult to detect.
Innovation Solution
A touch substrate design featuring interlaced and enclosed branch circuits with equal areas for touch electrodes, enhancing the distribution of the mutual capacitance electric field and increasing the effective parasitic capacitance change upon touch, thereby improving sensitivity and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If touch electrodes are directly manufactured on upper surfaces of thin-film encapsulation layers, then the display structure is compact and flexible, but the distance between touch electrodes and cathodes becomes small, resulting in large parasitic capacitance and reduced touch sensitivity
Solution Approach 1:
The patent introduces a third dimension by inserting an insulating layer between the touch electrode layer and cathode layer, vertically separating the electrodes that would otherwise be closely spaced in a planar configuration. This dimensional separation reduces parasitic capacitance while maintaining the compact overall structure of the display.
Solution Approach 2:
The patent introduces an insulating layer as an intermediary substance between the touch electrode and cathode. This intermediate layer acts as a mediator that reduces the direct capacitive coupling between the two electrodes, thereby reducing parasitic capacitance while allowing the electrodes to remain in close proximity for structural compactness.
2Ease of manufacture
If hollow metal mesh material is used for touch electrodes, then the electrode is flexible and manufacturable, but the actual effective conductive electrode area is smaller than traditional full-surface transparent ITO material, resulting in smaller capacitance change that is difficult to detect
Solution Approach 1:
The patent segments the touch electrode into multiple independent electrode patterns (first electrode pattern, second electrode pattern, third electrode pattern, fourth electrode pattern) arranged in an interlaced manner. This segmentation increases the total effective electrode area while maintaining the flexibility and manufacturability of the hollow metal mesh material, thereby enhancing capacitance change detection.
Solution Approach 2:
The patent utilizes multiple layers (first, second, third, and fourth electrode patterns at different positions) to increase the effective electrode area in the vertical dimension. This multi-layer interlaced configuration compensates for the limited area of hollow metal mesh material while preserving its manufacturing advantages.
3Measurement precision
If touch electrode area is increased to improve capacitance change detection, then capacitance change becomes larger and easier to detect, but the RC delay increases due to larger electrode area, reducing touch response speed
Solution Approach 1:
The patent divides the touch electrode into multiple smaller interlaced patterns rather than using a single large continuous electrode. This segmentation increases the total effective area for capacitance detection while reducing the RC delay by creating multiple smaller conductive paths with lower individual resistance and capacitance values.
Solution Approach 2:
The patent distributes electrode patterns across multiple layers in the vertical dimension, increasing effective area without proportionally increasing the planar footprint. This multi-layer configuration optimizes the balance between detection sensitivity and response speed by reducing parasitic effects while maintaining adequate sensing area.
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
The design enhances the sensitivity and accuracy of touch detection by increasing the parasitic capacitance change and reducing RC delay, allowing for more precise recognition of touch positions.
Implementation Method 1
The capacitive touch screens detect specific positions of finger touch by detecting capacitance change at the positions touched by the fingers
Implementation Method 2
a distance between touch electrodes and cathodes is small, resulting in large parasitic capacitance between driving electrodes (transmitters, TXs)/sensing electrodes (receivers, RXs) and the cathodes
Data Source
AI summary
A touch substrate and a display panel are provided. The touch substrate includes a plurality of touch units. Each of the touch units includes a first electrode and a second electrode disposed electrically insulated from each other. The first electrode includes a first main branch electrode extending along a first direction, and at least one first branch pattern and at least one third branch pattern respectively disposed on two sides of the first main branch electrode. The second electrode includes a second main branch electrode extending along a second direction perpendicular to the first direction, and at least one second branch pattern and at least one fourth branch pattern respectively disposed on two sides of the second main branch electrode.