Touch Panel Force Position Sensing Segmentation
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Solution Overview
Problem
Current touch panels face challenges in efficiently sensing both touch position and touch force due to structural limitations, increased parasitic capacitance, and complex manufacturing processes, which hinder their application and accuracy in force sensing.
Innovation Solution
A touch panel design incorporating a first touch sensor for force sensing and a second touch sensor for position sensing, utilizing an elastic dielectric layer on a cover substrate and a timing controller to manage touch driving signals, allowing for simultaneous and efficient detection of touch force and position, while minimizing interference with display driving.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an elastic dielectric is provided on the TFT array substrate to sense touch force, then touch force sensing capability is improved, but display driving is interfered with and manufacturing complexity increases
Solution Approach 1:
The touch sensing function is segmented into two independent parts: touch force sensing (first touch sensor with elastic dielectric on cover substrate) and touch position sensing (second touch sensor using common electrode). This segmentation allows each sensor to be optimized for its specific function without interfering with display driving or each other, resolving the contradiction between force sensing capability and manufacturing complexity.
Solution Approach 2:
The elastic dielectric layer 160 acts as an intermediary element that enables touch force sensing without requiring modification of the TFT array substrate. By placing the elastic dielectric on the cover substrate rather than the TFT substrate, the invention mediates between the need for force sensing and the requirement to maintain simple display manufacturing processes.
2Area of stationary object
If all touch electrodes are sensed by self capacitance method with multiple channels, then complete touch coverage is achieved, but touch driver size increases and parasitic capacitance increases
Solution Approach 1:
The touch sensing is segmented into two independent sensing systems: first touch sensor for force sensing and second touch sensor for position sensing. This segmentation allows each sensor to use optimized sensing methods, reducing the overall complexity and parasitic capacitance compared to a single comprehensive sensing system.
Solution Approach 2:
The common electrode serves multiple functions: it acts as both a display electrode and a touch position sensing electrode (second touch sensor). This multi-functionality reduces the need for separate dedicated touch electrodes, thereby reducing touch driver size and parasitic capacitance while maintaining complete touch coverage.
3Measurement precision
If touch driving time is increased to sense both position and force, then sensing accuracy is improved, but display period is shortened
Solution Approach 1:
The touch sensing is divided into two independent sensing operations: touch force sensing and touch position sensing. This segmentation allows the system to perform both sensing functions within the available time frame without requiring an extended total sensing time, thereby maintaining adequate display period.
Solution Approach 2:
The first touch sensor provides touch force sensing information that allows the system to partially determine touch characteristics without completing full position sensing for all electrodes. This partial action approach enables the system to gather sufficient sensing data within limited time, maintaining both sensing accuracy and display period.
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 design enhances touch sensing efficiency by reducing the touch driving time and improving accuracy in both touch position and force sensing, while maintaining sufficient display period and image quality, thus addressing the limitations of existing technologies.
Implementation Method 1
an elastic dielectric layer 160 which changes in thickness when a force of a touch is applied to the display panel 101
Implementation Method 2
the first touch sensor 140, 120, 130 supplied with a first touch driving signal TDS1 to sense a touch force by using an all point self capacitance touch method
Data Source
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AI summary
Disclosed is a touch sensing display device capable of sensing both touch position and touch force, shortening a driving time for the touch sensing, and improving touch sensing efficiency, and an apparatus for driving thereof. The display device can include a color filter (112), a plurality of first touch electrodes (140) for touch force sensing, and a plurality of second touch electrodes (120) for touch position sensing and separated from the first touch electrodes (140) by the color filter (112). The display can also include a force sensing touch driver (310) for the first touch electrodes (140) and a touch position touch driver (320) for the second touch electrodes (120).