Touch Substrate Pressure Sensing via Mutual-Capacitance Integration
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Solution Overview
Problem
Current pressure sensing technologies in display devices, such as mobile phones and tablets, face challenges in achieving high detection accuracy due to structural design changes and large assembly tolerances, necessitating a more efficient method for pressure sensing with minimal hardware modification.
Innovation Solution
A touch substrate with touch pressure driving electrodes and sensing electrodes forming a mutual-capacitance structure, integrated with a touch detection chip, allows for simultaneous touch and pressure detection by altering capacitance values, enabling two-dimensional touch detection with reduced parasitic capacitance interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If additional parts are added in the backlight part of the LCD panel or the frame part to achieve pressure sensing, then pressure sensing function is achieved, but structural design complexity increases and assembly tolerance becomes larger
Solution Approach 1:
The patent combines pressure sensing electrodes with the existing touch screen electrode structure, integrating pressure sensing functionality into the existing touch display device without adding separate structural components. The pressure sensing electrodes are formed on the same substrate as the touch detecting electrodes, merging multiple functions into a unified structure.
Solution Approach 2:
The touch screen substrate serves multiple functions: it acts as both the touch detection interface and the pressure sensing interface. The same substrate carrier supports both touch detecting electrodes and pressure sensing electrodes, making the structure multi-functional and eliminating the need for separate pressure sensing components.
2Adaptability or versatility
If additional parts are added in the backlight part of the LCD panel or the frame part to achieve pressure sensing, then pressure sensing function is achieved, but detection accuracy is limited due to large assembly tolerance
Solution Approach 1:
By merging the pressure sensing electrodes with the touch screen electrode structure on the same substrate, the patent eliminates assembly interfaces between separate components. This integration removes assembly tolerance accumulation, thereby improving detection accuracy while maintaining pressure sensing functionality.
3Ease of manufacture
If touch pressure driving electrodes and sensing electrodes are integrated in the same layer as touch detecting electrodes, then manufacturing is simpler, but parasitic capacitance interference increases
Solution Approach 1:
The patent resolves the conflict between manufacturing simplicity and parasitic capacitance by transitioning from a two-dimensional planar arrangement to a three-dimensional stacked arrangement. Pressure sensing electrodes are placed in different layers from touch detecting electrodes, vertically separating them to reduce parasitic capacitance while maintaining manufacturing feasibility through multi-layer deposition processes.
4Adaptability or versatility
If separate pressure sensing structure is added outside the touch substrate, then pressure sensing is achieved, but hardware modification becomes more significant
Solution Approach 1:
The patent merges pressure sensing functionality directly into the touch substrate by forming pressure sensing electrodes on the same substrate carrier. This integration eliminates the need for separate pressure sensing structures and reduces hardware modification to minimal process additions, achieving pressure sensing as an inherent function of the touch display device.
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 solution enhances detection accuracy for both touch position and pressure sensitivity by minimizing hardware changes and integrating touch and pressure detection functions within existing display device structures, effectively addressing the limitations of existing technologies.
Implementation Method 1
each of the touch pressure driving electrodes and a corresponding touch pressure sensing electrode constituting a mutual-capacitance structure
Implementation Method 2
detect a change of capacitance value of each of the touch detecting electrodes so as to determine a touch position
Implementation Method 3
detect a change of signal amount of each of the touch pressure sensing electrodes caused by a pressure on the touch position
Data Source
AI summary
A touch substrate, a display device and a driving method thereof, touch pressure driving electrodes and touch pressure sensing electrodes provided between the layer where the touch detecting electrodes is located and the substrate carrier are added within the touch substrate, and the touch pressure sensing electrodes and the touch pressure driving electrodes constitute a mutual-capacitance structure. When the touch substrate is pressed, the distance between the touch substrate and the underlying metal layer becomes small, causing that capacitance value of the mutual-capacitance structure becomes small. During the time period for detecting pressure, through applying the touch driving signal to the touch pressure driving electrodes to detect the change of signal amount of the touch pressure sensing electrodes caused by the pressure on the touch position, the change of the capacitance value of the mutual-capacitance structure can be determined to achieve the function of pressure sensing. During the time period for detecting touching, the touch detecting electrodes, the touch pressure driving electrodes, and the touch pressure sensing electrodes are applied with the same touch detecting signal simultaneously, the touch position can be determined by detecting the change of the capacitance value of each of the touch detecting electrodes, and the function of the two-dimensional detection of touching can be realized.