Integrated Touch and Pressure Sensor for Input Devices
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Solution Overview
Problem
Current touch input devices can only detect touch position and not the pressure magnitude, limiting their functionality in computing systems.
Innovation Solution
A capacitance type touch sensor with a pressure sensor integrated into the touch input device, using drive and receiving electrodes to detect changes in capacitance that correspond to touch pressure, allowing for the detection of both touch position and pressure magnitude.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a generic touch sensor panel is used to detect touch position, then the device is simple and easy to operate, but it cannot detect touch pressure magnitude
Solution Approach 1:
The patent combines a pressure sensor with a touch sensor panel into an integrated sensing system. The pressure sensor is positioned in direct contact with the touch sensor panel, allowing simultaneous detection of both touch position (via the touch sensor panel) and touch pressure magnitude (via the pressure sensor), thereby resolving the limitation of generic touch screens that can only detect position.
2Adaptability or versatility
If a pressure sensor is added to detect touch pressure, then pressure magnitude can be detected, but the device structure becomes more complex
Solution Approach 1:
The integrated sensing system serves multiple functions: the touch sensor panel detects touch position while the pressure sensor detects touch pressure magnitude. This multi-functional configuration allows the device to recognize various input types (tap, press, long-press) based on pressure levels, enhancing adaptability without requiring separate independent systems for each function.
3Measurement precision
If the pressure sensor is placed close to the display module, then touch pressure can be accurately detected, but it may affect display module integrity or image quality
Solution Approach 1:
The pressure sensor is positioned in direct contact with the touch sensor panel at the specific location where touch pressure needs to be measured, rather than being integrated throughout the entire display structure. This localized placement ensures accurate pressure detection at the point of contact while minimizing interference with the overall display module integrity and image quality.
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 accurate detection of touch pressure in addition to touch position, enhancing the operational capabilities of touch input devices without compromising display module integrity or image quality.
Implementation Method 1
A capacitance type touch sensor with a pressure sensor integrated into the touch input device, using drive and receiving electrodes to detect changes in capacitance that correspond to touch pressure
Data Source
Figure 1a~1b
Figure 2~4a
Figure 4b~4d
AI summary
A touch input device may be provided that includes: a cover; a display module disposed under the cover; and a pressure sensing unit disposed under the display module. The pressure sensing unit includes a first elastic foam, a pressure sensor disposed on the first elastic foam, and a first adhesive layer disposed between the first elastic foam and the pressure sensor. A change amount of a stress of the first elastic foam required for the first elastic foam to be compressed to half of the thickness thereof from its original state is less than the change amount of the stress of the first elastic foam required for the first elastic foam to be compressed from half of the thickness thereof to the thickness to which the first elastic foam is able to be maximally compressed.