Touch Detection Drive Signal Amplitude Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices with touch detection functions face challenges in improving touch detection sensitivity without affecting display operations, as existing methods often use the same drive signal for both display and touch detection, which can compromise display performance.
Innovation Solution
The implementation of a display device with multiple common drive electrodes and a scan drive section that applies distinct display and touch detection drive signals in a time-divisional manner, using a touch detection drive signal with a larger amplitude than the display drive signal to enhance sensitivity while minimizing interference with display operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the same drive signal is used for both display operation and touch detection operation, then the device complexity is reduced, but the touch detection sensitivity deteriorates
Solution Approach 1:
The drive signal configuration is segmented into two distinct signals: a display drive signal with smaller amplitude for normal display operation, and a touch detection drive signal with larger amplitude for enhanced touch sensitivity. The scan drive section separates the timing of these two operations, applying the appropriate signal at the appropriate time, thereby resolving the contradiction between device simplicity and detection precision.
Solution Approach 2:
The amplitude parameter of the drive signal is changed based on the operational mode. During touch detection periods, the amplitude is increased to improve sensitivity, while during normal display periods, the amplitude remains smaller to maintain display performance. This dynamic parameter adjustment resolves the contradiction between simplicity and precision.
2Measurement precision
If the waveform of the drive signal is devised to improve the touch detection property, then the touch detection sensitivity is improved, but the display operation is affected
Solution Approach 1:
The scan drive section implements periodic switching between display drive mode and touch detection drive mode. During touch detection periods, a waveform with larger amplitude variations is applied to improve detection sensitivity. During normal display periods, the standard display waveform is applied to maintain display stability. This periodic alternation allows both improved touch detection and stable display operation.
Solution Approach 2:
The system performs touch detection operations at predetermined timings when the display is not actively updating, or during periods when the display output is less sensitive to drive signal variations. This preliminary planning of when to apply enhanced detection waveforms prevents interference with critical display operations while still improving touch sensitivity when appropriate.
3Measurement precision
If a touch detection drive signal with larger amplitude is applied to the common electrode, then the touch detection sensitivity is improved, but the display quality deteriorates
Solution Approach 1:
The drive signal application is segmented into distinct time periods: touch detection periods where larger amplitude signals are applied to improve sensitivity, and display periods where standard amplitude signals are applied to maintain display quality. The scan drive section controls this segmentation, ensuring that high-amplitude signals are only applied during touch detection operations, thereby resolving the contradiction between detection precision and display quality.
Solution Approach 2:
The system periodically switches between touch detection mode and display mode. During touch detection periods, the common electrode receives drive signals with larger amplitude to enhance sensitivity. During display periods, the amplitude is reduced to maintain display quality. This periodic action allows the system to achieve both improved touch detection and maintained display quality without permanent degradation.
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 approach improves touch detection sensitivity while maintaining the integrity of display operations by using separate drive signals for display and touch detection, reducing the impact on display performance.
Implementation Method 1
a touch detection element which is of an electrostatic capacitance type and detects an external proximity object based on a touch detection drive signal
Data Source
AI summary
A display device with a touch detection function includes a plurality of common drive electrodes arranged side by side to extend in one direction, a display element performing display, based on a pixel signal and a display drive signal, a touch detection element of electrostatic capacitance type detecting an external proximity object based on a touch detection drive signal with an amplitude larger than that of the display drive signal, and a scan drive section performing first scan drive and second scan drive, the first scan drive allowing the plurality of common drive electrodes to be sequentially supplied with the display drive signal in a time-divisional manner, and the second scan drive allowing the plurality of common drive electrodes to be sequentially supplied with the touch detection drive signal in a time-divisional manner.