Capacitive Touch Panel Barrier-Type 3D Display Noise Mitigation
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Solution Overview
Problem
Conventional touch control barrier-type 3D display devices experience accuracy issues due to transient barrier voltage noise and voltage leakage during scanning operations, affecting the accuracy of touch detection.
Innovation Solution
The proposed method involves performing sensing voltage readout operations only when the transient barrier voltage noise is below a preset value, using driving signals with different pulse amplitudes based on the barrier voltage polarity to minimize noise and leakage effects, and conducting raw data processing and coordinate calculations during noise-free periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the touch IC performs scanning operation continuously, then the touch detection function is maintained, but the transient barrier voltage noise causes wrong touched point coordinates
Solution Approach 1:
The patent applies preliminary action by performing a preliminary scanning operation before the formal scanning operation. This preliminary scan detects and identifies noise periods caused by barrier voltage transients, allowing the system to avoid performing formal scanning during these problematic periods. The preliminary action prepares the system by marking noisy time segments, ensuring that subsequent measurements avoid these regions and thus maintain coordinate accuracy.
Solution Approach 2:
The patent implements feedback by using the results of the preliminary scanning operation to control whether the formal scanning operation should be performed. The system feeds back the identified noise period information to the scanning control logic, which then adjusts the timing of formal scans to avoid noisy periods. This feedback mechanism dynamically adapts the scanning schedule based on real-time noise conditions, maintaining measurement precision.
2Measurement precision
If the driving voltage level is larger than the barrier voltage level, then the touch IC can detect touch status, but voltage leakage occurs on the data readout lines
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the driving voltage amplitude based on the barrier voltage polarity. When the barrier voltage is positive, the driving voltage uses one amplitude level; when the barrier voltage is negative, the driving voltage uses a different amplitude level. This parameter adaptation allows the system to maintain sufficient signal levels for accurate touch detection while minimizing voltage leakage by optimizing the driving voltage magnitude for each barrier voltage condition.
3Productivity
If the scanning operation is performed during barrier voltage transient, then the touch detection process continues, but the noise affects the accuracy of scanning operation
Solution Approach 1:
The patent uses preliminary scanning operation to identify noise periods before formal scanning. This preliminary action creates a map of problematic time regions, allowing the system to skip formal scanning during noisy periods while continuing to scan during clean periods. This approach maintains overall productivity by utilizing available noise-free time windows while preserving accuracy by avoiding contaminated measurement regions.
Solution Approach 2:
The patent implements periodic scanning operations interspersed with noise identification periods. Instead of continuous scanning, the system alternates between preliminary noise-detecting scans and formal data-collecting scans. This periodic structure allows the system to rhythmically assess noise conditions and adjust scanning activity accordingly, maintaining both productivity through continued operation and precision through selective scanning.
Data Source
AI summary
An exemplary operating method of a capacitive touch panel adapted to a touch control barrier-type three-dimensional display device and including a sensing device is disclosed. In the operating method, a sensing voltage readout operation is performed only during a signal caused by a transient of a barrier voltage is smaller than a preset value. The voltage readout operation includes steps of: providing a first driving signal to the sensing device for performing the sensing voltage readout operation during the barrier voltage is at a logic high level; and providing a second driving signal to the sensing device for performing the sensing voltage readout operation during the barrier voltage is at a logic low level. A pulse amplitude of the first driving signal is smaller than that of the second driving signal.