Touch Sensor IC Phase Synchronization to Reduce Display Flicker
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Solution Overview
Problem
Electronic devices with touch screens experience flicker or screen flicker due to the close proximity of touch sensors and displays, which causes signal noise and deteriorates sensitivity and image quality.
Innovation Solution
The electronic device employs a touch sensor IC that applies measurement signals with different phases to the electrodes, ensuring that the application periods of these signals overlap with the display driving signal periods, thereby reducing noise interference and flicker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the touch sensor and display are placed in close proximity to achieve small-sized thin electronic devices, then device thickness is reduced, but signal noise increases causing flicker and deteriorating sensitivity and image quality
Solution Approach 1:
The patent applies periodic action by using different phases for measurement signals applied to different electrodes. The touch sensor IC alternates between first measurement signals with a first phase and second measurement signals with a second phase, creating a periodic pattern that desynchronizes noise from the display driving signal, thereby reducing flicker while maintaining close proximity between touch sensor and display
Solution Approach 2:
The patent changes the phase parameter of measurement signals to resolve the contradiction. By varying the phase of measurement signals applied to different electrodes (first phase vs. second phase), the system reduces noise interference and flicker effects while maintaining the thin device structure, thus changing a key signal parameter to eliminate harmful effects
2Measurement precision
If different frequencies are used for mutual capacitance measurement and self-capacitance measurement to improve measurement accuracy, then measurement precision is improved, but flicker or screen flicker occurs due to lack of synchronization with display driving signal
Solution Approach 1:
The patent uses periodic action with multiple phases to simultaneously achieve measurement precision and eliminate flicker. By applying first measurement signals with a first phase and second measurement signals with a second phase in an alternating periodic manner, the system maintains accurate capacitance measurements while the phase differences prevent synchronization with display driving signals, thereby eliminating flicker
Solution Approach 2:
The patent applies dynamics by making the measurement signal phases changeable and adaptive. The system dynamically switches between different phases (first phase and second phase) for different electrodes and measurement types, allowing flexible adjustment that maintains measurement precision while preventing flicker through non-synchronized phase relationships
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 effectively minimizes flicker and enhances the accuracy of touch position detection while maintaining image quality by synchronizing touch sensor measurements with display driving signals.
Implementation Method 1
The touch sensor IC may be configured to: provide a plurality of first measurement signals corresponding to a first phase to at least some first electrodes of the plurality of electrodes with a first periodicity, and provide a plurality of second measurement signals corresponding to a second phase different from the first phase to at least some second electrodes of the plurality of electrodes
Implementation Method 2
mutual capacitance may be formed between the electrodes. For example, when the touch panel is implemented as a capacitive type, the electronic device may apply a driving signal to at least one electrode of the touch panel, that is, a driving electrode, and the driving electrode may form an electric field
Implementation Method 3
the electronic device may measure the self-capacitance of each electrode
Data Source
AI summary
An electronic device according to an embodiment comprises: a display; a display-driving integrated circuit (IC) set to apply one or more driving signals to the display; a touch sensor including a plurality of electrodes; and a touch sensor IC configured to check an input position on the touch sensor, wherein the touch sensor IC is configured to: acquire, from the display-driving IC, a first vertical synchronization signal from among the one or more driving signals, provide a plurality of first measurement signals corresponding to a first phase at intervals of a first duration to at least a first portion of electrodes among the plurality of electrodes based on the acquisition of the first vertical synchronization signal, and, after providing the plurality of first measurement signals, provide a plurality of second measurement signals corresponding to a second phase, different from the first phase, at intervals of the first duration to at least a second portion of electrodes among the plurality of electrodes, wherein at least a portion of the application period of the plurality of first driving signals and the plurality of second driving signals can overlap with at least a portion of the application period of the one or more driving signals.