Touch Sensor Electrode Phasing to Reduce Display Flicker
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Solution Overview
Problem
Conventional Y-OCTA touch screen panels suffer from flickering issues on the display panel due to touch sensor operation, malfunction in Low Ground Mass (LGM) situations, and high power consumption, which existing solutions like dithering and adjusting driving voltage do not adequately address.
Innovation Solution
A touch input device with a touch sensor comprising first and second electrodes, where different driving signals with 180-degree phase reversal are applied to the second electrodes, and differential signals are processed to detect touch positions, reducing noise and flickering, and incorporating a control unit to manage these signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If dithering or voltage adjustment is used to reduce flicker, then flicker is partially reduced, but the problem is not completely solved and power consumption remains high
Solution Approach 1:
The touch sensor electrodes are divided into multiple groups (first electrode group and second electrode group) that are driven independently with different driving signals. This segmentation allows selective activation of electrode groups, reducing the overall operation time and power consumption while maintaining touch detection functionality. The division into groups enables the system to avoid driving all electrodes simultaneously, thereby reducing flicker and energy consumption.
Solution Approach 2:
The patent implements periodic driving of electrode groups where only certain groups are activated at specific time intervals rather than continuous operation. The control unit selectively drives the first and second electrode groups in a periodic manner, which reduces the duty cycle of touch sensor operation. This periodic action decreases power consumption and reduces flicker effects on the display panel while maintaining effective touch detection capability.
2Measurement precision
If touch sensor operates continuously to ensure accurate detection, then detection accuracy is maintained, but power consumption increases and flicker occurs
Solution Approach 1:
The patent implements dynamic control of electrode group driving where the control unit adaptively selects which electrode groups to drive based on operational needs. The driving scheme is not static but dynamically adjusted - the system can switch between driving different groups of electrodes based on touch detection requirements. This dynamic approach maintains detection accuracy when needed while reducing power consumption during normal operation by keeping some electrode groups inactive.
3Productivity
If all second electrodes are driven simultaneously to improve touch detection speed, then detection speed improves, but flicker increases on the display panel
Solution Approach 1:
The second electrodes are divided into multiple groups (first and second electrode groups) that are driven independently rather than all simultaneously. This segmentation allows the system to drive only the necessary electrode groups at any given time, maintaining touch detection capability while reducing the total number of active electrodes. By avoiding simultaneous driving of all second electrodes, the overall driving signal strength is reduced, thereby minimizing flicker effects on the display panel.
4Use of energy by moving object
If driving voltage is lowered to reduce power consumption, then power consumption decreases, but touch detection accuracy and reliability deteriorate
Solution Approach 1:
By dividing the electrodes into groups and selectively driving only the necessary groups, the system maintains sufficient signal strength for reliable touch detection while reducing the overall power consumption. The segmented approach ensures that when electrodes are driven, the signal quality remains high enough for accurate detection, but the reduced duty cycle and fewer active electrodes collectively lower the average power consumption.
Solution Approach 2:
The patent changes the driving parameters by implementing different driving schemes for different electrode groups rather than using a uniform low voltage across all electrodes. The control unit can adjust which groups are driven and with what signal characteristics, optimizing the balance between power consumption and detection reliability. This parameter variation allows maintaining reliability for driven electrodes while achieving overall power reduction.
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
The solution effectively prevents flickering, reduces touch operation time, and decreases power consumption while maintaining accurate touch detection even in LGM states, enhancing the overall performance of the touch input device.
Implementation Method 1
a touch sensor comprising a plurality of first electrodes and a plurality of second electrodes... different driving signals to be applied simultaneously to at least two second electrodes... a driving signal to be applied to the 2b electrode pattern... the driving signal is a signal of a phase which is reversed by 180 degrees from a driving signal applied to the 2a electrode pattern... detect a touch position of an object located on the touch sensor based on signals received from the plurality of first electrodes
Data Source
AI summary
A touch input device includes a touch sensor and a control unit. In one embodiment, the touch sensor includes first touch electrodes, second touch electrodes, first pen electrodes, and second pen electrodes. Each of the first touch electrodes includes a pair of electrode portions. A first electrode portion of the pair is disposed adjacent to a partial touch electrode of the second touch electrodes. A second electrode portion of the pair is disposed adjacent to a remaining touch electrode of the plurality of second touch electrodes. A first drive signal is simultaneously applied to a first electrode portion of the first touch electrode, and a second drive signal is simultaneously applied to a second electrode portion of the first touch electrode. The second driving signal is a signal of a phase of the first driving signal shifted by 180 degrees.