Integer-Multiple Touch Scanning for TPIC–DDIC Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Interference between touch chip (TPIC) signals and display driver chip (DDIC) signals in electronic devices with touch and display functions affects the displayed image, leading to issues like ghosting.
Innovation Solution
A touch scanning method is implemented where the touch scanning signal is output based on a second frame rate that is an integer multiple of the display's first frame rate, with synchronization and adjustable delays to minimize interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the touch scanning signal is output at a high frame rate to improve touch response speed, then touch responsiveness is improved, but interference with the display drive signal increases causing ghosting
Solution Approach 1:
The patent implements periodic action by setting the touch scanning frame rate as an integer multiple of the display frame rate (e.g., 240Hz touch scanning with 60Hz display). This periodic relationship creates synchronized timing cycles where touch scanning occurs at regular intervals that are harmonically related to the display refresh, reducing electromagnetic interference while maintaining high touch responsiveness.
Solution Approach 2:
The patent applies dynamics by making the touch scanning frame rate adjustable and dynamically configurable. The system can adaptively change the touch scanning frequency based on operational conditions, allowing optimization between touch response speed and interference reduction. The frame rate is not fixed but can be modified to balance performance and ghosting prevention.
2Loss of time
If the touch scanning frequency is increased to reduce touch detection latency, then touch detection speed is improved, but signal interference with DDIC increases
Solution Approach 1:
By establishing a periodic relationship where touch scanning frequency is an integer multiple of display frequency (e.g., 240Hz/60Hz = 4x), the system achieves high touch detection speed while the periodic synchronization ensures that scanning operations occur in coordinated cycles that minimize electromagnetic coupling and signal interference with the DDIC.
Solution Approach 2:
The patent changes the frequency parameter of the touch scanning signal from a fixed value to an adjustable parameter that can be set to different integer multiples of the display frame rate. This parameter flexibility allows optimization of touch detection latency by increasing frequency while simultaneously controlling signal interference through the integer multiple relationship with the display frequency.
3Object-affected harmful factors
If synchronous scanning is implemented to reduce interference, then signal interference is reduced, but touch scanning flexibility is limited
Solution Approach 1:
The patent resolves the contradiction between synchronous scanning and flexibility by implementing dynamic configurability. The touch scanning frame rate can be adjusted to different integer multiples of the display frame rate (2x, 3x, 4x, etc.), allowing the system to adapt to different operational requirements while maintaining the interference-reducing synchronous relationship. This dynamic parameter adjustment preserves adaptability within the constrained synchronous framework.
Data Source
AI summary
Embodiments of this application provide a touch scanning method, a touch chip, a display module, and an electronic device, and relate to the field of display technologies, to reduce interference between a TPIC signal and a DDIC signal. The touch scanning method is applied to a touch chip TPIC of a display, and the display is configured to receive a display drive signal based on a first frame rate. The touch scanning method includes: outputting a touch scanning signal to the display based on a second frame rate; receiving touch data fed back by the display; and outputting a touch scanning result based on the touch data, where the first frame rate is an adjustable frame rate, and the second frame rate is an integer multiple of the first frame rate.