Touch Control Chip Impedance Adjustment for Display Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As screens become thinner, the proximity of the touch control layer to the display layer causes interference patterns, known as water ripples, due to driving signals affecting the display, which negatively impacts user experience.
Innovation Solution
A touch control chip with a driving circuit that adjusts its impedance during specific intervals to minimize the influence of driving signals on the display layer, using resistances with different values or an adjustable resistance to increase impedance during pixel update intervals, thereby reducing signal interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the screen thickness is reduced to make the touch control layer closer to the display layer, then the display can be thinner and more compact, but driving signals from the touch control layer interfere with the display layer causing water ripple patterns
Solution Approach 1:
The patent applies dynamics by making the driving impedance adjustable rather than fixed. The control circuit dynamically changes the driving impedance based on the timing of pixel updates in the display layer, increasing impedance during sensitive intervals to reduce interference and decreasing it during other intervals to maintain signal strength. This dynamic adjustment resolves the contradiction between thin screen design and signal interference reduction.
Solution Approach 2:
The patent changes the electrical parameter of driving impedance to solve the interference problem. By varying the impedance value in response to display update timing, the system reduces harmful electromagnetic coupling between the touch control layer and display layer during critical moments, while maintaining normal operation during other times. This parameter change enables thin screen design without water ripple artifacts.
2Object-affected harmful factors
If the driving impedance is increased during display sensitive intervals to reduce interference, then water ripples are reduced, but signal attenuation increases
Solution Approach 1:
The patent implements periodic action by adjusting the driving impedance in sync with the periodic pixel update cycles of the display layer. The control circuit increases impedance during specific periodic intervals when pixels are being updated (creating water ripples) and decreases impedance during other intervals. This periodic adjustment ensures interference is reduced only when needed, while signal strength is maintained during normal operation, resolving the contradiction between interference reduction and signal attenuation.
Solution Approach 2:
The dynamic adjustment of driving impedance based on timing information allows the system to optimize the trade-off between interference reduction and signal strength. By making impedance a time-varying parameter rather than a fixed value, the system can tolerate higher attenuation during brief sensitive intervals in exchange for eliminating water ripples, while maintaining strong signals during the majority of the operation cycle.
Data Source
AI summary
A touch control chip, a coding method, and an electronic device are provided, which can effectively reduce influence of a coding signal of a touch control layer of a screen on a display layer. The touch control chip includes: a driving circuit configured to output the coding signal to a display layer of the screen; and a control circuit configured to adjust a driving impedance of the driving circuit during a period when the driving circuit outputs the coding signal, so that a value of the driving impedance in a display sensitive interval of the display layer is greater than a value of the driving impedance in a time interval outside the display sensitive interval, where the display sensitive interval includes a pixel update interval of the display layer, and the pixel update interval is the time interval for a pixel in the display layer to receive a data signal.