Touch Display Driving Circuit Noise Reduction via Periodic Mode Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional in-cell touch display panels face noise interference and accuracy issues due to changes in dielectric constants and capacitance between electrodes during different color/brightness levels, which existing solutions attempt to address by modifying the common electrode design, increasing costs.
Innovation Solution
A driving circuit and method that selectively operates in display or touch modes, performing touch detection during idle timeslots with minimal design changes, using a display data generating circuit and touch control circuit to transmit signals and detect capacitance changes on data lines, while synchronizing common electrode signals with touch driving signals to reduce noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If touch detection is performed during display operation, then continuous touch monitoring is achieved, but noise interference increases due to capacitance changes from color/brightness variations
Solution Approach 1:
The patent implements periodic touch detection by alternating between display mode and touch mode in dedicated time slots. During touch mode, the display is turned off and touch detection is performed, while during display mode, normal display operation occurs. This periodic switching eliminates noise interference from simultaneous display operations while maintaining continuous touch monitoring capability through regular detection cycles.
Solution Approach 2:
The patent extracts the touch detection function from the continuous display operation by dedicating specific time slots solely for touch detection. During these extracted time slots, the display is suspended and only touch detection circuits are active, thereby separating the two functions in time and eliminating mutual interference while maintaining both display and touch capabilities.
2Measurement precision
If common electrode design is modified to eliminate noise interference, then touch detection accuracy improves, but manufacturing costs increase
Solution Approach 1:
Instead of modifying the common electrode design, the patent uses temporal separation by switching between display mode and touch mode in periodic time slots. This approach achieves noise-free touch detection through timing control rather than structural modification, avoiding increased manufacturing costs while maintaining touch detection accuracy.
Solution Approach 2:
The patent implements dynamic switching of the common electrode between different operational states (display mode voltage and touch mode voltage) based on the current time slot. This dynamic control allows the same hardware structure to serve dual purposes without modification, eliminating the need for additional manufacturing costs associated with static design modifications.
3Adaptability or versatility
If display and touch modes constantly alternate, then both functions are maintained, but system complexity increases due to coordination requirements
Solution Approach 1:
The patent makes the common electrode and data lines multi-functional by using them for both display operation and touch detection depending on the operational mode. The same hardware components serve dual purposes through temporal multiplexing, reducing the need for separate dedicated circuits and thereby simplifying the overall system architecture despite the alternating modes.
Solution Approach 2:
The systematic periodic switching between display mode and touch mode with dedicated time slots provides a structured control mechanism that simplifies coordination. By establishing regular alternation patterns rather than ad-hoc switching, the control logic becomes more predictable and manageable, reducing system complexity despite maintaining dual functionality.
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 enhances touch detection accuracy with minimal design modifications, reducing noise interference and maintaining display performance without increasing costs, thereby improving user experience by ensuring accurate and efficient touch detection without compromising image display.
Implementation Method 1
performs touch detection by detecting capacitance changes on the multiple data lines
Implementation Method 2
rotation angles of liquid crystal molecules are different and that results in different dielectric constants
Data Source
AI summary
A driving circuit for a touch control panel, that selectively operates in a display mode or a touch mode, includes a display data generating circuit and a touch control circuit. When the driving circuit operates in the display mode, the display data generating circuit transmits display data to multiple data lines of a pixel array of the touch display panel. When the driving circuit operates in the touch mode, the touch control circuit transmits a touch driving signal to the multiple data lines, and performs touch detection by detecting capacitance changes on the multiple data lines.