Touch Display Driving Circuit Pause Time Signal Interference
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Solution Overview
Problem
The increasing requirement for lighter and thinner touch display apparatuses leads to interference between the display screen and touch screen, resulting in erroneous touch detection and abnormal display due to signal coupling.
Innovation Solution
A driving circuit for touch display apparatuses that includes a main control unit, a driving unit, and a data buffering module, where the driving unit sends display data at a higher speed than received image data, creating a pause time period for touch detection, reducing interference between display drive and touch detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the distance between display screen and touch screen is reduced to make the apparatus lighter and thinner, then the portability and compactness are improved, but signal coupling interference occurs between display and touch detection
Solution Approach 1:
The patent divides the frame period into multiple segments: display data transmission periods and touch detection pause periods. By segmenting the time domain, the system can transmit display data at high speed during allocated periods while performing touch detection during pause periods when no display data is transmitted, thus eliminating signal coupling interference while maintaining the thin form factor
Solution Approach 2:
The patent implements periodic alternation between display data transmission and touch detection. The driving unit periodically transmits display data and periodically pauses for touch detection within each frame period. This periodic action ensures that touch detection always occurs during interference-free pause periods while display updates continue regularly, resolving the contradiction between thin design and signal interference
2Speed
If high speed display data transmission is used to improve display performance, then the display refresh rate is improved, but interference to touch detection increases
Solution Approach 1:
The patent extracts the touch detection function from the continuous display transmission process by creating dedicated pause periods where display data transmission is temporarily suspended. During these extracted pause periods, touch detection can be performed without any display signal interference, while the high-speed transmission capability is retained for the remaining transmission periods
Solution Approach 2:
The pause period acts as an intermediary time window between display data transmission cycles. During this intermediary period, the transmission channel is idle and can be used for touch detection without affecting the high-speed display transmission capability, which resumes after the pause period
3Productivity
If touch detection is performed continuously to improve touch detection report rate, then the responsiveness is improved, but signal coupling interference increases
Solution Approach 1:
The patent implements periodic touch detection during pause periods within each frame period. Although touch detection is not continuous, the periodic execution during interference-free pause periods ensures reliable touch detection without signal coupling, achieving an optimal balance between report rate and detection accuracy
Data Source
AI summary
Provided is a driving circuit for a touch display apparatus. The driving circuit includes: a main control unit, providing image data for image display at a first speed; a driving unit, receiving the image data and sending display data to the touch display apparatus according to the received image data; a data buffering module, disposed in the driving unit, sending the display data at a second speed higher than the first speed, and forming, due to the difference between the second speed and the first speed, a pause time for stopping sending the display data to the touch display apparatus during the process that the main control unit provides the image data; and a touch detection unit, performing touch detection of the touch display apparatus in the pause time.