Touch Sensing Display Panel Noise Reduction via Temporal Segmentation
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Solution Overview
Problem
The reliability of sensing signals in touch sensing display panels is compromised due to electrical coupling noise that occurs when data voltage interferes with the sensing signal during image display.
Innovation Solution
A method of driving the touch sensing display panel involves outputting image data during the active period of a frame and reading out sensing signals during the blanking period, using a two-frame interlace scan mode or progressive scan mode, and employing a look-up table to remove coupling noise based on preset coupling values corresponding to image data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the sensing signal is read out simultaneously while the image is being displayed, then the productivity is improved, but the reliability of the sensing signal deteriorates due to electrical coupling noise
Solution Approach 1:
The frame period is segmented into distinct time periods: an active period for image data output and a blanking period for sensing signal reading. This temporal segmentation separates the image display function and touch sensing function, preventing electrical coupling noise from affecting the sensing signal while maintaining both functions within the same frame cycle.
Solution Approach 2:
The patent implements periodic alternation between image display mode and sensing signal reading mode within each frame period. During the active period, image data is displayed; during the blanking period, sensing signals are read out. This periodic action ensures that sensing operations occur only when no image data is being transmitted, eliminating coupling noise while maintaining regular display refresh rates.
2Loss of time
If the sensing signal is read out during the active period, then the response time is improved, but the measurement precision deteriorates due to coupling noise interference
Solution Approach 1:
The sensing signal reading is scheduled to occur during the blanking period, which is预先 allocated in the frame timing structure. This preliminary arrangement ensures that sensing operations are performed in advance of the next active display period, maintaining accurate touch detection without interfering with image display while preserving timing precision.
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 effectively reduces coupling noise between image and sensing signals, thereby improving the reliability of the sensing signals.
Implementation Method 1
If an outer touch is applied on the touch sensing display panel, a light becomes incident on the sensing element, and a photocurrent is generated in the sensing element by the incident light.
Data Source
AI summary
In a method of driving touch sensing display panel and a display apparatus for performing the method, image data are outputted to the touch sensing display panel during an active period of a frame, the touch sensing display panel comprising a display substrate including a switching element connected to a data line extending in a column direction and a gate line extending in a row direction, and a touch sensing substrate including a light sensing part connected to a read-out line substantially parallel to the data line and a scan line substantially parallel to the gate line. A sensing signal is read out through the read-out line during a blanking period of the frame.