In-Cell Touch Display Data Line Voltage Control
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Solution Overview
Problem
In display devices with integrated in-cell type touch screens, the mutual capacitance error caused by parasitic capacitance affects touch performance due to overlapping data lines and common electrodes, leading to reduced accuracy and reliability in touch sensing.
Innovation Solution
The display device sets different data voltage states for the driving electrode area and sensing electrode area, applying a ground voltage to driving area data lines and floating sensing area data lines during touch driving mode to reduce parasitic capacitance, thereby enhancing touch performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If voltages in the same state are respectively applied to data lines during touch driving mode, then the display device can maintain simple voltage control, but parasitic capacitance increases causing mutual capacitance error and reduced touch performance
Solution Approach 1:
The patent segments the data lines into two distinct groups: driving area data lines and sensing area data lines. This segmentation allows different voltage states to be applied to each group, reducing parasitic capacitance interference in the sensing area while maintaining proper display driving in the driving area. The segmentation directly addresses the technical contradiction by enabling differentiated voltage control that improves touch sensing accuracy without significantly increasing overall system complexity.
Solution Approach 2:
The patent applies local quality by setting different voltage states for different spatial regions. Specifically, sensing area data lines are set to a first voltage state (e.g., ground or floating) while driving area data lines are set to a second voltage state (e.g., common voltage). This local differentiation reduces parasitic capacitance in the sensing region while maintaining display functionality in the driving region, thereby improving touch sensing accuracy without requiring complete system redesign.
2Adaptability or versatility
If common electrodes are segmented into touch driving areas and touch sensing areas to generate mutual capacitance, then touch sensing capability is enabled, but parasitic capacitance from overlapping data lines increases causing mutual capacitance error
Solution Approach 1:
The patent segments both the common electrodes and data lines into driving area and sensing area components. This dual segmentation enables the generation of mutual capacitance for touch sensing while simultaneously reducing parasitic capacitance interference. By separating the functional zones, the patent maintains touch sensing capability while improving reliability through reduced measurement errors.
Solution Approach 2:
The patent applies different voltage states to data lines in different spatial locations. Sensing area data lines receive a first voltage state optimized for touch sensing (reducing parasitic effects), while driving area data lines receive a second voltage state optimized for display driving. This local quality differentiation enables reliable touch sensing by minimizing parasitic capacitance in the critical sensing region while maintaining overall system 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 effectively decreases parasitic capacitance, improving touch sensing accuracy and reliability by separately managing the voltage states of data lines in the driving and sensing electrode areas, resulting in enhanced touch performance.
Implementation Method 1
When the panel operates in the touch driving mode, since voltages in the same state are respectively applied to data lines, parasitic capacitance increases, or a voltage of a data line is affected by the driving pulse. For this reason, a mutual capacitance error occurs
Data Source
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AI summary
Disclosed is a display device with an integrated touch screen (110). The display device includes a panel (100) configured to operate in a display driving mode and a touch driving mode, the panel (100) including a plurality of driving electrodes (112), a plurality of sensing electrodes (114), and a plurality of data lines (DL1-DLd) including a plurality of first data lines (TUDL1, TUDL2) and a plurality of second data lines (RUDL); and a display driver IC (300) configured to apply data voltages to the plurality of first data lines (TUDL1, TUDL2) and the plurality of second data lines (RUDL) during the display driving mode of the panel (100), and the display driver IC (300) configured to apply a ground voltage to the plurality of first data lines (TUDL1, TUDL2) and float the plurality of second data lines (RUDL) during the touch driving mode of the panel.