Capacitive In-Cell Touch Panel Gate Line Repositioning
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Solution Overview
Problem
Current touch screen panels face challenges in achieving high aperture ratio and cost-effectiveness, with add-on mode panels being costly and thick, while in-cell touch panels struggle with precision and signal interference.
Innovation Solution
A capacitive in-cell touch panel structure with a TFT array substrate and color filter substrate, where every two adjacent rows of pixel units form a group, and touch driving lines are positioned between pixel unit groups to reduce the area occupied by gate signal lines, allowing for time-division signal transfer and improved precision, while touch sensing electrodes on the color filter substrate enhance touch functionality without obstructing display.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If touch driving lines are positioned within pixel units, then touch functionality is achieved, but aperture ratio decreases due to increased black matrix area
Solution Approach 1:
The patent moves touch driving lines from the horizontal direction (within pixel units) to the vertical direction (between pixel unit groups), utilizing the gap space that would otherwise be wasted. This dimensional repositioning allows touch functionality to be maintained while minimizing impact on aperture ratio, as the vertical positioning leverages existing structural gaps rather than consuming horizontal pixel area.
Solution Approach 2:
The touch driving lines positioned between pixel unit groups serve multiple functions: they provide touch scanning signals, act as common electrode connections, and utilize the gap space for signal routing. This multi-functionality allows the same structural element to serve both display and touch functions without requiring additional dedicated space, thereby maintaining high aperture ratio while achieving touch capability.
2Reliability
If separate signal lines are used for display and touch functions, then signal interference is avoided, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent implements time-division multiplexing where touch driving lines alternately transmit display common electrode signals during display time periods and touch scanning signals during touch time periods. This periodic switching allows a single physical line to carry multiple signal types sequentially, reducing the total number of signal lines required while maintaining signal integrity through temporal separation rather than spatial separation.
Solution Approach 2:
The touch driving lines dynamically switch between different signal transmission modes based on operational requirements. During display operation, they function as common electrode signal lines; during touch operation, they function as touch scanning signal lines. This dynamic reconfiguration allows the system to adapt signal line functionality in real-time, reducing overall system complexity while preventing signal interference through temporal isolation.
3Ease of manufacture
If in-cell touch structure is implemented, then manufacturing cost and thickness are reduced, but aperture ratio and touch precision are compromised
Solution Approach 1:
The patent segments the display area into pixel unit groups with clear boundaries, and positions touch driving lines in the gaps between these groups rather than within them. This segmentation approach creates dedicated touch signal pathways that are spatially separated from pixel structures, reducing signal interference and improving touch precision while maintaining the cost-effective in-cell structure where touch electrodes are integrated into the display substrate.
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 design achieves a high aperture ratio and cost-effective touch screen panel with reduced signal interference, ensuring precise touch functionality and improved light transmittance by optimizing the placement of touch driving lines and electrodes, thereby enhancing the overall performance of the capacitive in-cell touch panel.
Implementation Method 1
a liquid crystal layer between the color filter substrate and the TFT array substrate
Implementation Method 2
the color filter substrate includes a plurality of touch sensing electrodes extending in a column direction of pixel units
Data Source
AI summary
A capacitive in cell touch panel, its driving method and a display device, in which, on the TFT array substrate, a pixel structure in which two adjacent rows of pixel units form one pixel unit group and two gate signal lines are disposed between the two rows of pixel units of the pixel unit group is adopted. Positions of gate signal lines between adjacent pixel unit groups can be saved by modifying positions of gate signal lines of two adjacent rows of pixel units and TFT switches. As such, touch driving lines with touch function can be set at the saved positions for gate signal lines and touch sensing electrodes can be disposed on the color filter substrate and extend in the column direction of the pixel units to realize touch function while ensuring high aperture ratio.