Touch Signal Line Multiplexing for Narrow Bezel Display Design
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Solution Overview
Problem
The increasing number of touch electrodes in display devices for improved touch recognition accuracy leads to a corresponding increase in touch pins, complicating fan-shaped wiring designs and making it difficult to achieve a narrow bezel, thereby increasing design difficulties and reducing efficiency.
Innovation Solution
The implementation of a display device with touch electrode groups and touch switch groups, where multiplexers with n touch switches, m input terminals, and n output terminals are used to reduce the number of touch signal lines and touch pins, allowing for efficient touch recognition while maintaining design simplicity and enabling a narrow bezel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of touch electrodes is increased to improve touch recognition accuracy, then the touch recognition accuracy is improved, but the number of touch pins increases which complicates fan-shaped wiring design and makes it difficult to achieve narrow bezel
Solution Approach 1:
Multiple touch electrode groups (first, second, third, and fourth touch electrode groups) are merged and connected to shared touch pins through the display panel. This allows multiple electrodes to share common signal paths, reducing the total number of touch pins required while maintaining the ability to recognize touches across all electrode groups. The merging of electrode groups with shared pin connections directly resolves the contradiction by enabling high touch recognition accuracy without proportionally increasing pin count and wiring complexity.
2Measurement precision
If the number of touch electrodes is increased to improve touch recognition accuracy, then the touch recognition accuracy is improved, but the number of touch pins increases which makes it difficult to achieve narrow bezel
Solution Approach 1:
The patent merges multiple touch electrode groups into a unified structure where the first, second, third, and fourth touch electrode groups share common touch pins. This consolidation reduces the total pin count required at the bezel edge, enabling narrower bezel design while maintaining comprehensive touch coverage and high recognition accuracy across the entire display area.
3Device complexity
If multiplexers are used to reduce the number of touch pins, then the number of touch pins is reduced and design is simplified, but the scanning time for all touch electrodes may increase
Solution Approach 1:
The patent implements periodic scanning of touch electrodes through sequential activation of different touch pin groups. The touch controller scans touches in a structured sequence across multiple periods, systematically activating different combinations of touch pins to cover all electrode groups. This periodic scanning approach maintains efficient touch recognition speed while utilizing the reduced pin configuration enabled by the multiplexer structure.
Solution Approach 2:
The touch electrode groups are segmented into four distinct groups that can be scanned in an organized sequence. Each group can be addressed independently through the shared pin structure, allowing the system to divide the scanning task into manageable segments rather than scanning all electrodes simultaneously or in a single long sequence, thereby maintaining scanning efficiency with fewer pins.
Data Source
AI summary
A display device and a method for driving the same are provided. Touch electrode groups of a display panel of the display device correspond to the touch switch groups in one-to-one correspondence, each touch electrode group includes d touch electrodes subgroups arranged in a first direction, each touch switch group includes multiplexers, and each multiplexers includes m input terminals, and n output terminals electrically connected to the touch electrodes in one-to-one correspondence, where d=n/m. One touch analog front end group corresponds at least two touch pin groups. In one touch pin group and one touch analog front end group corresponding thereto, every two touch analog front ends are electrically connected to a same number of the touch pins. In one touch pin group and one touch switch group corresponding thereto, every two touch pins are electrically connected to a same number of the input terminals.