Touch Sensor Integrated Display Device Multiplexing
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Solution Overview
Problem
Existing touch sensor integrated type display devices face challenges in accurately recognizing touch positions due to parasitic capacitance and complex line structures, limiting their application to large-sized displays and increasing manufacturing costs.
Innovation Solution
The implementation of a touch sensor integrated type display device that includes a display panel with touch/common electrodes driven using a multiplexing unit, which supplies a common voltage during display driving periods and touch driving voltages during touch sensing periods, utilizing self-capacitive and mutual capacitive methods in sequence to accurately detect touch locations, thereby reducing the number of touch channels and manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a mutual capacitive touch sensor is used, then multi-touch recognition capability is improved, but parasitic capacitance between gate line and data line increases making accurate touch position recognition difficult
Solution Approach 1:
The touch sensor is divided into multiple sensing regions with separate sensing electrodes, allowing independent measurement of touch positions in different areas. This segmentation reduces the impact of parasitic capacitance on overall measurement accuracy while maintaining multi-touch recognition capability.
Solution Approach 2:
Different sensing methods are applied to different regions of the touch sensor. The sensing structure is optimized locally to minimize parasitic capacitance effects in critical measurement areas while maintaining multi-touch capability across the entire sensor surface.
2Adaptability or versatility
If multiple touch driving lines and touch sensing lines are formed on the common electrode for multi-touch recognition, then multi-touch recognition capability is improved, but line structure complexity increases
Solution Approach 1:
The common electrode serves multiple functions: it acts as both a display electrode and a touch sensing electrode. By making the common electrode multi-functional, the patent eliminates the need for separate touch driving lines and sensing lines, thereby reducing line structure complexity while maintaining multi-touch recognition capability.
Solution Approach 2:
The touch sensing function is merged with the display common electrode function. The sensing electrodes are integrated into the existing common electrode structure, combining two functions into one element and simplifying the overall line structure.
3Area of stationary object
If the display device size is increased for large-screen applications, then display area is improved, but manufacturing cost increases
Solution Approach 1:
The common electrode is designed to serve dual purposes in display and touch sensing functions. This multi-functionality reduces the total number of electrodes and conductive structures needed, simplifying the manufacturing process and reducing costs associated with large-screen display production.
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 solution enables accurate touch recognition on large-screen displays with reduced manufacturing costs by employing a multiplexing unit to manage touch sensing through self-capacitive and mutual capacitive methods, enhancing touch resolution and reducing the complexity of line structures.
Implementation Method 1
The multiplexing unit supplies a common voltage to the plurality of touch/common electrodes during the display driving period, supplies a touch driving voltage to the plurality of touch/common electrodes several times during the touch driving period, and senses the plurality of touch/common electrodes several times using a self-capacitive method
Implementation Method 2
The multiplexing unit supplies a common voltage to the plurality of touch/common electrodes during the display driving period, supplies a touch driving voltage to the plurality of touch/common electrodes several times during the touch driving period, and senses the plurality of touch/common electrodes several times using a self-capacitive method and a plurality of mutual capacitive methods in sequence
Data Source
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AI summary
A touch sensor integrated type display device includes a display panel (100), a data driving circuit (202), a scan driving circuit (204), a multiplexing unit (MUX), a readout integrated circuit (ROIC) and a touch controller (TC). The display panel (100) is time-division driven in a display driving period and a touch driving period. The data driving circuit (202) supplies a video data voltage to the data lines (D1, ..., Dm) during the display driving period. The scan driving circuit (204) sequentially supplies a scan pulse to the gate lines (G1, ..., Gn) during the display driving period. The multiplexing unit (MUX) supplies a common voltage to the touch/common electrodes (T11, ..., T45) during the display driving period, supplies a touch driving voltage (Vtx) to the touch/common electrodes (T11, ..., T45) several times during the touch driving period, and senses the touch/common electrodes (T11, ..., T45) several times using a self-capacitive method and a mutual capacitive method.