Common Electrode Touch Detection Circuit
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Solution Overview
Problem
Conventional display devices with touch detection functions face challenges in scaling due to the requirement for a large number of detection circuits matching the number of sensor electrodes, leading to increased complexity and power consumption.
Innovation Solution
The implementation of a display device structure that utilizes a sensor drive controller with a switch drive circuit, sensing circuit, and common voltage drive circuit to selectively use common electrodes as sensor electrodes, guard electrodes, or floating electrodes, reducing the number of detection circuits needed and optimizing power usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of sensor electrodes is increased to improve detection performance or increase display panel size, then detection performance or display size is improved, but the number of detection circuits must be increased proportionally, leading to increased device complexity
Solution Approach 1:
The common electrode is designed to serve multiple functions: it acts as a sensor electrode for touch detection, a common electrode for display operation, and can be selectively switched between sensing and non-sensing states. This multi-functionality eliminates the need for separate sensor electrodes and detection circuits, resolving the contradiction between improved detection performance and increased device complexity
Solution Approach 2:
The patent implements dynamic switching of the common electrode between sensing and non-sensing states using switch circuits. During sensing periods, the common electrode functions as a sensor electrode; during display periods, it returns to its common electrode function. This dynamic reconfiguration allows the system to adapt its functionality based on operational requirements, maintaining high detection performance while avoiding permanent increases in device complexity
2Measurement precision
If the number of detection circuits is increased to match the number of sensor electrodes, then detection performance is improved, but power consumption increases
Solution Approach 1:
The patent employs periodic switching between sensing and display modes, where the common electrode alternates between serving as a sensor electrode and a common electrode. During non-sensing periods, the electrode returns to its low-power common electrode state. This periodic action enables touch detection functionality while significantly reducing average power consumption compared to continuously active detection circuits
Solution Approach 2:
By making the common electrode multi-functional, the system eliminates dedicated high-power detection circuits. The same electrode structure serves both display and sensing functions, reducing the need for separate power-consuming detection circuitry while maintaining detection performance
3Area of stationary object
If sensor electrodes are provided in matrix in the display area, then detection coverage is improved, but manufacturing complexity increases due to thin metal lines connecting each sensor electrode to detection circuits
Solution Approach 1:
The patent extracts the sensing function from the display structure by utilizing the existing common electrode rather than adding separate sensor electrodes. This eliminates the need for additional thin metal line connections between sensor electrodes and detection circuits, significantly reducing manufacturing complexity while maintaining full display area coverage for touch detection
Solution Approach 2:
The common electrode is transformed into a multi-functional element that provides both display common electrode functionality and sensor electrode functionality. This eliminates the need for separate sensor electrode structures and their associated metal line connections, simplifying manufacturing while achieving comprehensive detection coverage across the entire display area
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 allows for efficient touch detection with fewer detection circuits, enabling scalable display devices while minimizing power consumption and manufacturing complexity.
Implementation Method 1
a sensing circuit which supplies a sensor signal to the common electrode selected for sensing
Data Source
AI summary
According to one embodiment, a display device includes a plurality of gate lines, a plurality of data lines intersecting with the gate lines, a plurality of pixel electrodes, and a sensor drive controller which includes a plurality of common electrodes facing the pixel electrodes and detects a touch by controlling the common electrodes. The sensor drive controller selects at least one of the common electrodes, and supplies a sensor signal to the selected common electrode to set the selected common electrode to a sensing state. The sensor drive controller sets at least the common electrode adjacent to the common electrode set to the sensing state to a guard state and sets the other common electrodes to a floating state.