Display Capacitive Sensor Matrix with Metal Leads for Precise Touch Detection
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Solution Overview
Problem
Existing electrostatic capacitance-type sensors in display devices face challenges in achieving high detection precision and sensitivity due to non-uniformity in detection electrode sizes, parasitic capacitance, and noise interference, particularly when using ITO lead lines, which complicates multi-touch and close-proximity detection.
Innovation Solution
The implementation of a matrix arrangement of detection electrodes with independent lead lines formed of metal, combined with a guard electrode to reduce parasitic capacitance and enhance sensitivity, while maintaining device thickness and reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If ITO lead lines are used in electrostatic capacitance-type sensors, then manufacturing cost is reduced and ease of manufacture is improved, but detection precision deteriorates due to non-uniform electrode sizes and parasitic capacitance
Solution Approach 1:
The patent changes the material parameter of lead lines from ITO to metal, which has fundamentally different electrical properties. This parameter change reduces parasitic capacitance and improves conductivity uniformity, thereby enhancing detection precision while maintaining ease of manufacture through established metal deposition processes
Solution Approach 2:
The patent employs composite material structures by combining metal lead lines with guard electrodes and detection electrodes in specific configurations. This composite approach creates a sensor system that leverages the high conductivity of metal while using guard electrodes to minimize parasitic effects, achieving both manufacturing feasibility and high detection precision
2Device complexity
If detection electrode sizes are not uniform, then manufacturing complexity is reduced, but detection precision deteriorates due to non-uniform capacitance values
Solution Approach 1:
The patent standardizes the geometric parameters of detection electrodes and lead lines, ensuring uniform width, length, and spacing. This parameter standardization creates consistent capacitance values across all sensors, improving detection precision while the modular matrix design keeps the overall device structure relatively simple
Solution Approach 2:
The patent implements homogeneity in the sensor array by making all detection electrodes identical in size and shape, and all lead lines uniform in dimensions. This homogeneous design ensures consistent electrical characteristics across the sensor array, improving multi-touch and close-proximity detection accuracy without significantly increasing manufacturing complexity
3Measurement precision
If guard electrodes are added to reduce parasitic capacitance, then detection sensitivity is improved, but device complexity increases
Solution Approach 1:
The patent introduces guard electrodes as intermediary elements positioned between the lead lines and detection electrodes. These guard electrodes act as mediators that capture and redirect parasitic electric fields, preventing them from interfering with the primary sensing function. This intermediary structure improves detection sensitivity while adding only moderate complexity to the device architecture
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 configuration improves detection precision and sensitivity for both single-touch, multi-touch, and close-proximity detection by minimizing noise interference and ensuring uniform electrode sizes, thereby enhancing the overall performance of the electrostatic capacitance-type sensor-equipped display devices.
Implementation Method 1
detects a variation in electrostatic capacitance (strength/weakness of electrostatic capacitive coupling) which occurs in the above-described electrode by the approach of the input means to the electrode
Implementation Method 2
combined with a guard electrode to reduce parasitic capacitance and enhance sensitivity
Data Source
AI summary
According to one embodiment, an electrostatic capacitance-type sensor-equipped display device includes a display panel with a display surface which displays an image. The sensor includes a plurality of detection electrodes disposed in a matrix, the detection electrodes being mutually electrically independently provided above the display surface and being configured to detect a variation in electrostatic capacitance, and a plurality of lead lines provided above the display surface, connected to the detection electrodes in a one-to-one correspondence, and formed of a metal.