Touch Sensor Electrode Routing for Capacitance Uniformity
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Solution Overview
Problem
Display devices with sensor arrays experience reliability issues due to significant capacitance differences between sensor electrodes, leading to degradation in touch input sensing accuracy and reliability.
Innovation Solution
The display device incorporates a sensor array design with distinct signal line configurations for sensor electrodes, including varying capacitance and resistance values to compensate for non-uniform capacitances caused by protective films, ensuring uniformity and improved touch input detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If protective films are added to the display device, then durability and protection are improved, but capacitance uniformity deteriorates causing sensor reliability issues
Solution Approach 1:
The patent applies different capacitance compensation values to different sensor electrodes based on their local position relative to protective films. Edge sensors receive different compensation than center sensors, creating local quality variations that counteract the non-uniform capacitance effects introduced by protective films at different locations.
Solution Approach 2:
The patent changes the capacitance compensation parameter for each sensor electrode individually. By adjusting the compensation value based on the specific capacitance measurement of each electrode, the system compensates for variations caused by protective films and maintains uniform sensing performance across the entire sensor array.
2Measurement precision
If sensor electrodes are arranged densely to improve touch detection precision, then measurement precision is improved, but capacitance non-uniformity worsens due to edge effects and protective film variations
Solution Approach 1:
The patent implements a feedback mechanism where the actual capacitance value of each sensor electrode is measured and used to determine an appropriate compensation value. This measured feedback information is then applied to adjust the sensing threshold or reference value for each electrode, ensuring that touch detection precision is maintained uniformly across densely packed sensors despite edge effects and protective film variations.
3Ease of manufacture
If signal line configurations are simplified to reduce device complexity, then manufacturing ease is improved, but capacitance compensation capability deteriorates
Solution Approach 1:
The patent makes the signal lines universal by designing them to serve multiple functions: carrying sensing signals, providing capacitance compensation, and enabling edge sensor correction. By integrating compensation capabilities directly into the standard signal line structure rather than adding separate compensation circuits, the patent maintains manufacturing simplicity while achieving reliable capacitance compensation across all sensor electrodes.
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 enhances the reliability and accuracy of touch input sensing by minimizing capacitance variations and maintaining consistent signal integrity across the sensor array, preventing malfunctions and improving overall device performance.
Implementation Method 1
Capacitive methods have been used in such sensor devices. However, when the sensor devices include specific types of protective film, significant capacitance differences may occur between a corresponding sensor electrode and surrounding sensor electrodes
Data Source
AI summary
A display device may include a display panel, a sensor array including first and second sensor electrode groups, first and second signal lines respectively connected to the sensor electrodes of the first and second sensor electrode groups, and a sensor driver connected to the sensor array through the first and second signal lines. The sensor electrodes of the first sensor electrode group may include a first sensor electrode adjacent to an edge of the sensor array, and a second sensor electrode spaced apart from the edge. A signal line connected to the first sensor electrode among the first signal lines may include first and second routing lines connected to first and second ends of the first sensor electrode. A signal line connected to the second sensor electrode among the first signal lines may include a third routing line connected to a first end of the second sensor electrode.