Sensor Panel Connection Wiring for Stable Capacitive Position Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The accuracy of position detection in capacitive position detection devices is reduced when connection wires are arranged in multiple regions due to uneven distribution of coupling capacitance and external noise, which cannot be canceled out effectively using existing methods.

Innovation Solution

The introduction of extension lines and dummy lines that connect to the sensor controller but not directly to the sensor electrodes, allowing for the derivation of differential signals that minimize the impact of coupling capacitance and external noise by ensuring a consistent distribution of coupling capacitance and canceling out noise components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If connection wires are arranged in multiple regions in a distributed manner, then the device can accommodate increased screen size and reduced bezel width, but the coupling capacitance distribution becomes uneven and position detection accuracy decreases

Engineering Contradiction:

Improvescreen sizeVSAvoidposition detection accuracy

Core Design Contradiction:

Area of stationary objectVSMeasurement precision

Solution Approach 1:

Extension lines are introduced as intermediary elements between sensor electrodes and connection wires. These extension lines are arranged to extend along the connection wires in specific regions, acting as mediators that balance the coupling capacitance distribution. By adding these intermediate components, the system can maintain uniform capacitance characteristics even when connection wires are distributed across multiple regions for larger screens.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Area of stationary object

If connection wires are arranged in multiple regions in a distributed manner, then the device can accommodate reduced bezel width, but external noise interference increases and position detection accuracy decreases

Engineering Contradiction:

Improvebezel width reductionVSAvoidexternal noise interference

Core Design Contradiction:

Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

Extension lines serve as intermediary elements that help manage noise interference. By strategically positioning these extension lines along the connection wires in multiple regions, the system creates additional capacitance paths that can help filter or compensate for external noise, allowing the device to maintain accuracy even with reduced bezel width and distributed wire arrangements.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If extension lines are added to balance coupling capacitance, then position detection accuracy is maintained, but device complexity increases

Engineering Contradiction:

Improveposition detection accuracyVSAvoidconnection wire arrangement complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The extension lines are not uniformly distributed throughout the entire device but are strategically placed only in specific regions where connection wires are arranged in a distributed manner. This localized approach allows the system to address capacitance imbalance issues only where they occur, rather than adding extension lines everywhere, thereby limiting the increase in overall device complexity to essential areas only.

Inventive Principle:

Principle #3Local quality

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 maintains a consistent distribution of coupling capacitance and effectively cancels out external noise, thereby minimizing the reduction in accuracy caused by the distributed arrangement of connection wires, improving the precision of position detection.

Implementation Method 1

coupling capacitance occurs between adjacent ones of the sensor electrodes and between adjacent ones of the connection wires

Methodology Applied

Scientific EffectCoupling capacitance: Capacitance

Implementation Method 2

a known sensor controller is configured to derive differentials between reception intensities at adjacent sensor electrodes instead of the reception intensity at each sensor electrode

Methodology Applied

Scientific EffectDifferential signaling:

Data Source

PatentUS12169605B2Extension wires and connection wires for position detection device and sensor panel

Publication Date: 2024.12.17 WACOM CO LTD

AI summary

A position detection device includes first and second sensor electrodes that are adjacent to each other, connection wires connected to the respective sensor electrodes and including first and second connection wires connected to the first and second sensor electrodes, respectively, a sensor controller connected to the connection wires, and a first extension line; and a second extension line. Some of the plurality of connection wires, including the first connection wire, extend at regular intervals in a first region. The connection wires, including the second connection wire, are arranged to extend at regular intervals in a second region different from the first region. The first extension line extends along the second connection wire in the second region and is electrically connected to the first sensor electrode. The second extension line extends along the first connection wire in the first region and is electrically connected to the second sensor electrode.