Curved Transmission Electrode Layout for Longer-Range Proximity Sensing

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Solution Overview

Problem

Existing proximity sensors have limited detection sensitivity to sensing targets, particularly in improving the ability to detect targets at a distance.

Innovation Solution

A mutual capacitance proximity sensor design featuring a conductor, a receiving electrode, and transmission electrodes with upper surfaces bulging in the upward direction, enhancing the change in electrostatic capacitance when a sensing target approaches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional flat transmission electrodes are used, then the device structure is simple, but the detection sensitivity to sensing targets is limited

Engineering Contradiction:

Improvedetection sensitivityVSAvoidelectrode structure complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The transmission electrode is designed with a convex curved upper surface instead of a flat surface. This curvature increases the surface area of the transmission electrode that faces the sensing target, thereby enhancing the electrostatic capacitance change when the target approaches. The curved shape specifically oriented toward the sensing target improves detection sensitivity without requiring complex multi-electrode arrangements

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention transitions from a two-dimensional flat electrode surface to a three-dimensional convex curved surface. This dimensional change increases the effective sensing area and creates a more pronounced electrostatic field distribution, allowing for greater capacitance variation when objects approach, thus improving detection sensitivity

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Length of stationary object

If conventional flat electrodes are used, then manufacturing is simpler, but the sensing range is limited

Engineering Contradiction:

Improvesensing rangeVSAvoidelectrode fabrication

Core Design Contradiction:

Length of stationary objectVSEase of manufacture

Solution Approach 1:

The convex curved upper surface of the transmission electrode extends the electrostatic field interaction zone toward the sensing target. This curvature allows the electric field to reach further distances, thereby extending the sensing range without requiring additional electrodes or increasing the overall device footprint

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Measurement precision

If conventional flat transmission electrodes are used, then the electrode configuration is simple, but the change in electrostatic capacitance is insufficient

Engineering Contradiction:

Improvecapacitance change magnitudeVSAvoidelectrode geometry

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The convex curved upper surface creates a more distributed and extended electrostatic field compared to a flat surface. When a sensing target approaches, this curved geometry produces a larger variation in the electric field distribution and consequently a larger change in electrostatic capacitance, improving measurement precision

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention changes the geometric parameter of the transmission electrode from a flat surface to a convex curved surface. This parameter change directly affects the electrostatic capacitance characteristics, increasing the magnitude of capacitance change when targets approach, thereby improving detection sensitivity

Inventive Principle:

Principle #35Parameter changes

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

The design significantly improves detection sensitivity, allowing for the sensing of targets at greater distances and minimizing the movement required for detection, thereby enhancing the accuracy and range of proximity sensing.

Implementation Method 1

a first transmission electrode 51... The first transmission electrode 51 and the receiving electrode 4 are aligned with each other in a second direction... a mutual capacitance proximity sensor

Methodology Applied

Scientific EffectElectrostatic capacitance: Capacitance

Data Source

PatentUS12203782B2Proximity sensor, control system, and equipment

Publication Date: 2025.01.21 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A proximity sensor includes a conductor, a receiving electrode, and a first transmission electrode. The conductor has an upper surface. The receiving electrode is separate from the upper surface of the conductor in an upward direction and extends along a first direction. The first direction is orthogonal to the upward direction. The first transmission electrode is separate from the upper surface of the conductor in the upward direction and extends along the first direction. The first transmission electrode and the receiving electrode are aligned with each other in a second direction. The second direction is orthogonal to both the upward direction and the first direction. The first transmission electrode has an upper surface having a shape bulging in the upward direction in a cross section orthogonal to the first direction.