Capacitive Door Handle Electrode Segmentation for False Detection

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Solution Overview

Problem

The existing door handle electrostatic sensors often falsely detect locking operations when the user's finger approaches the wiring connected to the sensor, leading to incorrect locking or unlocking of the door, especially when the finger is near the intermediate region between the lock detection electrodes.

Innovation Solution

A door handle design with separate first and second detection electrodes and a controller that measures capacitance between each electrode and the user's finger, ensuring accurate detection by preventing false signals from the intermediate region by not summing capacitance values from the connection electrode and wiring electrode.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the door lock electrostatic sensor is located within the door handle case, then the sensor is protected and integrated, but the position of the sensor cannot be correctly identified from the outside, leading to false detection when the user's finger approaches the wiring

Engineering Contradiction:
Improvedetection accuracyVSAvoidsensor positioning complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The door handle is divided into multiple detection regions with separate detection electrodes. The first detection electrode corresponds to a first detection region and the second detection electrode corresponds to a second detection region. This segmentation allows the system to distinguish between intentional locking operations (finger approaching the correct detection region) and false operations (finger approaching wiring or incorrect regions), thereby improving detection accuracy while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If the controller measures total capacitance between detection electrodes, then the measurement is simpler, but false detection occurs when the finger approaches the intermediate region between electrodes

Engineering Contradiction:
Improvemeasurement complexityVSAvoiddetection accuracy
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

Instead of measuring total capacitance uniformly across all electrodes, the controller measures capacitance values separately for each detection electrode independently. When the user's finger approaches the first detection region, only the first capacitance value changes significantly; when approaching the second detection region, only the second capacitance value changes. This local measurement approach enables precise identification of the finger's position and prevents false detection in intermediate regions, improving detection accuracy without excessive complexity.

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 design reduces false detection of locking operations when the user intends to unlock the door, ensuring that the door handle only locks when the user's finger approaches the intended lock detection electrodes, thereby preventing unintended locking.

Implementation Method 1

a first capacitance value is measured at terminals of a detection electrode, a second capacitance value is measured at terminals of an additional electrode

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

an electrostatic sensor or the like that detects an operation by the user's hand is provided

Methodology Applied
Scientific EffectElectrostatic sensor detection: Electrostatic Induction

Data Source

PatentEP3770364B1Door handle
Publication Date: 2023.04.05 ALPS ALPINE CO LTD
  • EP3770364B1 patent drawingFigure 1
  • EP3770364B1 patent drawingFigure 2
  • EP3770364B1 patent drawingFigure 3

AI summary

A door handle includes door handle case, a first detection electrode and a second detection electrode disposed in the door handle case, and a controller connected to the first detection electrode and the second detection electrode. The controller separately measures a first capacitance between the first detection electrode and an operation body and a second capacitance between the second detection electrode and the operation body, and the controller determines whether an operation is performed by the operation body based on the first capacitance or the second capacitance.