Capacitive Sensor Seal for Moisture Interference

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Solution Overview

Problem

Capacitive sensors in vehicle door handles experience interference due to moisture-induced coupling in humid environments, leading to erroneous detections, and existing solutions like waterproofing are costly and aesthetically unsuitable.

Innovation Solution

Incorporating a seal, such as a flexible lip or added-on seal, to prevent moisture communication between detection areas of the capacitive sensor, ensuring mutual seal-tightness and eliminating interference without the need for costly waterproofing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If two capacitive sensors are placed close together in the handle to save space, then the device complexity is reduced, but moisture creates coupling between the sensors causing erroneous detections

Engineering Contradiction:

Improvesensor arrangementVSAvoiddetection accuracy

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The handle is divided into two separate detection areas with distinct functions: a first area for unlocking and a second area for locking. This segmentation allows each area to operate independently, preventing moisture-induced coupling interference while maintaining compact integration in the handle assembly.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A capacitive sensor acts as an intermediary element between the user's hand and the locking mechanism. The sensor detects proximity in the first detection area to trigger unlocking and in the second detection area to trigger locking, enabling contactless control while maintaining reliable operation in humid environments.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the handle is made watertight by coating sensors in resin, then moisture interference is prevented, but the manufacturing process becomes long and costly

Engineering Contradiction:

Improvemoisture protectionVSAvoidmanufacturing process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The capacitive sensor is divided into two spatially separated detection areas within the handle, each with distinct unlocking and locking functions. This segmentation eliminates the need for complete waterproofing by preventing moisture coupling between areas through geometric separation and functional isolation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of protecting the sensors from moisture through waterproofing coatings, the invention inverts the approach by designing the sensor arrangement to inherently prevent moisture interference through spatial separation and functional segmentation, making the system tolerant to humid conditions without additional protective measures.

Inventive Principle:

Principle #13The other way round (Inversion)

3Object-affected harmful factors

If flow orifices are added to facilitate water flow, then water presence is reduced, but the handle becomes non-watertight and coupling occurs in very damp atmospheres

Engineering Contradiction:

Improvewater presenceVSAvoiddetection accuracy

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The handle incorporates two separately positioned detection areas with distinct unlocking and locking functions. This segmentation allows the system to operate reliably in damp atmospheres without requiring complete watertightness, as moisture cannot couple between the separated areas to cause interference.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the handle are assigned different functions: the first detection area for unlocking and the second detection area for locking. This local differentiation allows each area to be optimized for its specific function while maintaining overall system reliability in humid conditions through spatial separation.

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

Effectively suppresses interference caused by moisture, allowing capacitive sensors to function accurately in humid conditions without compromising aesthetics or increasing production costs.

Implementation Method 1

means preventing the communication of the moisture between the detection areas so as to avoid the capacitive coupling between the different areas

Methodology Applied

Scientific EffectPhysical barrier sealing:

Implementation Method 2

capacitive sensor which detects the proximity of the hand

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentUS8830659B2Device for suppressing interference phenomenon between capacitive detection areas of a sensor

Publication Date: 2014.09.09 VITESCO TECH FRANCE

AI summary

The invention relates to a device for suppressing the interference phenomena between several detection areas (A, B) of a capacitive sensor (30) submitted to a humid ambient environment, characterised in that it comprises means for preventing the propagation of humidity (50) between the detection areas (A, B) in order to prevent any capacitive coupling between the different areas. The invention also relates to an opening handle (10) for an automobile.