Motor Vehicle Interface Cover for Capacitive Touch Screen Signal Interference

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Solution Overview

Problem

Conventional capacitive touch screen interfaces for motor vehicle components face reliability issues due to signal interference from metal parts and user finger detection, leading to potential command interpretation errors.

Innovation Solution

A control member with a metal index and a capacitive touch screen, where a cover is integrated with the movable gripping element to hide user fingers from the screen, enhancing the signal-to-noise ratio and allowing for a larger metal index for improved detection reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a capacitive touch screen is used to detect the position of the metal index, then the detection capability is improved, but the reliability is reduced due to signal interference from metal parts and user fingers

Engineering Contradiction:
Improvedetection capabilityVSAvoidreliability of detection
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

A cover element is introduced as an intermediary between the user's fingers and the capacitive touch screen. This cover blocks the capacitive coupling between fingers and the screen, preventing false detection signals while allowing the metal index to be detected when it is in the correct position.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The cover is designed with specific local properties: it is positioned only in certain areas to block finger detection, has specific dimensions (projecting extent of 4-12 mm, thickness of 2-4 mm), and is integrated only with the mobile gripping element. This localized approach allows finger blocking while maintaining metal index detection capability.

Inventive Principle:
Principle #3Local quality

2Reliability

If the metal index is enlarged to improve the signal-to-noise ratio, then the detection reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvedetection reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cover and the mobile gripping element are merged into a single integral structure. This reduces the number of separate components and assembly steps while still providing the enlarged metal index area needed for improved signal-to-noise ratio and detection reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cover serves multiple functions: it blocks user fingers from being detected by the capacitive screen, provides structural support for the enlarged metal index, and is integrated with the mobile gripping element. This multi-functionality reduces the need for additional separate components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution effectively prevents finger detection errors and enhances the signal-to-noise ratio, improving the reliability of detecting the metal index's position, thus reducing the risk of command interpretation errors.

Implementation Method 1

a capacitive touch screen configured to detect the position of the metal index

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentEP3436302B1Interface for a motor vehicle
Publication Date: 2020.01.22 DAV
  • EP3436302B1 patent drawingFigure 1~2
  • EP3436302B1 patent drawingFigure 3~4b
  • EP3436302B1 patent drawingFigure 5~7

AI summary

The invention relates to an interface (1; 1') for controlling at least one function of a motor vehicle component, comprising: – a control member (2; 20) comprising: – a metallic index (6), – a mobile holding element (4; 40), and – a guide (5; 50), the mobile holding element (4; 40) being supported and guided in movement by the guide (5; 50), and – a capacitive touch screen (3) configured to detect the position of the metallic index (6), the guide (5; 50) being fixed to the capacitive touch screen (3), characterized in that the control member (2; 20) further comprises a cover (8; 80) secured to the end (4a) of the mobile holding element (4; 40) facing the capacitive touch screen (3) so as to conceal at least one finger of the user from the capacitive touch screen (3), the cover (8; 80) projecting out in a plane parallel to the capacitive touch screen (3), the metallic index (6) being positioned facing the capacitive touch screen (3) and borne by the end (4a) of the mobile holding element (4; 40) and/or by the cover (8; 80).