Capacitance Switch Protrusion Tactile Feedback

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Solution Overview

Problem

Existing electrostatic capacitance switch apparatuses for vehicles do not effectively convey the feeling of pressing the switch to operators, making it difficult for them to confirm successful operation.

Innovation Solution

A switch apparatus design featuring a protrusion on the pressing section close to the electrostatic capacitance sensor, with a specific clearance and hardness, and an insert molding method to enhance tactile feedback, allowing for effective realization of the pressing operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a protrusion is added to the pressing section to improve tactile feedback, then the operator's awareness of pressing action is improved, but the device complexity increases

Engineering Contradiction:
Improveoperator awareness of pressing actionVSAvoidstructure complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

A protrusion is introduced as an intermediary element between the pressing section and the operator's finger. This protrusion mediates the interaction by providing a localized contact point that concentrates the pressing force and creates noticeable tactile feedback, resolving the contradiction between simplicity and effectiveness of operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Instead of making the entire pressing section complex, the invention applies local quality by adding a protrusion only at the specific location where tactile feedback is needed. This localized modification provides enhanced operator awareness without requiring complex changes to the overall device structure.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If the pressing section is made harder to provide tactile feedback, then the operator can feel the pressing action, but the displacement at contact point decreases

Engineering Contradiction:
Improvetactile feedbackVSAvoiddisplacement at contact point
Core Design Contradiction:
Ease of operationVSLength of moving object

Solution Approach 1:

The invention optimizes the hardness parameter of the pressing section to a specific range (25-70 on the A-scale durometer). This parameter change balances the competing requirements: the material is hard enough to provide tactile feedback through the protrusion but soft enough to allow sufficient displacement (0.5-1.8 mm) for effective operation.

Inventive Principle:
Principle #35Parameter changes

3Speed

If the clearance between pressing section and sensor is reduced to improve responsiveness, then the detection speed is improved, but the tactile feedback is reduced

Engineering Contradiction:
Improvedetection responsivenessVSAvoidtactile feedback
Core Design Contradiction:
SpeedVSEase of operation

Solution Approach 1:

The invention segments the interaction into two distinct phases: a first clearance (0.3-2.0 mm) that provides tactile feedback during the pressing action, and a second, smaller clearance (0.01-0.3 mm) between the protrusion tip and sensor that ensures rapid detection. This segmentation allows both tactile feedback and fast responsiveness to be achieved simultaneously.

Inventive Principle:
Principle #1Segmentation

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 operator awareness of the pressing action, providing a favorable tactile experience and ensuring the operation is effectively recognized, while preventing unnecessary force on the sensor.

Implementation Method 1

an electrostatic capacitance switch apparatus that detects variation of an electrostatic capacitance caused by touching or pressing of a pressing region

Methodology Applied
Scientific EffectElectrostatic capacitance: Capacitance

Implementation Method 2

the pressing section is made of a rubber-like elastic body

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3116010B1Switch apparatus
Publication Date: 2021.04.28 SHIN ETSU POLYMER CO LTD
  • EP3116010B1 patent drawingFigure 1A~1B
  • EP3116010B1 patent drawingFigure 2A~2C
  • EP3116010B1 patent drawingFigure 3A~3C

AI summary

The present invention makes it possible for an operator to more effectively realize that a pressing region was pressed. A switch apparatus (1) has a pressing section (2) that is formed of a rubber-like elastic material and has a pressing region (2a) that is pressed in a predetermined pressing direction; and a capacitance sensor (6) for detecting the pressing of the pressing region (2a) on the basis of capacitance. The capacitance sensor (6) is positioned apart from the pressing section (2) in the pressing direction, and is configured so that when the pressing region (2a) is not being pressed, a space (clearance) is maintained between the part (the lowermost surface (22a) of a protruding section (22)) of the pressing section (2) on the side towards the capacitance sensor (6) corresponding to the pressing region (2a) and another member (base housing (4)) disposed in the vicinity of the pressing region along the pressing direction, said space (clearance) allowing the part on the side towards the capacitance sensor (6) to move in the pressing direction.