Capacitive Touch Switch Assembly for Stable Cooker Operation

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Solution Overview

Problem

Conventional heating cookers face issues with unstable operation feelings, complex configurations, high manufacturing costs, and high defect rates due to variations in electrode placement and vibration-induced peeling of conductive electrodes, leading to inconsistent operation and appearance quality.

Innovation Solution

An electrostatic capacity type touch switch operation device with an electrode terminal portion, guide holder, and spring portion that securely contacts the back surface of the top plate, ensuring stable operation and easy assembly, and a light shielding portion to prevent light leakage and enhance visibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a copper foil flat-shaped electrode is brought into close contact with the back surface of the top plate, then the electrostatic touch switch can be operated, but the distance between the top plate and the electrode varies, causing unstable operation feeling

Engineering Contradiction:
Improveoperation feeling stabilityVSAvoidelectrode placement consistency
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The electrode terminal portion is divided into a detection portion (contacting the top plate) and a slide portion (moving within the guide holder). This segmentation allows the detection portion to maintain stable contact with the top plate while the slide portion accommodates positioning variations through controlled movement, resolving the contradiction between operational stability and manufacturing precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrode terminal portion is designed to be movable rather than fixed, with the slide portion sliding within the guide holder. This dynamic structure compensates for variations in top plate positioning during assembly, ensuring that the detection portion maintains consistent contact pressure and distance with the top plate regardless of manufacturing tolerances, thereby stabilizing the operation feeling.

Inventive Principle:
Principle #15Dynamics

2Reliability

If a conductive thin film is attached to the back surface of the top plate, then the touch switch can be configured, but vibration causes the conductive electrode to peel off, leading to high defect rates

Engineering Contradiction:
Improvetouch switch functionalityVSAvoidelectrode adhesion
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The electrode terminal portion is segmented into a detection portion and a slide portion, with the detection portion specifically designed to contact the top plate. This segmentation concentrates the adhesion requirement only at the detection portion interface, while the slide portion is retained by the guide holder structure, preventing peeling during vibration and reducing defect rates.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The guide holder acts as an intermediary structure that secures the electrode terminal portion in place. Instead of relying solely on adhesion between the conductive film and the top plate, the guide holder provides mechanical retention, preventing peeling during vibration while allowing the detection portion to maintain stable contact.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If multiple separate components are used for the operation device, then the configuration is flexible, but the device complexity increases and manufacturing cost rises

Engineering Contradiction:
Improveconfiguration flexibilityVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The detection portion, spring portion, and slide portion are integrally formed as a single electrode terminal portion, which is then retained by the guide holder. This merging reduces the number of separate components and assembly steps compared to using entirely separate parts, simplifying the overall device structure and reducing manufacturing complexity while maintaining the necessary functional flexibility.

Inventive Principle:
Principle #5Merging (Combining)

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 provides a stable operation feeling, high reliability, and excellent operability with a simple configuration, reducing manufacturing costs and defect rates while maintaining appearance quality.

Implementation Method 1

a change of an electrostatic capacity in the electrode terminal portion is output as an operation signal

Methodology Applied
Scientific EffectElectrostatic capacity: Capacitance

Data Source

PatentEP2461645B1Operation device and heating cooker using operation device
Publication Date: 2019.04.10 PANASONIC HOLDINGS CORP
  • EP2461645B1 patent drawingFigure 1~2
  • EP2461645B1 patent drawingFigure 3
  • EP2461645B1 patent drawingFigure 4A~4B

AI summary

The present invention provides an operation device which has a stable operation feeling with a simple configuration and has a high reliability and an excellent operability. An electrode terminal portion which is arranged just below an operation region on a top plate made of a material having an electric insulating property, and serves as an electrostatic capacity type touch switch has a detection portion which comes into close contact with a back surface of the operation region, a spring portion which has an elastic force pressing the detection portion to the back surface of the top plate, and a slide portion which is movably retained in the guide holder.