Rotary Microwave Waveguide for Continuous Defrost and Grilling

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Solution Overview

Problem

Conventional microwave cooking devices require users to perform complex operations to switch between defrosting and grilling functions, leading to inefficiencies and suboptimal cooking results due to microwave blockage and lack of continuous operation capability.

Innovation Solution

A microwave cooking device with a glass-fitted door and a directional rotary waveguide that utilizes the door as a microwave transmission channel, allowing for automatic and continuous defrosting and grilling functions without user intervention, by controlling the orientation of the waveguide to maximize microwave diffraction to the heating plate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a heating plate with microwave absorber is provided inside the heating chamber for grilling function, then grilling capability is improved, but microwave transmission to the object to be heated is blocked causing uneven heating

Engineering Contradiction:
Improvegrilling capabilityVSAvoidheating uniformity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The waveguide is made rotatable to change its orientation dynamically. During defrosting, the waveguide rotates to face the door to maximize microwave transmission through the glass door to the object on the heating plate. During grilling, the waveguide rotates to face the heating plate to transmit microwaves to the microwave absorber. This dynamic repositioning resolves the contradiction by allowing both functions to operate effectively at different orientations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The orientation angle of the waveguide is changed as a controllable parameter. By adjusting the waveguide's angular position, the system optimizes microwave transmission paths for different cooking modes. The waveguide can be positioned at specific angles to direct microwaves either through the door for defrosting or toward the heating plate for grilling, thus resolving the heating uniformity issue while maintaining grilling capability.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the waveguide is fixed in position, then device complexity is reduced, but the ability to perform both defrosting and grilling functions effectively is compromised

Engineering Contradiction:
Improvewaveguide positioning mechanismVSAvoidcooking function performance
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The waveguide is equipped with a rotation mechanism driven by a motor, allowing it to change orientation based on the selected cooking function. The control unit activates the motor to rotate the waveguide to appropriate angles for defrosting or grilling. This dynamic positioning capability enables the system to perform both functions effectively without requiring multiple fixed waveguides or complex mechanical structures.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A single waveguide structure serves multiple functions by rotating to different positions. The same waveguide transmits microwaves for both defrosting (when oriented toward the door) and grilling (when oriented toward the heating plate). This multi-functionality approach reduces the need for separate waveguide systems for each cooking mode, balancing complexity and versatility.

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

3Productivity

If the glass door is used as a microwave transmission channel, then defrosting efficiency is improved, but microwave leakage risk increases

Engineering Contradiction:
Improvedefrosting efficiencyVSAvoidmicrowave leakage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The glass door acts as an intermediary transmission medium for microwaves during defrosting. The glass material allows microwave transmission while providing physical containment. The waveguide is oriented to direct microwaves through the glass door, utilizing its transparency to microwaves while maintaining safety containment, thus improving defrosting efficiency without significant leakage risk.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The orientation of the waveguide is changed to optimize the transmission path through the glass door. By positioning the waveguide at specific angles, the system maximizes microwave transmission through the glass while minimizing potential leakage paths. The glass door's physical and electromagnetic properties are utilized to balance transmission efficiency and safety.

Inventive Principle:
Principle #35Parameter changes

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

Enables efficient and automatic performance of defrosting and grilling functions, improving cooking efficiency and user experience by ensuring uniform heating and eliminating the need for manual reconfiguration.

Implementation Method 1

utilizing the door as a microwave transmission channel

Methodology Applied
Scientific EffectMicrowave transmission through glass: Dielectric

Implementation Method 2

controlling the orientation of the waveguide to maximize microwave diffraction to the heating plate

Methodology Applied
Scientific EffectMicrowave diffraction: Diffraction

Implementation Method 3

a microwave absorber, such as ferrite, that absorbs microwaves to generate heat

Methodology Applied
Scientific EffectMicrowave absorption: Absorption (EM radiation)

Implementation Method 4

Magnetron 302 represents a microwave generating device. Waveguide 303 transmits microwaves radiated from magnetron 302

Methodology Applied
Scientific EffectMicrowave generation: Electromagnetic Induction

Implementation Method 5

a temperature of the heating plate is raised with microwaves to cook food placed thereon

Methodology Applied
Scientific EffectDielectric heating: Dielectric Heating

Data Source

PatentEP2348257B1Microwave cooking device
Publication Date: 2016.06.29 PANASONIC HOLDINGS CORP
  • EP2348257B1 patent drawingFigure 1
  • EP2348257B1 patent drawingFigure 2
  • EP2348257B1 patent drawingFigure 3A~3C

AI summary

The configuration of the invention includes: heating chamber (34) provided with glass-fitted door (31b) at a front opening, for housing an object to be heated; waveguide (33) for transmitting microwaves from microwave generating section (32) to heating chamber (34); directional feeding section (39) having directivity, for supplying the microwaves from waveguide (33) to heating chamber (34); driving section (41) for rotationally driving directional feeding section (39); and control section (411) for controlling driving section (41) to turn directional feeding section (39) to a direction of the door and supply the microwaves into a space above the tray, using the inside of the glass as a principal transmission channel, wherein a defrosting function and a grilling function are performed in an automatic and continuous manner without a user's operation.