Multi-Stage Choke Seal for Microwave Leakage Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional microwave cookers experience significant microwave leakage when the door is initially opened, leading to inferior damping functions and contamination of the choke seal or microwave sealing unit, making it difficult to prevent leakage and maintain cleanliness.

Innovation Solution

A multi-stage choke seal with different resonant frequencies positioned higher than the central frequency of the microwave, comprising a first and second choke seal with LC resonant circuits, spaced with a gap corresponding to 1/15 to 1/8 of the microwave wavelength, to prevent leakage and enhance cleaning by using a transparent window and control plate design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional choke seal with a single resonant frequency is used, then the microwave damping function is effective at a specific frequency, but the damping function deteriorates when the door gap varies or when operating at frequencies偏离 the resonant frequency

Engineering Contradiction:

Improvemicrowave damping functionVSAvoidfrequency adaptation range

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The single resonant frequency choke seal is divided into multiple resonant frequency sections. Each section has a different resonant frequency, collectively covering a broader frequency range and maintaining effective damping across varying operating conditions and door gaps.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple resonant frequencies are introduced by varying the physical parameters (such as cavity dimensions, inductance, capacitance) of different sections. This allows the sealing structure to adapt to different frequency regions and maintain effective microwave damping across a wider range of operating conditions.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If the resonant frequencies are spaced far apart to achieve wide bandwidth, then the frequency coverage is improved, but the damping function between resonant frequencies is reduced

Engineering Contradiction:

Improvebandwidth coverageVSAvoiddamping function between resonant frequencies

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

Each resonant frequency section is optimized for its specific frequency range with locally tailored parameters. The sections are arranged and parameterized such that their individual damping characteristics complement each other, ensuring continuous effective damping across the entire bandwidth without significant gaps between resonant frequencies.

Inventive Principle:

Principle #3Local quality

3Ease of operation

If a large gap between the body and door is allowed for ease of operation, then the ease of operation is improved, but microwave leakage increases significantly

Engineering Contradiction:

Improvedoor opening easeVSAvoidmicrowave leakage

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The choke seal structure incorporates dynamic adaptability through multiple resonant frequencies, allowing it to maintain effective damping across varying door gap conditions. As the door gap changes during operation, at least one resonant frequency section remains effective at blocking microwave leakage, providing continuous protection regardless of the instantaneous gap size.

Inventive Principle:

Principle #15Dynamics

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 multi-stage choke seal significantly enhances microwave leakage blocking by at least 20 dB compared to conventional designs, effectively preventing leakage even with larger gaps and maintaining a stable damping function across varying door gaps, while allowing easy cleaning of the inner surfaces.

Implementation Method 1

having different resonant frequencies at a frequency region higher than a central frequency of microwave, and having different LC resonant circuits for preventing the microwave from being leaked between the body and the door

Methodology Applied

Scientific EffectLC resonance: Resonance

Implementation Method 2

a multi-stage choke seal formed at the door... for preventing the microwave from being leaked between the body and the door

Methodology Applied

Scientific EffectMicrowave radiation blocking: Absorption (EM radiation)

Data Source

PatentUS7402784B2Microwave oven with multi-stage choke seal

Publication Date: 2008.07.22 LG ELECTRONICS INC

AI summary

A microwave cooker comprises a body having a cooking chamber therein, the cooking chamber having one opened side, a microwave source disposed at the body for supplying microwave to the cooking chamber, a door coupled to the body for opening and closing the cooking chamber, and a multi-stage choke seal formed at the door, having different resonant frequencies at a frequency region higher than a central frequency of microwave, and having different LC resonant circuits for preventing the microwave from being leaked between the body and the door.