Microwave Oven Illumination Hole Layout for Shielding and Brightness

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Solution Overview

Problem

The existing high-frequency cookers face a contradiction between radio wave shielding properties and illumination intensity due to the design of illumination holes, leading to reduced light transmittance and visibility issues, necessitating increased power output and number of LED elements.

Innovation Solution

The use of quadrilateral-shaped illumination holes in the heating chamber wall surface allows for improved radio wave shielding while maintaining light transmittance, using a small number of high-intensity LED elements to illuminate the interior effectively, with one side of the hole parallel to the chamber opening being longer than the other, directing light towards the rear for better coverage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the pore diameter of illumination holes is reduced to improve radio wave shielding properties, then radio wave shielding is improved, but the intensity of illumination inside the heating chamber is decreased

Engineering Contradiction:
Improveradio wave shielding propertiesVSAvoidintensity of illumination inside heating chamber
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The illumination holes are designed with an asymmetric rectangular shape rather than circular or symmetric shapes. The longer side is positioned to face the rear of the heating chamber, creating directional light transmission that optimizes both shielding and illumination effectiveness.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

Different regions of the heating chamber wall are provided with illumination holes having different orientations and dimensions. The holes are strategically positioned and sized to provide localized illumination where needed while maintaining overall radio wave shielding properties of the chamber.

Inventive Principle:
Principle #3Local quality

2Reliability

If the pitch between illumination holes is increased to improve radio wave shielding properties, then radio wave shielding is improved, but the transmittance of light is decreased and shadows are generated

Engineering Contradiction:
Improveradio wave shielding propertiesVSAvoidtransmittance of light and visibility
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The asymmetric rectangular shape of illumination holes allows for optimized spacing arrangements. The longer dimension of each hole compensates for increased pitch between holes, maintaining adequate light transmission while improving radio wave shielding through strategic positioning.

Inventive Principle:
Principle #4Asymmetry

3Illumination intensity

If the number of LED elements is increased to maintain illumination intensity with smaller pore diameters, then illumination intensity is maintained, but device complexity and power consumption increase

Engineering Contradiction:
Improveillumination intensity inside heating chamberVSAvoidnumber of LED elements
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The asymmetric rectangular illumination holes are strategically positioned and oriented to maximize light distribution throughout the chamber. This geometric optimization allows fewer LED elements to achieve uniform illumination coverage compared to conventional symmetric hole arrangements.

Inventive Principle:
Principle #4Asymmetry

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

This configuration enables bright illumination of the chamber corners with fewer LED elements, enhancing radio wave shielding and reducing energy consumption while preventing strong light from entering the user's eyes.

Implementation Method 1

an LED element which is used for chamber illumination in the heating chamber

Methodology Applied
Scientific EffectLight Emitting Diode: Light Emitting Diode

Implementation Method 2

the light from the LED element passes through the quadrilateral hole and if projected onto the interior of the chamber

Methodology Applied
Scientific EffectLight transmission: Light

Data Source

PatentEP2738473B1High-frequency cooker
Publication Date: 2015.11.25 PANASONIC HOLDINGS CORP
  • EP2738473B1 patent drawingFigure 1(a)~1(b)
  • EP2738473B1 patent drawingFigure 2
  • EP2738473B1 patent drawingFigure 3

AI summary

Light from an LED element provided on a surface of an LED substrate 7 provided outside of a wall surface of a heating chamber 2 passes through an illumination hole 1 that has a quadrilateral shape, and is projected in the chamber. In this case, since the LED element provided in a vicinity of the wall surface has a small light source and has high directivity of light, even when the size of the illumination hole 1 does not affect radio wave shielding properties, and the light is not hindered from passing through the quadrilateral illumination hole 1, whereby the interior of the chamber can be illuminated without decreasing the transmittance of light.