Cooking Chamber Contamination Detection Using Light Scattering

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for detecting contamination in cooking appliances are not robust or reliable, leading to inefficient cleaning processes and potential functional impairment of surfaces exposed to cooking chambers.

Innovation Solution

A method involving illumination of a measuring area within the cooking chamber with a focused light beam, measuring the intensity of scattered radiation, and calculating a scattering value to determine contamination levels, which is used to trigger cleaning actions when thresholds are reached.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing optical sensor methods are used to detect contamination, then contamination detection is possible, but the detection is not robust or reliable

Engineering Contradiction:
Improvecontamination detection reliabilityVSAvoidcontamination measurement accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

Instead of measuring light transmission through the contamination layer (existing method), the invention measures light reflection from the contamination layer. The optical sensor detects the intensity of reflected light, which increases with contamination level. This inverted measurement approach provides more robust and reliable contamination detection.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The invention utilizes changes in optical properties (reflectivity) of the surface as it becomes contaminated. The optical sensor detects variations in light reflection intensity, which correlates with the degree of contamination. This optical property change provides a reliable basis for contamination measurement.

Inventive Principle:
Principle #32Color changes

2Reliability

If cleaning processes are triggered frequently to maintain surface functionality, then surface functionality is maintained, but energy consumption and operational time increase

Engineering Contradiction:
Improvesurface functionalityVSAvoidcleaning energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The optical sensor provides continuous feedback on contamination levels to the control unit. The control unit triggers cleaning processes only when the reflected light intensity exceeds a predetermined threshold, indicating significant contamination. This feedback-based triggering optimizes cleaning frequency, maintaining surface functionality while minimizing unnecessary cleaning cycles and energy consumption.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The optical sensor continuously monitors contamination levels before they reach critical levels that would impair surface functionality. By detecting contamination early and triggering cleaning proactively, the system prevents functional impairment while avoiding excessive cleaning operations.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If pyrolytic cleaning is used to clean the cooking chamber, then thorough cleaning is achieved, but the cooking chamber must be heated to high temperatures requiring significant energy

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidpyrolysis energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The optical sensor provides real-time feedback on contamination levels, enabling the control unit to determine whether pyrolytic cleaning is necessary. By monitoring reflected light intensity continuously, the system triggers high-energy pyrolytic cleaning only when contamination reaches levels that require such thorough cleaning, thereby minimizing energy consumption while maintaining cleaning effectiveness.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention uses optical parameters (reflected light intensity) to monitor contamination levels and dynamically adjusts cleaning strategy. Less severe contamination is detected optically and may be addressed with minimal or no cleaning, while only significant contamination triggers pyrolytic cleaning, optimizing the balance between cleaning effectiveness and energy consumption.

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

This approach allows for precise and timely detection of contamination, optimizing cleaning processes and maintaining surface functionality by ensuring that surfaces are cleaned before they become irreversibly dirty.

Implementation Method 1

a measuring area of the surface is illuminated and an intensity of light radiation emitted by the measuring area is measured

Methodology Applied
Scientific EffectLight scattering: Scattering

Data Source

PatentEP3610199B1Determining a degree of contamination in a cooking chamber
Publication Date: 2023.11.01 BSH HAUSGERATE GMBH
  • EP3610199B1 patent drawingFigure 1~3
  • EP3610199B1 patent drawingFigure 4~6
  • EP3610199B1 patent drawing

AI summary

The invention relates to a method for determining a contamination of a surface (5), which is exposed to a cooking chamber (2) of a cooking appliance (1), wherein the method comprises illuminating a measurement region (10) of the surface (5) by means of a light bundle (L), measuring a strength (I, l0) of scatter radiation emitted from the measurement region (10), and determining a scatter value (A) from the scatter radiation as a measure of the contamination. The invention further relates to a cooking appliance (1), having a cooking chamber (2), at least one light source (7) for irradiating with a light bundle (L) a measurement region (10) of a surface (5), which is exposed to the cooking chamber (2), at least one light sensor (12) for measuring scatter radiation from the measurement region (10) and a processing device (13), which is coupled to the at least one light source (7) and to the at least one light sensor (12) and which is designed to determine a scatter value from the scatter radiation as a measure of the contamination. The invention can be particularly advantageously applied to ovens, particularly to self-cleaning ovens.