Multi-Wavelength Bread Color Sensing for Toasting Control

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Solution Overview

Problem

Conventional toasters lack an efficient method to determine the optimal toasting time for bread based on its color, type, moisture content, and condition, leading to difficulties in achieving the desired level of browning.

Innovation Solution

A device that uses a light source emitting at least two wavelengths to detect reflected light, with a sensor to determine the chromatic property of the bread by calculating the relation between different wavelengths, and a controller to adjust the toasting time based on temperature corrections, allowing for precise control of browning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional timer is used to set toasting time, then the device is simple to operate, but it cannot account for variations in bread color, type, moisture content, and condition leading to inconsistent toasting results

Engineering Contradiction:
Improvechromatic property measurementVSAvoiddevice structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The device segments the broadband light into multiple wavelength components using filters, allowing separate detection of reflected light at different wavelengths. This enables precise chromatic property measurement by analyzing the relationship between outputs at different wavelengths, while keeping each detector element relatively simple.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The device uses a single broadband light source and detector system that can measure multiple chromatic properties across different wavelengths. By using one multi-functional detection system rather than multiple separate sensors, the device achieves comprehensive chromatic characterization without proportionally increasing complexity.

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

2Measurement precision

If temperature correction is applied to reflected light detection, then measurement accuracy is improved, but the device requires additional temperature sensing and correction mechanisms

Engineering Contradiction:
Improvereflected light detection accuracyVSAvoidtemperature correction mechanism
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The device incorporates temperature sensing that provides feedback to the control unit, which then applies correction factors to the reflected light measurements. This feedback loop compensates for temperature-induced variations in detector sensitivity and light source emission, maintaining measurement accuracy across different operating conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The device changes the operational parameters of the light source and detector based on temperature measurements. By adjusting detection thresholds and correction factors according to temperature, the system maintains consistent chromatic property measurements despite environmental variations.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If multiple wavelength detection is implemented, then chromatic property characterization is enhanced, but the device requires multiple filters or detector elements increasing complexity

Engineering Contradiction:
Improvechromatic property characterizationVSAvoidfilter and detector arrangement
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The device segments the broadband light into multiple wavelength components using filters, allowing separate detection of reflected light at different wavelengths. This enables precise chromatic property measurement by analyzing the relationship between outputs at different wavelengths, while keeping each detector element relatively simple.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The device uses optical filters as intermediary elements to separate different wavelength components of the broadband light before detection. These filters act as mediators that enable multi-wavelength measurement without requiring complex spectral analysis capabilities in the detector itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Manufacturing precision

If automatic toasting control based on chromatic properties is implemented, then toasting consistency is improved, but the device requires complex control algorithms and processing

Engineering Contradiction:
Improvebrowning consistencyVSAvoidcontrol system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The control unit continuously monitors the chromatic properties of the bread surface during toasting and provides feedback to adjust heating power accordingly. This real-time feedback control ensures consistent browning by maintaining the bread's reflectance within target ranges, automatically compensating for variations in bread type, moisture, and initial color.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The device uses the bread's own reflected light characteristics as the control signal, eliminating the need for external sensors or complex imaging systems. The bread effectively serves itself as the reference standard for determining when optimal browning has been achieved.

Inventive Principle:
Principle #25Self-service

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 accurate determination of the chromatic property of bread, ensuring consistent browning by correcting for temperature influences and allowing for precise control of the toasting process.

Implementation Method 1

a sensor device which comprises a sensor for detecting a radiation intensity reflected by the product to be cooked

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

the device may comprise a sensor for measuring the temperature

Methodology Applied
Scientific EffectTemperature measurement:

Data Source

PatentEP2874525B1A device and a method for characterising a chromatic property of foodstuff
Publication Date: 2018.08.22 SENSABILITY
  • EP2874525B1 patent drawingFigure 1
  • EP2874525B1 patent drawingFigure 2(a)~2(c)
  • EP2874525B1 patent drawingFigure 3(a)~3(c)

AI summary

The present disclosure provides a device for characterising a chromatic property of foodstuff. The device comprises a light source arranged to emit light having at least two wavelengths or wavelength ranges. The light source is further arranged to direct the light to a surface of at least the foodstuff. The device also comprises a detector positioned to detect at least a portion of reflected light and arranged to generate an output that is indicative of an intensity of detected reflected light. The device is arranged such that respective outputs are generated for the at least two wavelengths or wavelength ranges. A relation between the output for one of the at least two wavelengths or wavelength ranges and the output for the other or another one of the at least two wavelengths or wavelength ranges is indicative of the chromatic property of the surface of the foodstuff.