Hob Light-Guide Temperature Sensing With IR Emission Compensation

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Solution Overview

Problem

Existing cooktops using infrared sensors for temperature determination face limitations in accuracy and reliability, particularly in assigning temperature values with significant deviations, which affects the precision of temperature parameter determination for objects behind the light guide element.

Innovation Solution

A domestic appliance with a light guide element and a sensor unit comprising a light sensor and additional sensor elements to determine temperature parameters, utilizing a light-guiding unit that transmits light from one point to another, and an evaluation electronics system to calculate corrected temperature parameters considering reflection and emission models, ensuring improved temperature determination with minimal deviation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a light guide element is used to transmit infrared light for temperature measurement, then non-contact temperature sensing is enabled, but the light guide element itself emits infrared radiation that interferes with the measurement accuracy

Engineering Contradiction:
Improvenon-contact temperature sensingVSAvoidtemperature measurement accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent introduces an evaluation electronics system that acts as an intermediary between the light sensor and the temperature determination. This intermediary processes the sensor signals by separating the target object's infrared radiation from the light guide element's self-emission, enabling accurate non-contact temperature measurement despite the light guide's interference

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The evaluation electronics implement a feedback mechanism where temperature parameters of the light guide element are continuously monitored and used to correct the temperature measurement of the target object. This feedback loop compensates for the light guide's self-emission interference, maintaining measurement accuracy

Inventive Principle:
Principle #23Feedback

2Device complexity

If the light guide element temperature is not compensated, then the measurement system remains simple, but the temperature determination shows significant deviations

Engineering Contradiction:
Improvemeasurement system simplicityVSAvoidtemperature determination accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The evaluation electronics continuously monitor the light guide element's temperature and use this information to correct the target object's temperature measurement in real-time, achieving high precision without significantly increasing device complexity

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces complex mechanical temperature compensation mechanisms with electronic signal processing. The evaluation electronics use mathematical models and signal algorithms to compensate for thermal interference, achieving high precision with minimal physical complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If additional sensor elements are added to measure light guide element parameters, then temperature determination accuracy improves to within 1K deviation, but the device complexity increases

Engineering Contradiction:
Improvetemperature determination accuracyVSAvoidsensor unit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The additional sensor elements serve multiple functions: they monitor the light guide element's temperature, characterize its infrared emission properties, and provide data for compensation algorithms. This multi-functionality justifies the increased component count by achieving sub-1K temperature measurement accuracy

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

Solution Approach 2:

The patent replaces complex mechanical characterization methods with electronic sensing and computational analysis. Additional sensors provide electrical signals that are processed through mathematical models, achieving high precision temperature measurement with controlled complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 solution enables precise temperature determination with a deviation of up to 1K, enhancing the accuracy and reliability of temperature measurement for cooking utensils and food, and can be applied to various domestic appliances requiring non-contact temperature sensing.

Implementation Method 1

a light sensor (22, 24) and is intended to detect light transmitted through the light guide element (17)

Methodology Applied
Scientific EffectInfrared transmission: Infrared Radiation

Implementation Method 2

a sensor element which is intended to measure an intensity of incident infrared radiation

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 3

the light-guiding unit (30) being intended to transmit light from a first point to a second point

Methodology Applied
Scientific EffectOptical transmission: Light

Data Source

PatentEP2893261B1Domestic appliance
Publication Date: 2019.04.03 BSH HAUSGERATE GMBH
  • EP2893261B1 patent drawingFigure 1~3
  • EP2893261B1 patent drawingFigure 2

AI summary

The invention proceeds from a domestic appliance apparatus (12), more particularly a hob apparatus with at least one light-guiding element (17, 33, 39) and at least one sensor unit (20), which has at least one light sensor (22, 24) and is provided to detect light transmitted by the light-guiding element (17, 33, 39) and determine at least one temperature characteristic. In order to make possible improved temperature measurement it is proposed that the sensor unit (20) has at least one further sensor element (40, 42, 44) which is provided to determine at least one characteristic of the at least one light-guiding element (17, 33, 39).