Infrared Sensor Contamination Detection via Distance Adjustment

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Infrared sensors in image forming devices, such as fusers, are prone to contamination by paper dust and toner, leading to errors in temperature detection, and existing methods assume contamination rather than accurately measuring it.

Innovation Solution

A temperature detector system with an infrared sensor positioned not to contact the measured object, an infrared transmission filter to block the sensor, and a distance changer to vary the distance between the object and filter, allowing the sensor to detect infrared rays passed through the filter at different distances to assess contamination levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the infrared sensor is positioned close to the measured object for accurate temperature detection, then the temperature measurement precision is improved, but the sensor becomes contaminated by paper dust and toner

Engineering Contradiction:

Improvetemperature detection accuracyVSAvoidsensor contamination

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

An infrared transmission filter is introduced as an intermediary component between the infrared sensor and the measured object (fusing roller). The filter allows infrared rays to pass through while preventing direct contact and contamination of the sensor by paper dust and toner. This mediator enables the sensor to maintain measurement precision without being exposed to harmful contaminants in the imaging device environment.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system segments the detection path into two distinct zones: a first distance zone where the infrared sensor detects temperatures during imaging operations (with the filter in place to prevent contamination), and a second distance zone where the sensor detects temperatures at a greater distance for contamination assessment. This segmentation allows the sensor to operate in protected mode while still performing accurate measurements.

Inventive Principle:

Principle #1Segmentation

2Object-affected harmful factors

If the infrared sensor is protected from the measured object using a filter, then sensor contamination is prevented, but the detection precision may deteriorate due to filter interference

Engineering Contradiction:

Improvesensor contamination preventionVSAvoidtemperature detection accuracy

Core Design Contradiction:

Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The system dynamically adjusts the detection distance between the infrared sensor and the infrared transmission filter based on operational mode. During normal imaging operations, the sensor operates at a first distance optimized for temperature measurement through the filter. For contamination detection, the sensor moves to a second distance (greater than the first) to assess filter contamination levels. This dynamic distance adjustment allows the system to maintain measurement precision while preventing contamination.

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

This setup prevents sensor contamination, allows for accurate detection of contamination levels in the infrared transmission filter, and enables reliable temperature measurement by differentiating between the object and filter temperatures, facilitating easier maintenance and correction.

Implementation Method 1

an infrared sensor which detects infrared rays, which have passed through the infrared transmission filter, to detect a temperature of the measured object

Methodology Applied

Scientific EffectInfrared radiation detection: Infrared Radiation

Implementation Method 2

infrared rays emitted from the measured object

Methodology Applied

Scientific EffectBlackbody radiation: Thermal Radiation

Implementation Method 3

an infrared transmission filter which is located between the infrared sensor and the measured object so as to block the infrared sensor from the measured object, and through which infrared rays emitted from the measured object pass

Methodology Applied

Scientific EffectInfrared transmission filtering: Filter (optical)

Data Source

PatentUS8534913B2Temperature detector, image forming device having temperature detector, and contamination detection method for temperature detector

Publication Date: 2013.09.17 KONICA MINOLTA BUSINESS TECH INC

AI summary

A temperature detector has: an infrared sensor located so as not to be in contact with a measured object; an infrared transmission filter which is located between the infrared sensor and the measured object so as to block the infrared sensor from the measured object, and through which infrared rays emitted from the measured object pass; and a distance changer for changing a distance between the measured object and the infrared transmission filter, wherein the infrared sensor is provided so as to detect the infrared rays, which have passed through the infrared transmission filter, to detect a temperature of the measured object even when the distance is changed by the distance changer.