Sensor Protection Tube for Temperature Detection Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-contact temperature detection sensors in image forming apparatuses face contamination from dust such as toner and paper dust, reducing detection accuracy, and existing solutions like fluorine coating or cover members have limitations in effectively preventing dust attachment.
Innovation Solution
A sensor protection tube is used to encase the non-contact temperature detection sensor, positioned outside the housing of the fixing unit, with one end surrounding the sensor and the other end near the heating roller, creating a gap to prevent dust entry and maintain detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a non-contact type temperature detection sensor is used to avoid damaging the heating roller surface, then the roller surface is protected, but dust such as toner and paper dust attaches to the temperature detection surface reducing detection accuracy
Solution Approach 1:
A protection tube is introduced as an intermediary component between the temperature detection sensor and the dust-contaminated environment. The protection tube allows the sensor to maintain its non-contact positioning relative to the heating roller while physically blocking dust particles from reaching the temperature detection surface, thus resolving the contradiction between surface protection and detection accuracy maintenance
2Ease of repair
If fluorine coating is applied to the temperature detection surface to enable easy contamination removal, then cleaning becomes simpler, but the sensor still requires regular maintenance and detection accuracy may be reduced during contamination periods
Solution Approach 1:
Instead of preparing for contamination removal after it occurs (fluorine coating), the protection tube prevents contamination from occurring in the first place by creating a physical barrier. This preliminary protective action eliminates the need for regular cleaning maintenance and ensures continuous detection accuracy without the periodic accuracy degradation that occurs with coated sensors during contamination periods
3Object-affected harmful factors
If the temperature detection sensor is mounted inside the housing to protect it from dust, then dust attachment is reduced, but the sensor becomes difficult to access for maintenance and replacement
Solution Approach 1:
The protection tube is segmented from the main housing structure, creating a separate accessible chamber that houses the temperature detection sensor. This segmentation allows the sensor to be positioned in a location that is protected from dust by the tube while remaining externally accessible through the housing, thus enabling easy maintenance and replacement without compromising dust protection
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 effectively prevents dust attachment to the temperature detection surface, maintains detection accuracy, and allows for easier maintenance by keeping the sensor outside the housing, reducing costs and resource usage.
Implementation Method 1
The sensor protection tube includes a hollow cylindrical body passing through a side wall portion of the housing. One end of the sensor protection tube abuts a mounting surface of the temperature detection sensor in the sensor board so as to surround a periphery of the temperature detection sensor.
Implementation Method 2
The temperature detection sensor is a non-contact type sensor. The temperature detection sensor has a temperature detection surface facing a surface of the heating roller while being spaced apart from the surface of the heating roller.
Data Source
AI summary
The fixing unit has a housing that has a heating roller and a pressing roller accommodated therein. A temperature detection sensor and a sensor board are provided outside the housing. An image forming apparatus includes a sensor protection tube. The sensor protection tube includes a hollow cylindrical body passing through a side wall portion of the housing. One end of the sensor protection tube abuts a mounting surface of the temperature detection sensor in the sensor board so as to surround a periphery of the temperature detection sensor. The other end of the sensor protection tube is positioned in the housing.