External Heating Belt Stability in Image Fixing Devices
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Solution Overview
Problem
Conventional image heating apparatuses face challenges in maintaining the stability of external heating belts, which affects the productivity when processing thick paper sheets, due to difficulties in achieving precise parallelism between supporting rollers, leading to heat loss and improper fixing of toner images.
Innovation Solution
The image heating apparatus incorporates an external heating belt assembly with a swinging intermediary frame and regulating members to maintain the belt's stability, ensuring consistent contact with the fixing roller and preventing widthwise offset, thereby enhancing the temperature maintenance and heating efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the contact area between the external heating belt and the fixing roller is increased by using two supporting rollers, then the temperature maintaining property is improved, but the traveling stability of the external heating belt deteriorates due to difficulty in achieving high precision parallelism
Solution Approach 1:
The intermediary frame is made swingable about a swing shaft, allowing the supporting rollers to dynamically adjust their position and orientation. This dynamic capability enables the system to maintain the external heating belt's contact with the fixing roller while automatically compensating for parallelism errors, thus resolving the contradiction between temperature maintenance and traveling stability.
Solution Approach 2:
The swingable intermediary frame enables the system to self-correct parallelism deviations without external intervention. When the external heating belt experiences widthwise shifting, the swingable frame automatically adjusts the supporting rollers' alignment, allowing the system to maintain both temperature and stability without requiring high-precision manual assembly.
2Stability of the object's composition
If one of the supporting rollers is inclined relative to the other to control the shifting of the external heating belt, then the traveling stability is improved, but the heating function deteriorates because part of the supporting roller region separates from the external heating belt
Solution Approach 1:
Instead of using a fixed inclined configuration, the intermediary frame is made swingable, allowing the supporting rollers to dynamically adjust their relative positions. This enables the system to maintain both the contact between supporting rollers and external heating belt (preserving heating function) and control widthwise shifting (improving traveling stability) simultaneously.
3Productivity
If the fixing speed is increased to enhance productivity, then the print number per unit time is improved, but the heat quantity required increases significantly for thick paper sheets
Solution Approach 1:
The external heating belt acts as an intermediary heating element that transfers heat from the supporting rollers to the fixing roller. This intermediary mechanism increases the effective heating area and improves heat transfer efficiency, allowing the fixing operation to process thick paper sheets at higher speeds without proportionally increasing the total heat quantity required.
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 solution improves the traveling stability of the external heating belt, allowing for higher productivity and proper fixing of toner images on thick paper sheets without compromising the heating function, ensuring consistent image quality and increased print speed.
Implementation Method 1
an external heating type has been proposed in which a heating member is contacted to an outer surface of a fixing roller (rotatable heating member) to maintain an outer surface temperature of the fixing roller at a target temperature
Implementation Method 2
the intermediary frame is swingable about a swing shaft extending in a direction substantially perpendicular to a generatrix of the fixing roller
Implementation Method 3
the swing shaft is disposed at a position offset from a center of the contact plane toward an upstream side with respect to a rotational moving direction of the fixing roller
Data Source
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AI summary
A fixing device is provided in which an external heating belt 105 for heating a fixing roller 101 from an outside is capable of correcting offset movement of supporting rollers 103, 104 in an axial direction. the external heating belt 105 is rotatable about a rotation shaft 209 so as to cross relative to a generatrix direction of the fixing roller 101. further, the rotational shaft 209 is disposed at a position offset toward an upstream side with respect to a rotational moving direction of the fixing roller 101.