Fixing Device Nip Formation Pad Thermal Conductivity Control
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Solution Overview
Problem
Existing fixing devices in image forming apparatuses suffer from overheating issues due to uneven heat distribution along the fixing belt, leading to inefficiencies in toner image fixation and increased energy consumption.
Innovation Solution
The implementation of a nip formation pad with alternating increased and decreased thermal conductivity portions, where the increased thermal conductivity portion is positioned opposite the overheating span of the fixing rotator to absorb excess heat and the decreased thermal conductivity portion is used in the conveyance spans to maintain optimal temperature, facilitating efficient heat conduction and preventing overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a heater is used to heat the fixing rotator, then the toner image fixation is improved, but overheating occurs in certain spans of the fixing rotator
Solution Approach 1:
The nip formation pad is designed with non-uniform thermal conductivity distribution, featuring a first region with higher thermal conductivity and a second region with lower thermal conductivity. This local quality variation allows different parts of the pad to perform different thermal functions: the first region conducts heat away from overheating spans, while the second region maintains heat in areas needing it, thereby resolving the overheating problem while preserving fixation quality.
Solution Approach 2:
The nip formation pad acts as an intermediary thermal management component between the heater and the fixing rotator. By introducing this intermediate layer with strategically designed thermal conductivity variations, the system can control heat distribution more precisely, preventing direct overheating of the fixing rotator while ensuring adequate heat transfer for toner fixation.
2Ease of manufacture
If uniform thermal conductivity is used in the nip formation pad, then manufacturing is simplified, but heat distribution becomes uneven causing overheating
Solution Approach 1:
The nip formation pad is segmented into distinct regions with different thermal conductivity characteristics. The pad comprises a first region and a second region, each with specific thermal conductivity values. This segmentation allows precise control over heat distribution patterns, addressing the overheating issue while maintaining reasonable manufacturing complexity through defined regional variations rather than completely uniform construction.
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 effectively addresses overheating issues, ensuring consistent toner image fixation, reducing energy waste, and enhancing the operational efficiency of the fixing device by maintaining optimal temperatures across the fixing belt.
Implementation Method 1
A heater is disposed opposite the fixing rotator to heat the fixing rotator
Implementation Method 2
The nip formation pad includes a decreased thermal conduction portion having a decreased thermal conductivity and an increased thermal conduction portion having an increased thermal conductivity to conduct heat in a thickness direction of the nip formation pad
Implementation Method 3
an increased thermal conduction portion having an increased thermal conductivity to conduct heat in the thickness direction of the nip formation pad perpendicular to an axial direction of the fixing rotator. The increased thermal conduction portion is disposed opposite an overheating span of the fixing rotator
Implementation Method 4
The nip formation pad includes a decreased thermal conduction portion having a decreased thermal conductivity to conduct heat in the thickness direction of the nip formation pad
Data Source
AI summary
A fixing device includes a fixing rotator and an opposed rotator disposed opposite the fixing rotator to form a fixing nip therebetween through which a recording medium bearing a toner image is conveyed. A heater disposed opposite the fixing rotator heats the fixing rotator. A nip formation pad disposed opposite an inner circumferential surface of the fixing rotator includes a decreased thermal conduction portion having a decreased thermal conductivity to conduct heat in a thickness direction of the nip formation pad perpendicular to an axial direction of the fixing rotator and an increased thermal conduction portion having an increased thermal conductivity to conduct heat in the thickness direction of the nip formation pad. The increased thermal conduction portion is disposed opposite an overheating span of the fixing rotator in the axial direction thereof where the fixing rotator is susceptible to overheating.