Induction Heating Fixing Device for Uniform Nip Temperature
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Solution Overview
Problem
Existing fixing devices for image forming apparatuses using induction heating systems face issues with heat distribution, leading to insufficient heat on the pressurizing member during high-speed color image fixation, potentially resulting in defective image quality.
Innovation Solution
A fixing device is designed with a heat-generating member and a belt that opposes the heat-generating member, where both are heated by induction current generating devices, and a pressing member is used to ensure adequate heat transfer and nip formation, ensuring consistent heat distribution across the belt and heat roller.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If induction heating is applied only to the heat-generating roller to speed up warming, then warming speed is improved, but heat amount on the pressurizing member side becomes insufficient during continuous high-speed color image fixation
Solution Approach 1:
The heating system is divided into two independent induction heating units: one for the heat-generating roller and another for the pressurizing member. This segmentation allows each component to be heated independently and simultaneously, resolving the contradiction by enabling both rapid warming and sufficient heat delivery during continuous operation.
Solution Approach 2:
The pressurizing member is preheated by a dedicated induction heating unit before the fixing process begins. This preliminary heating ensures that when continuous high-speed color image fixation occurs, the pressurizing member already has sufficient temperature and heat capacity to maintain image quality without waiting for heat transfer from the heat-generating roller alone.
2Loss of time
If heat-generating roller is heated by induction to reduce warming time, then warming time is reduced, but heat distribution uniformity deteriorates during continuous color image fixation
Solution Approach 1:
The heating function is segmented between two independent induction heating units, each controlling the temperature of a different component (heat-generating roller and pressurizing member). This allows both components to reach optimal temperatures simultaneously and maintain uniform heat distribution throughout the fixing process, even during continuous high-speed operation.
Solution Approach 2:
Each component (heat-generating roller and pressurizing member) is equipped with its own induction heating unit, allowing localized temperature control and optimization. This ensures that both the heat source and the pressurizing surface maintain appropriate temperatures independently, achieving uniform heat distribution across the entire fixing interface during continuous operation.
3Device complexity
If single induction heating is used on heat-generating roller, then device complexity is reduced, but image quality deteriorates during high-speed color fixation
Solution Approach 1:
The heating system is segmented into two independent induction heating units, each dedicated to a specific component. This segmentation improves reliability by ensuring both the heat-generating roller and pressurizing member maintain sufficient temperatures during continuous high-speed color fixation, preventing image quality deterioration despite increased device complexity.
Solution Approach 2:
The pressurizing member acts as an intermediary heat transfer medium, with its own induction heating unit ensuring it maintains adequate temperature. This intermediary approach guarantees uniform heat distribution across the fixing interface, maintaining image quality during high-speed operation while the dual-heating system manages the complexity through modular design.
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 configuration improves image quality by preventing defective image fixation during high-speed color image formation by ensuring sufficient heat is applied uniformly across the nip, enhancing the fixing process and reducing the risk of image defects.
Implementation Method 1
a heat-generating member having a metal layer which is to be injection-heated, a first induction current generating device arranged in the proximity to the heat-generating member
Implementation Method 2
a second induction current generating device arranged on the periphery of the belt for heating the belt by the induction heating
Data Source
AI summary
A fixing device according to an embodiment of the invention is provided with a center coil and a side coil to induction heat a metal roller which supports a belt. An auxiliary pressurizing member which is adjacent to an opposing roller which supports the belt and presses the belt against a heat roller is provided. The distance from the center position of induction heating of a heat roller to an entrance of a nip is equalized to the distance from the center position of induction heating of the metal roller to the entrance of the nip. The distance from the temperature reading position of the heat roller to the center position of induction heating of the heat roller is equalized to the distance from the temperature reading position of the belt to the center position of induction heating of the metal roller.