Fixing Belt Heating Stop Device Thermal Expansion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fixing devices in electrographic image forming apparatuses face issues with premature operation of the heating stop device due to a narrow facing interval, leading to incorrect temperature regulation and potential delays in stopping the heat source when the fixing belt is stationary.
Innovation Solution
The fixing device incorporates a first heating stop device positioned to face the outer circumferential face of the fixing belt, which deforms and comes into contact with the belt during thermal expansion when the heat source heats it in a stopped state, allowing for timely operation and adjusting the facing interval to prevent unnecessary activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the facing interval between the fixing belt and the heating stop device is narrow, then the heating stop device can respond quickly to temperature rises, but it operates prematurely even when the temperature does not excessively rise
Solution Approach 1:
The patent changes the physical state of the fixing belt from rigid to flexible by adding an elastic layer, enabling thermal expansion parameter changes that activate the heating stop device only under genuine overheating conditions rather than through narrow spacing alone
Solution Approach 2:
The elastic layer acts as an intermediary between the heat source and the heating stop device, translating thermal energy into mechanical deformation that reliably triggers the heating stop function only when necessary
2Reliability
If the facing interval is wide, then the heating stop device avoids premature operation, but the timing of operation delays when the heat source causes runaway heating
Solution Approach 1:
The fixing belt's thermal expansion under runaway heating conditions provides a rapid mechanical response that activates the heating stop device without delay, compensating for the wider facing interval through increased deformation magnitude
3Stability of the object's composition
If the heat source heats the fixing belt while rotation is stopped, then heating can occur uniformly, but the heating stop device may not operate timely without thermal expansion mechanism
Solution Approach 1:
The fixing belt undergoes a phase transition from elastic deformation to plastic deformation at high temperatures, providing a reliable mechanical trigger for the heating stop device during stationary heating conditions
Solution Approach 2:
The elastic layer serves as a mediator that converts thermal energy during stationary heating into mechanical displacement, ensuring the heating stop device operates timely regardless of belt rotation state
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 ensures accurate temperature control by preventing the heating stop device from operating unnecessarily and allows for a wider facing interval, thereby improving the reliability and longevity of the fixing device.
Implementation Method 1
the closest part to the heat source of the fixing belt is deformed by a thermal expansion and comes into contact with the first heating stop device
Data Source
AI summary
A fixing device includes a fixing belt, a pressuring member, a heat source, a pressing member and a first heating stop device. The fixing belt is provided to be rotatable around a rotation axis. The pressuring member is configured to be rotatable and to come into pressure contact with the fixing belt so as to form a fixing nip. The heat source is arranged at an inner diameter side of the fixing belt, provided at a position displaced from the rotation axis and configured to heat the fixing belt. The pressing member is configured to press the fixing belt to a side of the pressuring member. The first heating stop device is configured to face an outer circumferential face of a closest part to the heat source of the fixing belt and to operate at a first operating temperature so as to stop the heat source from heating the fixing belt.