Image Heating Roller Temperature Control via Segmented Heaters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image heating apparatuses experience significant downtime and nonuniform temperature distribution when switching between high and low target temperatures, leading to reduced fixation performance and image quality.
Innovation Solution
The implementation of a dual-heater system with a main and subordinate heater, where the main heater has higher heat generation at the center and the subordinate heater has higher heat generation at the ends, allowing independent temperature control and adjusting the ratio of heater usage based on the recording medium size, along with strategic use of cooling fans to maintain uniform temperature distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a cooling fan is used to forcefully cool the fixation roller to reduce downtime when switching target temperatures, then the downtime is reduced, but the temperature distribution becomes nonuniform with end portions becoming too low in temperature
Solution Approach 1:
The invention divides the heating function into multiple independent heating zones along the width direction of the fixation roller. By segmenting the heating elements, each zone can be controlled independently to compensate for nonuniform cooling effects, thereby maintaining uniform temperature distribution while reducing downtime during temperature switching.
Solution Approach 2:
The invention applies different heating characteristics to different locations of the fixation roller. Heating elements with different heat generation capacities are positioned at specific locations (center and end portions) to compensate for the nonuniform cooling effect, ensuring that each region receives appropriate heat to maintain uniform temperature distribution.
2Loss of time
If the thermal capacity of the fixation roller is reduced to reduce downtime during temperature switching, then the downtime is reduced, but the fixation speed cannot be increased further while maintaining fixation performance
Solution Approach 1:
The invention makes the heating system dynamic by enabling independent control of multiple heating zones. This allows the system to adapt quickly to temperature switching requirements while maintaining the thermal capacity needed for high-speed fixation, resolving the trade-off between downtime reduction and fixation speed.
Solution Approach 2:
The invention changes the heating parameters by using multiple heating elements with different heat generation capacities positioned at different locations. This allows precise control of temperature distribution during both rapid temperature switching and high-speed fixation operations, eliminating the need to compromise between downtime and fixation speed.
3Temperature
If spontaneous heat radiation is used to reduce the temperature of the fixation roller when switching to lower target temperature, then the temperature is reduced, but the downtime becomes substantial
Solution Approach 1:
The invention performs preliminary heating in specific zones before temperature switching occurs. By pre-positioning heat in the end portions and center region through controlled heating element operation, the system compensates for the slow passive cooling effect, enabling faster temperature switching without substantial downtime.
Solution Approach 2:
The invention uses temperature detection means to monitor temperature distribution across the fixation roller and provides feedback control to the heating elements. This allows the system to detect temperature deviations and adjust heating in real-time, enabling rapid temperature switching while maintaining uniform temperature distribution and minimizing downtime.
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 significantly reduces downtime and ensures uniform temperature distribution across the image heating member, enabling faster switching between target temperatures and maintaining high fixation performance without nonuniformity in glossiness.
Implementation Method 1
a main heater which heats up the image heating member in a width direction center region
Implementation Method 2
a subordinate heater which heats up the image heating member in width direction end portions
Implementation Method 3
the image heating apparatus is forcefully cooled by a cooling fan
Implementation Method 4
it is only the spontaneous heat radiation that is used for reducing the temperature of the fixation roller
Data Source
AI summary
An image heating apparatus includes a heating rotatable member for heating, in a nip, an image on a recording material; a heater for heating the image heating member; a cooling device for cooling the image heating member, wherein when a target temperature of the image heating member is changed to a low temperature which is lower than the target temperature, the apparatus is operable in a mode wherein a temperature of the image heating member is lowered by the cooling device to a transition temperature which is lower than the low temperature, and then, the temperature of the image heating member is raised by the heater to the low temperature.