Pressure Roller Temperature Control via Dynamic Speed and Spacing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electrophotographic image forming processes, the surface temperature of pressure rollers decreases due to heat transfer, leading to undesirable curling and low-temperature offsets, especially in low-temperature environments, and existing solutions like extended warm-up periods or increased temperature control settings either require excessive time or increase energy consumption.
Innovation Solution
The image forming apparatus switches between two modes: a first mode with a lower circumferential speed and shorter sheet-to-sheet distance, and a second mode with a higher circumferential speed and longer sheet-to-sheet distance, controlled by temperature sensors to maintain the surface temperature of the pressure roller, thereby optimizing heat transfer and maintaining yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the warm-up period is extended immediately after activation, then the surface temperature of pressure roller can be maintained, but the time required for image formation increases
Solution Approach 1:
The patent changes operational parameters (circumferential speed and sheet-to-sheet distance) dynamically based on temperature conditions. During warm-up, the system operates in a first mode with lower speed and shorter distance; after warm-up completion, it switches to a second mode with higher speed and longer distance, resolving the contradiction between maintaining temperature and reducing time loss
Solution Approach 2:
The patent implements dynamic mode switching between two operational states. The control section transitions from a first mode (lower circumferential speed, shorter sheet-to-sheet distance) during warm-up to a second mode (higher circumferential speed, longer sheet-to-sheet distance) after warm-up, allowing the system to adapt to temperature conditions and eliminate unnecessary time loss
2Reliability
If the temperature control set values are increased, then the fixing characteristic can be improved, but the energy consumption increases
Solution Approach 1:
The patent uses temperature sensors to detect the surface temperature of the pressure roller and provides feedback to the control section. Based on this feedback, the system determines whether warm-up is complete and switches modes accordingly, ensuring reliable fixing characteristics only when necessary and reducing energy consumption during normal operation
3Temperature
If the yield is reduced immediately after activation, then the surface temperature drop of pressure roller can be reduced, but the productivity decreases
Solution Approach 1:
The patent dynamically adjusts the sheet-to-sheet distance based on operational mode. During warm-up (first mode), a shorter distance is used; after warm-up completion (second mode), a longer distance is implemented. This dynamic adjustment maintains temperature stability without permanently reducing productivity
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 approach prevents surface temperature drops of the pressure roller, maintains good fixing characteristics, and reduces energy consumption without requiring extended warm-up times or decreased yield, effectively addressing the issues of curling and low-temperature offsets.
Implementation Method 1
surface temperature of the heating roller decreases because of heat transfer, for example, from the surface of heating roller to the medium
Implementation Method 2
surface temperature of the heating roller is detected using a temperature sensor such as a thermistor
Implementation Method 3
the pressure roller is heated using a heat source such as a heater
Data Source
Figure 1
Figure 2
Figure 3A~3C
AI summary
An image forming apparatus (100) includes image forming means (3), a heat source (51, 55), a fixing rotating body (52) receiving heat supplied from the heat source, a pressurizing rotating body (54) adapted to form a nip portion (57) with the fixing rotating body, feeding means (42, 43, 44) for feeding a medium, temperature adjusting means (56, 6) for controlling an amount of heat generated by the heat source such that the temperature of fixing rotating body attains to a prescribed value, and control means (6). The control means switches between a first mode in which the fixing rotating body and the pressurizing rotating body rotate at a first circumferential speed and the medium is fed to the image forming means at a first distance interval, and a second mode in which the fixing rotating body and the pressurizing rotating body rotate at a second circumferential speed higher than the first circumferential speed and the medium is fed to the image forming means at a second distance interval longer than the first distance interval.