Pressing Roller Temperature Control for Dew Condensation Slip
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image forming apparatuses face issues with dew condensation slip, leading to image rubbing and creases due to uneven print ratios across the width of the recording material, causing frictional force imbalances and subsequent defects during the fixing process.
Innovation Solution
An image forming apparatus with a controller that adjusts the interval between recording materials based on print ratio unevenness, warming the pressing roller surface to prevent dew condensation by increasing the sheet interval and controlling the heating distribution to maintain consistent feeding force across the width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sheet interval is increased to prevent dew condensation on the pressing roller, then dew condensation slip is suppressed, but productivity decreases due to reduced printing speed
Solution Approach 1:
The pressing roller surface temperature is controlled non-uniformly in the widthwise direction, with higher temperature at positions corresponding to high print ratio regions. This localized temperature control prevents dew condensation only where needed (high print ratio areas), while maintaining normal operating conditions in low print ratio areas, thus avoiding the need to increase the overall sheet interval.
Solution Approach 2:
The pressing roller surface temperature distribution is dynamically adjusted based on the print ratio distribution of the image to be formed. By changing the temperature parameter locally according to image characteristics, the system prevents dew condensation slip without requiring a uniform increase in sheet interval that would reduce productivity.
2Reliability
If the pressing roller surface temperature is uniformly increased to prevent dew condensation, then dew condensation slip is suppressed, but image quality deteriorates due to excessive heating in low print ratio regions
Solution Approach 1:
Instead of uniform temperature increase, the pressing roller is heated non-uniformly with higher temperature at high print ratio regions and lower temperature at low print ratio regions. This localized approach suppresses dew condensation where needed while preventing excessive heating that would damage image quality in other regions.
Solution Approach 2:
The temperature parameter of the pressing roller is spatially varied according to the print ratio distribution. This creates a temperature profile that matches the image characteristics, preventing dew condensation in high print ratio areas while maintaining appropriate temperature in low print ratio areas to preserve image quality.
3Reliability
If the sheet interval is increased to warm the pressing roller surface, then dew condensation is prevented, but the feeding force unevenness cannot be corrected for images with large print ratio differences
Solution Approach 1:
The pressing roller surface temperature is controlled to be higher at positions corresponding to high print ratio regions, creating a localized warming effect that prevents dew condensation. Simultaneously, this local temperature control compensates for feeding force unevenness by reducing friction in high print ratio areas where dew condensation would otherwise occur.
Solution Approach 2:
The temperature parameter is spatially modulated according to the print ratio distribution, creating a temperature profile that simultaneously achieves dew condensation prevention and feeding force uniformity. This dynamic parameter adjustment corrects feeding force unevenness without requiring increased sheet interval.
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 reduces the occurrence of image rubbing and creases by maintaining consistent feeding force and preventing dew condensation, even with large print ratio unevenness, ensuring high-quality image formation without throughput reduction.
Implementation Method 1
When dew forms on a surface of a rotatable member (pressing roller), a frictional force with a follower rotatable member or the recording material is reduced, so that a phenomenon in which the recording material slips (so-called dew condensation slip) occurs.
Implementation Method 2
a frictional force with a follower rotatable member or the recording material is reduced
Implementation Method 3
The toner image is subsequently heated at a fixing nip downstream of the transfer nip with respect to a recording material feeding direction.
Data Source
AI summary
An image forming apparatus for forming a toner image on a recording material. The image forming apparatus includes an image forming portion configured to form the toner image on the recording material, a fixing portion including a heater and configured to fix the toner image on the recording material by heating the toner image formed on the recording material, and a controller configured to control the image forming apparatus. When toner images are continuously formed on a plurality of recording materials, the controller sets an interval between a preceding recording material and a subsequent recording material depending on unevenness of a print ratio of the subsequent recording material with respect to a direction perpendicular to a recording material feeding direction of the subsequent recording material.