Independent Cooling Zones for Fixing Roller Temperature Control
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Solution Overview
Problem
In image forming apparatuses, lateral shifting sheet passing leads to uneven temperature distribution in the fixing device, causing improper fixing and heat quantity issues, especially when small-sized papers are processed alongside larger ones, as the existing cooling mechanisms fail to accurately target only the abnormally heated end portions.
Innovation Solution
The implementation of an image forming apparatus with independently operable first and second cooling portions at each end of the fixing device, controlled by thermistors and shutters, ensures that only the abnormally heated regions are cooled during lateral shifting sheet passing, maintaining optimal heat for fixing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a cooling mechanism blows air against both end portions of the fixing portion to suppress non-sheet-passing portion temperature rise, then temperature control is improved, but when lateral shifting sheet passing occurs, the other end portion is also cooled causing insufficient heat quantity for proper fixing
Solution Approach 1:
The cooling mechanism is divided into first and second cooling portions that can operate independently. The first cooling portion cools the first end region while the second cooling portion cools the second end region. This segmentation allows selective cooling of only the end portion experiencing abnormal temperature rise during lateral shifting sheet passing, preventing unnecessary cooling of the other end portion and maintaining sufficient heat quantity for proper fixing.
Solution Approach 2:
The cooling mechanism transitions from a static, simultaneous cooling of both ends to a dynamic, selective cooling system. The control unit dynamically determines which cooling portion to activate based on real-time detection of lateral shifting sheet passing conditions, enabling adaptive temperature management that maintains fixing reliability while suppressing abnormal temperature rises.
2Device complexity
If a single cooling mechanism is used for both end portions, then device complexity is reduced, but the ability to selectively cool only abnormally heated regions is lost
Solution Approach 1:
The cooling mechanism is segmented into independent first and second cooling portions, each capable of selective operation. This segmentation increases adaptability by enabling the system to respond differently to temperature conditions at each end portion, while the overall structure remains relatively simple through the use of separate but functionally similar cooling units.
Solution Approach 2:
The cooling system implements local quality by allowing different cooling actions at different locations. The first cooling portion can be activated independently to cool the first end region, and the second cooling portion can be activated independently to cool the second end region. This localized control provides adaptability to handle asymmetric temperature conditions during lateral shifting sheet passing without requiring a complex unified cooling system.
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 suppresses temperature rises in non-passed regions and ensures reliable fixing properties by precisely controlling cooling at both ends of the fixing device, even during erroneous paper alignment, thereby maintaining image quality and heat efficiency.
Implementation Method 1
a cooling mechanism for cooling the non-sheet-passing portion by blowing the air against the non-sheet-passing portion
Implementation Method 2
blowing the air against the non-sheet-passing portion
Implementation Method 3
a fixing portion for fixing an image on a recording material by heating the image carried on the recording material while conveying the recording material by a fixing nip
Data Source
AI summary
An image forming apparatus includes: a fixing portion for fixing an image on a recording material by heating the image carried on the recording material while conveying the recording material by a fixing nip; a first cooling portion for cooling one end region of the fixing portion with respect to a direction perpendicular to a recording material conveyance direction; and a second cooling portion for cooling the other end region of the fixing portion with respect to the direction perpendicular to the recording material conveyance direction. The first cooling portion and the second cooling portion are operable independently from each other.