Dual-Belt Sheet Feeding for Stable Loop Control in Long Paper Paths
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Solution Overview
Problem
In image forming apparatuses, the feeding of elongated sheets between the transfer and fixing portions is unstable, leading to loop control issues due to the increased distance, which affects sheet feeding performance and stability.
Innovation Solution
The apparatus incorporates a belt feeding unit with two belt feeding portions and suction fans to control sheet feeding speed and position, using height detection to adjust suction force and speed differences to stabilize sheet movement, preventing buckling and loop formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the transfer portion and fixing portion are upsized to realize high image quality and high productivity, then image quality and productivity are improved, but the sheet feeding distance becomes long and loop control cannot be stabilized
Solution Approach 1:
The sheet feeding system is divided into multiple feeding means (first feeding means with first endless belt, second feeding means with second endless belt) positioned at different locations. Each feeding means independently controls sheet feeding in its respective region, allowing stabilized loop control even over long feeding distances caused by upsized transfer and fixing portions.
2Manufacturing precision
If the sheet feeding distance is increased due to upsized components, then high image quality and productivity are achieved, but the sheet feeding performance deteriorates
Solution Approach 1:
Multiple feeding means act as intermediary components between the transfer portion and fixing portion. These feeding means include air permeable belts with air sucking portions that create controlled suction to hold and feed sheets, serving as mediators that maintain feeding performance over extended distances without compromising image quality.
3Length of moving object
If an elongated sheet is subjected to loop control over a long feeding distance, then the sheet feeding distance is increased, but loop control cannot be carried out
Solution Approach 1:
The feeding system employs dynamic control through height detecting means that continuously monitor sheet position and height. The controller adjusts the air sucking portions and belt speeds in real-time based on detected sheet conditions, enabling adaptive loop control for elongated sheets over long feeding distances.
Solution Approach 2:
Height detecting means provide feedback on sheet height and position to the controller. This feedback loop enables the controller to adjust feeding parameters dynamically, maintaining stable loop control even when feeding distances exceed sheet lengths, thereby solving the contradiction between long feeding distance and loop control capability.
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
Stabilizes sheet feeding between the transfer and fixing portions, ensuring reliable loop control and improved sheet handling for elongated sheets, enhancing image forming quality and productivity.
Implementation Method 1
a first air sucking portion capable of attracting the sheet to the first feeding surface by sucking air through the first belt portion
Implementation Method 2
capable of attracting the sheet to the first feeding surface by sucking air through the first belt portion
Data Source
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AI summary
An image forming apparatus includes an image bearing member, a transfer portion, a fixing portion, a first sheet feeding portion including a first belt portion for forming a first feeding surface, a second sheet feeding portion including a second belt portion for forming a second feeding surface, a height detecting portion for outputting a signal depending on a height of a sheet from the first feeding surface at a detecting position, and a controller for receiving the signal outputted from the height detecting portion and for controlling the fixing portion.