Dual-Roller Sheet Conveyance Mechanism for Adhesion Control
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Solution Overview
Problem
In sheet supply devices of image forming apparatuses, strong adhesion forces between sheets can lead to double feeding issues due to the sheets sticking together, causing conveyance problems.
Innovation Solution
The implementation of a dual-roller system with independent rotational control, where the first roller applies a force to the uppermost sheet in the forward direction, and the second roller, positioned downstream, applies a force after a delay, allowing for controlled separation and conveyance, reducing adhesion forces through deflection and precise timing adjustments based on sheet type.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single roller is used to convey sheets, then the device complexity is low, but double feeding occurs due to strong adhesion between sheets
Solution Approach 1:
The single roller is divided into two separate rollers (first roller and second roller) positioned at different locations. The first roller applies force to the uppermost sheet, and the second roller applies force downstream after a time delay. This segmentation allows independent control of each roller's timing and force, preventing double feeding while maintaining conveyance reliability.
2Speed
If the second roller is positioned close to the first roller, then the conveyance speed is high, but adhesion forces cause double feeding
Solution Approach 1:
The second roller is positioned downstream from the first roller, creating a spatial separation that allows the first roller to initiate sheet separation before the second roller applies its force. This preliminary action by the first roller reduces adhesion effects, enabling the second roller to complete conveyance without causing double feeding, thus maintaining both speed and reliability.
3Productivity
If both rollers rotate simultaneously, then the conveyance efficiency is high, but strong adhesion causes the second sheet to be fed along with the first
Solution Approach 1:
The rollers operate in a periodic sequence rather than simultaneously. The control unit rotates the first roller during a first period to apply force to the uppermost sheet, then rotates the second roller during a second period after a time delay. This periodic action ensures the first sheet is partially separated before the second roller engages, preventing the second sheet from being accidentally fed while maintaining high conveyance efficiency.
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 adhesion forces between sheets, preventing double feeding and ensuring smooth, reliable sheet conveyance by strategically applying forces to separate and guide the uppermost sheet, enhancing the operational efficiency of the image forming apparatus.
Implementation Method 1
The first roller is configured to apply a force in a conveyance direction to an uppermost sheet among the sheets stacked on the sheet stacking part by rotating in a forward direction
Implementation Method 2
The second roller is configured to apply the force in the conveyance direction to the uppermost sheet by rotating in the forward direction
Data Source
AI summary
A sheet stacking part stacks sheets. A first roller applies a force in a conveyance direction to an uppermost sheet among sheets stacked on the sheet stacking part by rotating in a forward direction. A second roller is separated from the first roller on the downstream side in the conveyance direction. The second roller applies the force in the conveyance direction to the uppermost sheet by rotating in the forward direction. A controller controls rotation of the first roller and the second roller so that a second main operation is performed after a first main operation. The first main operation is an operation of rotating only the first roller of the first roller and the second roller in the forward direction. The second main operation is an operation of rotating both the first roller and the second roller in the forward direction.