Sheet Feeding Device Roller Rotation Control
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Solution Overview
Problem
In image forming systems, the skew correction process causes positional displacement of sheets due to natural rotation of resist rollers, leading to errors in sheet feeding, especially when driven by a single motor or different motors, resulting in inaccurate sheet placement.
Innovation Solution
A sheet feeding device with a control mechanism that adjusts the rotation of first and second rollers to perform butting and intake feeding controls, using a control section to correct the target rotation amount of the second roller based on observed rotation phenomena, thereby minimizing positional displacement and ensuring accurate sheet placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the resist roller pair is stopped or rotated in reverse direction for skew correction, then skew correction is achieved, but the balance of force is lost and natural rotation occurs during switching causing sheet position displacement
Solution Approach 1:
The control section executes butting control before intake feeding control, making the first roller rotate forwardly while the second roller rotates reversely or stops, to feed the sheet so as to butt against the second roller at an intake position. This preliminary butting action positions the sheet correctly before the second roller starts forward rotation for intake feeding.
Solution Approach 2:
The control section obtains information indicating a rotation amount of the second roller by a rotation phenomenon of the second roller which occurs in a period after the butting control to the start of the intake feeding control. The target setting section then sets a target rotation amount to an amount corrected from a standard target rotation amount based on the obtained rotation information, compensating for natural rotation effects.
2Device complexity
If the paper feeding roller and resist roller are driven by a single motor, then device complexity is reduced, but switching rotation direction and power transmission system causes loss of force balance and natural rotation
Solution Approach 1:
The system dynamically switches the rotation direction of the motor and the power transmission system from the motor to the respective rollers before and after skew correction. The control section controls the rotations of the first and second rollers to execute butting control and then intake feeding control, adapting the system behavior to different operational phases.
3Ease of operation
If different motors are used for paper feeding roller and resist roller, then independent control is achieved, but the resist roller rotates naturally due to force acting to eliminate sheet bending, causing sheet position displacement
Solution Approach 1:
The obtaining section obtains information indicating a rotation amount of the second roller by a rotation phenomenon of the second roller which occurs in a period after the butting control to the start of the intake feeding control. This feedback information is used to correct the target rotation amount, compensating for natural rotation caused by independent motor control.
Solution Approach 2:
The target setting section sets a target rotation amount, which is a rotation amount of the second roller that should be achieved in the intake feeding control, to an amount corrected from a standard target rotation amount based on the rotation amount information obtained. This parameter correction compensates for natural rotation effects.
Data Source
AI summary
A sheet feeding device includes: a feeding mechanism having a first roller and a second roller provided downstream in a sheet feeding path from the first roller and feeding a sheet by rotations of the first and second rollers; a control section executing a butting control by controlling the first and second rollers to feed the sheet from the first roller so as to butt against the second roller at an intake position, and executing an intake feeding control by controlling the second roller to feed the sheet downstream in the feeding path from the intake position; an obtaining section obtaining information indicating a rotation amount of the second roller in a period after the butting control to the start of the intake feeding control; and a target setting section setting a target rotation amount of the second roller that should be achieved in the intake feeding control.