Sheet Conveying Skew Correction with Preliminary Shutter Positioning
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Solution Overview
Problem
In image forming apparatuses, the existing skew correcting mechanisms struggle to correct sheet skew efficiently at high conveyance speeds and short inter-sheet distances, leading to potential sheet damage and reduced productivity due to the need for longer inter-sheet distances to allow shutter member movement.
Innovation Solution
A sheet conveying apparatus with a first and second rotator pair and a moving member that allows the sheet to pass through without interference, enabling the shutter member to move from a passage state to an abutment state without the rear end of the sheet obstructing the moving trajectory, thus allowing for skew correction in a shorter inter-sheet distance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the shutter member is moved to correct sheet skew after the preceding sheet passes through, then the skew correction function is maintained, but the inter-sheet distance must be increased to allow sufficient movement time
Solution Approach 1:
The shutter member is moved to the standby position in advance before the front end of the sheet reaches it, rather than moving after the sheet passes through. This preliminary positioning ensures the shutter member is ready to correct skew immediately when the sheet arrives, eliminating the need for extended inter-sheet distances while maintaining correction accuracy
Solution Approach 2:
The shutter member transitions from a static position to a dynamic system that can quickly move between the standby position and the sheet contact position. This dynamic capability allows the shutter member to be positioned optimally for skew correction of each sheet without requiring fixed, extended timing intervals between sheets
2Productivity
If the sheet conveyance speed is increased to improve productivity, then the number of sheets processed per unit time increases, but the shutter member cannot return to the skew correction position in time for the following sheet
Solution Approach 1:
The shutter member is positioned at the standby position in advance, before the sheet reaches it, rather than returning to position after the sheet passes. This allows the system to maintain accurate skew correction timing even at higher conveyance speeds, as the shutter member is already prepared and does not need to move during the sheet passage time
Solution Approach 2:
The shutter member maintains continuous readiness to perform skew correction by being positioned at the standby position throughout the sheet conveyance process. This continuous preparedness ensures that skew correction can be performed accurately at any conveyance speed without interruption or timing delays
Data Source
AI summary
A sheet conveying apparatus includes a first roller pair conveying a sheet, a second roller pair provided downstream, in a sheet conveying direction, of the first roller pair, and a moving member having an abutment portion. The moving member moves from an abutment position in a sheet conveying path upstream of a nip portion of the second roller pair to a passing position at which the sheet conveyed by the first roller pair is allowed to pass through. In a case where a first sheet and a second sheet are conveyed successively by the first roller pair, when the moving member is at the abutment position in which the abutment portion is pushed by the second sheet while the first sheet is conveyed by the second roller pair, a rear end of the first sheet is located upstream of the nip portion of the second roller pair.