Sheet Alignment Mechanism for Wrinkle-Free Edge Positioning
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Solution Overview
Problem
Conventional sheet processing apparatuses face challenges in reliably aligning side edges of sheets due to sliding issues and wrinkling, leading to poor-looking sheet bundles and reduced image forming efficiency.
Innovation Solution
A sheet processing apparatus with a cross-directionally moving device and a cross-side restricting member that adjusts its position based on sheet size and curl detection, decelerates movement speed, and abuts the sheet against the restricting member to prevent sliding and wrinkling, ensuring accurate alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the cross-directionally moving member moves at constant speed to abut the sheet against the cross-side restricting member, then the side edge alignment process is completed, but the sheet side edge portion becomes wrinkled and the sheet is rebounded
Solution Approach 1:
The cross-directionally moving member changes its movement speed periodically - moving at a first speed during the approach phase and at a second speed (slower than the first) during the abutting phase. This periodic speed change allows the sheet to be gently pressed against the restricting member without wrinkling, while still achieving accurate alignment.
Solution Approach 2:
The patent applies parameter changes by varying the movement speed of the cross-directionally moving member based on the operational phase. The speed parameter is changed from a first speed (faster) during approach to a second speed (slower) during contact, optimizing both alignment accuracy and sheet integrity.
2Productivity
If the cross-directionally moving member moves at high speed to improve processing efficiency, then productivity increases, but the cross-directionally moving member slides relative to the sheet and disturbs alignment
Solution Approach 1:
The cross-directionally moving member uses periodic speed variation - moving fast during the approach phase to maintain productivity, then slowing down during the abutting phase to ensure reliable contact without sliding. This resolves the contradiction between speed and reliability.
3Manufacturing precision
If the cross-directionally moving member rides onto the other side edge of the preceding sheet through the succeeding sheet, then the succeeding sheet can be aligned, but the alignment of the preceding sheet is disturbed
Solution Approach 1:
The system performs preliminary action by first accurately aligning the preceding sheet against the cross-side restricting member before moving to align the succeeding sheet. This sequential preliminary alignment of the preceding sheet prevents disturbance to its position during the subsequent alignment operation.
Solution Approach 2:
The cross-side restricting member acts as an intermediary reference that both sheets align against sequentially. By using this fixed reference and processing sheets one at a time in sequence, the alignment stability of the preceding sheet is maintained while enabling alignment of the succeeding sheet.
4Manufacturing precision
If the cross-directionally moving member contacts the central portion of the sheet to move it in the width direction, then the sheet can be aligned with the cross-side restricting member, but the side edge portion of the sheet becomes wrinkled
Solution Approach 1:
The patent applies local quality by differentiating the treatment of different sheet regions. The cross-directionally moving member contacts the sheet in a way that prioritizes the side edge region for alignment against the restricting member, while avoiding excessive force on the central portion that would cause wrinkling. The slower second speed during contact further protects the sheet surface quality.
Data Source
AI summary
A sheet processing apparatus including a cross-directionally moving device for moving a sheet in a direction crossing a sheet discharging direction, and a cross-side restricting member for receiving one side edge of the sheet moved in the crossing direction by the cross-directionally moving device, and restricting the movement of the sheet, wherein the cross-directionally moving device moves the next sheet from a position between the other side edge of the sheet received by the cross-side restricting member and the cross-side restricting member to the cross-side restricting member.