Sheet Conveyance Apparatus Lateral Movement Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sheet conveyance systems in image forming apparatuses face challenges in preventing long sheets from twisting when nipped by roller pairs and laterally moved, which can lead to creasing, folding, or skewing and result in defective images.
Innovation Solution
A sheet conveyance apparatus with a control unit that executes different modes for conveying sheets of varying lengths. For non-long sheets, the apparatus moves the sheet laterally while nipping it via the registration roller pair but not the pre-registration roller pair. For long sheets, the apparatus moves the sheet laterally while nipping it via both the registration roller pair and the pre-registration roller pair, ensuring proper alignment and reducing twisting stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the trailing edge of the long sheet is nipped by an upstream roller pair, then the sheet can be conveyed, but the lateral movement of the registration roller pair causes twisting stress that twists the sheet
Solution Approach 1:
The control unit dynamically adjusts the nipping state of roller pairs based on sheet length. For long sheets, the upstream roller pair is released during lateral movement to eliminate twisting stress, while for short sheets, both roller pairs nip the sheet for stable conveyance. This dynamic control resolves the contradiction between conveyance capability and sheet integrity.
Solution Approach 2:
The system changes the operational parameters of the roller pairs by switching between two modes: first mode for short sheets where the upstream roller pair nips the sheet, and second mode for long sheets where the upstream roller pair is released. This parameter change prevents twisting stress while maintaining conveyance functionality.
2Ease of operation
If the nip portion of the upstream roller pair is released to prevent twisting, then the sheet can be laterally moved, but the sheet receives large frictional resistance from the guide member
Solution Approach 1:
The system applies different nipping conditions to different parts of the sheet based on its length. For long sheets, the upstream roller pair releases the trailing edge to enable lateral movement, while the registration roller pair maintains nipping at the leading edge to provide guidance and reduce frictional resistance from guide members. This localized quality control resolves the contradiction between ease of lateral movement and force resistance.
3Manufacturing precision
If the sheet is nipped by the registration roller pair for lateral movement, then the sheet position can be corrected, but the sheet may be creased, folded, or skewed resulting in defective images
Solution Approach 1:
The control unit dynamically controls the nipping state of roller pairs based on sheet length. For long sheets, the upstream roller pair is released during lateral movement to prevent creasing and folding, while the registration roller pair maintains nipping for position correction. This dynamic control ensures both position accuracy and image quality.
Solution Approach 2:
For long sheets, the upstream roller pair releases the trailing edge in advance before lateral movement begins, preventing twisting stress from developing during the conveyance process. This preliminary action eliminates the risk of creasing and folding that would otherwise occur during position correction.
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 prevents long sheets from twisting and being creased or skewed during lateral movement, ensuring high-quality image formation by maintaining sheet integrity and alignment.
Implementation Method 1
a feed roller configured to feed a sheet stacked on the sheet supporting portion
Implementation Method 2
a first conveyance roller pair configured to pinch and convey the sheet fed by the feed roller
Implementation Method 3
move the sheet in a lateral direction perpendicular to the sheet conveyance direction to correct a sheet position in the lateral direction
Data Source
AI summary
A sheet conveyance apparatus includes a sheet supporting portion, a feed roller, a first conveyance roller pair for conveying the sheet and moving the sheet in a lateral direction, a second conveyance roller pair, disposed upstream of the first conveyance roller pair, for conveying the sheet and moving the sheet in the lateral direction, and a control unit. The control unit can execute a first mode for conveying a first sheet, the first mode being configured to move a first sheet in the lateral direction, while nipping the first sheet via the first conveyance roller pair and not nipping the first sheet via the second conveyance roller pair, and a second mode for conveying a second sheet, the second mode being configured to move the second sheet in the lateral direction, while nipping the second sheet via the first conveyance roller pair and the second conveyance roller pair.