Sheet Conveyance Edge Curl Prevention via Halting Position Control
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Solution Overview
Problem
Sheet-conveying devices in image-reading devices often cause sheet edges to curl into the shape of curved or bent segments of the conveying path, leading to issues like paper jams and incorrect stacking during discharge.
Innovation Solution
A sheet-conveying device with a controller that halts conveyance when either the leading or trailing edge of the sheet is positioned in a straight segment of the conveying path, preventing curling by ensuring the edge is not stopped within a curved segment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sheet-conveying device halts conveyance when an edge of the sheet is present in a curved or bent segment of the conveying path, then the edge portion of the sheet becomes curved or bent in the shape of the segment, but this causes sheet edges to curl and leads to paper jams and incorrect stacking
Solution Approach 1:
The controller determines in advance whether halting the sheet at the current position would cause the edge to be positioned in a curved segment of the conveying path. If so, it adjusts the halting position to a straight segment before actually halting, preventing the curling issue before it occurs.
Solution Approach 2:
The invention applies different positioning requirements to different parts of the sheet based on their location in the conveying path. Specifically, it ensures that when halting, the edge portion (which is sensitive to curling) is positioned in a straight segment rather than a curved segment, while other parts of the sheet can be in various positions.
2Productivity
If the conveying unit continuously conveys the sheet without halting, then productivity is maintained, but motor temperature increases and overheating occurs
Solution Approach 1:
The conveying unit operates in periodic cycles, alternating between conveying mode (for productivity) and halting mode (for motor cooling). The controller manages these periodic halts to occur only when the sheet edge is in a straight segment, balancing thermal management with production efficiency.
3Reliability
If the controller halts conveyance frequently to prevent edge curling, then sheet discharge reliability improves, but productivity decreases due to more halts
Solution Approach 1:
The controller continuously monitors the position of the sheet edge relative to the conveying path geometry (curved vs. straight segments). This feedback mechanism allows it to make intelligent decisions about when halting is necessary, minimizing the number of halts while ensuring reliability.
Data Source
AI summary
A sheet conveying device includes: a conveying unit; and a controller. The conveying unit is configured to convey a sheet along a conveying path. The sheet has a leading edge and a trailing edge. The conveying path includes a segment that is curved. The controller is configured to control the conveying unit to convey the sheet, determine whether or not a halting condition for halting conveyance of the sheet is met, and halt, if the halting condition is met, conveyance of the sheet when one of the leading edge and the trailing edge of the sheet is positioned in a segment of the conveying path different from the segment that is curved.