Sheet Discharge Device Presser Mechanism for Folded Sheet Alignment
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Solution Overview
Problem
Existing sheet discharge devices face challenges in efficiently stacking and aligning folded sheets, leading to misalignment, swelling, and potential blockages due to the lack of effective pressing mechanisms and detection systems, which affects the stackability and alignment of folded sheets.
Innovation Solution
The sheet discharge device incorporates a sheet discharge part with a discharge roller pair, a sheet discharge tray, a fullness detection sensor, a first sheet presser member, and a second sheet presser member. The first presser member presses the rear end of the folded sheets, while the second presser member presses the fore end, ensuring proper alignment and preventing swelling, with the fullness detection sensor monitoring the stack height to adjust the pressing positions accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If folded sheets are discharged and stacked without pressing mechanisms, then the discharge process is simple, but misalignment and swelling occur reducing stackability
Solution Approach 1:
The pressing mechanism is divided into multiple independent presser members (first presser member and second presser member) that can be positioned at different locations along the sheet stack. Each presser member independently presses specific regions (rear end and fore end respectively), allowing distributed pressure application without requiring a single complex pressing system.
Solution Approach 2:
The presser members are positioned and activated before the sheets are fully discharged and stacked. The first presser member presses the rear end side of sheets as they are being discharged, and the second presser member presses the fore end side, preventing swelling and misalignment from occurring in the first place rather than correcting them afterward.
2Reliability
If multiple presser members are added to prevent swelling and misalignment, then stacking quality improves, but device complexity increases
Solution Approach 1:
Both the first presser member and second presser member serve multiple functions: they press sheets to prevent swelling, guide sheet alignment during discharge, and work together with the fullness detection sensor to control the stacking process. This multi-functionality reduces the need for separate dedicated components for each function.
Solution Approach 2:
The presser members are designed to automatically adjust their positioning based on the sheet stack height. As sheets are discharged and accumulate, the presser members naturally maintain contact with the sheets and adjust their pressing force without requiring external control mechanisms, making the system self-regulating.
3Measurement precision
If fullness detection sensor is positioned centrally, then detection is simple, but it cannot detect stack fullness accurately when sheets are misaligned
Solution Approach 1:
The fullness detection sensor is positioned not directly above the stack center, but offset in the widthwise direction at a location corresponding to the rear wall portion. This dimensional repositioning allows the sensor to detect stack fullness by monitoring when sheets contact the rear wall, providing accurate detection even when sheets are misaligned or swollen, as the rear wall contact is a reliable indicator of stack completion.
Data Source
AI summary
The sheet discharge device includes: a sheet discharge part; a sheet discharge tray having a tray upper surface and a rear wall portion; a fullness detection sensor for detecting that a height of a stack surface of folded sheets; and a first sheet presser member and a second sheet presser member for pressing a rear end side and a fore end side in a discharge direction, of the folded sheet. In a first pressing position in which the first sheet presser member extends from above the detection sensor to below the detection region, and is brought into contact with the folded sheet of a minimum size stacked on the tray upper surface. When a stack number of the folded sheets has exceeded a specified number, the first sheet presser member is retracted upward from the first pressing position by the rise of the stack surface.