Sheet Discharge Device with Adaptive Wings for Thickness-Based Alignment
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Solution Overview
Problem
Conventional sheet discharge devices struggle to maintain optimal alignment and prevent smearing of printed images when discharging sheets of varying thickness, as thick sheets float due to elasticity and thin sheets sag or fly due to low elasticity, leading to misalignment and damage during printing, especially in inkjet and double-sided printing.
Innovation Solution
A sheet discharge device with sensing means to detect sheet thickness, adjusting the discharge wings' position to maintain a U-shape curl corresponding to the sheet thickness, ensuring proper alignment and preventing misalignment or damage by controlling the wings' shift mode based on the detected thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the nip force and suction force are increased to prevent thick sheets from floating, then the sheets can be conveyed without floating, but the sheets may be damaged during conveying or suffer ink transfer contamination and blurred images
Solution Approach 1:
The patent applies dynamics by making the flying induction members movable in the sheet thickness direction. The members dynamically adjust their position based on sheet thickness: for thick sheets, they move closer to increase nip force without requiring excessive force, while for thin sheets, they move farther apart to reduce force. This dynamic adjustment resolves the contradiction by maintaining reliable conveyance stability while preventing sheet damage and ink transfer contamination through adaptive force control.
Solution Approach 2:
The patent changes the physical parameter of the flying induction members' position in the sheet thickness direction. By varying this parameter according to sheet thickness, the system optimizes the balance between nip force and suction force. For thick sheets, reduced distance increases force to prevent floating; for thin sheets, increased distance reduces force to prevent damage. This parameter change resolves the contradiction between conveyance reliability and prevention of harmful effects.
2Reliability
If the width of sheet discharge wings is broadened or installation height is lowered to give a small U shape curl to thick sheets, then the sheets can be discharged, but the width of side fence of discharge tray has to be broadened, causing misalignment of discharged sheets
Solution Approach 1:
The patent applies dynamics by making the flying induction members movable in the sheet width direction. For thick sheets, the members move inward to broaden the effective discharge width, enabling proper U-shape curl formation without requiring permanent structural changes to the discharge tray. For thin sheets, they return to normal position to maintain precise alignment. This dynamic adjustment resolves the contradiction between discharge capability and alignment accuracy.
Solution Approach 2:
The patent introduces movement in the sheet width direction as an additional degree of freedom for the flying induction members. This dimensional change allows the system to adjust the discharge geometry dynamically: broadening the effective width for thick sheets to enable proper curling, while maintaining narrow width for thin sheets to ensure alignment accuracy. This resolves the contradiction without requiring physical modification of the discharge tray structure.
3Reliability
If a conventional sheet discharge device is used for thin sheets, then the sheets may be discharged, but the sheets could sag downward from exit port due to low elasticity, and alignment of discharged sheets is not stable and uniform
Solution Approach 1:
The patent applies dynamics by making the flying induction members movable in both sheet thickness and width directions. For thin sheets with low elasticity, the members dynamically adjust to positions that provide optimal support and guidance during discharge. This dynamic positioning ensures that thin sheets maintain proper U-shape curl without sagging, while achieving stable and uniform alignment. The dynamic adjustment resolves the contradiction between maintaining discharge function and achieving precision alignment for thin sheets.
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
The device ensures neat and uniform alignment of discharged sheets irrespective of thickness, preventing smearing and damage, even at low discharge speeds, by dynamically adjusting the U-shape curl of the sheets during discharge.
Implementation Method 1
a suction force of a suction section maintaining a print sheet on a conveyor belt
Implementation Method 2
the repulsive elasticity of the thick sheet wins over a nip force (the dead weight of a sheet discharge roller, or its dead weight+spring pressure) and a suction force of a suction section
Data Source
AI summary
A sheet discharge device neatly and uniformly aligns edges of print sheets irrespective of the thickness of a print sheet, and exerts the same effect even at a low discharge speed. The sheet discharge device includes: sheet information sensing means for detecting thickness of a print sheet to judge the sheet as a thick sheet, a regular sheet, or a thin sheet; conveying means for discharging the print sheet bearing a printed image in a predetermined direction; a discharge tray that accommodates a stack of the print sheets discharged by the conveying means; wings arranged at a tail end portion of the conveying means, coming in contact with two side edges in a widthwise direction of the print sheet so as to give a U shape curl by curving the sheet in a rough U shape during discharge; control means for commanding, based on the judgment by the sheet information sensing means, the wing to take a predetermined shift mode during discharge of the print sheet; and drive means for moving the wing in a shift mode designated by the control means.