Sheet Stacking Device Velocity Control for Alignment Precision
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Solution Overview
Problem
Existing sheet processing devices struggle to accurately align and process sheets with special qualities or sizes, such as coated or large-sized papers, leading to incomplete alignment, reduced productivity, and potential damage due to high friction and inertia.
Innovation Solution
A sheet stacking device with a sheet-end regulating member and a controller that adjusts the velocity of sheets as they abut against the regulating member based on sheet conditions, ensuring proper alignment and processing of multiple sheets in a high-speed image forming apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple sheets are superimposed and conveyed to the stacking unit, then the productivity is improved, but the alignment precision deteriorates due to high friction and inertia
Solution Approach 1:
The moving unit dynamically adjusts the velocity at which sheets abut against the sheet-end regulating member based on sheet conditions (size, quality, thickness). This dynamic velocity control allows multiple sheets to be conveyed efficiently while maintaining proper alignment by preventing excessive impact forces that would cause non-aligning or buckling.
Solution Approach 2:
The controller changes the velocity parameter of the moving unit according to detected sheet conditions. By adjusting this key parameter, the system optimizes the balance between conveying speed (productivity) and alignment accuracy, resolving the contradiction between processing speed and alignment precision.
2Productivity
If the velocity at which sheets abut against the sheet-end regulating member is increased, then the productivity is improved, but the sheets may buckle or be damaged due to excessive impact
Solution Approach 1:
The system employs dynamic velocity adjustment rather than a fixed high speed. The moving unit's velocity is continuously adapted based on real-time sheet condition detection, allowing high productivity when conditions permit while preventing damage when sheets are thick, large-sized, or have special coatings that make them susceptible to impact damage.
Solution Approach 2:
The controller receives feedback about sheet conditions (size, quality, thickness) and adjusts the velocity parameter accordingly. This feedback loop ensures that the velocity is optimized for each batch of sheets, preventing excessive impact forces that would cause buckling or damage while maintaining high productivity when sheets can tolerate higher speeds.
3Manufacturing precision
If the velocity is adjusted according to sheet conditions, then the alignment precision is improved, but the device complexity increases due to the controller and velocity adjustment mechanism
Solution Approach 1:
The controller serves multiple functions: it detects sheet conditions (size, quality, thickness), determines appropriate velocity parameters, controls the moving unit's velocity, and coordinates the sheet-end regulating member's positioning. By consolidating these functions into a single multi-functional controller, the system achieves high alignment precision without proportionally increasing overall device complexity.
4Productivity
If multiple sheets are conveyed simultaneously, then the productivity is improved, but the sheets may not be completely returned to the rear end stopper due to high friction
Solution Approach 1:
The moving unit dynamically adjusts velocity to overcome friction effects when conveying multiple sheets. By optimizing the velocity profile based on sheet conditions, the system ensures that all sheets are properly conveyed to the stacking unit and returned to the rear end stopper, preventing incomplete alignment that would occur with fixed velocity operation.
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 solution enables effective alignment and processing of sheets with varying qualities and sizes, improving productivity by controlling the return velocity of sheets to prevent non-aligning and damage, thus enhancing the overall efficiency of the sheet post-processing device.
Implementation Method 1
the bundle discharge rollers 180a and 180b rotate in the reverse direction in such a way that the sheet bundle of three sheets P1, P2, and P3 is returned in the direction in which the sheets abut against a rear-end stopper 3 of the processing tray 101 by moving inertia
Implementation Method 2
alignment is performed in such a way that the bundle discharge roller 180b is separated from the bundle discharge roller 180a just before the rear end of the sheet bundle abuts against the rear-end stopper 3 and the sheet bundle abuts against the rear-end stopper 3 by moving inertia
Data Source
AI summary
A bundle discharge roller pair is made to rotate backward in a holding state in which the sheets are held between the bundle discharge roller pair, and, at the same time, the upper bundle discharge roller of the pair is separated from the lower bundle discharge roller of the pair. The released sheets slide down on the inclined processing tray at a return velocity Vb; and are made to run into the rear end stopper for aligning. The return velocity Vb may be controlled according to the reverse-rotational speed of the bundle discharge roller pair and is set at a low velocity, when it is found that, for example, the size of the sheet is large, and the return velocity Vb is increased in the case of coated paper with a large coefficient of friction.