Printer Tray Elevation and Conveyance Speed Control
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Solution Overview
Problem
The existing post-processing apparatuses do not effectively detect the stacking state of print media, leading to issues like excessive projection or rising of print media due to curling, causing defective alignment and paper jams.
Innovation Solution
Incorporating a detection unit with actuators that detect the top surface of the print media and adjusting the conveyance speed of the bundle pawl drive mechanism based on discharge time to prevent excessive or insufficient projection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the conveyance speed is kept constant, then the discharge process is simple, but defective alignment and paper jams occur due to print medium curling
Solution Approach 1:
The conveyance speed is changed dynamically based on the stacking state of the print medium. The control unit adjusts the conveyance speed of the bundle pawl drive mechanism according to detection results from the detection unit, which detects whether the print medium is curled upward or downward. This dynamic speed adjustment prevents defective alignment and paper jams while maintaining system simplicity.
2Manufacturing precision
If the conveyance speed is adjusted frequently, then alignment quality improves, but the control system becomes more complex
Solution Approach 1:
A detection unit is provided that detects the stacking state of the print medium on the tray. The control unit receives detection results and automatically adjusts the conveyance speed accordingly. This feedback mechanism ensures accurate discharge position while keeping the control system relatively simple through automated decision-making based on detection data.
Solution Approach 2:
The conveyance speed parameter is changed based on the stacking state of the print medium. The control unit selects different conveyance speeds according to whether the print medium is curled upward or downward, as detected by the detection unit. This parameter adjustment improves discharge position accuracy without requiring complex control algorithms.
3Productivity
If the conveyance speed is increased, then productivity improves, but paper jams occur due to excessive projection
Solution Approach 1:
The conveyance speed is adjusted dynamically based on the stacking state. When the detection unit detects that the print medium is curled downward (prone to excessive projection), the control unit reduces the conveyance speed to prevent paper jams. When the print medium is curled upward, the conveyance speed can be increased to improve productivity. This dynamic adjustment balances productivity and reliability.
Data Source
AI summary
A post-processing apparatus includes a conveyance unit, a discharge port, a tray, an elevation unit, a detection unit, and a control unit. The conveyance unit conveys a print medium supplied from an image forming apparatus. The discharge port discharges the print medium conveyed by the conveyance unit. The tray is stacked with the print medium discharged from the discharge port and can be raised and lowered in a vertical direction. The elevation unit raises and lower the tray in the vertical direction. The detection unit detects a top surface of an uppermost print medium of one or more sheets of print media stacked on the tray. The control unit controls the conveyance unit and the elevation unit and hold a relative position of the top surface with respect to the discharge port if the print medium is discharged from the discharge port at a first position. The control unit causes the conveyance unit to convey the print medium at a first speed if a discharge time from a first timing indicating the timing relating to discharge of the print medium from the discharge port to a second timing indicating the timing when the print medium is detected by the detection unit is a first time and causes the conveyance unit to convey the print medium at a second speed different from the first speed if the discharge time is a second time.