Printer Sheet Conveyance Timing Control via Variable Speed
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Solution Overview
Problem
Delays in the conveying route to upstream conveying rollers in printers can cause sheets to jam by overlapping or colliding, necessitating a technique to easily correct the timing at which sheets reach the registration rollers.
Innovation Solution
A printer configuration with a conveyor system that includes a conveyer, conveying rollers, and a controller to control conveying speeds based on the time from a preceding sheet's exit to a following sheet's arrival, allowing sheets to abut on registration rollers at a slower speed to correct timing and prevent collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If sheets are conveyed at high speed to maintain productivity, then productivity is improved, but sheet delay occurs causing timing errors at registration rollers
Solution Approach 1:
The system uses sheet sensors to detect the actual position and timing of sheets during conveyance, and the controller adjusts conveying speeds based on this feedback to correct timing delays and prevent sheet collision at the registration rollers
Solution Approach 2:
The conveying rollers operate at variable speeds rather than a fixed speed, allowing the system to accelerate sheets quickly while then slowing down near the registration rollers to ensure precise timing and prevent overlap, thus maintaining both high productivity and timing accuracy
2Reliability
If conveying speed is reduced to correct timing delays, then timing accuracy is improved, but productivity decreases
Solution Approach 1:
The conveying system uses periodic acceleration and deceleration cycles, where sheets are conveyed at high speed for most of the path, then periodically slowed down near the registration rollers for precise timing, creating a rhythm that maintains both speed and accuracy
Solution Approach 2:
The system performs preliminary high-speed conveyance to cover distance efficiently, then executes a controlled deceleration phase in advance before sheets reach the registration rollers, ensuring timing correction is completed before the critical registration point
3Adaptability or versatility
If sheets are sent through multiple conveying routes (simplex and duplex) simultaneously, then versatility is improved, but sheet delay and collision risk increase
Solution Approach 1:
The system separates the conveying routes for simplex and duplex printing into distinct controllable paths, allowing independent speed and timing control for each route, thus managing sheet flow from multiple sources without collision
Solution Approach 2:
Sheet sensors monitor sheets in both conveying routes independently, and the controller adjusts speeds for each route based on real-time detection, ensuring synchronized timing at the registration rollers despite different path lengths and sheet sources
Data Source
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AI summary
A controller (6) is configured to drive a conveying roller (18) to allow a sheet (P) to abut on a registration roller (31) and stop, and to drive the registration roller to convey the sheet abutting on the registration roller to the printing unit (3) at a set sheet interval. The controller is configured to control a conveying speed of the conveying roller based on a time from a first timing to a second timing, the first timing at which a preceding sheet conveyed from the registration roller to the printing unit exits the conveying roller, the second timing at which a following sheet reaches the conveying roller.