Staggered Motor Current Cutoff for Paper Conveyance Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing image forming apparatus faces challenges in conveying paper sheets effectively after loop formation, particularly with thick or high-stiffness papers, as the restoring force causes high loads on motors, leading to potential out-of-synchronization issues among motor-driven roller pairs during restart.
Innovation Solution
The apparatus includes a registration roller pair, a loop roller pair, and multiple conveyance roller pairs driven by motors, with a processor controlling the exciting currents to synchronize and stagger the motor startup, allowing for controlled release of static torque and gradual absorption of restoring forces to prevent high loads and synchronization issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the conveyance of a paper sheet is restarted after loop formation, then the paper sheet can be conveyed into the secondary transfer nip while performing skew correction, but high load is imposed on motors to drive the conveyance roller pairs due to the restoring force of the paper sheet
Solution Approach 1:
The processor cuts off the exciting current to the motor before restarting the conveyance roller pairs, releasing the static torque in advance. This preliminary action allows the paper sheet's restoring force to be gradually absorbed without imposing high load on the motor during restart, while still enabling skew correction functionality
2Productivity
If the conveyance of a paper sheet having stopped on high load condition is restarted, then the paper sheet can be conveyed, but all the motors may not be started synchronously, causing out of synchronization among the plurality of motors
Solution Approach 1:
The processor cuts off the exciting current to the motor before restarting, releasing static torque in advance. This preliminary current cutoff ensures that when the conveyance roller pairs are restarted, the motors can start synchronously without being hindered by high load conditions, thereby maintaining motor synchronization and reliable conveyance
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
This solution enables appropriate paper sheet conveyance by managing the restoring forces and motor synchronization, preventing out-of-synchronization and ensuring smooth operation even with thick or stiff papers.
Implementation Method 1
a plurality of motors that are provided for the plurality of conveyance roller pairs so as to rotate the plurality of conveyance roller pairs
Data Source
AI summary
An image forming apparatus that controls to cut off exciting currents supplied to a plurality of motors to drive conveyance roller pairs after a leading end of a paper sheet is brought in contact with a registration roller pair, and, when cutting off the exciting currents, cut off the exciting current for at least one of the motors at a different timing from the other motors.