Roll Sheet Conveyance Torque Control for Slippage
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Solution Overview
Problem
In image recording apparatuses, the variation in tension of the roll sheet due to inertial weight and peripheral speed causes slippage and inaccuracies in conveyance, leading to issues like white or black stripes in recorded images, and it is difficult to correct the feeding amount effectively.
Innovation Solution
A conveyance apparatus with a control unit that adjusts the torque of the motor based on sheet information to eliminate slack, using a supply unit and a roller pair to pinch and convey the sheet, ensuring minimal slippage and maintaining accurate feeding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a fixed winding-back force is applied to eliminate slack in the roll sheet, then the slack is removed, but the roll sheet slips on the conveyance roller causing nip position deviation and white stripes in recorded images
Solution Approach 1:
The patent applies dynamics by making the winding-back force variable rather than fixed. The control unit adjusts the magnitude of the winding-back force based on detected sheet types (slippery vs. non-slippery) and conveyance speeds, allowing the system to adapt the taking-up force dynamically to prevent slippage while effectively removing slack.
Solution Approach 2:
The patent changes the parameter of winding-back force magnitude based on sheet characteristics and operating conditions. By detecting sheet type and conveyance speed, the system modifies the torque applied during winding-back to optimize slack removal without causing slippage, thereby resolving the contradiction between removing slack and preventing slippage.
2Manufacturing precision
If a fixed winding-back force is applied to eliminate slack, then the slack removal process is simple, but insufficient slack removal occurs in high stiffness sheets causing reverse tension and black stripes
Solution Approach 1:
The system dynamically adjusts the winding-back force based on detected sheet stiffness characteristics. For high stiffness sheets, the control unit increases the taking-up force magnitude to ensure adequate slack removal, preventing reverse tension and black stripe defects while maintaining the ability to handle various sheet types.
Solution Approach 2:
The patent modifies the winding-back force parameter according to sheet stiffness and other characteristics. By detecting sheet type and adjusting the torque accordingly, the system ensures sufficient slack removal for stiff sheets while avoiding excessive force that could cause damage or slippage in more compliant materials.
3Stability of the object's composition
If the roll member has large inertial weight to maintain rotation, then the conveyance operation is stable, but excessive slack is generated in the roll sheet
Solution Approach 1:
The patent applies preliminary action by performing winding-back of the roll sheet during the recording period (when the conveyance roller is stopped). This eliminates slack generated by the roll member's inertial rotation before the next conveyance operation begins, preventing excessive slack accumulation while maintaining stable conveyance with appropriately weighted roll members.
Solution Approach 2:
The system maintains continuous useful action by utilizing the recording period (when the conveyance roller is stationary) to perform slack elimination through winding-back. This ensures that slack is continuously managed throughout the operating cycle, preventing accumulation during conveyance while maintaining stable roll member rotation.
4Productivity
If the conveyance roller operates at high peripheral speed to increase productivity, then the recording efficiency is improved, but greater slack is generated due to roll member inertia
Solution Approach 1:
The patent applies preliminary action by eliminating slack during the recording period at high-speed conveyance operations. The control unit performs winding-back when the conveyance roller is stopped, proactively removing slack generated by high-speed inertial rotation before it affects conveyance precision, thereby enabling high productivity without sacrificing accuracy.
Solution Approach 2:
The system changes the winding-back force parameter based on conveyance speed. At higher peripheral speeds where more slack is generated, the control unit increases the taking-up force magnitude to compensate and effectively remove the increased slack, maintaining conveyance precision across a range of operating speeds and productivity levels.
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 effectively suppresses slippage between the conveyance roller and the sheet, ensuring precise and consistent conveyance operations, preventing image defects and maintaining high accuracy in feeding.
Implementation Method 1
a motor configured to rotate the roll member; a control unit configured to set the torque of the motor according to sheet information related to the sheet when taking up the sheet on the roll member
Implementation Method 2
a roller pair configured to convey the sheet supplied from the supply unit while pinching the sheet
Data Source
AI summary
A conveyance apparatus includes: a supply unit rotatably supporting a roll member around which a sheet is wound in form of a roll and configured to supply the sheet from the roll member; a motor for rotating the roll member; a roller pair configured to convey the sheet supplied from the supply unit while pinching the sheet; and a control unit configured to set the torque of the motor according to sheet information related to the sheet when taking up the sheet on the roll member by driving the motor while the sheet is pinched by the roller pair being stopped.