Printer Back Feed Drive Disengagement for Accurate Label Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional printers face challenges in accurately performing back feed due to slippage caused by load resistance, which can lead to inaccurate conveyance and reduced printing accuracy.
Innovation Solution
The printer incorporates a drive train mechanism that disengages the winding roller from the motor during back feed, allowing for precise control of the label sheet conveyance by reversing the second motor before reversing the first motor, and utilizing a one-way clutch and torque limiter to maintain accurate alignment and prevent slack.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the base sheet is pulled out from the winding shaft during back feed while resisting the load caused by non-exciting torque, then the back feed operation can be performed, but slippage is likely to occur in the conveyance of the base sheet due to the influence of the load, resulting in inaccurate conveyance
Solution Approach 1:
The patent extracts the winding function from the drive system during back feed by disengaging the drive train from the winding shaft. This allows the platen roller to pull out the base sheet without resistance from the winding shaft's non-exciting torque, eliminating slippage and ensuring accurate conveyance during back feed operation.
Solution Approach 2:
The patent implements dynamic control of the drive train engagement state. The drive train is engaged during forward conveyance for winding but disengaged during back feed to eliminate resistance. This dynamic switching of engagement states optimizes the system performance for different operational phases, preventing slippage during back feed while maintaining winding function during forward conveyance.
2Productivity
If the drive train remains engaged during back feed, then the winding shaft can maintain its winding function, but the load resistance causes slippage and reduces conveyance accuracy
Solution Approach 1:
The patent segments the operational phases into forward conveyance (winding) and back feed (repositioning), with the drive train engagement state corresponding to each phase. During forward conveyance, the drive train is engaged for winding; during back feed, it is disengaged for accurate repositioning. This segmentation allows both winding function continuity and conveyance accuracy to be maintained in their respective phases.
3Force
If the second motor is controlled to rotate in the second direction without disengaging the drive train, then the winding shaft resists the pull-out force, but this resistance causes slippage in base sheet conveyance
Solution Approach 1:
The patent converts the potentially harmful resistance force into a beneficial controlled state. By intentionally disengaging the drive train during back feed, the system eliminates the harmful slippage caused by resistance while maintaining the winding function's capability. The controlled disengagement transforms the resistance issue into a precision conveyance opportunity.
Data Source
AI summary
A printer includes a platen roller conveying a label sheet, a first motor rotating the roller, a print head facing the roller and printing on a label of the sheet, a discharge port, a winding roller for winding the sheet from which the label has been detached, a second motor rotating the winding roller, a drive train by which a rotational force can be transmitted from the second motor to the winding roller, and a processor controlling the motors to rotate in a first direction to convey the sheet in a forward direction and controlling the head to print on a first label of the sheet, and after the label is discharged, controlling the motors to rotate in a second direction opposite to the first direction. The drive train disengages the winding roller from the second motor when the second motor is controlled to rotate in the second direction.