Duplex Print Conveyance Speed Control for Media Deflection
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Solution Overview
Problem
Existing printing apparatuses face challenges in maintaining the posture of print media during double-sided printing, particularly due to deflection caused by ink discharge, leading to position deviation and potential jams.
Innovation Solution
The apparatus employs a reversal conveyance unit to change the conveyance speed based on the ink discharge amount in the edge region, switching between normal and low-speed modes to stabilize the print medium during double-sided printing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the printing unit performs printing on the first surface with normal conveyance speed, then printing efficiency is maintained, but the print medium may deflect due to ink discharge causing position deviation
Solution Approach 1:
The conveyance speed is dynamically adjusted based on the printing state. When printing on the first surface, the conveyance unit operates at normal speed to maintain efficiency. When the print medium is conveyed back for second surface printing, the speed is reduced to prevent deflection and ensure positioning accuracy. This dynamic speed adjustment resolves the contradiction between maintaining printing efficiency and ensuring position accuracy.
Solution Approach 2:
The conveyance speed parameter is changed according to the printing stage and ink discharge amount. By monitoring the ink discharge amount in edge regions and adjusting the conveyance speed accordingly, the system optimizes both productivity and manufacturing precision. The speed parameter is increased or decreased based on real-time printing conditions to balance efficiency and accuracy.
2Manufacturing precision
If the conveyance speed is reduced to prevent deflection during double-sided printing, then printing position accuracy is improved, but printing productivity decreases
Solution Approach 1:
The printing process is segmented into different stages with different speed requirements. First surface printing uses normal conveyance speed for efficiency, while second surface printing uses reduced speed for accuracy. This segmentation allows the system to optimize for productivity during first surface printing and for precision during reversal and second surface printing, resolving the contradiction between speed and accuracy.
Solution Approach 2:
The conveyance unit alternates between normal speed mode and reduced speed mode based on the printing cycle. During first surface printing, normal speed is maintained. After reversal, reduced speed is applied during second surface printing. This periodic switching between different operational modes allows the system to achieve both high productivity and high precision at appropriate times in the printing cycle.
3Loss of time
If the print medium is conveyed quickly through the reversal conveyance unit, then cycle time is reduced, but deflection and position deviation increase
Solution Approach 1:
The conveyance speed during reversal is dynamically adjusted based on the ink discharge amount detected in the first edge region. When large amounts of ink are discharged, the speed is reduced to prevent deflection. When ink discharge is minimal, the speed can be increased to reduce cycle time. This dynamic adjustment resolves the contradiction between minimizing cycle time and maintaining position accuracy.
Solution Approach 2:
The system uses feedback from ink discharge amount detection to control conveyance speed. The detection unit monitors ink discharge in edge regions, and this information feeds back to the control unit which adjusts the conveyance speed accordingly. This closed-loop control ensures that the conveyance speed is optimized for each specific printing condition, balancing cycle time and positioning accuracy.
Data Source
AI summary
A printing apparatus includes a first conveyance unit for conveying a print medium, a printing unit for printing by discharging ink, a second conveyance unit for conveying the print medium printed by the printing unit, and a reversal conveyance unit for reversing the print medium whose first surface is printed and conveying it to the first conveyance unit, wherein an edge region on an upstream side in a conveyance direction in a case of printing on the first surface is defined as a first edge region, and in a case that the printing unit prints on a second surface of the print medium, a conveyance speed of the print medium until the print medium from the reversal conveyance unit reaches the second conveyance unit changes depending on an ink discharge amount in the first edge region.