Sheet Feeding Control for Intermittent Printing Overlap
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing printing apparatuses require time to start feeding a succeeding sheet as they wait for confirmation of the marginal overlap between the trailing edge of the preceding sheet and the leading edge of the succeeding sheet, leading to inefficiencies in the printing process.
Innovation Solution
A printing apparatus with a control unit that synchronizes the feeding motor with the conveyance motor before detecting the leading edge of the succeeding sheet, allowing it to drive at a higher speed once detected, ensuring the succeeding sheet overlaps the preceding sheet efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the apparatus waits for confirmation of marginal overlap between sheets before starting to feed the succeeding sheet, then the sheet positioning precision is improved, but the printing productivity deteriorates due to time loss
Solution Approach 1:
The control unit initiates feeding of the succeeding sheet in advance before the detection unit confirms the leading edge position. The feeding amount is controlled to achieve proper overlap with the preceding sheet, eliminating the need to wait for complete detection before starting the feeding process.
Solution Approach 2:
The detection unit detects the leading edge of the succeeding sheet, and this detection information is fed back to the control unit which adjusts the feeding amount to achieve the desired overlap with the preceding sheet, ensuring positioning precision while maintaining continuous operation.
2Productivity
If the apparatus continuously feeds sheets without waiting for detection, then the printing productivity is improved, but the sheet positioning precision deteriorates due to potential misalignment
Solution Approach 1:
The detection unit provides real-time feedback on the leading edge position of the succeeding sheet. The control unit uses this feedback to dynamically adjust the feeding amount, ensuring that the succeeding sheet overlaps the preceding sheet by the correct amount, thus maintaining positioning precision during continuous operation.
Solution Approach 2:
The feeding mechanism transitions from static predetermined feeding to dynamic adaptive feeding. The feeding amount is adjusted in real-time based on the detection results, allowing the system to maintain precision while operating continuously at high speed.
3Productivity
If the feeding motor is driven at high speed continuously, then the printing productivity is improved, but the sheet conveying precision deteriorates due to speed variations
Solution Approach 1:
The feeding motor operates in periodic cycles: running at high speed to advance the succeeding sheet, then pausing briefly to allow the detection unit to detect the leading edge position. This periodic operation maintains high productivity while ensuring positioning precision through speed control.
Solution Approach 2:
The feeding motor speed is dynamically adjusted based on the operational phase. It runs at high speed during the feeding phase and slows down or pauses during the detection phase, optimizing both productivity and precision without requiring continuous high-speed operation.
Data Source
AI summary
A printing apparatus includes a first feeding roller, a feeding motor configured to drive the first feeding roller, a second feeding roller, a conveyance roller, a conveyance motor configured to drive the conveyance roller, a printing unit configured to print the printing sheet, a detection sensor configured to detect the leading edge of the printing sheet, and a control unit configured to, when the printing unit performs a printing operation on a preceding sheet, drive the feeding motor in synchronization with the conveyance motor before the detection sensor detects the leading edge of a succeeding sheet, and continuously drive the feeding motor so that the conveying speed of the succeeding sheet by the feeding motor becomes higher than that of the preceding sheet after the detection sensor detects the leading edge of the succeeding sheet.