Variable Image Spacing in Inkjet Cutting to Reduce Sheet Waste
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Solution Overview
Problem
Existing image forming apparatuses face challenges in maintaining constant image distance, leading to inefficiencies in inkjet recording, such as ink drying, nozzle inspection patterns, and defective images, which result in wasted sheets and reduced productivity.
Innovation Solution
An image forming apparatus that allows continuous high-speed printing even when sheet conveyance is stopped during cutting, using a cutting device with movable and fixed blades to minimize sheet loops and optimize non-image portion length for efficient ink usage and defect detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the distance between images is increased to record inspection patterns at irregular timing, then nozzle inspection and defect detection can be performed, but the sheet is wasted due to increased non-image portions
Solution Approach 1:
The patent makes the distance between images variable rather than constant. The image forming apparatus adjusts the spacing between images based on whether nozzle inspection patterns need to be recorded, allowing flexible accommodation of inspection requirements without always increasing sheet consumption
Solution Approach 2:
The patent changes the parameter of image spacing from a fixed value to a variable value. By dynamically adjusting the distance between images according to inspection needs, the system achieves reliable nozzle inspection while minimizing sheet waste when inspection is not required
2Loss of substance
If the distance between images is decreased to reduce sheet waste, then sheet consumption is reduced, but inspection patterns cannot be recorded at desirable timing
Solution Approach 1:
The patent implements dynamic adjustment of image spacing to balance sheet consumption and inspection timing. When inspection is needed, spacing increases to allow proper timing; when inspection is not needed, spacing decreases to minimize waste
Solution Approach 2:
The patent employs periodic nozzle inspection patterns that are recorded at specific intervals. By coordinating the periodic inspection requirements with variable image spacing, the system ensures inspection timing accuracy while optimizing sheet usage across different operating cycles
3Manufacturing precision
If the continuous sheet conveyance is stopped during cutting, then cutting accuracy is improved, but continuous high-speed printing is interrupted
Solution Approach 1:
The patent divides the cutting operation into segments where only the necessary portions of the sheet are stopped for cutting, while other portions continue to be processed. This segmented approach allows cutting accuracy to be maintained without completely interrupting the continuous printing process
Solution Approach 2:
The patent performs preliminary positioning and preparation of the sheet before cutting, allowing the cutting operation to be completed quickly with high accuracy. This preliminary action minimizes the duration of conveyance stoppage, thereby reducing impact on continuous printing productivity
Data Source
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AI summary
An image forming apparatus includes first conveying means (4) provided downstream of image forming means (1); second conveying means (5) provided downstream the first conveying means (4); first cutting means (2) provided downstream the second conveying means (5); and second cutting means (3) provided downstream the first cutting means (2). One of the first cutting means (2) and the second cutting means (3) cuts an upstream end of an image on the continuous sheet (7), the other cuts a downstream end of the same image. The second conveying means (5) is stopped during the cutting by the first cutting means (2) to form a loop of the continuous sheet (7), and then if the cutting is ended, the second conveying means (5) conveys the continuous sheet (7) at a higher conveyance speed than a conveyance speed by the first conveying means (2) to reduce the loop.