Print Job Scheduling to Prevent Nozzle Clogging in Inkjet Printers
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Solution Overview
Problem
Ink jet printers face productivity losses and print quality issues due to idle printing elements, as ink drying leads to nozzle clogging, especially in multi-color printing where different colors have varying permissible idle times and usage frequencies.
Innovation Solution
A method of scheduling print jobs that calculates constraint times for each color to prevent malfunction by ensuring regular operation or maintenance, rearranging print jobs to extend these times by operating elements before they expire, thereby reducing the frequency of maintenance treatments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If maintenance treatment is performed frequently to prevent nozzle clogging, then reliability of printing elements is improved, but productivity deteriorates due to time-consuming operations
Solution Approach 1:
The system performs preliminary scheduling of print jobs to proactively utilize printing elements before their constraint times expire. By calculating constraint times for each color and arranging jobs in advance, the system prevents nozzle clogging before it occurs, eliminating the need for reactive maintenance treatments that would interrupt productivity.
Solution Approach 2:
The system dynamically calculates and updates constraint times for each printing element based on individual failure times and usage patterns. The scheduling arrangement is continuously adapted as new print jobs are added to the queue, optimizing the utilization of printing elements in real-time to balance reliability and productivity.
2Productivity
If print jobs are rearranged to extend constraint times, then productivity is improved by reducing maintenance frequency, but complexity of scheduling increases
Solution Approach 1:
The system segments the scheduling problem by calculating constraint times independently for each color channel based on individual failure times. This segmentation allows the complex multi-color scheduling problem to be broken down into manageable color-specific calculations, reducing overall system complexity while maintaining productivity benefits.
Solution Approach 2:
The system uses feedback from job completion times and constraint time calculations to dynamically adjust the scheduling arrangement. By monitoring when printing elements are used and updating constraint times accordingly, the system automatically optimizes productivity without requiring complex manual intervention.
3Adaptability or versatility
If white ink is used rarely in print jobs, then adaptability to diverse print requirements is improved, but reliability of white printing elements deteriorates due to long idle times
Solution Approach 1:
The system proactively schedules print jobs that utilize white ink before the white printing element's constraint time expires. By calculating the specific failure time for white ink and arranging jobs in advance, the system ensures periodic activation of the white nozzle without compromising the flexibility to accept diverse print job requirements.
Solution Approach 2:
The system applies different scheduling strategies to different color channels based on their individual usage patterns and failure times. White ink receives special attention with dedicated constraint time monitoring and targeted job scheduling, while other colors follow their own utilization patterns, allowing each color to be optimized independently for both reliability and adaptability.
Data Source
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AI summary
A method of scheduling print jobs for printing on a printer which has printing elements provided for printing in a number of different colors, characterized by the steps of: a) calculating, for each color, a constraint time (TcY - TcW) which specifies a time at which the printing elements for the respective color should be either operated or subjected to a maintenance treatment in order to avoid a risk of malfunction; b) calculating, for each of a plurality of print jobs (a - d) that have been scheduled already and are waiting in a print queue, an operation time (To) at which the printing elements will be operating in the course of the processing of the print job; and c) when a new print job (e) is to be scheduled and the print jobs, including the new print job, comprise at least one job in which printing elements for at least one color (W) are not operated, determining a sequence of the print jobs in the print queue, with corresponding recalculation of the constraint times (TcY - TcW) and operation times (To), with an aim to extend the constraint times by operating the printing elements before expiry of their previously calculated constraint times.