Recording Head Divided Maintenance for Print Density Uniformity
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Solution Overview
Problem
Existing image forming apparatuses face issues with ink mist causing nozzle clogging and density unevenness during maintenance, which affects print quality.
Innovation Solution
The apparatus performs divided maintenance operations on the recording head, interrupting print jobs to minimize ink spread during maintenance, using a cleaning unit with an absorber or centrifugal force to clean the nozzle surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If maintenance operation is performed on the recording head, then nozzle clogging is prevented, but ink spread causes density unevenness
Solution Approach 1:
The recording head is divided into multiple unit regions, and maintenance is performed on one unit region at a time while other regions continue printing. This segmentation allows maintenance operations to be conducted without stopping the entire print process, reducing the time ink remains on the recording medium and minimizing spread that causes density unevenness.
Solution Approach 2:
The system determines in advance which unit region requires maintenance based on print data analysis, and schedules maintenance during scans with small ejection amounts. By planning maintenance ahead of time during low-ink-demand periods, the system prevents ink spread issues while ensuring nozzles are maintained before they become clogged.
2Productivity
If maintenance is performed during print job, then productivity is maintained, but ink spread during standby causes density unevenness
Solution Approach 1:
The print job is divided into multiple scans, and maintenance is performed on specific unit regions during scans with small ejection amounts. This allows the print job to continue with other regions while maintenance is conducted, maintaining productivity while minimizing ink spread during maintenance standby time.
Solution Approach 2:
Maintenance operations are performed periodically on different unit regions in a cyclic manner. The control unit schedules maintenance during scans with small ejection amounts, creating a periodic pattern that balances productivity maintenance with print quality preservation by limiting ink spread opportunities.
3Reliability
If maintenance is performed on entire recording head, then all nozzles are maintained, but print quality deteriorates due to ink spread
Solution Approach 1:
The recording head is segmented into multiple unit regions, and maintenance is performed on one unit region at a time. This allows other regions to continue printing without interruption, reducing the overall standby time during maintenance and minimizing ink spread that would cause density unevenness across the entire printed image.
Solution Approach 2:
Maintenance operations are localized to specific unit regions rather than the entire recording head. The control unit identifies which unit region needs maintenance based on local nozzle performance and schedules maintenance for that specific region during appropriate scans, preserving print quality in other regions while maintaining reliability where needed.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces density unevenness and maintains print quality by minimizing ink spread during maintenance, ensuring consistent image formation.
Implementation Method 1
the cleaning unit includes an absorber, and cleans the maintenance member by pressing the absorber against the maintenance member
Implementation Method 2
the cleaning unit includes a motor that rotates the maintenance member, and cleans the maintenance member using a centrifugal force generated by rotating the maintenance member
Implementation Method 3
the cleaning unit includes: a motor that rotates the maintenance member; and a liquid reservoir that stores a cleaning liquid, and the cleaning unit cleans the maintenance member by rotating the maintenance member to pass the maintenance member through the cleaning liquid in the liquid reservoir
Data Source
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AI summary
Disclosed is an image forming apparatus including: a recording head that performs a print operation on a recording medium while scanning; a maintenance unit that performs a maintenance operation on the recording head with a maintenance member; and a hardware processor that controls the recording head and the maintenance unit. The hardware processor interrupts the print operation during a print job to cause the maintenance unit to perform the maintenance operation. The maintenance unit performs divided maintenance in which the recording head is divided into multiple unit regions, and the maintenance operation includes multiple divided maintenance operations performed respectively on the unit regions. The maintenance unit performs one of the divided maintenance operations at a time of a scan in which an ejection amount of nozzles of the recording head in one scan is small, the nozzles ejecting an ink onto the recording medium in the print operation.