Liquid Jetting Apparatus Nozzle Timing Correction
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Solution Overview
Problem
Liquid jetting apparatuses face challenges in maintaining uniformity of image edges due to differences in ink expansion and contraction along the scanning direction, leading to deviations in the printed image's alignment and margin length.
Innovation Solution
A liquid jetting apparatus with a conveyor and a liquid jet head featuring nozzle groups aligned in the conveyance direction, where the jet-timing is adjusted based on correction parameters to minimize deviations by varying the timing for nozzles upstream and downstream of a reference position, ensuring consistent ink placement across the recording medium.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If uniform jet-timing is used for all nozzles, then the printing process is simple, but the image edges become inclined and margins vary in length due to recording paper expansion/contraction
Solution Approach 1:
The patent applies local quality by setting different jet-timing correction parameters for different nozzle groups based on their positions. Specifically, nozzles are divided into multiple groups along the conveyance direction, and each group is assigned a specific correction parameter to compensate for local variations in recording paper expansion or contraction, thereby achieving precise image edge alignment without complicating the overall control system
Solution Approach 2:
The patent implements parameter changes by introducing jet-timing correction parameters that are added to the basic jet-timing values for different nozzle groups. These correction parameters are determined based on the degree of recording paper expansion or contraction and are used to adjust the jet-timing of each nozzle group, enabling accurate image positioning while maintaining a relatively simple control structure
2Manufacturing precision
If jet-timing is adjusted to position image edges on a straight line, then image alignment improves, but margin length difference between upstream and downstream parts increases
Solution Approach 1:
The patent resolves this contradiction by applying local quality through differentiated correction parameters for different nozzle groups. By setting specific correction parameters for upstream and downstream nozzle groups based on their respective positions, the system achieves both straight image edges and uniform margin lengths, as each local region is optimized for its specific expansion/contraction characteristics
Solution Approach 2:
The patent employs dynamics by making the jet-timing correction parameters adaptable to different recording medium types and conveyance directions. The correction parameters are dynamically selected based on the specific printing conditions, allowing the system to maintain both image edge alignment and margin length uniformity across various printing scenarios
3Manufacturing precision
If different correction parameters are used for different nozzle groups, then deviation in scanning direction is reduced, but device complexity increases
Solution Approach 1:
The patent manages parameter complexity by systematically organizing correction parameters for different nozzle groups. The controller stores and manages these parameters in a structured manner, selecting appropriate parameters based on the recording medium type and conveyance direction, thereby achieving high positioning accuracy without excessive operational complexity
Solution Approach 2:
The patent applies preliminary action by pre-determining the correction parameters for different nozzle groups based on the recording medium type and conveyance direction before actual printing. This preparation step allows the system to quickly switch between different parameter sets without real-time calculation complexity, maintaining both precision and ease of operation
Data Source
AI summary
There is provided a liquid jetting apparatus including a conveyor, a liquid jet head, a carriage, a carriage moving device, and a controller. The controller carries out printing by repeating a scan-printing operation and a conveyance operation, and carries out a process of determining a jet-timing such that the jet-timing and a predetermined reference timing may deviate oppositely from each other between a print area on the upstream side and a print area on the downstream side along a scanning direction for the carriage to move in the scan-printing operation with respect to a predetermined reference position in the scanning direction, based on a value of a correction parameter. The correction parameter is set to the same value for nozzles included in an identical one of nozzle groups and to different values for the corresponding nozzles included in different ones of the nozzle groups.