Inkjet Recording Head Nozzle Ejection Control for Banding Suppression
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Solution Overview
Problem
Inkjet recording technologies using multiple heads often experience banding issues due to differences in droplet amounts and landing positions between the end and central nozzles, especially when calibration is insufficient, leading to noticeable defects in overlapping areas.
Innovation Solution
The inkjet recording device and method involve switching ink ejection between heads based on nozzle positions to blur boundaries and prevent banding by using overlapping nozzles strategically, avoiding nozzles at the ends of nozzle rows, and ensuring continuous recording areas to maintain consistent dot patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If printing is performed using nozzles at the end portions of recording heads in overlapping areas, then the recording coverage is improved, but banding occurs due to variations in droplet amounts and landing positions
Solution Approach 1:
The patent extracts and eliminates the problematic end portion nozzles from the overlapping recording area. By having at least one head refrain from ejection using nozzles disposed at ends of nozzle rows in the overlapping area, the source of banding (variations in droplet amounts and landing positions from end nozzles) is removed while maintaining recording coverage through the other head's nozzles
Solution Approach 2:
The patent applies different recording strategies to different regions: in overlapping areas, one head refrains from ejection using end nozzles while the other head continues normal operation; in non-overlapping areas, both heads operate normally. This local differentiation eliminates banding in critical overlapping regions while maintaining overall recording efficiency
2Productivity
If multiple recording heads are used to increase productivity, then the recording speed is improved, but banding occurs in overlapping areas due to calibration issues
Solution Approach 1:
The patent converts the potentially harmful effect of having multiple heads (which causes banding in overlapping areas) into a benefit by strategically controlling which head ejects ink in overlapping regions. The redundancy of multiple heads is maintained for productivity, while the ejection control logic eliminates banding by having one head refrain from ejection in overlapping areas, thus converting the multi-head configuration's drawback into an advantage
3Adaptability or versatility
If nozzles at the ends of nozzle rows are used for recording, then the nozzle utilization is improved, but dot variations occur due to inconsistent droplet ejection
Solution Approach 1:
The patent segments the nozzle usage by function and position: end portion nozzles are excluded from overlapping recording areas where they cause instability, while central nozzles are used for overlapping areas where they provide consistent performance. This segmentation allows the system to maintain high nozzle utilization in non-overlapping areas while ensuring dot recording consistency in overlapping areas
Data Source
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AI summary
An object is to suppress occurrence of banding in an inkjet recording technology using a plurality of heads. Control is performed on two heads (1, 2) in which some of nozzles of one head overlap nozzles of the other head such that at least one head does not perform ejection from nozzles (A8, B8, C1, D1) included in the overlapping nozzles (A5 to A8, B5 to B8, C1 to C4, D1 to D4) and positioned at ends of nozzle rows.