Liquid Discharge Head Masking Against High-Speed Airflow
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Solution Overview
Problem
Existing liquid discharge apparatuses experience image quality deterioration due to deflection or variations of discharged liquid droplets caused by strong airflows generated at high conveyance speeds, especially when multiple heads are arranged to handle wide media.
Innovation Solution
The apparatus employs multiple heads with controlled nozzle arrays and mask patterns to alternately discharge liquid droplets, ensuring that nozzles in overlapping regions are selectively activated or deactivated to maintain consistent discharge patterns despite airflow interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple discharge heads are arranged to handle wide media at high conveyance speeds, then productivity is improved, but image quality deteriorates due to deflection or variations of discharged liquid droplets caused by strong airflow
Solution Approach 1:
The patent divides the discharge heads into multiple segments (first discharge head and second discharge head) with distinct nozzle arrays. Each head handles specific regions, and the overlapping regions are carefully managed by selecting discharge/no-discharge nozzles independently for each head, allowing high-speed operation while maintaining image quality through segmented control
Solution Approach 2:
The patent applies different discharge patterns to different regions of the nozzle arrays. In overlapping regions, specific nozzles are selected as discharge nozzles for one head and non-discharge nozzles for the other head, creating locally optimized discharge patterns that compensate for airflow effects at high conveyance speeds while maintaining overall image quality
2Manufacturing precision
If nozzles in overlapping regions are used to prevent positioning accuracy issues, then image quality is maintained, but discharge variations occur due to strong airflow at high speeds
Solution Approach 1:
The patent changes the operational parameters of nozzles in overlapping regions by dynamically selecting which nozzles discharge liquid and which do not, based on their position and the airflow conditions. This parameter adjustment compensates for discharge variations caused by strong airflow while maintaining positioning accuracy
Data Source
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AI summary
A liquid discharge apparatus includes multiple heads including a first head (100A) and a second head (100B), and a controller (1007). The controller (1007) forms a first mask pattern to select first discharge nozzles (1a) to discharge liquid droplets and first non-discharge nozzles (1b) not discharging the liquid droplets from first nozzles (1a, 1b) in first nozzle arrays (200) of the first head (100A) in a first overlapping region and a second mask pattern to select second discharge nozzles (2a) to discharge the liquid droplets and second non-discharge nozzles (2b) not discharging the liquid droplets from second nozzles (2a, 2b) in second nozzle arrays (200) of the second head (100B) in a second overlapping region. The controller (1007) causes a pattern of the first discharge nozzles (1a) in the first mask pattern to differ from a pattern of the second discharge nozzles (2a) in the second mask pattern.