Dual Nozzle Line Head Ink Placement Correction
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Solution Overview
Problem
The existing printing apparatuses face a challenge in maintaining image quality due to errors in the conveyance of the print medium, as ink may not land on the predetermined position, leading to reduced image quality.
Innovation Solution
A printing apparatus with a line head featuring two nozzle rows aligned in the conveying direction, where the nozzles are shifted in the width direction, and a controller that stores and prints correction-pattern images to adjust for positional shifts, ensuring accurate ink placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single nozzle row is used for printing, then the device complexity is reduced, but the image quality deteriorates due to conveyance errors causing ink to miss the predetermined position
Solution Approach 1:
The single nozzle row is segmented into two separate nozzle rows (first nozzle row and second nozzle row) positioned at different locations in the conveying direction. Each nozzle row discharges ink to form dots that overlap to create a single dot on the print medium. This segmentation allows the system to compensate for conveyance errors by using the overlap region, thereby maintaining ink placement precision while managing device complexity.
2Productivity
If conveyance speed is increased to improve productivity, then the printing efficiency is improved, but the image quality deteriorates due to larger positional shifts from conveyance errors
Solution Approach 1:
The system performs preliminary action by having the first nozzle row discharge ink before the second nozzle row. The first nozzle row forms a preliminary dot on the print medium, and then the second nozzle row discharges ink to form an overlapping dot. This preliminary action allows the system to accommodate conveyance speed variations while maintaining dot position accuracy through the overlap mechanism.
Solution Approach 2:
The system changes parameters by varying the discharge timing and positional relationship between the two nozzle rows. By adjusting the relative positions of the first and second nozzle rows in the conveying direction and controlling their discharge timing, the system can maintain accurate dot placement even when conveyance speed changes, thus improving productivity without sacrificing image quality.
3Manufacturing precision
If multiple nozzle rows are added to compensate for conveyance errors, then the image quality is improved, but the device complexity increases
Solution Approach 1:
The system merges the functions of two nozzle rows to achieve precise ink placement. Both the first nozzle row and second nozzle row discharge ink that overlaps to form a single dot on the print medium. By combining their outputs in the overlap region, the system achieves high manufacturing precision while keeping the device complexity manageable through a relatively simple dual-nozzle-row configuration.
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 configuration reduces the lowering of image quality caused by errors in print medium conveyance by ensuring precise ink placement on the print medium, enhancing overall image quality.
Implementation Method 1
the nozzles being configured to discharge liquid
Implementation Method 2
a first dot and a second dot which overlap with each other are formed on the print medium by liquid discharged from the first nozzle row and liquid discharged from the second nozzle row, respectively
Data Source
AI summary
A printing apparatus includes: a conveying roller which conveys a print medium in a conveying direction; a line head having first and second nozzle rows arranged in the conveying direction; and a controller. Each of the first and second nozzle rows includes nozzles aligned along a width direction orthogonal to the conveying direction. The nozzles are configured to discharge liquid, and the nozzles in the first nozzle row and the nozzles in the second nozzle row are shifted in the width direction. The first nozzle row has: first nozzles forming a group; and second nozzles forming a group adjacently in the width direction to the group of first nozzles in the first nozzle row. The second nozzle row has: first nozzles forming a group; and second nozzles forming a group adjacently in the width direction to the group of first nozzles in the second nozzle row.