Inkjet Nozzle Overlap Density Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet printers with nozzles arranged across the width of a medium face challenges in achieving high precision and uniform ink ejection, leading to density unevenness in images due to differences in ink ejection from nozzles at the ends of nozzle rows, which are overlapped to cover the entire width.
Innovation Solution
A method and apparatus where nozzle rows are arranged parallel to each other with overlapping ends in the intersecting direction, allowing nozzles in the overlap area to have different positions, and a controller determines the ink ejection method based on image density to adjust ink ejection accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple ink ejection heads are arranged in the width direction to cover the entire width, then the width coverage is improved, but the positional precision and uniformity of ink ejection deteriorate due to end portion nozzles having different ejection characteristics
Solution Approach 1:
The patent applies local quality by determining different ink ejection methods for nozzles in the overlap area compared to nozzles in non-overlap areas. The controller selectively applies different ejection control strategies based on the specific location of each nozzle, recognizing that nozzles in the overlap region have different characteristics from those in non-overlap regions. This allows optimization of ink ejection uniformity in the overlap area without compromising the overall width coverage capability.
2Area of stationary object
If nozzles at the end portion of nozzle rows are used to cover the entire width, then the width coverage is improved, but density unevenness is caused in the printed image
Solution Approach 1:
The patent implements dynamics by making the ink ejection method adaptive rather than fixed. The controller dynamically determines which nozzle to activate and how much ink to eject based on real-time detection of image density characteristics. This dynamic adjustment allows the system to compensate for the inherent differences in nozzle performance, particularly in the overlap area, thereby maintaining image density uniformity while preserving full width coverage.
Solution Approach 2:
The patent employs feedback mechanisms where the controller detects the actual density of the printed image and uses this information to adjust subsequent ink ejection operations. By continuously monitoring the density characteristics and comparing them against target values, the system can identify when end portion nozzles are causing density unevenness and automatically adjust their ejection parameters to maintain uniformity across the entire printed width.
Data Source
AI summary
Density unevenness caused in an image formed with an overlap portion of nozzles is suppressed. For this purpose, a method of determining an ink ejection method includes: transporting a medium in a transporting direction; forming an image with a nozzle unit having a plurality of nozzle rows in which a plurality of nozzles for ejecting ink are arranged at a predetermined interval in an intersecting direction intersecting the transporting direction, wherein the plurality of nozzle rows are arranged parallel to each other, one end side in the intersecting direction in a particular nozzle row and the other end side in the intersecting direction in another nozzle row are overlapped with each other in the transporting direction so as to form an overlap area, and in the overlap area, the nozzle in the particular nozzle row and the nozzle in the other nozzle row are at different positions in the intersecting direction; and determining an ink ejection method from the nozzles in the overlap area, based on a density of the image.