Ink Jet Head Nozzle Row Configuration for Bidirectional Printing
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Solution Overview
Problem
Ink jet heads with bidirectional printing capabilities face challenges in maintaining image quality due to differences in ink landing order and separation distances between nozzle rows, leading to chromogenic differences and decreased print quality when jetting multiple ink types.
Innovation Solution
The ink jet head is configured with additional nozzle rows for specific inks, where some rows are aligned and others are shifted, ensuring equal separation distances and consistent ink landing order between forward and backward movements, allowing for high-speed printing while maintaining image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of nozzle rows for a specific ink is increased to raise print speed, then productivity is improved, but device complexity increases due to additional nozzle rows with different positions
Solution Approach 1:
The nozzle rows are segmented into two functional groups: coincident nozzle rows (used for both color and black ink jetting) and non-coincident nozzle rows (used only for black ink jetting). This segmentation allows the system to independently optimize for color printing quality and black ink printing speed without interfering with each other's functionality.
Solution Approach 2:
The coincident nozzle rows serve multiple functions: they are used for jetting color inks during color printing operations and for jetting black ink during black-and-white printing operations. This multi-functionality reduces the total number of nozzle rows needed while maintaining high print speed capability.
2Productivity
If nozzle rows are arranged with different positions to increase print speed, then productivity is improved, but manufacturing precision requirements increase to maintain equal separation distances
Solution Approach 1:
The patent employs asymmetric nozzle row positioning where non-coincident nozzle rows are deliberately offset from the standard positions. This asymmetric arrangement is compensated by strategic placement to ensure that the separation distance between adjacent nozzle rows remains uniform, thereby maintaining manufacturing precision while enabling higher print speed through increased nozzle density.
3Productivity
If bidirectional printing is implemented to increase print speed, then productivity is improved, but image quality deteriorates due to different ink landing orders
Solution Approach 1:
The patent reverses the conventional approach to bidirectional printing by arranging nozzle rows symmetrically with respect to the scanning direction. This inversion of the traditional asymmetric nozzle layout ensures that the ink landing order remains consistent whether the head moves in the forward or backward direction, thereby maintaining image quality while enabling bidirectional printing for higher productivity.
Data Source
AI summary
A channel-structure has first to third nozzle-rows for first-ink, and first and second nozzle-rows for second-ink. Between the first nozzle-row for the first-ink and the first nozzle-row for the second-ink, and between the second nozzle-row for the first-ink and the second nozzle-row for the second-ink, each nozzle is located in the same position. The third nozzle-row for the first-ink is located in a different position with respect to the first and second nozzle-rows. Either the first and the second nozzle-rows for the second-ink are arranged between the first and second nozzle-rows for the first-ink, or the first and second nozzle-rows for the first-ink are arranged between the first and second nozzle-rows for the second-ink. A distance between the first nozzle-row for the first-ink and the first nozzle-row for the second-ink is equal to a distance between the second nozzle-row for the first-ink and the second nozzle-row for the second-ink.