Liquid Ejection Head Asymmetric Nozzle Spacing for Airflow Compensation
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Solution Overview
Problem
Ink jet recording apparatuses face challenges in maintaining droplet landing accuracy due to inflowing airflow, especially at higher speeds, as the air flow between the ejection opening surface and the printed medium causes deviations in droplet landing positions, which existing methods struggle to effectively suppress.
Innovation Solution
The liquid ejection head is designed with recording element substrates having ejection opening rows where the arrangement intervals of ejection openings in the end portion area of the most upstream row are smaller than those of the most downstream row, effectively mitigating the influence of inflowing airflow and autogenous airflow to improve landing precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the speed of relative movement between the liquid ejection head and the printed medium is increased to achieve high-speed recording, then productivity is improved, but the influence of inflowing airflow becomes larger causing droplet landing position deviation
Solution Approach 1:
The patent applies local quality by differentiating the arrangement intervals of ejection openings based on their position within the ejection opening row. Specifically, ejection openings in the end portion area have different arrangement intervals compared to those in the center portion, allowing each local region to be optimized for its specific airflow characteristics. This resolves the contradiction by enabling high-speed recording while maintaining droplet landing accuracy through localized geometric optimization.
2Manufacturing precision
If the arrangement intervals of ejection openings in the end portion area are made smaller to correct droplet position deviation, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent implements local quality by introducing different arrangement intervals for ejection openings in different regions (end portion vs. center portion). This localized differentiation allows the system to correct droplet position deviation without requiring complete redesign of the entire ejection opening array, thus improving precision while limiting the increase in overall device complexity to only the affected regions.
3Device complexity
If the arrangement intervals of ejection openings are made uniform throughout, then device complexity is reduced, but droplet landing position accuracy deteriorates due to airflow effects
Solution Approach 1:
The patent resolves this contradiction by applying local quality - different arrangement intervals are assigned to ejection openings in the end portion area compared to the center portion. This allows the system to maintain simplicity in the majority of the ejection opening array while introducing targeted geometric optimization only where needed to compensate for airflow effects, thereby achieving both simplicity and precision.
Solution Approach 2:
The patent employs asymmetry by creating non-uniform arrangement intervals in the end portion area of the ejection opening rows. This asymmetric design specifically addresses the airflow-induced position deviation that affects end openings differently than center openings, allowing the system to achieve accurate droplet placement without requiring complete symmetry throughout the entire ejection array.
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 significantly reduces droplet deviation caused by airflow, enabling high-speed, high-quality printing by optimizing the arrangement intervals of ejection openings to counteract airflow effects, ensuring accurate droplet placement on the printed medium.
Implementation Method 1
the air having viscosity situated around the flying droplets is dragged by the movement of the droplets and is moved as well
Implementation Method 2
an area between an ejection opening surface provided with the ejection openings and the printed medium tends to become lower in pressure than the surroundings thereof
Implementation Method 3
the influence of an airflow flowing between an ejection opening surface of the liquid ejection head and the printed medium (hereinafter, merely referred to as an inflowing airflow) becomes larger
Data Source
AI summary
A liquid ejection head including recording element substrates each including ejection opening rows in which ejection openings ejecting liquid are arranged, the plurality of ejection opening rows being juxtaposed in a relative movement direction with respect to the printed medium. In the relative movement direction of the printed medium when the printed medium is viewed from the liquid ejection head, and in the plurality of ejection opening rows provided in the recording element substrate, among the plurality of recording element substrates, positioned on an upstream side in the relative movement direction, arrangement intervals of ejection openings in an end area of an ejection opening row positioned on a most upstream side in the relative movement direction are smaller than arrangement intervals of ejection openings in an end area of an ejection opening row positioned on a most downstream side in the relative movement direction.