Ink Ejection Control for Non-Permeable Media
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Solution Overview
Problem
Inkjet printing on non-permeable materials like vinyl chloride film results in ink coalescence due to poor wettability of treatment agents, leading to poor image quality, increased ink usage, and distorted dot shapes.
Innovation Solution
An ink ejection control apparatus that performs a two-step ink ejection process, initially ejecting ink until a predetermined printing rate is reached, then coating a treatment agent containing a coagulant to prevent coalescence and ensure proper dot formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a treatment agent is coated onto a non-permeable material to prevent ink coalescence, then ink coalescence is suppressed, but the treatment agent forms droplets with poor wettability causing local coagulation and insufficient dot size
Solution Approach 1:
The patent applies preliminary action by coating the treatment agent onto the non-permeable material before ink ejection. This preliminary coating creates a uniform layer that prevents ink coalescence during the subsequent ink ejection process, ensuring proper dot size and shape while suppressing harmful coalescence effects
Solution Approach 2:
The patent changes the physical and chemical parameters of the treatment agent to improve its wettability on non-permeable materials. By adjusting parameters such as surface tension, contact angle, and chemical composition, the treatment agent forms a uniform coating rather than droplets, enabling effective ink placement without local coagulation
2Reliability
If ink is ejected onto droplets of treatment agent, then coalescence force is enhanced, but the landing position deviates and dot shape becomes distorted
Solution Approach 1:
The patent modifies the parameters of the treatment agent coating to achieve optimal wettability. By controlling surface tension and contact angle parameters, the treatment agent forms a uniform, non-droplet coating that allows ink to land accurately at target positions without deviation or distortion, while still preventing coalescence
3Reliability
If treatment agent forms droplets on material, then local coagulation occurs, but sufficient dot size cannot be obtained and solid filling property deteriorates
Solution Approach 1:
The patent changes the physical parameters of the treatment agent to eliminate droplet formation. By optimizing surface tension, contact angle, and coating uniformity parameters, the treatment agent creates a continuous uniform layer that enables sufficient ink absorption and distribution, achieving both coalescence suppression and improved solid filling property
Solution Approach 2:
The patent applies local quality by ensuring the treatment agent provides uniform protection across the entire material surface. The uniform coating creates consistent local conditions for ink placement, preventing the localized coagulation issues that occur with droplet formation and improving overall solid filling property
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
Improves image quality by preventing ink coalescence, securing sufficient dot size, and maintaining accurate dot shapes, thereby enhancing the solid filling property of printed images.
Implementation Method 1
a treatment agent that contains a coagulant that coagulates ink
Data Source
AI summary
An inkjet printing apparatus includes: a first and a third head that ejects ink onto a print medium to form a printed image; a second head that coats the print medium with a treatment agent that contains a coagulant that coagulates ink; and a control unit that performs a two step ink ejection control process to control the first through third heads such that ink is ejected onto the print medium until a printing rate in a predetermined region of the print medium reaches a threshold value which is set in advance, coats the treatment agent thereafter, and then ejects ink according to a remaining printing rate after the treatment agent is coated.