【Inkjet】🖨️ 01. Inkjet DTS: Design Trade-offs Between Drop Density, Throughput, and Spread

topics: [“inkjet”, “design”, “trade-off”, “modeling”, “DTS”]

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📌 Introduction

Inkjet technology has evolved under conflicting requirements such as
higher resolution, higher speed, and stable print quality.

In practice, engineers frequently face questions like:

• Why does print quality degrade when speed increases?
• Why do higher dot densities cause bleeding and non-uniformity?
• Where exactly is the design limit?

This article introduces the Inkjet DTS (Density–Throughput–Spread) model,
which organizes these questions not as empirical know-how,
but as a design-oriented trade-off model.

This model is intended:

👉 not to explain inkjet physics itself, but
👉 to provide a minimal framework to support design decisions.

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🧩 What Is Inkjet DTS?

Inkjet DTS abstracts inkjet printing using three variables:

Symbol	Meaning	Design Interpretation
D	Drop Density	Dot density (resolution, gradation)
T	Throughput	Throughput (speed, productivity)
S	Spread	Dot spread (bleeding, image degradation)

These three variables are not independent.
They are inherently linked by unavoidable trade-offs.

Increasing D tends to worsen S
Increasing T tends to increase S
Suppressing S constrains achievable D and T

Inkjet DTS visualizes this inevitable relationship as a structure,
rather than treating it as scattered empirical rules.

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🧠 Why Modeling Is Necessary

Inkjet development routinely involves decisions such as:

• Reducing nozzle pitch
• Increasing carriage or transport speed
• Modifying ink viscosity or surface tension
• Adjusting drying or fixation conditions

In many cases, these decisions rely heavily on:

• Local optimization
• Generation-specific constraints
• Tacit knowledge of experienced engineers

Inkjet DTS aims to:

• Create a shared design language
• Elevate discussion from intuition to structure
• Provide a comparison axis for next-generation technologies

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📐 Fundamental DTS Relationship (Conceptual Model)

Inkjet DTS assumes the following conceptual relationships:

• Dot spread S increases as a function of
  drop density D and throughput T
• Design is the problem of
  maximizing D and T while keeping S within an acceptable range

This is not a strict physical or mathematical model,
but a coarse-grained abstraction usable for design decisions.

This intentional simplification allows:

• Technology-independent discussion
• Applicability across different head architectures
• Consistent reasoning across generations

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📊 Visualization and Design Insight

By visualizing the D–T–S space, Inkjet DTS reveals:

• Regions that are physically unsafe
• Regions where control or compensation is feasible
• Regions dominated by material limitations

In other words:

Design limits appear not as a single line, but as a surface.

This provides structural answers to questions like:
“Why does this condition fail?”

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🧭 Positioning of Inkjet DTS

Inkjet DTS is:

• Not a replacement for CFD or detailed physical simulations
• Not a rejection of experiments or measurements

Instead, it serves as a design framework for:

• Pre-experimental condition setting
• Early-stage technology comparison
• Design reviews, education, and discussions

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🔗 Implementation and Demo Page

The Inkjet DTS concept is published with
visualizations, demos, and implementation examples at the following site:

👉 Inkjet DTS Demo Page
https://samizo-aitl.github.io/inkjet-dts/

For design philosophy, visualization examples, and model structure,
please refer to the above page.

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📝 Summary

• Inkjet DTS is an abstract design model for inkjet systems
• It structures the D–T–S trade-off explicitly
• It elevates empirical knowledge into a design language
• It is applicable across technologies and generations

For those who want to treat inkjet technology
not merely as a phenomenon, but as a design problem,
this model is intended to serve as a stable thinking framework.

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