Inkjet Head Nozzle Diameter and Repellent Layer Design

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Solution Overview

Problem

Current inkjet recording devices require multiple inks with different dye concentrations for high-resolution images without granularity, which complicates the process and increases costs.

Innovation Solution

An inkjet recording device with an inkjet head having a nozzle diameter of 17 µm to 19 µm and an ink repellent layer, using an aqueous dye ink with a viscosity of 5 mPa·s to 12 mPa·s, capable of discharging small droplets for high-resolution imaging without the need for dark and light inks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If multiple inks with different dye concentrations are used to achieve high-resolution images without granularity, then image quality is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improveimage qualityVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent changes the physical parameter of nozzle diameter to a specific range (17-19 µm) to achieve high-resolution imaging without granularity using a single ink type, eliminating the need for multiple inks with different dye concentrations. This parameter optimization resolves the contradiction by maintaining image quality while simplifying the printing process.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Instead of using multiple inks (dark and light) to achieve high resolution without granularity, the patent inverts the approach by using a single ink type with optimized nozzle dimensions. This reversal of the conventional approach eliminates process complexity while maintaining image quality.

Inventive Principle:
Principle #13The other way round (Inversion)

2Manufacturing precision

If multiple inks with different dye concentrations are used to achieve high-resolution images without granularity, then image quality is improved, but manufacturing cost increases

Engineering Contradiction:
Improveimage qualityVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent optimizes the nozzle diameter parameter to 17-19 µm, enabling high-resolution imaging without granularity using a single ink formulation. This eliminates the need to manufacture and manage multiple ink types with different dye concentrations, thereby reducing manufacturing costs while maintaining image quality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent merges the functions of multiple inks (dark and light inks with different concentrations) into a single ink system by optimizing the nozzle diameter. This consolidation eliminates the need for separate ink formulations, reducing manufacturing complexity and cost while achieving the desired image quality.

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If smaller nozzle diameters are used to discharge smaller droplets for high-resolution imaging, then image resolution is improved, but discharge stability deteriorates

Engineering Contradiction:
Improveimage resolutionVSAvoiddischarge stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent identifies and optimizes the nozzle diameter parameter to a specific range (17-19 µm) that balances two competing requirements: small enough to discharge fine droplets for high-resolution imaging, but large enough to maintain stable discharge performance. This precise parameter optimization resolves the contradiction between resolution and stability.

Inventive Principle:
Principle #35Parameter changes

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

Stable discharge of small droplets enables high-resolution imaging with no granularity, simplifying the process and reducing costs by eliminating the need for multiple inks.

Implementation Method 1

an inkjet head including a nozzle plate and an ink repellent layer disposed on a surface of the nozzle plate

Methodology Applied
Scientific EffectInk repellency: Hydrophobe

Data Source

PatentEP3406449B1Inkjet recording device and inkjet recording method
Publication Date: 2020.11.25 RICOH CO LTD
  • EP3406449B1 patent drawingFigure 1
  • EP3406449B1 patent drawingFigure 2
  • EP3406449B1 patent drawingFigure 3

AI summary

Provided is an inkjet recording device, satisfying elements (1) through (4) below, (1) the inkjet recording device including an ink discharging unit configured to discharge an ink, (2) the ink discharging unit including an inkjet head having a nozzle diameter of 17 µm or greater but 19 µm or less, (3) the inkjet head including a nozzle plate and an ink repellent layer disposed on a surface of the nozzle plate, and (4) the inkjet recording device using, as the ink, an aqueous dye ink including a water-soluble dye and having a viscosity of 5 mPa·s or greater but 12 mPa·s or less at 25°C.