Inkjet Penetration Liquid Control for Two-Sided Density Uniformity

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Solution Overview

Problem

Existing ink jet recording apparatuses face challenges in achieving equal density on both sides of a print paper sheet, especially when the type of paper changes, leading to insufficient ink penetration and uneven glossiness.

Innovation Solution

A printing apparatus with a transport unit and reciprocating movement unit that adjusts the discharge amount of penetration liquid based on transport speed and calibration curves to ensure equal density on both sides, using a diaphragm with varying oscillation frequency and amplitude to control liquid droplet size and volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If ink to which penetrant has been added is used to promote penetration, then ink penetration into recording medium is improved, but density uniformity between both sides of recording medium deteriorates when paper type changes

Engineering Contradiction:
Improveink penetrationVSAvoiddensity uniformity across different paper types
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The penetrant is separated from the ink into a distinct process liquid that is applied separately. This segmentation allows independent control of ink formulation and penetrant application, enabling adaptation to different recording medium types without changing the ink itself.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The process liquid (penetrant) is applied to the recording medium before ink application. This preliminary action prepares the recording medium surface to enhance subsequent ink penetration, ensuring consistent results across different paper types by pre-conditioning the substrate.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If process liquid is applied separately from ink at different timings, then glossiness uniformity is improved, but density equality between both sides of recording medium deteriorates

Engineering Contradiction:
Improveglossiness uniformityVSAvoiddensity equality
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The timing and amount of process liquid application are made dynamic rather than fixed. The system adjusts the application timing and quantity based on the specific recording medium type and desired penetration depth, allowing optimization of both glossiness uniformity and density equality for each medium.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The application parameters (timing, amount, concentration) of the process liquid are varied based on the recording medium type. This parameter adjustment enables the system to achieve optimal density equality while maintaining glossiness uniformity across different paper varieties.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If fixed amount of penetration liquid is discharged, then device complexity is reduced, but printing quality adapts poorly to different transport speeds

Engineering Contradiction:
Improvepenetration liquid discharge controlVSAvoidprinting quality across different speeds
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The system incorporates feedback control where the discharge amount of penetration liquid is adjusted based on detected transport speed. This feedback mechanism maintains optimal penetration quality across varying speeds without requiring complex manual intervention or pre-programming for each speed setting.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The penetration liquid discharge system transitions from a fixed static configuration to a dynamic adjustable system. The discharge amount varies automatically with transport speed, enabling the system to adapt to different operating conditions while maintaining relatively simple overall device architecture.

Inventive Principle:
Principle #15Dynamics

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 solution enables stable and rapid printing with minimal density difference between sides, making the printed product suitable for reversible use, such as scarves, by accurately adjusting the penetration liquid discharge.

Implementation Method 1

a cavity which is filled with the penetration liquid and in which pressure is increased and reduced by vibration of the diaphragm

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

a cavity which is filled with the penetration liquid and in which pressure is increased and reduced by vibration of the diaphragm

Methodology Applied
Scientific EffectPressure change: Pressure Increase

Data Source

PatentEP3318406B1Printing apparatus and printing method
Publication Date: 2021.06.16 SEIKO EPSON CORP
  • EP3318406B1 patent drawingFigure 1
  • EP3318406B1 patent drawingFigure 2
  • EP3318406B1 patent drawingFigure 3

AI summary

A printing apparatus configured to perform printing on a sheet-like recording medium into which liquid can penetrate includes: a discharge unit configured to discharge, onto one side of the recording medium, ink and penetration liquid which promotes penetration of the ink into the other side of the recording medium; a movement unit configured to move the discharge unit and the recording medium relative to each other when the printing is performed; and an adjustment unit configured to adjust a discharge amount of the penetration liquid discharged from the discharge unit onto the recording medium on the basis of at least a relative movement speed of the discharge unit to the recording medium.