Inkjet Image Formation With Stepwise Pretreatment Patterns

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Solution Overview

Problem

Existing inkjet image forming apparatuses face issues with ink permeability variations across different recording media, leading to image defects like bleeding or voids, despite using pretreatment agents to adjust permeability, as they do not account for all contributing factors.

Innovation Solution

The apparatus includes two inkjet heads for pretreatment agent and ink, with a controller forming adjustment images of varying pretreatment agent amounts to determine optimal amounts based on density measurements, optimizing image density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a pretreatment agent is applied to adjust ink permeability, then image defects such as bleeding or voids are suppressed, but ink density changes and desired image quality cannot be obtained

Engineering Contradiction:
Improveimage qualityVSAvoidink density
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent changes the concentration parameter of the pretreatment agent by creating multiple patterns with different concentrations (first concentration and second concentration different from the first). This allows the system to find the optimal concentration that balances permeability adjustment with maintaining desired ink density, thereby resolving the contradiction between suppressing image defects and preserving image quality.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the amount of pretreatment agent is increased to suppress image defects, then permeability is adjusted, but ink density changes and desired image quality cannot be obtained

Engineering Contradiction:
Improveimage qualityVSAvoidamount of pretreatment agent
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies different amounts of pretreatment agent to different regions by creating multiple patterns with different concentrations on the recording medium. Instead of uniformly increasing the pretreatment agent amount across the entire medium, the system locally varies the concentration to find the optimal amount needed for each specific region, thus suppressing image defects while minimizing the overall quantity of pretreatment agent used.

Inventive Principle:
Principle #3Local quality

3Productivity

If information on recording medium is used to determine pretreatment agent amount, then pretreatment is optimized, but image defects may still occur due to other permeability factors not included in the information

Engineering Contradiction:
Improvepretreatment efficiencyVSAvoidimage quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism by forming multiple test patterns with different pretreatment agent concentrations on the actual recording medium, measuring the results, and determining the optimal amount based on actual performance. This closed-loop approach allows the system to account for various permeability factors beyond basic medium information, ensuring reliable image quality while maintaining productivity through systematic optimization.

Inventive Principle:
Principle #23Feedback

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 method allows for precise adjustment of image density, ensuring high-quality images by accounting for all permeability factors, even with unknown media types, enhancing productivity and accuracy.

Implementation Method 1

a first inkjet head that ejects a pretreatment agent; a second inkjet head that ejects an ink

Methodology Applied
Scientific EffectInkjet ejection:

Data Source

PatentEP4613491A1Image forming apparatus, density adjustment method, and recording medium
Publication Date: 2025.09.10 KONICA MINOLTA INC
  • EP4613491A1 patent drawingFigure 1
  • EP4613491A1 patent drawingFigure 2
  • EP4613491A1 patent drawingFigure 3

AI summary

Provided are an image forming apparatus, a density adjustment method, and a program each capable of determining the amount of a pretreatment agent appropriately and adjusting the density of a formed image. The image forming apparatus (1) includes: a first inkjet head (262) that ejects a pretreatment agent; a second inkjet head (242) that ejects an ink; and a controller (40) that controls ejection by the first inkjet head and the second inkjet head. The controller causes an adjustment image to be formed on a recording medium (P), where the adjustment image includes the pretreatment agent and the ink and has a plurality of patterns in which an amount of the pretreatment agent is changed stepwise, and determines the amount of the pretreatment agent based on respective densities of the plurality of patterns in the adjustment image.