Inkjet Recording Device Fluorescent Test Chart Detection

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Solution Overview

Problem

Inkjet recording devices face challenges in detecting test charts recorded with white or transparent ink, which have poor visibility, making it difficult to identify nozzle ejection failures using inline sensors, especially when the recording medium does not contain phosphor.

Innovation Solution

Incorporating a phosphor into the white ink that emits light in the visible region when irradiated with ultraviolet rays, allowing for accurate detection of test charts by image readers, regardless of the recording medium's characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If white ink or transparent ink is used for recording, then the image quality (light fastness, water resistance, gloss) is improved, but the visibility of the test chart deteriorates making detection by inline sensor impossible

Engineering Contradiction:
Improveimage qualityVSAvoidtest chart visibility
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies fluorescence principle to change the optical properties of white and transparent inks. By incorporating fluorescent materials into these inks, they become visible under ultraviolet light while maintaining their original image quality properties. This allows the test chart to be detected by inline sensors using UV illumination without compromising the light fastness, water resistance, or gloss properties of the printed image.

Inventive Principle:
Principle #32Color changes

2Difficulty of detecting and measuring

If a special recording medium containing phosphor is used, then the test pattern detection is enabled, but the adaptability to different recording media deteriorates

Engineering Contradiction:
Improvetest pattern detectabilityVSAvoidrecording medium compatibility
Core Design Contradiction:
Difficulty of detecting and measuringVSAdaptability or versatility

Solution Approach 1:

The patent introduces fluorescent material as an intermediary component within the ink formulation itself, rather than requiring it to be present in the recording medium. This allows the test chart to be made detectable through the ink's fluorescent properties while maintaining compatibility with various recording media, eliminating the need for special phosphor-containing substrates.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If conventional inline sensor reading method is used, then the detection process is simple, but the detection precision of invisible ink deteriorates

Engineering Contradiction:
Improvedetection process simplicityVSAvoidtest chart reading accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent changes the illumination parameter from visible light to ultraviolet light in the inline sensor system. This parameter change enables the detection of fluorescent test charts printed with white or transparent inks while maintaining the simplicity of the inline detection process. The sensor system remains relatively simple but achieves high detection precision through UV illumination and fluorescence detection.

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

This approach enhances the detection accuracy of test charts formed with white or transparent ink, enabling effective identification of nozzle ejection failures even on non-phosphor containing recording media, improving the reliability of inkjet recording devices.

Implementation Method 1

Incorporating a phosphor into the white ink that emits light in the visible region when irradiated with ultraviolet rays

Methodology Applied
Scientific EffectPhosphorescence: Phosphorescence

Implementation Method 2

a test pattern of detecting a test pattern by recording the test pattern on a recording medium to be recorded having an ink receiving layer containing a phosphor, then irradiating the recording medium to be recorded on which the test pattern is recorded with ultraviolet rays, and detecting fluorescence emitted from the phosphor

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP3434486B1Inkjet recording device and test chart detection method
Publication Date: 2021.11.24 KONICA MINOLTA INC
  • EP3434486B1 patent drawingFigure 1
  • EP3434486B1 patent drawingFigure 2
  • EP3434486B1 patent drawingFigure 3

AI summary

There are provided an inkjet recording device (1) and a test chart detection method capable of improving detection accuracy of a test chart recorded on a recording medium (P) by ink having poor visibility irrespective of characteristics of the recording medium (P). An inkjet recording device (1) includes: a fluorescent inkjet head (8) that forms a fluorescent image on a recording medium (P) by ejecting ink containing a phosphor onto the recording medium (P); an ultraviolet light source (55) that irradiates the fluorescent image formed on the recording medium (P) with ultraviolet rays; and an imager (52) that detects fluorescence emitted by the fluorescent image by the irradiation of the ultraviolet rays.