Fluorescent Ink Imaging for Defect Detection on Photosensitive Prints

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Solution Overview

Problem

Existing fluorescence imaging systems that use UV or visible light wavelengths less than 480 nm to detect defects in electrochemical devices degrade the performance of photosensitive materials, such as silver-silver chloride electrodes, due to photosensitivity.

Innovation Solution

A fluorescence imaging system using red or near-infrared wavelengths of excitation light with fluorescent markers that absorb at 595 nm or greater and emit at 650 nm or greater, combined with a photosensitive electrochemical ink containing metal/metal salts, to identify print defects without degrading the electrochemical performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If UV or visible light wavelengths less than 480 nm are used for fluorescence imaging, then defect detection capability is improved, but photosensitive materials are degraded

Engineering Contradiction:
Improvedefect detection capabilityVSAvoidphotosensitivity degradation
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent changes the wavelength parameter of excitation light from UV/visible range (less than 480 nm) to red/near-infrared range (595 nm or greater). This parameter change allows the fluorescence imaging system to detect defects while avoiding the harmful photosensitivity degradation that occurs with shorter wavelengths.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a specialized fluorescent marker as an intermediary substance that absorbs red/near-infrared light (595 nm or greater) and emits fluorescence. This intermediary enables defect detection using wavelengths that do not harm photosensitive materials, bridging the gap between detection capability and material safety.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If red or near-infrared wavelengths are used for excitation, then photosensitive materials are protected, but fluorescence emission intensity may be reduced

Engineering Contradiction:
Improvematerial degradationVSAvoidfluorescence emission intensity
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The fluorescent marker acts as an intermediary that efficiently converts absorbed red/near-infrared energy into visible fluorescence emission. This mediator enables effective energy transfer at longer wavelengths while maintaining sufficient emission intensity for defect detection.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The fluorescent marker exhibits color change properties by absorbing light at 595 nm or greater (red/near-infrared) and emitting at 650 nm or greater (red visible light). This color transformation enables detection using wavelengths that protect photosensitive materials while producing detectable fluorescence signals.

Inventive Principle:
Principle #32Color 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

The method effectively detects print defects on photosensitive electrochemical devices without altering their performance, using longer wavelengths that do not discolor or degrade the materials, and provides improved image contrast for defect identification.

Implementation Method 1

providing a photosensitive electrochemical ink that comprises at least one fluorophore as a fluorescent marker that absorbs light at wavelengths equal to or greater than 595 nm, and emits fluorescent light at wavelengths equal to or greater than 650 nm

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP4573360B1Fluorescent ink and imaging system for defect detection on printed photosensitive objects
Publication Date: 2026.01.14 SUN CHEMICAL CORP
  • EP4573360B1 patent drawingFigure 1~2
  • EP4573360B1 patent drawingFigure 3
  • EP4573360B1 patent drawingFigure 4

AI summary

The present application discloses a method for optical detection of defects (4,5,6,7) on a photosensitive object (1) by fluorescence imaging in the infrared and near-infrared wavelengths of light. The method of fluorescence imaging enables fast and efficient defect detection on the object for quality control. Furthermore, the imaging process does not alter, discolor, or degrade electrical performance of the photosensitive object.