Inkjet Registration Using UV-Detected Precoating Marks

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Solution Overview

Problem

Inkjet image forming apparatuses face issues with image position shifting and color mixing due to stretchability in printing materials like a plastic film, which affects the image forming position and registration during color printing.

Innovation Solution

An inkjet image forming apparatus with a precoating unit, UV lighting device, and camera system forms a position adjustment mark using a UV-absorbing precoating liquid, which is irradiated with a camera, allowing precise image registration by capturing the mark under UV light.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a position adjustment mark is printed on the printing base material in advance, then the image forming position can be adjusted, but the position of the position adjustment mark shifts when the printing base material is stretched during conveying

Engineering Contradiction:
Improveposition adjustment accuracyVSAvoidimage forming position accuracy
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The position adjustment mark is formed on the printing base material by the precoating unit before the image forming unit processes it. This preliminary action ensures that the mark is created under the same material conditions (including any stretching) that will be present during actual image formation, eliminating position shifts between mark detection and image formation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system changes the state of the position adjustment mark by using UV-reactive precoating liquid that becomes visible or detectable only after UV irradiation. This parameter change (from invisible to visible/detectable) allows the mark to be formed in advance without premature detection, maintaining accuracy throughout the conveying process

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If the position adjustment mark is formed in advance, then registration can be performed, but color mixing occurs at the time of color printing due to position shifts

Engineering Contradiction:
Improveregistration processVSAvoidcolor printing registration accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The position adjustment mark is created in advance by the precoating unit before the image forming unit performs color printing. This preliminary action establishes the registration reference under identical material conditions, preventing position shifts that would cause color mixing during subsequent color printing operations

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system creates a reference copy (position adjustment mark) of the printing base material state before image formation. By detecting this copied reference mark under the same stretched conditions, the system can accurately register color printing without the position shifts that would otherwise cause color mixing

Inventive Principle:
Principle #26Copying

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

Enhances image position accuracy and prevents color mixing by forming the position adjustment mark immediately before printing, ensuring alignment under consistent material conditions.

Implementation Method 1

a precoating unit, which ejects a precoating liquid having a property of absorbing UV light

Methodology Applied
Scientific EffectUV light absorption: Absorption (EM radiation)

Implementation Method 2

a UV lighting device which irradiates the printing base material conveyed on the fluorescent coating surface with UV light

Methodology Applied
Scientific EffectUV light emission: Light

Implementation Method 3

a camera which photographs the printing bae material irradiated with the UV light

Methodology Applied
Scientific EffectOptical detection: Photography

Data Source

PatentEP4574437B1Inkjet image forming apparatus
Publication Date: 2025.12.10 KYOCERA DOCUMENT SOLUTIONS INC
  • EP4574437B1 patent drawingFigure 1
  • EP4574437B1 patent drawingFigure 2
  • EP4574437B1 patent drawingFigure 3

AI summary

An inkjet image forming apparatus (1) includes an image forming part (9), a precoating unit (5), a fluorescent coating surface (15a), a UV lighting device (33), and a camera (35). The image forming part (9) forms an image on the printing base material. The precoating unit (5) ejects a precoating liquid having a property of absorbing UV light. On the fluorescent coating surface (15a), the printing base material is conveyed. The UV lighting device (33) irradiates the printing base material conveyed on the fluorescent coating surface (15a) with UV light. The camera (35) photographs the printing base material irradiated with the UV light. A position adjustment mark is formed on the printing base material by using the precoating liquid, the formed position adjustment mark is irradiated with the UV light by the UV lighting device (33), the irradiated position adjustment mark is photographed by the camera (35), and the image forming part (9) forms an image based on the photographed position adjustment mark.