Printing Medium Inversion Conveyance for Stable Color-White Ink Separation

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Solution Overview

Problem

Existing printing apparatuses face challenges in stably conveying a printing medium while ensuring a sufficient time gap between the discharge of color inks and white ink to prevent mixing, often leading to issues like meandering and crease formation due to the use of air turn bars.

Innovation Solution

A printing apparatus and method that utilizes an elongated belt conveyor system with rotary bodies contacting the non-recording surface of the printing medium to invert the recording surface twice, securing the time gap between color and white ink discharge without air turn bars, ensuring stable conveyance and ink drying.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If air turn bars are used to fold the printing medium upward, then the printing medium can be conveyed vertically, but the printing medium becomes unstable due to meandering and crease formation

Engineering Contradiction:
Improveconveyance speedVSAvoidconveyance stability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The invention removes air turn bars from the system entirely. Instead of using air turn bars to fold and convey the printing medium upward, the system uses a different mechanism (rotating rollers or a belt system) that contacts only the non-recording surface, eliminating the source of meandering and crease formation while maintaining vertical conveyance capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces an intermediary mechanism (rotating rollers or belt system) that mediates between the color printing unit and white printing unit. This intermediary conveys the printing medium upward without direct contact with the recording surface, preventing disturbance to the printed image while ensuring stable transport

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of time

If a vertically folded path is used to secure time between color and white ink discharge, then ink mixing is prevented, but the device complexity increases

Engineering Contradiction:
Improvetime gap between ink dischargeVSAvoidconveyor configuration
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The conveying system is designed to perform multiple functions: it conveys the printing medium horizontally between printing units, provides vertical transport to create time delay, and simultaneously protects the recording surface from contact. This multi-functional design reduces the need for separate components and simplifies the overall system

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

Instead of folding the printing medium with the recording surface facing downward (which causes instability), the invention inverts the approach by using a mechanism that contacts only the non-recording surface to perform the folding and vertical conveyance, thereby simplifying the conveyor configuration while maintaining the time gap function

Inventive Principle:
Principle #13The other way round (Inversion)

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

Stable conveyance of the printing medium is achieved with the rotary body system, preventing ink mixing and crease formation, while allowing for efficient drying of both color and white inks.

Implementation Method 1

a plurality of rotary bodies configured to rotate while being in contact with only the non-recording surface of the printing medium

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3885150B1Printing apparatus, printing system and printing method
Publication Date: 2025.07.09 SCREEN HOLDINGS CO LTD
  • EP3885150B1 patent drawingFigure 1
  • EP3885150B1 patent drawingFigure 2
  • EP3885150B1 patent drawingFigure 3

AI summary

The printing medium M after color printing is performed on the front surface M1 (recording surface) by the color printing unit 32 can be conveyed while the front surface M1 and the back surface M2 of the printing medium M are inverted twice by the only rollers 471 to 478 (rotary bodies) in contact with the back surface M2 (non-recording surface) of the printing medium M (inverting conveying part 47). In this way, without providing air turn bars, a time to convey the printing medium M from the color printing unit 32 to the white printing unit 33 can be secured while the printing medium M is firmly supported by the rollers 471 to 478 in contact with the back surface M2 of the printing medium M.