Inkjet Sheet Drying With Radiant Front and Contact Back Heating

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Inkjet printing apparatuses face challenges in efficiently drying water-based inks on cut sheets without causing sheet deformation or conveyance issues, particularly when using hot air or single-sided heating methods.

Innovation Solution

The apparatus employs a combination of a first heat source that heats the ink ejection face with electromagnetic radiation and a second heat source that contacts the back surface of the sheet, ensuring uniform heating and preventing deformation by using radiant heat and heat conduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If hot air is blown to the front surface side of the sheet to dry ink, then the drying efficiency is improved, but the sheet is lifted from the heating-type conveyance belt causing conveyance failure and jams

Engineering Contradiction:

Improvedrying efficiencyVSAvoidsheet conveyance stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent replaces the mechanical hot air blowing system with a radiant heating system that uses electromagnetic waves (infrared radiation) to heat the sheet from above. This substitution eliminates the mechanical force that caused sheet lift-off while maintaining effective drying through direct radiant heat transfer to the ink and sheet surface.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a radiant heat source as an intermediary between the heating system and the sheet. Instead of using hot air as the heating medium, the radiant heater directly transfers thermal energy through electromagnetic radiation, allowing heating without the mechanical disturbance caused by air flow.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If hot air is blown to the front surface side of the sheet, then the drying speed is improved, but the back surface side of the sheet is not normally heated causing non-uniform heating and sheet deformation

Engineering Contradiction:

Improvedrying speedVSAvoidsheet flatness

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent divides the heating function into two independent segments: a radiant heater for heating the front surface (ink ejection side) and a heating-type conveyance belt for heating the back surface. This segmentation allows each heating element to independently heat its respective surface, ensuring uniform temperature distribution across the entire sheet and preventing deformation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs asymmetric heating arrangements where the radiant heater is positioned above the sheet to heat the front surface, while the heating-type conveyance belt is positioned below to heat the back surface. This asymmetric configuration optimizes heat transfer to each surface according to its specific drying requirements while maintaining sheet flatness.

Inventive Principle:

Principle #4Asymmetry

3Device complexity

If only the back surface of the sheet is heated, then the heating process is simplified, but both the front and back surfaces of the sheet are not uniformly heated causing sheet deformation

Engineering Contradiction:

Improveheating system complexityVSAvoidsheet flatness

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent segments the heating system into two independent heating zones: one for the front surface (radiant heater) and one for the back surface (heating-type conveyance belt). This segmentation, while slightly increasing device complexity, ensures uniform heating of both surfaces and prevents sheet deformation, thereby improving overall printing quality.

Inventive Principle:

Principle #1Segmentation

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 allows for efficient drying of both sides of the sheet without curling or jamming, enhancing conveyance speed and quality of printed matter.

Implementation Method 1

The first heat source emits an electromagnetic wave to heat the ink ejection face by radiant heat

Methodology Applied

Scientific EffectRadiant heat: Thermal Radiation

Implementation Method 2

a second heat source that is arranged to face the first heat source and comes into contact with a back surface of the sheet opposite to the ink ejection face to heat the sheet

Methodology Applied

Scientific EffectHeat conduction: Conduction (thermal)

Data Source

PatentUS12447757B2Inkjet printing apparatus, sheet drying apparatus, and sheet drying method

Publication Date: 2025.10.21 KONICA MINOLTA INC

AI summary

An inkjet printing apparatus comprises: a conveyance section that conveys a cut sheet; an ink ejection section that ejects an ink to form an image when the sheet passes a predetermined position; a first heat source that is provided on a downstream side of the ink ejection section and dries an ink ejection face of the sheet; and a second heat source that is arranged to face the first heat source and comes into contact with a back surface of the sheet opposite to the ink ejection face to heat the sheet. The first heat source emits an electromagnetic wave to heat the ink ejection face by radiant heat.