Duplex Printing Apparatus Heated Air Drying Unit

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Solution Overview

Problem

Existing duplex printing technologies face challenges in increasing print throughput due to the long ink drying time required for natural drying, which delays the printing process and causes ink transfer issues when sheets are not fully dried before being handled.

Innovation Solution

A duplex printing apparatus with a rational arrangement of units, including a drying unit that employs heated air or electromagnetic waves to rapidly dry ink, allowing for high-speed duplex printing by reducing ink drying time and optimizing sheet processing paths to prevent ink transfer and warping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If natural drying is used for ink drying, then the apparatus structure is simple, but the ink drying time is long which reduces print throughput

Engineering Contradiction:
Improveapparatus structureVSAvoidprint throughput
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent replaces natural drying (passive process) with a heating unit that actively heats the sheet to accelerate ink drying. This substitution of the drying mechanism resolves the contradiction by providing controlled, rapid drying without requiring excessively long residence times, thereby maintaining simpler apparatus structure while significantly improving print throughput.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the temperature parameter by introducing a heating unit that raises the sheet temperature to accelerate ink evaporation. By controlling the heating temperature and duration, the system achieves rapid ink drying in a controlled manner, resolving the contradiction between simple apparatus structure and high print throughput.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If sheets are processed quickly through the apparatus, then print throughput increases, but ink transfer occurs when sheets are not sufficiently dried

Engineering Contradiction:
Improveprint throughputVSAvoidink transfer prevention
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by heating and drying the ink before the sheet is stacked or handled further. The heating unit is positioned to dry the ink on the fly during the printing process, ensuring the ink is sufficiently dried before subsequent handling operations, thus preventing ink transfer while maintaining high throughput.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The heating unit acts as an intermediary between the printing process and sheet handling. It provides the necessary drying function in between ink application and sheet stacking, ensuring ink fixation without requiring extended natural drying time, thereby preventing ink transfer while maintaining rapid processing.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If duplex printing is performed with large amounts of ink on both surfaces, then printing quality improves, but natural drying time becomes excessively long

Engineering Contradiction:
Improveprinting qualityVSAvoiddrying time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent replaces passive natural drying with active thermal heating to accelerate ink drying. For duplex printing with heavy ink coverage on both surfaces, the heating unit provides controlled thermal energy to rapidly evaporate the ink, resolving the contradiction between high printing quality (requiring sufficient drying) and excessive drying time.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the temperature and energy parameters by introducing a heating unit that supplies thermal energy to accelerate ink evaporation. This parameter change enables rapid drying of heavily inked duplex sheets, resolving the contradiction between printing quality and drying time loss.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If sheets are cut and stacked immediately after printing, then processing speed increases, but ink transfer occurs to the next sheet

Engineering Contradiction:
Improveprocessing speedVSAvoidink transfer
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary action by drying the ink on the fly immediately after printing using the heating unit, before the sheet is cut and stacked. This preliminary drying prevents ink transfer to subsequent sheets while maintaining rapid processing speed, as the drying occurs during the normal sheet transport rather than requiring a separate drying stage.

Inventive Principle:
Principle #10Preliminary action

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 solution enables a significant increase in print throughput by ensuring rapid ink drying and efficient sheet handling, reducing the risk of ink transfer and allowing for continuous operation without delaying the printing process.

Implementation Method 1

a drying unit that employs heated air or electromagnetic waves to rapidly dry ink

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

a drying unit that employs heated air or electromagnetic waves to rapidly dry ink

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

a drying unit that employs heated air or electromagnetic waves to rapidly dry ink

Methodology Applied
Scientific EffectElectromagnetic radiation heating: Dielectric Heating

Data Source

PatentEP2363293B1Printing apparatus, printing method, and sheet processing method
Publication Date: 2015.12.23 CANON KK
  • EP2363293B1 patent drawingFigure 1
  • EP2363293B1 patent drawingFigure 2
  • EP2363293B1 patent drawingFigure 3

AI summary

An apparatus for performing duplex printing having a sheet feeding unit (1), a printing unit (4), a cutter unit (6), a drying unit (8), and a reverse unit (9). In duplex printing, the printing unit (4) prints images on a first surface of a continuous sheet fed from the sheet feeding unit (1). The sheet printed on the first surface passes through the drying unit (8) and is led to the reverse unit (9). The reverse unit (9) feeds the reversed sheet to the printing unit (4), which prints a plurality of images on a second surface that is a back of the first surface of the sheet fed from the reverse unit (9). The cutter unit (6) cuts the sheet printed on the second surface into a plurality of cut sheets each having the image printed thereon. The cut sheets pass through the drying unit (8) and are ejected.