Adaptive Air Knife for Electro-Photographic Fusing

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Solution Overview

Problem

Existing printing machines face challenges in optimizing the air knife parameters for efficient stripping of coated and uncoated papers, particularly in achieving optimal conditions for lead edge and body stripping, due to differences in media characteristics such as thickness and weight, which can result in paper jams or incomplete separation.

Innovation Solution

A method and apparatus that determine and adjust the air knife's angles (phi and theta) and distance (d) based on acquired electro-photographic machine objectives and media characteristics, allowing for controlled rotation and positioning of the air knife to optimize air pressure and stream direction for effective stripping, utilizing a processor and controller to regulate the air knife's operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If fixed air knife parameters are used, then the device complexity is reduced, but the stripping effectiveness for different media types deteriorates

Engineering Contradiction:
Improveair knife parameter control systemVSAvoidstripping effectiveness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements dynamic adjustment of air knife parameters including angle (phi and theta), distance (d), and air pressure based on detected media type. The system transitions from static fixed parameters to dynamic adaptive parameters that change according to the specific media being processed, resolving the contradiction between device simplicity and stripping effectiveness.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes physical parameters of the air knife (angular position, distance from impingement point, air pressure) according to media characteristics. Different parameter sets are applied for different media types to optimize stripping performance, directly addressing the contradiction by making parameters adaptive rather than fixed.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If optimized air knife parameters are implemented for different media, then the stripping effectiveness is improved, but the device complexity increases

Engineering Contradiction:
Improvestripping effectivenessVSAvoidair knife parameter control system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system incorporates media detection feedback that identifies the type of media being processed and automatically adjusts air knife parameters accordingly. This feedback mechanism enables the system to maintain optimal stripping effectiveness without requiring manual intervention or complex mechanical adjustments, resolving the contradiction through intelligent control.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The air knife system is designed to handle multiple media types (coated and uncoated paper) with a single unified device that can adapt its parameters. Rather than requiring separate air knives for different media, one multi-functional air knife with adjustable parameters performs all stripping tasks, reducing overall system complexity while maintaining effectiveness.

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

3Device complexity

If air pressure and stream direction are not optimized, then the device complexity is reduced, but paper jams and incomplete separation increase

Engineering Contradiction:
Improveair knife control systemVSAvoidpaper jams
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The system optimizes air pressure and stream direction parameters based on media type detection. By adjusting these parameters dynamically, the system prevents paper jams and incomplete separation that would occur with suboptimal fixed parameters, resolving the contradiction between system simplicity and operational reliability.

Inventive Principle:
Principle #35Parameter 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

This approach enhances the efficiency and reliability of paper stripping by optimizing air knife parameters, reducing paper jams and maintaining the integrity of the paper path, thereby improving the overall performance of the printing machine.

Implementation Method 1

an air knife having an orifice directing a stream of pressurized air at an impingement point on the fuse roll

Methodology Applied
Scientific EffectPressurized air stream: Jet

Implementation Method 2

Pressure fixing involves applying pressure and heat for sufficient time to melt and flow the toner into the substrate

Methodology Applied
Scientific EffectPressure fixing:

Implementation Method 3

Once the paper has the material effectively fused, the paper must be removed from the fuse member

Methodology Applied
Scientific EffectThermal expansion and contraction: Thermal Expansion

Data Source

PatentEP2146254B1Printing machine and method of operating printing machine
Publication Date: 2019.09.11 XEROX CORP
  • EP2146254B1 patent drawingFigure 1
  • EP2146254B1 patent drawingFigure 2
  • EP2146254B1 patent drawingFigure 3

AI summary

There is provided a machine and method of optimizing such an electro-photographic reproduction machine having a fusing subsystem and an air knife. The methods acquire (610,620) at least one electro-photographic reproduction machine objective and media characteristic; and the acquired objective and characteristic data are used to determine (630) values for the pressurized air emitted from the air knife, the position of the air knife, and the rotation of the air knife relative to a fuse roll in the fusing subsystem. The methods further disclose acquiring the leading edge of the media being stripped and then using the beam strength of the media to assist in stripping the body of the sheet. The air knife is controlled (640) by a controller or a processor based on determined optimization parameter values that relate to the objectives and media characteristics.