Inkjet Controller Prefire Pulses Nozzle Viscosity

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Solution Overview

Problem

Inkjet printing systems face print quality issues due to increased ink viscosity, leading to incorrect ink droplet positioning and nozzle failures, particularly after prolonged print pauses, which result in first line effects and reduced print quality.

Innovation Solution

A controller and method are introduced to analyze print data and determine the need for prefire pulses in inkjet printing systems, which delay print data by N lines to induce nozzle arrangements to generate prefire pulses, reducing ink viscosity and maintaining print quality by preventing nozzle clogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If prefire pulses are continuously applied to prevent ink viscosity increase, then nozzle reliability is improved, but print productivity deteriorates due to unnecessary pulses during active printing

Engineering Contradiction:

Improvenozzle reliabilityVSAvoidprint productivity

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The system applies prefire pulses in advance during periods of non-use to prevent ink viscosity increase before it affects printing quality. By proactively maintaining the ink in nozzles during idle periods, the system ensures reliable printing resumes after pauses without requiring continuous prefire pulses during active printing, thus resolving the contradiction between reliability and productivity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The controller selectively applies prefire pulses periodically during periods of non-use rather than continuously during all printing operations. This periodic application maintains nozzle reliability when needed while avoiding unnecessary pulses during active printing, thereby preserving print productivity. The system monitors printing activity and applies prefire pulses only during identified idle periods.

Inventive Principle:

Principle #19Periodic action

2Manufacturing precision

If prefire pulses are applied to maintain print quality during pauses, then print quality is improved, but energy consumption increases

Engineering Contradiction:

Improveprint qualityVSAvoidenergy consumption

Core Design Contradiction:

Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The system applies prefire pulses in advance during idle periods to maintain ink readiness before printing resumes. This preliminary action ensures high print quality when printing restarts after pauses without requiring continuous energy consumption during active printing, thus resolving the contradiction between manufacturing precision and energy consumption.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system extracts and removes unnecessary prefire pulses from active printing sequences, applying them only during periods of non-use. This selective removal eliminates wasted energy consumption while maintaining print quality during actual printing operations, resolving the contradiction between manufacturing precision and energy consumption.

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If print data are delayed by N lines to insert prefire pulses, then nozzle reliability is improved, but printing speed deteriorates

Engineering Contradiction:

Improvenozzle reliabilityVSAvoidprinting speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The system delays print data processing to identify periods of non-use in advance, then inserts prefire pulses during these identified idle periods. By performing the reliability-maintaining action preliminarily during non-use time rather than interrupting active printing, the system improves nozzle reliability without sacrificing printing speed during productive periods.

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 effectively reduces ink viscosity and prevents nozzle failures, thereby maintaining high print quality even during extended periods of non-use, avoiding first line effects and ensuring consistent printing performance.

Implementation Method 1

Prefire pulses produce a stirring of the ink in the nozzle channel of a nozzle arrangement immediately behind the nozzle opening

Methodology Applied

Scientific EffectStirring: Stirring

Implementation Method 2

a prefire pulse...for stirring ink in a nozzle channel...induce the nozzle arrangement to generate a prefire pulse

Methodology Applied

Scientific EffectPressure wave: Pressure Gradient

Data Source

PatentUS9796175B2Controller to insert print image-dependent prefire pulses in an inkjet printing system

Publication Date: 2017.10.24 OCE HLDG BV

AI summary

A controller adapted for an inkjet printing system is described. The controller can include an analyzer and a prefire inserter. The analyzer can be configured to determine whether a nozzle arrangement should generate a fire pulse in a current line, and whether the last preceding fire pulse was further in the past than an interval value threshold N. The prefire inserter can be configured to insert one or more prefire pulses into the N lines before the current line.