Real-Time Defective Nozzle Compensation in Printing Systems

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Solution Overview

Problem

Current printers must be taken offline for uniformity compensation due to defective nozzles, leading to lost revenue and production downtime.

Innovation Solution

A real-time system for correcting jet-out conditions by using a method that involves generating inverse transfer functions for each nozzle, allowing for continuous printing without the need for offline compensation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If uniformity compensation is performed offline to correct defective nozzles, then printing quality is improved, but printer downtime increases and productivity decreases

Engineering Contradiction:
Improveprinting qualityVSAvoidprinter productivity
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The system dynamically adjusts compensation values for defective nozzles in real-time during printing operations. The print controller continuously monitors nozzle performance and updates compensation parameters without requiring printer shutdown, enabling adaptive correction while maintaining continuous production

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system pre-calculates and stores compensation values for potentially defective nozzles before they fully fail. By proactively identifying nozzles with degraded performance and applying compensation in advance, the system prevents quality issues before they manifest, eliminating the need for offline correction

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the printer operates continuously without offline compensation, then productivity is maintained, but printing quality deteriorates due to jet-out conditions

Engineering Contradiction:
Improveprinter productivityVSAvoidprinting quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The system implements real-time feedback monitoring of nozzle jetting performance during continuous operation. Sensors detect variations in ink droplet ejection and immediately feed this information back to the print controller, which automatically adjusts compensation parameters to maintain consistent print quality without interrupting production

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The print controller automatically performs quality correction by applying compensation values to defective nozzles without external intervention. The system self-diagnoses nozzle issues and self-corrects by adjusting ejection parameters, enabling continuous operation while maintaining quality standards

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4301603B1Defective nozzle compensation mechanism
Publication Date: 2025.05.07 RICOH CO LTD
  • EP4301603B1 patent drawingFigure 1
  • EP4301603B1 patent drawingFigure 2
  • EP4301603B1 patent drawingFigure 3

AI summary

A printing system is disclosed. The printing system includes at least one physical memory device to store calibration logic and one or more processors coupled with the at least one physical memory device to execute the calibration logic to generate a uniformity compensated halftone design for each of a plurality of pel forming elements, generate a missing neighbor corrected halftone design for each of the pel forming elements, generate a missing neighbor threshold lowering function for each of the pel forming elements based on the uniformity compensated halftone designs and the missing neighbor corrected halftone design and compute an average of the missing neighbor threshold lowering functions to generate an average missing neighbor threshold lowering function.