Binary Ink Developer Ghosting Correction via Roller Voltage Adjustment

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Solution Overview

Problem

Liquid electro-photographic (LEP) printing systems using silver-colored toner with metal particles face image ghosting issues due to electroconductivity, leading to print defects and increased costs from rejected print jobs and complex correction processes.

Innovation Solution

A binary ink developer (BID) system with a controller that adjusts the voltage of the cleaner roller based on current measurements at the electrode, developer roller, and squeegee roller to correct image ghosting by determining the ghost percentage and applying an adjusted voltage to the cleaner roller in a closed-loop control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If silver-colored toner with metal particles is used, then print appearance quality is improved, but image ghosting occurs due to electroconductivity

Engineering Contradiction:
Improveprint appearance qualityVSAvoidimage ghosting
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The system measures current at the developer roller and cleaner roller to detect ghosting conditions, then adjusts the cleaner roller voltage in real-time to correct the ghosting effect. This closed-loop feedback control enables the system to maintain print quality while eliminating the reliability issue caused by electroconductivity

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes the voltage parameter applied to the cleaner roller based on measured current values. By adjusting this electrical parameter in response to detected ghosting conditions, the system resolves the contradiction between using conductive silver toner and preventing image ghosting

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If conventional cleaning voltage is applied to cleaner roller, then toner removal is achieved, but image ghosting is not corrected

Engineering Contradiction:
Improvetoner removalVSAvoidimage ghosting
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The cleaner roller voltage transitions from a static conventional value to a dynamic adjusted value based on real-time current measurements. This dynamic adjustment enables the system to maintain effective toner removal while simultaneously correcting image ghosting that static voltage cannot address

Inventive Principle:
Principle #15Dynamics

3Reliability

If voltage adjustment based on current measurement is implemented, then image ghosting is corrected, but device complexity increases

Engineering Contradiction:
Improveimage ghosting correctionVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system implements feedback control by measuring current at existing rollers and adjusting the cleaner roller voltage accordingly. This approach corrects image ghosting using measurements from already-present components, minimizing the need for additional hardware while achieving reliability improvement

Inventive Principle:
Principle #23Feedback

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 BID system effectively reduces or eliminates image ghosting by stabilizing the electrical charge and toner transfer, improving print quality and reducing waste and operational complexity.

Implementation Method 1

A binary ink developer (BID) system with a controller that adjusts the voltage of the cleaner roller based on current measurements at the electrode, developer roller, and squeegee roller to correct image ghosting

Methodology Applied
Scientific EffectElectrostatic attraction: Electrostatics

Implementation Method 2

A current is generated in response to a voltage between a measurement electrode and a developer roller. The current flows through the conductive LEP ink layer.

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3853710B1Binary ink developers
Publication Date: 2024.06.05 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3853710B1 patent drawingFigure 1
  • EP3853710B1 patent drawingFigure 2
  • EP3853710B1 patent drawingFigure 3

AI summary

A binary ink developer (BID) may include a power supply electrically coupled to an electrode, a developer roller, and a cleaner roller. The BID may also include a controller to determine a level of image ghosting based on a sum of currents at the electrode, the developer roller and the cleaner roller, and instruct the power supply to provide an adjusted voltage to the cleaner roller in response to a determination of the level of image ghosting.