Segmented Electrode Control for Liquid Toner Distribution

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Solution Overview

Problem

Current liquid electro-photographic printing systems face challenges in efficiently controlling the electrostatic charging and discharging processes for precise image development, leading to suboptimal particle distribution and density on the photoconductor surface, which affects print quality and efficiency.

Innovation Solution

The system employs a segmented electrode arrangement and developer roller with individually controllable segments, along with a squeegee roller, to generate a radial electric field that selectively attracts and repels charged particles, allowing for precise control of particle density and distribution across the surface, enabling improved image development and transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional liquid electro-photographic printing system is used, then the printing process can be performed, but the particle distribution and density on the photoconductor surface are suboptimal, affecting print quality

Engineering Contradiction:
Improveparticle distribution controlVSAvoidelectrode arrangement complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The electrode arrangement is divided into multiple independently controllable segments along the circumferential direction. Each segment can be selectively charged or discharged to precisely control particle distribution in different radial zones, enabling superior particle density control while maintaining manageable system complexity through modular architecture

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the charging state of individual electrode segments in real-time based on the required particle distribution pattern. This dynamic control allows the electrode arrangement to adapt to different printing requirements, optimizing particle distribution control without requiring a permanently complex fixed structure

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If the electrode arrangement is segmented for precise control, then particle distribution is improved, but the device complexity increases

Engineering Contradiction:
Improveparticle density controlVSAvoidsegmented electrode structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The developer roller is divided into multiple independently controllable segments, each capable of selective charging. This segmentation enables precise control of particle density in different angular positions while maintaining a modular structure that simplifies control through independent segment management rather than a monolithic complex system

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different segments of the electrode arrangement can be charged to different voltage levels simultaneously, creating locally optimized electric fields tailored to specific printing requirements. This local quality control achieves superior particle density precision without requiring the entire system to be maximally complex

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If liquid toner is used, then image formation is enabled, but particle distribution uniformity is suboptimal

Engineering Contradiction:
Improveparticle distribution uniformityVSAvoidprinting efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The system employs periodic rotation of the developer roller in combination with selective charging of different segments during each rotation cycle. This periodic action with selective segment activation ensures uniform particle distribution across the entire photoconductor surface while maintaining continuous printing operation, thus preserving productivity

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The segmented electrode system maintains continuous particle deposition on the photoconductor through coordinated rotation and selective charging. The useful action of particle transfer continues uninterrupted while the segmented control ensures uniform distribution, avoiding idle time and maintaining high printing efficiency

Inventive Principle:
Principle #20Continuity of useful 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

This approach allows for precise control of charged particle layers on the developer roller, enhancing print quality by ensuring uniform density and reducing unwanted particle transfer, thereby improving the overall efficiency and accuracy of the printing process.

Implementation Method 1

The system employs a segmented electrode arrangement and developer roller with individually controllable segments, along with a squeegee roller, to generate a radial electric field that selectively attracts and repels charged particles

Methodology Applied
Scientific EffectElectric field: Electric Field

Implementation Method 2

LEP printing process may involve selectively charging/discharging a photoconductor, also referred to as photo imaging plate, PIP, to produce a latent electrostatic image

Methodology Applied
Scientific EffectElectrostatic charging: Electrostatics

Implementation Method 3

The charged particles may adhere to negatively charged or discharged areas on the photoconductor (discharged area development DAD) or to positively charged areas on the photoconductor (charged area development CAD)

Methodology Applied
Scientific EffectElectrostatic induction: Electrostatic Induction

Data Source

PatentEP3899668B1Liquid electro-photographic printing transfer
Publication Date: 2024.08.07 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3899668B1 patent drawingFigure 1
  • EP3899668B1 patent drawingFigure 2
  • EP3899668B1 patent drawingFigure 3~5

AI summary

A liquid electro-photographic printing system, comprising: a binary ink developer assembly, a power supply arrangement, a switching arrangement, and a controller. The binary ink developer assembly includes a plurality of members defining a flow path for a printing fluid containing charged particles, the plurality of members including a first member and a second member that are arranged to generate an electric field therebetween, the first member having a plurality of segments. The power supply arrangement continuously provides a supply of voltages during a print operation, the voltages including a first voltage and a second voltage having a different voltage level from that of the first voltage. The switching arrangement switches the supply of voltages to the segments of the first member on an individual segment basis, to cause charged particles to be attracted to the first member in the individual segment when the first voltage is supplied to the individual segment and to cause charged particles to be repelled from the first member in the individual segment when the second voltage is supplied to the individual segment. The controller to determine timing of when to switch the supply of voltages to the segments.