Printhead Cover Plate With Ferrite Layer Attenuating Electrostatic Discharge

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Solution Overview

Problem

High-speed production printers face issues with electrostatic discharges from print media to printheads, which can damage electronic systems and cause electrical noise, leading to undesirable nozzle behaviors.

Innovation Solution

The implementation of cover plates with multiple conductive layers sandwiching a nonconductive ferrite layer, equipped with connectors to direct current flow and openings aligned with printhead nozzles, attenuates electrostatic discharges by redirecting electrical energy through the ferrite layer, thereby reducing amperage and shielding electrical components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the web moves underneath the nozzles of the printheads during printing, then printing operation continues, but electrostatic discharges occur between the web and nozzles causing damage to electronic systems and electrical noise

Engineering Contradiction:

Improveprinting operation continuityVSAvoidelectrostatic discharge damage and electrical noise

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

A cover plate is introduced as an intermediary component between the printhead nozzles and the print web. The cover plate includes a ferrite layer that attenuates electrostatic discharges and conductive layers that provide a safe current pathway, thereby mediating the harmful interaction between the web and printhead while allowing printing to continue

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The conductive layers in the cover plate capture the harmful electrostatic discharge current and redirect it through a controlled pathway to ground. By converting the harmful electrostatic discharge into a controlled current flow through the ferrite layer, the system protects the printhead electronics while maintaining printing operation

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If conductive layers are added to the cover plate to redirect current flow, then electrostatic discharge is attenuated, but the structure becomes more complex

Engineering Contradiction:

Improveprotection from electrostatic dischargeVSAvoidcover plate structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The cover plate is constructed as a composite structure with multiple functional layers: a ferrite layer for attenuating electrostatic discharges and conductive layers for redirecting current flow. This composite material approach integrates multiple protection functions into a single component, achieving reliable ESD protection while maintaining reasonable structural complexity

Inventive Principle:

Principle #40Composite materials

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 solution effectively mitigates electrostatic discharges, protecting printhead circuitry from damage and noise, ensuring stable printing operations by attenuating electrical and magnetic fields generated by electrostatic discharges.

Implementation Method 1

a layer of nonconductive ferrite that is sandwiched between the multiple layers... which attenuates the amperage of incoming discharges

Methodology Applied

Scientific EffectElectrostatic discharge attenuation: Electrical Resistance

Implementation Method 2

multiple layers of electrically conductive material... at least one connector that penetrates through the multiple layers and the layer of nonconductive ferrite to form a conductive pathway for electric current

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 3

attenuating electrical and magnetic fields generated by electrostatic discharges... shielding electrical components

Methodology Applied

Scientific EffectElectromagnetic shielding: Magnetic Field

Data Source

PatentUS11490508B2Cover plates that attenuate electrostatic discharge at printheads

Publication Date: 2022.11.01 RICOH CO LTD

AI summary

Systems and methods are provided for cover plates for printheads. One embodiment is an apparatus that includes a cover plate for a printhead. The cover plate includes multiple layers of electrically conductive material, a layer of nonconductive ferrite that is sandwiched between the multiple layers, and at least one connector that penetrates through the multiple layers and the layer of nonconductive ferrite to form a conductive pathway for electric current between the multiple layers through the layer of nonconductive ferrite. The cover plate also includes at least one opening that penetrates through the multiple layers and the layer of nonconductive ferrite, and that is configured to align with nozzles of the printhead.