Fluid Ejection Die Dual-Recirculation System

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Solution Overview

Problem

Current fluid ejection devices in inkjet printing systems face issues with ink recirculation, leading to potential blockages, clogging, and inefficient waste heat management, which affect nozzle health and printing quality.

Innovation Solution

The implementation of a dual-recirculation system within the fluid ejection device, comprising a micro-recirculation system within the fluid ejection die and a macro-recirculation system within the supporting body, which recirculates fluid through the fluid ejection chamber and across the fluid feed slot, respectively, using a combination of thermal resistors or piezoelectric actuators to manage fluid flow and reduce ink wastage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If fluid is recirculated through the fluid ejection die, then waste heat management is improved, but blockages and clogging in the nozzles occur

Engineering Contradiction:
Improvewaste heat managementVSAvoidnozzle blockage
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The recirculation system is divided into two separate systems: a micro-recirculation system within the fluid ejection die and a macro-recirculation system within the body. This segmentation allows the micro-system to manage local heat at the nozzle level while the macro-system handles bulk fluid recirculation, preventing blockages by maintaining separate functional zones.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A fluid recirculating element is introduced as an intermediary component within the fluid ejection chamber to facilitate heat transfer and fluid movement. This intermediary element enables waste heat management without requiring direct recirculation through the nozzles, thus preventing blockages while achieving thermal management.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If fluid recirculation is implemented, then printing performance is improved, but ink wastage increases

Engineering Contradiction:
Improveprinting performanceVSAvoidink wastage
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The system recovers unused ink by recirculating it back into the fluid ejection chamber through the micro-recirculation system. Instead of discarding ink that hasn't been ejected, it is recovered and reused, reducing ink wastage while maintaining continuous supply for improved printing performance.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The dual-recirculation system ensures continuous useful action by constantly moving fluid through both micro and macro recirculation paths. This continuous circulation prevents ink from stagnating and wasting, while ensuring fresh ink is always available at the nozzles for optimal printing performance.

Inventive Principle:
Principle #20Continuity of useful action

3Ease of operation

If thermal resistors or piezoelectric actuators are used, then drop ejection is achieved, but fluid flow management becomes complex

Engineering Contradiction:
Improvedrop ejectionVSAvoidfluid flow management
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The micro-recirculation system merges the functions of thermal resistors or piezoelectric actuators with fluid recirculation by placing the fluid recirculating element within the same fluid ejection chamber. This combining allows a single integrated system to perform both drop ejection and fluid flow management, reducing overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The fluid recirculating element serves multiple functions: it manages fluid flow, assists in heat transfer, and works协同 with thermal resistors or piezoelectric actuators for drop ejection. This multi-functionality reduces the need for separate components, simplifying fluid flow management while maintaining effective drop ejection.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 enhances nozzle health by reducing blockages and clogging, improves pigment-ink separation, and effectively manages waste heat, resulting in improved printing performance and extended decap time.

Implementation Method 1

thermal resistors or piezoelectric material membranes as actuators within fluidic chambers to eject fluid drops

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

thermal resistors or piezoelectric material membranes as actuators within fluidic chambers to eject fluid drops

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 3

micro-recirculation system within the fluid ejection die and a macro-recirculation system within the supporting body, which recirculates fluid through the fluid ejection chamber

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3576953B1Fluid ejection die fluid recirculation
Publication Date: 2024.04.24 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3576953B1 patent drawingFigure 1
  • EP3576953B1 patent drawingFigure 2
  • EP3576953B1 patent drawingFigure 3

AI summary

A fluid ejection device includes a fluid ejection die to eject drops of fluid and a body to support the fluid ejection die, with the fluid ejection die including a fluid ejection chamber, a drop ejecting element within the fluid ejection chamber, and a fluid feed hole communicated with the fluid ejection chamber, and with the body including a fluid feed slot communicated with the fluid feed hole of the fluid ejection die. The fluid ejection device includes a micro-recirculation system to recirculate fluid within the fluid ejection die through the fluid ejection chamber, and a macro-recirculation system to recirculate fluid within the body through the fluid feed slot across the fluid feed hole of the fluid ejection die.