Valve System Air Purging Fluid Ejection Cartridge

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Solution Overview

Problem

Fluid ejection systems with replaceable ink supplies are susceptible to excessive air or gas accumulation, which affects printing quality and shortens the operational life of print nozzles, and existing air management systems are either inaccurately sized, require frequent priming, or increase system costs with additional components.

Innovation Solution

An air management system that employs a valve system with a check valve and a one-way, normally closed valve to purge air from a filter-side chamber into an inlet chamber without using the print head nozzles, activated only after a fluid supply change, reducing the need for frequent purging and minimizing fluid waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a replaceable ink supply is used to reduce operating costs, then the print head can be reused, but excessive air or gas accumulation occurs within the fluid ejection system

Engineering Contradiction:
Improveprint head operational lifeVSAvoidair or gas accumulation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts the harmful air and gas accumulation from the fluid ejection system by providing a dedicated purging pathway that removes these gases from the chamber adjacent to the print nozzles, preventing them from interfering with printing operations while maintaining the replaceable ink supply configuration

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a purging mechanism as an intermediary component that mediates between the replaceable ink supply and the print head, allowing air and gas to be removed from the system without requiring disposal of the print head or interrupting normal printing operations

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If traditional air purging methods are used, then air can be removed from the system, but printing operations are disrupted and frequent priming is required

Engineering Contradiction:
Improveair removalVSAvoidprinting operation continuity
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The patent implements preliminary action by providing a purging pathway that can be activated before air accumulation becomes problematic, allowing air to be removed proactively rather than reactively after it has disrupted printing operations, thereby maintaining continuous productivity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent ensures continuity of useful action by designing a purging mechanism that operates independently of the printing process, allowing air removal to occur without interrupting or disrupting active printing operations, thus maintaining continuous productivity

Inventive Principle:
Principle #20Continuity of useful action

3Object-generated harmful factors

If an air management system is added to purge air, then air accumulation is reduced, but system costs increase with additional components

Engineering Contradiction:
Improveair accumulation controlVSAvoidsystem component count
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies universality by designing a purging mechanism that serves multiple functions: it removes air and gas accumulation, maintains fluid flow, and prevents print head damage, all within a single integrated system that leverages existing components rather than adding numerous separate parts

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

Solution Approach 2:

The patent implements self-service by configuring the purging pathway to utilize the existing pump and fluid circulation system to automatically remove air and gas accumulation without requiring additional active components or external intervention, thereby controlling air accumulation with minimal added complexity

Inventive Principle:
Principle #25Self-service

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 system effectively purges air from the print cartridge without disrupting printing operations and reduces ink waste, maintaining print head health and extending its operational life, while being cost-effective by minimizing additional components.

Implementation Method 1

a first valve (e.g., a check valve) to control fluid flow between a filter-side chamber (e.g., a manifold of a print head mechanism) and a return or valve chamber

Methodology Applied
Scientific EffectCheck valve one-way flow: Valve

Implementation Method 2

To activate the valve system, the fluid ejection system employs a pressure source (e.g., a pump) to provide a series of pressure pulses during an air purge operation

Methodology Applied
Scientific EffectPressure pulsing: Pump

Implementation Method 3

the first and second valves cooperate to purge air from the filter-side chamber to the inlet chamber via the return chamber

Methodology Applied
Scientific EffectPressure differential flow: Pressure Gradient

Data Source

PatentEP2681049B8Valve systems for managing air in a fluid ejection system
Publication Date: 2019.06.19 HEWLETT PACKARD DEVELOPMENT COMPANY LP

AI summary

Valve systems for managing air in a fluid ejection system are described herein. One example valve system includes an inlet chamber (206), a return chamber (208) in communication with the inlet chamber (206), and a filter-side chamber (236) in communication with the inlet chamber (206) and the return chamber (208). A first valve (242) controls fluid flow between the filter-side chamber (236) and the return chamber (208), and a second valve (244) controls fluid flow between the return chamber (208) and the inlet chamber (206).