Liquid Ejecting Device Removable Reservoir Back Pressure Control

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Solution Overview

Problem

Inkjet printers face challenges in maintaining a stable ink supply system, including reduced ink storage volume and air bubble entry into the head due to existing back pressure control mechanisms, which increase system size and complexity.

Innovation Solution

A liquid ejecting device with a removable liquid reservoir connected to a container via a liquid and gas flow path, eliminating the need for a back pressure control mechanism and allowing for efficient ink transfer and air bubble prevention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a foam body is provided to the cartridge as a back pressure control mechanism, then the ink supply stability is improved, but the volume ratio of ink storable in the cartridge decreases and the cartridge size increases

Engineering Contradiction:
Improveink supply stabilityVSAvoidink storage volume
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The back pressure control mechanism is extracted from the cartridge and relocated to the container. The container includes a communication section that communicates the internal space of the container with atmosphere, while the cartridge simply stores and supplies ink to the container, eliminating the need for foam bodies or differential pressure valves in the cartridge structure.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If a differential pressure valve is provided to the cartridge as a back pressure control mechanism, then the ink supply stability is improved, but the ink supply system size increases

Engineering Contradiction:
Improveink supply stabilityVSAvoidink supply system size
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The back pressure control function is extracted from the cartridge and implemented in the container through a communication section. This eliminates the need for differential pressure valves in the cartridge, thereby downsizing the overall ink supply system while maintaining stable ink supply to the head.

Inventive Principle:
Principle #2Taking out (Extraction)

3Device complexity

If ink is supplied from the cartridge to the head without storing it on the way, then the ink supply system size is reduced, but air bubbles enter the head after the ink stored in the cartridge runs out

Engineering Contradiction:
Improveink supply system sizeVSAvoidair bubble prevention
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The container serves as an intermediate storage that receives ink from the cartridge before supply to the head. The communication section of the container is configured to communicate with atmosphere when the cartridge is removed, allowing air to enter the container but not the head, thereby preventing air bubbles from entering the head even after the cartridge ink is depleted.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If a back pressure control mechanism is provided to the cartridge, then the meniscus maintenance is improved, but the cartridge structure becomes more complex and larger

Engineering Contradiction:
Improvemeniscus maintenanceVSAvoidcartridge structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The back pressure control mechanism is completely extracted from the cartridge structure. The cartridge is simplified to only include the ink storage function, while the container with its communication section handles the back pressure control and meniscus maintenance functions, thereby simplifying the cartridge structure.

Inventive Principle:
Principle #2Taking out (Extraction)

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 configuration downsizes the ink supply system while increasing the ink storage volume and preventing air bubbles from entering the head, simplifying the reservoir design and extending the ink-ejectable period.

Implementation Method 1

when the liquid reservoir is attached to the container, the liquid stored in the liquid reservoir is transferred to and stored in the container

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

An internal space of the liquid reservoir is communicated with the internal space of the container through a liquid flow path and a gas flow path

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 3

An internal space of the liquid reservoir is communicated with the internal space of the container through a liquid flow path and a gas flow path in an attached state

Methodology Applied
Scientific EffectPressure equalization: Pressure Gradient

Data Source

PatentEP4124458A1Liquid ejecting device and liquid reservoir
Publication Date: 2023.02.01 BROTHER KOGYO KK
  • EP4124458A1 patent drawingFigure 1
  • EP4124458A1 patent drawingFigure 2
  • EP4124458A1 patent drawingFigure 3

AI summary

According to aspects of the disclosure, a liquid ejecting device and a liquid reservoir are provided. The liquid ejecting device includes a head (38) having a nozzle configured to eject liquid, a container (210) that is connected with the head and is configured to store the liquid, a communication section configured to communicate an internal space of the container with atmosphere, and the liquid reservoir (220) configured to store the liquid and to be removably attached to the container. An internal space of the liquid reservoir is communicated with the internal space of the container through a liquid flow path and a gas flow path in an attached state where the liquid reservoir is attached to the container.