Liquid Ejection Head With Separate Supply And Collection Channels

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Solution Overview

Problem

Existing liquid ejection apparatuses suffer from low ink circulation efficiency near ejection ports, leading to ink thickening and reduced ejection performance.

Innovation Solution

The apparatus incorporates a configuration with common supply and collection channels for ink circulation, utilizing pressure adjustment units and a circulation pump to maintain ink flow and prevent thickening, while minimizing tube length and reducing the need for ink collection channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If ink circulation channels are configured in conventional liquid ejection apparatuses, then ink circulation is enabled, but ink circulation efficiency deteriorates in the vicinities of ejection ports causing ink thickening

Engineering Contradiction:
Improveink circulation efficiencyVSAvoidink fluidity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The ink circulation system is segmented into multiple independent circulation paths, with separate supply channels and collection channels positioned at different locations. This segmentation allows different regions of the ink reservoir to be actively circulated, preventing dead zones where ink would stagnate and thicken near the ejection ports.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The circulation pump is configured to proactively circulate ink through the channels before the ink can stagnate and thicken. The supply channel introduces fresh ink to the ejection port region, and the collection channel removes used ink, maintaining optimal ink fluidity in advance before ejection occurs.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If circulation pump and pressure adjustment units are added to improve ink circulation, then ink fluidity is maintained, but device complexity increases

Engineering Contradiction:
Improveink fluidityVSAvoidcirculation system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The circulation pump and pressure adjustment units are integrated into the ink cartridge itself, allowing the ink circulation system to be self-contained and self-regulating. The system uses the ink's own pressure and flow characteristics to drive circulation, reducing the need for external control mechanisms and simplifying the overall device architecture.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The circulation pump, supply channel, and collection channel are merged into a single integrated circulation unit within the ink cartridge. This consolidation reduces the number of separate components and connections needed, simplifying both the device structure and maintenance while maintaining effective ink circulation.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If multiple ink collection channels are provided to improve circulation, then ink circulation efficiency is enhanced, but tube length increases and apparatus is upsized

Engineering Contradiction:
Improveink circulation efficiencyVSAvoidtube length
Core Design Contradiction:
ProductivityVSLength of stationary object

Solution Approach 1:

The circulation channels are arranged in a compact three-dimensional configuration within the ink cartridge, utilizing vertical and radial dimensions rather than extending horizontally. This dimensional optimization reduces the overall tube length while maintaining effective circulation coverage of the ink reservoir.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The supply channel and collection channel are nested within the compact ink cartridge structure, with channels positioned concentrically or in overlapping arrangements. This nesting minimizes the space required for circulation pathways, reducing tube length while maintaining circulation efficiency.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 enhances ink fluidity and ejection characteristics, maintains ejection performance, and downsizes the apparatus by reducing tube complexity and motor driving load, thereby lowering costs.

Implementation Method 1

utilizing pressure adjustment units and a circulation pump to maintain ink flow and prevent thickening

Methodology Applied
Scientific EffectPump: Pump

Implementation Method 2

utilizing pressure adjustment units and a circulation pump to maintain ink flow

Methodology Applied
Scientific EffectPressure adjustment: Pressure Increase

Data Source

PatentEP4197788B1Liquid ejection head and liquid ejection apparatus
Publication Date: 2025.09.24 CANON KK
  • EP4197788B1 patent drawingFigure 1A~1B
  • EP4197788B1 patent drawingFigure 2
  • EP4197788B1 patent drawingFigure 3A~3B

AI summary

An object is to provide a liquid ejection head and liquid ejection apparatus capable of preventing a deterioration in ink circulation efficiency in the vicinities of ejection ports. To this end, a common supply channel 18 and a common collection channel 19 are provided as separate channels. An ink supplied from the common supply channel 18 is supplied to pressure chambers 12 through supply connection channels 323, and collected from the pressure chambers 12 into the common collection channel 19 through collection connection channels 324. Also, the common supply channel and the common collection channel extend in a direction crossing a main scanning direction in which the liquid ejection head is scanned and the ejection direction of the liquid.