Liquid Ejection Head Opening Layout for Stable Ink Circulation

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Solution Overview

Problem

Conventional liquid ejection heads require complex mechanisms like pressure adjustment and pumps for ink circulation, leading to increased size and complexity, and existing chip configurations fail to optimize ejection and circulation characteristics.

Innovation Solution

A liquid ejection head with integrated first and second energy generation elements for ejecting and circulating ink, utilizing a straight or U-shaped ink circulation configuration to enhance ejection stability and reduce waste through controlled ink flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a differential pressure circulation method using pressure adjustment mechanisms and pumps is used, then ink circulation is achieved, but the main body of the recording apparatus and the head increase in size

Engineering Contradiction:
Improveink circulationVSAvoidhead size
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent extracts the circulation function from a separate pump mechanism and integrates it into the ejection nozzle itself through a second energy generation element. This eliminates the need for external pumps and pressure adjustment mechanisms, thereby reducing the head size while maintaining ink circulation capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The ejection nozzle is designed to perform multiple functions: the first energy generation element generates energy for ejecting ink, while the second energy generation element generates energy for circulating ink. This multi-functionality eliminates the need for separate circulation mechanisms, reducing overall device size.

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

2Productivity

If conventional chip configurations with energy generation elements are used, then ink ejection is achieved, but ejection characteristic and circulation characteristic for ink are not optimized

Engineering Contradiction:
Improveejection characteristicVSAvoidcirculation characteristic
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the energy generation function into two distinct elements: the first energy generation element dedicated to ink ejection and the second energy generation element dedicated to ink circulation. This segmentation allows each element to be optimized for its specific function, improving both ejection and circulation characteristics simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the chip are assigned different functions with appropriate energy generation elements. The first energy generation element is positioned and configured for optimal ejection performance, while the second energy generation element is positioned and configured for optimal circulation performance, allowing each local region to excel at its specific task.

Inventive Principle:
Principle #3Local quality

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

Improves ejection characteristics and reduces ink concentration near nozzles, minimizing waste and maintaining image quality by stabilizing ink flow and reducing the need for preliminary ejections.

Implementation Method 1

a first energy generation element that generates energy for ejecting the liquid from the ejection nozzle is provided at a position corresponding to the ejection nozzle

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

a first energy generation element that generates energy for ejecting the liquid from the ejection nozzle

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 3

a second energy generation element that generates energy for causing the liquid to flow is provided at a position different from that of the first energy generation element in the individual flow passage

Methodology Applied
Scientific EffectBubble generation and movement: Bubble

Implementation Method 4

a second energy generation element that generates energy for causing the liquid to flow

Methodology Applied
Scientific EffectThermal energy generation: Heating

Data Source

PatentEP4711141A1Liquid ejection head and liquid ejection apparatus
Publication Date: 2026.03.18 CANON KK
  • EP4711141A1 patent drawingFigure 1A~1B
  • EP4711141A1 patent drawingFigure 2A~2D
  • EP4711141A1 patent drawingFigure 3A~3D

AI summary

A liquid ejection head in which a plurality of ejection nozzles is arranged in a first direction includes: a first flow passage communicating with one end of each of a plurality of individual flow passages; a second flow passage communicating with the other end of each of the plurality of individual flow passages; a plurality of first openings provided in the first flow passage; and a plurality of second openings provided in the second flow passage, in which D2 > D1, in which D1 represents a size of a non-open part in a first direction between the two adjacent first openings, and D2 represents a size of a non-open part in the first direction between the two adjacent second openings.