Liquid Ejecting Module With Vertical Ink Circulation

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Solution Overview

Problem

Existing liquid ejecting modules face challenges in maintaining stable ink ejection due to evaporation of volatile components, leading to degradation and unevenness in ink distribution, especially when ejection ports are arranged in high density, as previous solutions either fail to effectively circulate ink close to the ports or compromise energy efficiency and resolution.

Innovation Solution

A liquid ejecting module with a configuration that includes a common supply and collection flow path for each block of printing elements, where the liquid delivery mechanism is positioned to circulate ink closely to the ejection ports, using actuators to manage ink flow and prevent pressure loss, allowing for high-density ejection port arrangements while maintaining energy efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ink is circulated using a bypass gap between die and die carrier, then ink circulation is achieved, but the circulation path is too far from the ejection port to effectively prevent evaporation at the port

Engineering Contradiction:
Improveink ejection stabilityVSAvoidcirculation path length
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent transitions from a planar circulation path (bypass gap between die and carrier) to a three-dimensional path that utilizes the vertical space above the ejection port. The circulation path is positioned in the Z-direction (ejecting direction) close to the ejection port, allowing fresh ink to be supplied directly to the port vicinity without extending the horizontal path length.

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

2Productivity

If circulation path is extended to reach distant ejection ports, then more ports can be served, but pressure loss increases and circulation efficiency decreases

Engineering Contradiction:
Improvenumber of served ejection portsVSAvoidpressure loss
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The circulation path is routed in the Z-direction (ejecting direction) rather than extending horizontally across the die surface. This vertical routing allows the path to reach multiple ejection ports arranged in the X-Y plane without increasing the overall path length, as the circulation occurs in the dimension perpendicular to the die surface.

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

Solution Approach 2:

The ejection surface is divided into multiple blocks, with each block having its own liquid delivery mechanism and circulation path. This segmentation allows each circulation path to serve a localized group of ejection ports efficiently, minimizing pressure loss while maintaining the ability to serve multiple ports through the modular block structure.

Inventive Principle:
Principle #1Segmentation

3Reliability

If liquid delivery mechanism is added close to ejection ports, then fresh ink supply is improved, but device complexity and size increase

Engineering Contradiction:
Improvefresh ink supply to ejection portVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The liquid delivery mechanism serves multiple functions: it supplies fresh ink to the ejection port, collects used ink, and provides a circulation path that also acts as a structural support element. By integrating these functions into a single mechanism positioned in the Z-direction, the patent avoids adding separate components for each function, thereby reducing overall device complexity.

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

Solution Approach 2:

The liquid delivery mechanism utilizes the Z-direction (ejecting direction) space that would otherwise be unused. By positioning the circulation path and liquid delivery components in this vertical dimension close to the ejection port, the patent achieves effective fresh ink supply without increasing the horizontal footprint or adding complex lateral structures.

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

4Manufacturing precision

If high-density ejection ports are arranged, then printing resolution is improved, but evaporation and ink degradation occur more rapidly

Engineering Contradiction:
Improveejection port densityVSAvoidink stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The circulation path is positioned in the Z-direction (ejecting direction) close to the ejection ports, creating a localized fresh ink supply zone. This vertical positioning allows the circulation mechanism to effectively serve high-density port arrangements without requiring increased horizontal spacing, thereby maintaining high resolution while preventing evaporation through proximity to each port.

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

Solution Approach 2:

The circulation system continuously supplies fresh ink to the ejection port vicinity before evaporation can occur. By maintaining constant ink flow and renewal at the port interface, the system proactively prevents the concentration increase and pigment coagulation that would otherwise occur during idle periods, ensuring stable ejection operation even in high-density configurations.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3421239B1Liquid ejecting module
Publication Date: 2021.02.17 CANON KK
  • EP3421239B1 patent drawingFigure 1
  • EP3421239B1 patent drawingFigure 2A~2B
  • EP3421239B1 patent drawingFigure 3

AI summary

The present invention provides a liquid ejecting module capable of performing stable ejection operation while circulating and supplying fresh ink to the vicinity of ejection ports arranged in high density. To achieve this, a liquid ejecting module (100) includes an element arranged face in which a plurality of ejecting elements are arranged, a circulation flow path including a supply flow path (5) which supplies liquid to a pressure chamber (3) and a collection flow path (6) which collects liquid from the pressure chamber (3), and a liquid conveying mechanism (8) provided in the circulation flow path for circulating liquid in the pressure chamber. The liquid conveying mechanism (8) is located lower than the element arranged face.