Liquid Ejecting Head Mask Plate Sealing Height Control

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Solution Overview

Problem

Existing inkjet apparatuses face challenges in maintaining precise spacing between the liquid ejecting head and the recording medium due to uneven sealing agent application, leading to reduced printing accuracy.

Innovation Solution

The design incorporates a mask plate with an L-shaped cross-section and a sealing member covered by the mask plate to control the height of the sealing agent, ensuring uniformity and precise positioning of the ejecting surface, along with an ink repellent film extending from the nozzle to the sealing member to prevent ink adherence and enhance reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sealing agent is used to seal the connection portion, then the electrical connection is protected, but unevenness occurs in the height of the ejecting surface

Engineering Contradiction:
Improvesealing protectionVSAvoidejecting surface height uniformity
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

A mask plate is introduced as an intermediary component between the sealing agent and the ejecting surface. The mask plate has a lower surface that contacts the solidified sealing agent, preventing the sealing agent from creating height variations on the ejecting surface while still providing the necessary sealing protection for the electrical connection.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sealing structure is segmented into multiple functional components: the sealing agent for electrical protection, the mask plate for surface height control, and the recess structure for positioning. This segmentation allows each component to perform its specific function without interfering with others, resolving the contradiction between sealing and surface uniformity.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the amount of sealing agent is increased to ensure adequate sealing, then protection is improved, but height variation of the ejecting surface increases

Engineering Contradiction:
Improvesealing adequacyVSAvoidejecting surface height consistency
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The mask plate is positioned in advance to define the maximum height of the sealing agent before the sealing agent is applied and solidified. This preliminary action ensures that even if excessive sealing agent is used, the ejecting surface height will not be compromised because the mask plate prevents the sealing agent from protruding beyond the designated area.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If spacing is increased between the liquid ejecting head and recording medium to accommodate sealing agent unevenness, then sealing reliability is maintained, but printing accuracy decreases

Engineering Contradiction:
Improvesealing reliabilityVSAvoidprinting accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The mask plate serves as a mediator that decouples the sealing function from the ejecting surface. By placing the mask plate between the sealing agent and the ejecting surface, the design allows the sealing agent to be applied generously for reliable sealing while the mask plate ensures the ejecting surface remains flat, eliminating the need for increased spacing and maintaining printing accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively suppresses variations in the ejecting surface height, maintaining high printing accuracy by ensuring consistent spacing and preventing ink-related issues, thereby improving the overall performance of the inkjet apparatus.

Implementation Method 1

a piezoelectric element type head ejects ink stored in an ink chamber by utilizing deformation of a piezoelectric element

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The heating element type inkjet head generates bubbles in the ink by supplying electric power to the heating elements in the ink flow path

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3686015B1Liquid ejecting head and liquid ejecting apparatus
Publication Date: 2022.08.24 TOSHIBA TEC KK
  • EP3686015B1 patent drawingFigure 1
  • EP3686015B1 patent drawingFigure 2
  • EP3686015B1 patent drawingFigure 3~4

AI summary

A liquid ejecting head includes a driving substrate including a driving element configured to, in response to a signal from an external controller, expand or contract so that a liquid is discharged from a pressure chamber through a nozzle, and a connection portion connecting the driving element to a wiring substrate connectable to the external controller; a sealing member that covers the connection portion and a part of the wiring substrate; and a mask plate partially covering a part of the driving substrate including the connection portion and contacting the sealing member.