Viscoelastic Damper for Liquid Discharge Head Pressure Control

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Solution Overview

Problem

High-density liquid discharge heads face challenges in maintaining consistent droplet velocity and volume due to pressure variations, leading to ejection failures and image quality degradation, particularly with increasing nozzle density and driving frequency, where existing damping solutions are costly, complex, and inefficient.

Innovation Solution

The liquid discharge head incorporates a diaphragm member with a three-layer structure and deformable thin-wall parts, using a viscoelastic damper material to absorb pressure variations, allowing for accurate meniscus control and reduced manufacturing costs by integrating the damper components with the diaphragm member.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number and density of nozzles are increased to achieve higher printing rates, then productivity is improved, but pressure variations propagate more easily causing ejection failures and image quality degradation

Engineering Contradiction:
Improveprinting rateVSAvoidejection stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

A vibration absorber is introduced as an intermediary component between the pressure liquid chamber and the common liquid chamber. This vibration absorber captures and dissipates pressure variations before they can propagate to adjacent chambers, thereby maintaining stable droplet ejection even when nozzle density and driving frequency are increased for higher productivity

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The vibration absorber is positioned in advance within the common liquid chamber to cushion against pressure variations before they can cause ejection failures. By preemptively absorbing these pressure fluctuations, the system maintains reliable droplet discharge despite the increased nozzle density required for high-speed printing

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If conventional vibration absorbers are used in the common liquid chamber, then ejection stability is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improveejection stabilityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The vibration absorber is constructed using a flexible membrane that forms a closed space within the common liquid chamber. This flexible shell structure absorbs pressure variations through elastic deformation, providing effective vibration damping while maintaining a simple, integrated design that avoids complex mechanical components

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The vibration absorber utilizes changes in the physical parameters of the enclosed space and flexible membrane to absorb pressure variations. By adjusting the volume, elasticity, and configuration of the flexible shell, the system achieves effective vibration absorption without requiring complex mechanical structures or additional components

Inventive Principle:
Principle #35Parameter changes

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 damps pressure variations, ensuring consistent droplet discharge and improving image quality by reducing the impact of pressure fluctuations, while also simplifying the manufacturing process and reducing costs.

Implementation Method 1

a vibration damping member formed of a viscoelastic material, which is provided in contact with the deformable member

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Implementation Method 2

the deformable member forms at least one wall face of a common channel; the deformable member deforms in response to a pressure variation in the common channel

Methodology Applied
Scientific EffectDeformation: Deformation

Data Source

PatentEP1849605B1Image forming apparatus
Publication Date: 2012.08.15 RICOH CO LTD
  • EP1849605B1 patent drawingFigure 1
  • EP1849605B1 patent drawingFigure 2
  • EP1849605B1 patent drawingFigure 3

AI summary

An image forming apparatus is disclosed that includes a liquid discharger including a liquid discharge head configured to discharge a droplet of liquid so as to form an image. The liquid discharge head includes multiple individual channels (6) communicating with corresponding nozzles (4) from which the liquid is discharged; a common channel (8) configured to supply the liquid to the individual channels; a deformable member (23) configured to form at least one wall face of the common channel; and a vibration damping member (24) formed of a viscoelastic material, the vibration member being provided in contact with the deformable member.