Integrally Connected Actuators for Continuous Ink Jet Printheads

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Solution Overview

Problem

Prior art actuators in continuous ink jet printheads face challenges due to manufacturing and assembly variations, requiring high accuracy in physical dimensions and strict control over ink composition and temperature, leading to poor jet break-up uniformity.

Innovation Solution

The droplet generator features an elongate cavity with nozzle orifices and integrally connected actuators to the mounting plate via a thin membrane, manufactured by laser metal sintering or melting, allowing for precise vibration and improved jet formation with reduced assembly complexity and increased tolerance in operating parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If actuators are manufactured separately and assembled, then assembly flexibility is improved, but manufacturing precision and jet break-up uniformity deteriorate

Engineering Contradiction:
Improveassembly flexibilityVSAvoidjet break-up uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent merges the actuator and mounting plate into a single integrally connected component. The actuator is directly formed as part of the mounting plate structure, eliminating separate assembly steps. This integration ensures precise positioning and consistent physical dimensions, directly resolving the contradiction by prioritizing manufacturing precision over assembly flexibility.

Inventive Principle:
Principle #5Merging (Combining)

2Manufacturing precision

If high accuracy is required in physical dimensions, then jet break-up uniformity is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvejet break-up uniformityVSAvoidmanufacturing difficulty
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The actuator and mounting plate are combined into a single integrally connected component, reducing the number of parts and assembly steps. This integration simplifies manufacturing while ensuring the required high precision for jet break-up uniformity is achieved through the unified structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a membrane with controlled thickness (less than 500 microns) as a key parameter. This thin membrane structure allows the integrally connected actuator to vibrate effectively while maintaining the required precision, enabling high jet break-up uniformity without excessive manufacturing complexity.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If very little stray is permitted in operating parameters, then jet break-up uniformity is improved, but adaptability to varying conditions deteriorates

Engineering Contradiction:
Improvejet break-up uniformityVSAvoidflexibility in operating parameters
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The thin membrane (less than 500 microns) acts as a compliant element that allows the integrally connected actuator to adapt to variations in operating parameters such as ink composition and temperature. The membrane's flexibility compensates for parameter variations while maintaining consistent jet break-up uniformity, resolving the contradiction between precision and adaptability.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If thin membrane is used to connect actuator to mounting plate, then manufacturing precision and tolerance are improved, but structural strength may deteriorate

Engineering Contradiction:
Improvetolerance in operating parametersVSAvoidmembrane strength
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The patent employs a thin membrane (less than 500 microns) as a flexible connection between the actuator and mounting plate. This thin film structure provides the necessary compliance for precision and adaptability while the integral connection design ensures sufficient structural strength to maintain the connection under operating conditions.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The membrane is integrally connected to both the actuator and mounting plate, creating a unified structure that distributes mechanical loads. This integration strengthens the thin membrane connection while maintaining the precision and flexibility benefits of the thin film design.

Inventive Principle:
Principle #5Merging (Combining)

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 design enhances jet break-up uniformity and reduces manufacturing complexity, enabling higher accuracy and flexibility in ink jet printheads by allowing for thinner features and more flexible operating conditions.

Implementation Method 1

Each of the plurality of actuators is integrally connected to the mounting plate by a membrane, the membrane providing a seal to maintain ink in the cavity

Methodology Applied
Scientific EffectSealing:

Implementation Method 2

A plurality of actuators is disposed in the cavity to vibrate the ink in the cavity such that each jet breaks up into ink droplets

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 3

The mounting plate and integrated actuators are preferably manufactured by laser metal sintering or laser metal melting

Methodology Applied
Scientific EffectLaser sintering: Selective Laser Sintering

Implementation Method 4

The mounting plate and integrated actuators are preferably manufactured by laser metal sintering or laser metal melting

Methodology Applied
Scientific EffectLaser melting: Laser Ablation

Data Source

PatentEP3038833B1Droplet generator for a continuous stream ink jet printhead
Publication Date: 2019.08.21 VIDEOJET TECH INC
  • EP3038833B1 patent drawingFigure 1
  • EP3038833B1 patent drawingFigure 2
  • EP3038833B1 patent drawingFigure 3

AI summary

A droplet generator for a continuous stream ink jet printhead includes an elongate cavity for containing ink and nozzle orifices in fluid communication with the cavity for passing the ink from the cavity to form jets. The nozzle orifices extend along a length of the cavity. A mounting plate provides a wall of the cavity opposite the nozzle orifices. A plurality of actuators is disposed in the cavity to vibrate the ink in the cavity such that each jet breaks up into ink droplets at substantially a same predetermined distance from the wall. Each of the plurality of actuators is integrally connected to the mounting plate by a membrane.