Droplet Discharge Device Using Liquid Ejection Layer

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Solution Overview

Problem

Conventional droplet discharge devices face inefficiencies in mounting and aligning jigs for printing on three-dimensional surfaces, requiring manual precision and increasing operator workload, especially when dealing with varied medium sizes and shapes.

Innovation Solution

A droplet discharge device equipped with a vacuum table, a droplet discharge unit, a relative movement unit, a holding-platform information acquiring unit, and a discharge control unit, which uses registration marks, barcode detection, and RFID/IC chip readers to automatically identify and align the holding platform, reducing manual intervention and improving positional accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a piezoelectric element is used to discharge droplets, then droplet discharge can be achieved, but bacteria may be attached to the piezoelectric element and cause contamination

Engineering Contradiction:
Improvedroplet discharge capabilityVSAvoidbacterial contamination
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the problematic function of droplet discharge from the piezoelectric element by introducing a dedicated discharge electrode. The piezoelectric element is separated into its original role of generating mechanical vibration, while the discharge electrode handles droplet ejection, preventing bacterial attachment to the piezoelectric element.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a liquid ejection layer as an intermediary between the piezoelectric element and the droplet discharge function. This layer receives vibration from the piezoelectric element and transfers it to the liquid, enabling droplet discharge without direct contact between the piezoelectric element and the liquid, thus preventing bacterial contamination.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If droplets are discharged using conventional methods, then droplet formation is achieved, but satellite droplets are generated causing misalignment and contamination

Engineering Contradiction:
Improvedroplet formation efficiencyVSAvoiddroplet alignment accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies mechanical vibration to the liquid ejection layer using a piezoelectric element, which controls the detachment of droplets from the liquid column. By adjusting the vibration frequency and amplitude, the system can precisely control droplet formation and eliminate satellite droplets, ensuring accurate droplet placement.

Inventive Principle:
Principle #18Mechanical vibration

3Productivity

If the piezoelectric element surface is made hydrophobic, then droplet discharge is improved, but bacteria can still attach to the element

Engineering Contradiction:
Improvedroplet discharge performanceVSAvoidbacterial attachment
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the droplet discharge function from the piezoelectric element surface by introducing a separate liquid ejection layer and discharge electrode. This allows the piezoelectric element to maintain its hydrophobic surface for optimal droplet discharge while preventing direct bacterial attachment to the element itself.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The liquid ejection layer acts as an intermediary that interfaces with the hydrophobic piezoelectric element surface while being the actual source of droplet discharge. This mediator layer prevents bacteria from attaching to the piezoelectric element while maintaining the benefits of the hydrophobic surface for droplet formation.

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 solution enhances work efficiency by automating the alignment process, allowing for precise and rapid adaptation to different medium shapes and sizes, thereby reducing operator workload and improving printing quality.

Implementation Method 1

a piezoelectric element 14 that vibrates the liquid ejection layer 12 in a vertical direction

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

vibrates the liquid ejection layer 12 at a resonance frequency

Methodology Applied
Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Implementation Method 3

a liquid ejection layer 12 that holds liquid 2 by surface tension

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Data Source

PatentEP2471606B1Droplet discharge device and droplet discharge method
Publication Date: 2015.09.23 MIMAKI ENGINEERING CO LTD
  • EP2471606B1 patent drawingFigure 1
  • EP2471606B1 patent drawingFigure 2
  • EP2471606B1 patent drawingFigure 3

AI summary

A printer (1) comprises: a vacuum table (13) for supporting a jig (50) which holds a medium (8); a printer head (32) for discharging droplets; and a relative movement means (40) for moving the printer head (32) relative to the medium (8); a registration mark detection unit (34) and barcode detection unit (35) for acquiring holding platform information (61) and support position information (62) for the jig (50); and a controller (22) for controlling the movement of the printer head (32) by the relative movement means (40) and controlling the discharge of droplets from the printer head (32) on the basis of the holding platform information (61), the support position information (62) and information pertaining to the desired pattern. As a result of this configuration, it is possible to generate image data without aligning the jig (50) with a reference position on the vacuum table (13).