3D Printing Head Unit Spatial Arrangement for Collision Avoidance

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Solution Overview

Problem

Existing three-dimensional object printing apparatuses face challenges in preventing contact between curing heads and distance measurement units with the workpiece while maintaining optimal functionality, particularly when positioning these components near the print head.

Innovation Solution

A three-dimensional object printing apparatus utilizing a vertical articulated robot with a head unit that includes a fixed positional relationship between the inkjet head, curing unit, and distance measurement unit, where the curing unit and distance measurement unit are positioned relative to the inkjet head to avoid contact with the workpiece, ensuring precise ink placement and curing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the curing head is arranged near the print head, then the curing efficiency is improved, but the risk of contact with the workpiece increases

Engineering Contradiction:
Improvecuring efficiencyVSAvoidcontact prevention
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent positions the curing head and distance measurement unit in a spatial arrangement where they operate from different dimensional zones. The curing head is positioned to cure ink after it contacts the workpiece surface, while the distance measurement unit measures from a different spatial location, allowing both functions to operate near the print head without physical contact with the workpiece.

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

2Measurement precision

If the distance measurement unit is positioned close to the print head, then the measurement precision is improved, but the likelihood of collision with the workpiece increases

Engineering Contradiction:
Improveirradiation distance measurement precisionVSAvoidcollision risk
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces the workpiece surface itself as an intermediary reference for distance measurement. The distance measurement unit measures the distance to the workpiece surface indirectly through the ink layer or air gap, rather than requiring direct proximity to the workpiece surface, thereby maintaining measurement precision while avoiding collision.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If multiple components are integrated near the print head, then the system compactness is improved, but the complexity of positioning and coordination increases

Engineering Contradiction:
Improvesystem compactnessVSAvoidpositioning and coordination
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The patent combines the print head, curing head, and distance measurement unit into a single integrated assembly that moves together as one unit. This merging of components into a compact configuration reduces the number of separate positioning systems needed while maintaining the functional relationships between components.

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 configuration enhances precision in ink placement and curing efficiency while preventing collisions with the workpiece, thereby achieving high-quality printing on complex surfaces.

Implementation Method 1

a head unit including a plurality of nozzles N arranged along a nozzle-row axis, and an ejecting direction c2 orthogonal to the nozzle-row axis, the head unit being configured to eject ink toward the surface WF of the workpiece W

Methodology Applied
Scientific EffectInkjet ejection:

Implementation Method 2

an energy emission unit configured to emit energy by which ink droplets landed on the surface WF of the workpiece W can be cured

Methodology Applied
Scientific EffectPhotocuring: Photopolymerisation

Implementation Method 3

a distance measurement unit configured to measure a distance between the head unit and the workpiece W

Methodology Applied
Scientific EffectTime of flight measurement: Time of Flight

Data Source

PatentEP4019258B1Three-dimensional object printing apparatus and three-dimensional object printing method
Publication Date: 2024.03.13 SEIKO EPSON CORP
  • EP4019258B1 patent drawingFigure 1
  • EP4019258B1 patent drawingFigure 2
  • EP4019258B1 patent drawingFigure 3

AI summary

A three-dimensional object printing apparatus includes a head unit (300) and a robot. The head unit includes a head and an energy emission unit (330). The head has an ejecting surface (F1) on which a nozzle is provided. The head is configured to eject ink from the nozzle toward a three-dimensional workpiece (W). The energy emission unit has an emitting surface (F2) from which energy for curing the ink is emitted. The robot changes relative position and relative orientation of the workpiece and the head unit. When a direction in which the head ejects the ink is defined as an ejecting direction, the ejecting surface is located closer to an ejecting direction side, which is a side toward which the ejecting direction goes, than the emitting surface is.