Beam Expansion Device for Additive Manufacturing Power Density Measurement

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Solution Overview

Problem

Existing devices for additive manufacturing of three-dimensional objects using energy beams face complexity and error-proneness in measuring power density due to the need for precise positioning of measuring devices relative to the focal plane, especially at high power densities, which can lead to damage and require cumbersome handling.

Innovation Solution

Incorporating an energy beam expansion device upstream of the measuring device to widen the energy beam, allowing for reduced energy input and enabling independent positioning of the measuring device relative to the focal plane, thus simplifying and automating the measurement process across a wide range of power densities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the measuring device is positioned close to the focal plane to measure high power density energy beams, then measurement precision is improved, but the measuring device is damaged due to excessive energy input

Engineering Contradiction:
Improvepower density measurement precisionVSAvoiddamage to measuring device
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

A beam expanding device is introduced as an intermediary component between the energy beam source and the measuring device. This device expands the energy beam before it reaches the measuring device, reducing the power density at the measurement point while maintaining measurement accuracy. The beam expanding device acts as a mediator that protects the measuring device from excessive energy input.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the measuring device is repositioned for each output power of the exposure device to avoid damage, then safety is improved, but device complexity and ease of operation deteriorate due to cumbersome handling

Engineering Contradiction:
Improvesafety of measuring deviceVSAvoidpositioning complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The beam expanding device automatically adjusts the beam diameter based on the output power of the exposure device, eliminating the need for manual repositioning of the measuring device. The system performs the adjustment function itself, making the measuring device position-independent while maintaining safety across different power levels.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If the measuring device is repositioned for each output power to maintain correct distance, then measurement precision is improved, but ease of operation deteriorates due to error-prone handling

Engineering Contradiction:
Improvepower density measurement precisionVSAvoidease of measuring device handling
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The beam expanding device serves as an intermediary that decouples the relationship between measuring device position and measurement precision. By expanding the beam upstream, it ensures that the measuring device receives appropriate power density regardless of its position, eliminating positioning errors and simplifying operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If the energy beam is expanded upstream of the measuring device, then ease of operation is improved by enabling fixed positioning, but device complexity increases due to additional components

Engineering Contradiction:
Improvemeasuring device positioningVSAvoidmeasurement system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The beam expanding device is integrated into the existing measurement system and can serve multiple functions: protecting the measuring device from damage, enabling fixed positioning, and maintaining measurement precision across different power levels. This multi-functionality justifies the additional component by providing multiple benefits from a single addition.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 reduces the risk of damage to the measuring device, simplifies handling, and enables standardized, automated measurement methods by allowing the measuring device to be positioned consistently, regardless of the energy beam's power density, improving reproducibility and safety.

Implementation Method 1

an energy beam expansion device (17) which is arranged upstream of the energy beam entrance surface (16) and is designed to expand an energy beam (4) to be measured with regard to its power

Methodology Applied
Scientific EffectBeam expansion: Lens

Implementation Method 2

a measuring device (13) which is configured to measure power, in particular power density, of the energy beam (4) generated by the exposure device (6)

Methodology Applied
Scientific EffectEnergy measurement:

Data Source

PatentEP3431261B1Device for additives production of three-dimensional objects
Publication Date: 2020.09.02 CL SCHUTZRECHTSVERW
  • EP3431261B1 patent drawingFigure 1
  • EP3431261B1 patent drawingFigure 2
  • EP3431261B1 patent drawingFigure 3

AI summary

Device (1) for the additive manufacturing of three-dimensional objects (2) by successive layer-by-layer selective exposure and the associated successive layer-by-layer selective solidification of building material layers made of a building material (3) that can be solidified by means of an energy beam (4), comprising: - an exposure device (6) which is configured to generate an energy beam (4) for the successive layer-by-layer selective exposure and the associated successive layer-by-layer selective solidification of building material layers made of a building material (3) that can be solidified by means of the energy beam (4), - a measuring device (13) which can be assigned to or associated with the exposure device (6) and which is configured to measure the power, in particular the power density, of the energy beam (4) generated by the exposure device (6), wherein the measuring device (13) comprises a measuring element (15) comprising an energy beam entry surface (16),and at least one energy beam expansion device (17) arranged or designed upstream of the energy beam entry surface (16), which is designed for expanding, in particular optically, an energy beam (4) to be measured with regard to its power.