Energy Beam Spot Verification Using Focus and Astigmatism Settings

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Solution Overview

Problem

Current methods for verifying the size and deflection speed of energy beams, such as laser or electron beams, in freeform fabrication are complex and require manual labor, lacking simplicity and efficiency.

Innovation Solution

A method involving varying focus and astigmatism lens settings to detect maximum intensity, comparing settings with stored values, and using cameras to verify beam spot size and deflection speed, which can be performed automatically and instantaneously without manual intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual methods are used to verify beam spot size and deflection speed, then measurement precision can be achieved, but device complexity and loss of time increase

Engineering Contradiction:
Improvebeam spot size verification accuracyVSAvoidverification system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses the energy beam itself to create verification patterns on the workpiece, and uses the workpiece surface as the measurement medium. The beam draws lines or patterns directly, and the camera captures these self-generated patterns for analysis, eliminating the need for separate calibration artifacts or complex measurement apparatus.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical measurement methods with an automated optical detection system. A camera captures images of the beam-induced patterns, and image processing algorithms automatically calculate beam spot size and deflection speed, substituting human-operated mechanical measurement tools with automated vision-based measurement.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If automated verification methods are implemented, then productivity increases, but device complexity increases

Engineering Contradiction:
Improveverification speedVSAvoidautomation system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The verification system uses the same energy beam and workpiece configuration for both production and verification purposes. The beam operates in normal mode during fabrication, then switches to verification mode by drawing test patterns, eliminating the need for separate verification equipment and enabling multi-functionality of the existing system components.

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

Solution Approach 2:

The patent introduces a camera as an intermediary detection device that captures the beam's action on the workpiece. This intermediary translates the physical beam effects into visual data that can be processed by computer algorithms, enabling automated verification without requiring complex direct sensing of beam parameters.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If comprehensive verification at multiple positions and powers is performed, then reliability increases, but loss of time increases

Engineering Contradiction:
Improvebeam parameter verification reliabilityVSAvoidverification process time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs verification at multiple beam powers and positions systematically, but the automated image capture and processing enable these comprehensive checks to be executed rapidly. The preliminary calibration data stored in memory allows for quick comparison against current measurements, reducing the time penalty of comprehensive verification.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The verification process is integrated into the normal operation workflow, allowing verification measurements to be taken continuously during or between production cycles. The automated system maintains continuous monitoring capability, and the beam can switch between production mode and verification mode without significant interruption to overall process continuity.

Inventive Principle:
Principle #20Continuity of useful action

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 method provides a simple, fast, and automated verification of beam spot size and deflection speed, ensuring accurate calibration and minimizing equipment requirements, applicable to both laser and electron beams, and capable of detecting deviations to prevent quality issues in three-dimensional article manufacturing.

Implementation Method 1

varying a focus and/or astigmatism lens setting for the first energy beam spot until max intensity for the first beam spot is detected

Methodology Applied
Scientific EffectFocusing: Focusing

Implementation Method 2

max intensity for the first beam spot is detected

Methodology Applied
Scientific EffectElectromagnetic radiation detection: Absorption (EM radiation)

Data Source

PatentEP3183082B1Energy beam size verification
Publication Date: 2024.02.28 ARCAM AB
  • EP3183082B1 patent drawingFigure 1
  • EP3183082B1 patent drawingFigure 2
  • EP3183082B1 patent drawingFigure 3

AI summary

A method for verifying a size of an energy beam spot, said method comprising the steps of providing a first beam spot having a predetermined size and power at a first position on a work piece, varying a focus and/or astigmatism lens setting for said first beam spot until max intensity for the beam spot is detected, comparing the detected settings of said focus lens and/or astigmatism lens for said maximum intensity of the beam spot with stored settings of said focus lens and/or astigmatism lens for the beam spot with said predetermined size and power, repeating step a-c for different predetermined beam powers, repeating step a-d for different positions on said work piece, wherein said beam spot size is verified if each detected settings of said focus lens and/or astigmatism lens are deviating less than a predetermined value from corresponding stored settings of said focus lens and/or astigmatism lens.