Multi-Scanner SLS Exposure Control for Balanced Build Time

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Solution Overview

Problem

Existing multi-scanner laser sintering or melting systems face inefficiencies in construction time due to varying irradiation times and areas among scanners, leading to suboptimal exposure distribution across the construction area.

Innovation Solution

The method involves recording and comparing irradiation times and areas for each scanner, dynamically adjusting scan field boundaries to equalize exposure times and areas, allowing for iterative optimization and incremental adjustments to minimize construction time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If multiple scanners are used to expose different sections of the construction field, then the construction area coverage is improved, but the construction time becomes unbalanced due to varying irradiation times and areas among scanners

Engineering Contradiction:
Improveconstruction field coverageVSAvoidconstruction time
Core Design Contradiction:
Area of stationary objectVSLoss of time

Solution Approach 1:

The patent implements dynamic adjustment of scan field boundaries between multiple scanners during the construction process. The control system continuously monitors irradiation times and areas for each scanner, then dynamically redistributes the construction field sections to equalize the exposure workload. This dynamic reassignment ensures that all scanners operate at optimal utilization levels, preventing any single scanner from becoming a bottleneck and thereby minimizing total construction time while maintaining full construction field coverage.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If scan field boundaries are fixed for each scanner, then the system operation is simplified, but streaking artifacts appear on the surface due to inconsistent exposure distribution

Engineering Contradiction:
Improvescanner control simplicityVSAvoidsurface quality
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent employs a feedback mechanism where the control system continuously monitors the irradiation parameters (time and area) for each scanner during the construction process. Based on this feedback, the system automatically adjusts the scan field boundaries to optimize exposure distribution across all scanners. This closed-loop control equalizes the workload among scanners, preventing the formation of streaking artifacts caused by inconsistent exposure, while the adjustments are made transparently without requiring complex manual intervention, thus maintaining ease of operation.

Inventive Principle:
Principle #23Feedback

3Device complexity

If the irradiation workload is unevenly distributed among scanners, then the system setup is simpler, but the overall productivity is reduced due to idle scanner time

Engineering Contradiction:
Improvescanner distribution configurationVSAvoidconstruction rate
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent implements dynamic load balancing that automatically optimizes the distribution of irradiation workload among multiple scanners during construction. The control system monitors the actual irradiation time and area for each scanner in real-time, then dynamically reassigns construction field sections to equalize the exposure workload. This ensures all scanners remain actively utilized throughout the construction process, eliminating idle time and maximizing overall system productivity, while the automatic nature of the optimization keeps the system configuration relatively simple.

Inventive Principle:
Principle #15Dynamics

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 approach significantly reduces construction time by ensuring balanced scanner usage and preventing streaking, maintaining optimal exposure distribution throughout the process.

Implementation Method 1

selective laser sintering or laser melting device for producing three-dimensional objects

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

laser sintering or laser melting device for producing three-dimensional objects by selectively irradiating a construction material

Methodology Applied
Scientific EffectLaser sintering: Selective Laser Sintering

Implementation Method 3

laser sintering or laser melting device for producing three-dimensional objects by selectively irradiating a construction material

Methodology Applied
Scientific EffectLaser melting: Laser Beam Welding

Data Source

PatentEP3218168B2Method and device for controlling the exposure of a selective laser sintering or laser melting device
Publication Date: 2024.03.06 CONCEPT LASER
  • EP3218168B2 patent drawingFigure 1
  • EP3218168B2 patent drawingFigure 2a~2c

AI summary

The invention relates to a method for controlling the exposure of a selective laser sintering or laser melting device for producing three-dimensional objects, with the following method steps: providing a selective laser sintering or laser melting device (1), in which three-dimensional objects can be produced by successively consolidating layers of a powder-like building material (6) that can be consolidated by means of radiation at the locations corresponding to the respective cross section of the object, wherein the device provided comprises an irradiating unit for irradiating layers of the building material that has a plurality of separately activatable scanners irradiating the building material simultaneously, comprising separately recording the irradiating times of each individual scanner (8a, 8b) and/or the irradiating areas covered by each individual scanner in a first step and storing the recorded irradiating times and/or irradiating areas; comparing the irradiating times and/or irradiating areas of the individual scanners with one another; re-determining the surface regions of a powder layer to be irradiated by each individual scanner in such a way that the irradiating times for each individual scanner are approximated to one another as much as possible and/or the irradiating areas of each individual scanner are made to match one another as far as possible in terms of their surface area.