Additive Manufacturing Light Valve Beam Array

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Solution Overview

Problem

Current additive manufacturing techniques using laser or energy beams are limited by the single focus point scanning speed, resulting in slow build processes that take many hours to complete an object due to inertial forces affecting the scanner's movement.

Innovation Solution

The use of a light valve to expand a radiation beam into a planar beam, which is then modulated into an array of individually controllable 'pixels' to rapidly scan and solidify material across a build area, allowing for precise control and increased build speed through a scanning device and lens arrangement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a single focus point laser beam is used to scan the build area, then manufacturing precision is maintained, but productivity is significantly reduced due to slow scanning speed

Engineering Contradiction:
ImproveprecisionVSAvoidbuild speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The single laser beam is segmented into multiple independent light spots arranged in a linear array, allowing simultaneous processing of multiple locations across the build area. This segmentation enables parallel processing while maintaining the precision of individual beam spots.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-point (0D) or point-to-point (1D) scanning approach to a linear array of light spots (1D spatial distribution), adding a spatial dimension to the beam configuration. This dimensional change allows multiple processing points to exist simultaneously across the build area.

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

2Productivity

If the scanner moves quickly across the build area, then productivity is improved, but manufacturing precision deteriorates due to inertial forces affecting scanner movement

Engineering Contradiction:
Improvescan speedVSAvoidpositioning accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent replaces the traditional mechanical scanning system that moves a single beam with an optical system that generates a linear array of light spots. This substitution eliminates the need for rapid mechanical scanning while maintaining positioning accuracy through optical control of the light valve array.

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

Solution Approach 2:

The linear array of light spots is pre-configured to cover the required build area, allowing the system to process multiple locations simultaneously without sequential movement. The entire array can be positioned and activated in advance, eliminating the need for rapid scanning during the building process.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If a linear array of light spots is used to cover the build area, then productivity is significantly improved, but device complexity increases due to additional optical components

Engineering Contradiction:
Improvebuild speedVSAvoidoptical system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The light valve assembly serves multiple functions: it generates the linear array of light spots, modulates the intensity of each individual spot, and controls the positioning of the entire array. This multi-functionality reduces the need for separate optical components for each function, thereby managing system complexity while achieving high productivity.

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 approach significantly reduces build time by enabling rapid movement and precise positioning of the light spots, improving detail and efficiency, with the ability to preheat and solidify material using the same components, thus enhancing the overall additive manufacturing process.

Implementation Method 1

an optical element realised to expand a radiation beam (generated by an energetic source of solidifying radiation) into a planar beam

Methodology Applied
Scientific EffectBeam expansion: Lens

Implementation Method 2

a light valve assembly arranged to receive the planar beam and to modulate the planar beam; The light valve essentially receives the planar beam and modulates this planar beam to produce an output array of individually switched 'pixels'

Methodology Applied
Scientific EffectLight modulation: Reflection

Implementation Method 3

a beam expander for expanding the modulated output of the light valve

Methodology Applied
Scientific EffectBeam expansion: Lens

Implementation Method 4

a scanning device configured to receive the expanded beam from the beam expander and to direct the expanded beam toward a build area surface

Methodology Applied
Scientific EffectLight deflection: Reflection

Implementation Method 5

a lens arrangement configured to correct distortion of the beam from the scanning device

Methodology Applied
Scientific EffectBeam correction: Lens

Implementation Method 6

additive manufacturing techniques using a laser or other energy beam to melt, fuse, cure, sinter or otherwise solidify material

Methodology Applied
Scientific EffectLaser solidification: Laser

Implementation Method 7

an energetic source of solidifying radiation

Methodology Applied
Scientific EffectEnergy absorption: Absorption (EM radiation)

Data Source

PatentEP3753705B1Additive manufacturing apparatus
Publication Date: 2023.11.08 EOS OF NORTH AMERICA INC
  • EP3753705B1 patent drawingFigure 1
  • EP3753705B1 patent drawingFigure 2~3
  • EP3753705B1 patent drawingFigure 4

AI summary

The invention describes an additive manufacturing apparatus for making an object (50) using an energetic source of solidifying radiation working upon a build material in a build area (22), comprising: an optical element (14) realised to expand a radiation beam into a planar beam (12); a light valve assembly (16) arranged to receive the planar beam (12) and to generate an output array of individually controllable light spots; a beam expander (20) for expanding the output of the light valve (16); a scanning device (24) configured to receive the expanded beam (26) from the beam expander (20) and to direct the expanded beam (26) toward the build area (22); a lens arrangement (28) configured to correct distortion of the expanded beam (26) from the scanning device (24); an input interface for receiving an output array pixel power string (130) for a desired exposure of a layer of the object (50); and a controller (130) configured to control at least the light valve assembly (16) and the scanning device (24) on the basis of the received pixel power string (130). The invention further describes an additive manufacturing method.