Recycled Light Optics for Higher-Throughput Additive Manufacturing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In laser-based additive manufacturing systems, a significant amount of light is wasted due to the rejection of unwanted light patterns, leading to inefficiencies in throughput and energy utilization.

Innovation Solution

An optical system is developed to recycle and reuse rejected light by employing a pixel addressable light valve and image relays, allowing the recycling of energy through beam shaping optics and image relays to maintain high throughput rates and increase intensity for printing difficult materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a mask is applied to pattern the light using a liquid crystal light valve, then the light can be spatially modulated to build parts, but the unwanted polarized light is rejected and wasted

Engineering Contradiction:
Improvespatial modulation precisionVSAvoidlight energy waste
Core Design Contradiction:
Manufacturing precisionVSLoss of energy

Solution Approach 1:

The patent converts the rejected unwanted polarized light, which was previously discarded as waste energy, into a useful resource by redirecting it through optical elements to combine with the original light beam, thereby increasing overall light intensity and reducing energy waste

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

Instead of discarding the rejected light at the beam dump, the system recovers this light by redirecting it through additional optical paths and combines it back with the main beam, effectively recovering energy that would otherwise be lost

Inventive Principle:
Principle #34Discarding and recovering

2Ease of operation

If rejected light is discarded to a beam dump, then the polarization state separation is achieved, but the energy utilization efficiency decreases

Engineering Contradiction:
Improvepolarization state separationVSAvoidenergy utilization efficiency
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The system transforms the previously harmful waste light into a beneficial resource by redirecting it through optical elements to augment the main light beam, thereby improving energy utilization while maintaining polarization separation functionality

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The optical system achieves multi-functionality by simultaneously maintaining polarization state separation for precise light patterning while also recovering and recycling the rejected light to improve overall energy efficiency

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

3Productivity

If the light intensity is increased by recycling rejected light, then the print rate increases, but the system complexity increases

Engineering Contradiction:
Improveprint rateVSAvoidoptical system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces intermediary optical elements (additional mirrors, beam combining optics) that mediate between the light valve and the build platform, enabling light recycling functionality while maintaining a modular system architecture

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The recycling of rejected light increases the overall light intensity, enabling faster print rates and more efficient use of energy, thereby maintaining high printing rates and reducing energy costs.

Implementation Method 1

Liquid crystal based light valves allow for the spatial modulation of transmitted or reflected light by rotating the electromagnetic wave polarization state

Methodology Applied
Scientific EffectPolarization rotation: Polarisation

Implementation Method 2

An optical system is developed to recycle and reuse rejected light by employing a pixel addressable light valve and image relays, allowing the recycling of energy through beam shaping optics and image relays

Methodology Applied
Scientific EffectLight recycling: Reflection

Data Source

PatentEP4173740B1Light recycling for additive manufacturing optimization
Publication Date: 2025.08.20 SEURAT TECHNOLOGIES INC
  • EP4173740B1 patent drawingFigure 1A
  • EP4173740B1 patent drawingFigure 1B
  • EP4173740B1 patent drawingFigure 2

AI summary

A method and an apparatus pertaining to recycling and reuse of unwanted light in additive manufacturing can multiplex multiple beams of light including at least one or more beams of light from one or more light sources. The multiple beams of light may be reshaped and blended to provide a first beam of light. A spatial polarization pattern may be applied on the first beam of light to provide a second beam of light. Polarization states of the second beam of light may be split to reflect a third beam of light, which may be reshaped into a fourth beam of light. The fourth beam of light may be introduced as one of the multiple beams of light to result in a fifth beam of light.