Programmable Beam Shaper Switching for Laser Processing

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Solution Overview

Problem

Existing laser beam shaping technologies face limitations in working frequency and imaging errors due to the image refresh rate of programmable beam shapers, which can lead to unintended transition states and thermal stress during machining processes.

Innovation Solution

A device and method utilizing a deflection unit to alternately direct a laser beam onto multiple beam shapers with different shaping patterns, combining the light paths via an optics unit, allowing for rapid switching between patterns without constant exposure to laser light, thereby reducing thermal load and imaging errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a single programmable beam shaper is used to shape laser beams, then the beam shaping function is provided, but the switching frequency between different beam shapes is limited and thermal stress accumulates

Engineering Contradiction:
Improveswitching frequencyVSAvoidbeam shaping accuracy
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The system divides the beam shaping function across multiple beam shapers (at least two) instead of using a single beam shaper. Each beam shaper can be independently controlled and switched between active and inactive states, enabling higher switching frequencies while distributing thermal load across multiple components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements periodic switching between multiple beam shapers, where each beam shaper is activated in alternating cycles. This periodic action allows each beam shaper to cool down during inactive periods while maintaining continuous beam shaping capability, thus increasing overall switching frequency and reducing thermal stress accumulation.

Inventive Principle:
Principle #19Periodic action

2Adaptability or versatility

If the beam shaper changes shaping patterns during active irradiation, then adaptability is improved, but unintended transition states occur causing imaging errors

Engineering Contradiction:
Improvebeam shape adjustment capabilityVSAvoidbeam shaping accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system pre-configures multiple beam shapers with different shaping patterns before operation. When switching between patterns, one beam shaper is already prepared and ready to take over immediately, eliminating transition states and imaging errors during pattern changes.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses a deflection unit as an intermediary to switch the laser beam between multiple beam shapers. This allows pattern changes to occur in the inactive beam shaper while the active beam shaper continues to provide stable beam shaping, preventing transition states from affecting the output beam quality.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If continuous irradiation of the beam shaper is used, then processing efficiency is maintained, but thermal stress increases reducing component lifespan

Engineering Contradiction:
Improveprocessing efficiencyVSAvoidthermal stress
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The system implements periodic switching between multiple beam shapers, where each beam shaper is activated for a period then deactivated for cooling. This periodic operation maintains continuous processing efficiency while allowing each component to dissipate heat during inactive periods, reducing thermal stress accumulation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system combines multiple beam shapers in parallel configuration, where at least two beam shapers work in alternation. This merging approach distributes the thermal load across multiple components while maintaining continuous beam shaping capability, thus preserving processing efficiency without excessive thermal stress on any single component.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances the switching frequency and reduces thermal stress on beam shapers, improving the quality and efficiency of laser processing by minimizing transition effects and objective speckles, allowing for faster processing times and improved machining results.

Implementation Method 1

a deflection unit for alternately directing the laser beam along a first light path and at least a second light path onto a first beam shaper and at least a second beam shaper

Methodology Applied
Scientific EffectLight reflection/deflection: Reflection

Implementation Method 2

an optical unit for combining the first and at least second light paths after beam shaping

Methodology Applied
Scientific EffectOptical beam combination: Interference

Implementation Method 3

Spatial Light Modulators (SLM) based on liquid crystals... they allow for the targeted adjustment of a desired wavefront shape for the output beam

Methodology Applied
Scientific EffectLiquid crystal refraction modulation: Refraction

Implementation Method 4

Digital Micromirror Devices in the form of one- or two-dimensional arrays of movable mirrors... allow for the targeted adjustment of a desired wavefront shape

Methodology Applied
Scientific EffectDigital micromirror device reflection modulation: Reflection

Implementation Method 5

a laser; a controllable light processing unit... a linearly polarized laser for generating a linearly polarized light beam

Methodology Applied
Scientific EffectLaser radiation: Laser

Data Source

PatentEP3346314B1Device and method for forming a laser beam by means of a programmable beam former
Publication Date: 2020.12.02 ROBERT BOSCH GMBH
  • EP3346314B1 patent drawingFigure 1

AI summary

The invention relates to a device for shaping a laser beam by means of a programmable beam shaper.According to the invention, a deflection unit is provided for alternately directing the laser beam along a first light path and at least a second light path onto at least two different areas of the beam shaper or onto a first beam shaper and at least a second beam shaper; an optical unit is provided for combining the first and at least second light paths after beam shaping; a control unit is provided for controlling the deflection unit (13) and the first and at least second beam shapers (14, 15); and the control unit (20) includes a sequence control for alternately directing the laser beam (12) onto the first light path (17) and at least second light path (18) as well as for controlling a shaping pattern on the first beam shaper (14) and the at least second beam shaper (15).