Rotating Optical Wedges for Adaptive Laser Spot Shaping

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Solution Overview

Problem

Existing laser processing devices lack flexibility in changing spot shapes during processing and have complex, expensive beam shaping and deflection optics, making them bulky and inflexible for different applications.

Innovation Solution

The use of rotating optical wedges, which can be made of suitable materials like glass or diffractive optical elements, allows for rapid and adaptive beam shaping by partially covering the laser beam, enabling a compact and space-saving design with dynamic beam shaping capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If complex beam shaping and deflection optics are used to change spot shapes during processing, then beam shaping flexibility is improved, but device complexity and size increase

Engineering Contradiction:
Improvebeam shaping flexibilityVSAvoidoptics complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The beam shaping and deflection function is segmented into multiple simple optical wedges (at least two) arranged in sequence, where each wedge can be independently rotated. This segmentation allows complex beam shaping to be achieved through simple, modular components rather than a single complex optical element.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The optical wedges are made rotatable about the optical axis through drives, enabling dynamic adjustment of spot shapes during processing. This dynamic capability allows the system to adapt beam shapes in real-time without requiring complex fixed optics for each possible shape.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If multiple optical elements are arranged to shape and deflect the laser beam, then spot shape control is improved, but the processing head becomes bulky

Engineering Contradiction:
Improvespot shape controlVSAvoidprocessing head volume
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The beam shaping function is divided into multiple simple optical wedges arranged in sequence, each with a relatively small cross-section. This segmentation allows the processing head to remain compact while achieving complex beam shaping through the combined effect of multiple simple elements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The optical wedges are arranged in a sequential configuration along the beam path rather than laterally, utilizing the longitudinal dimension to achieve beam shaping. This dimensional arrangement allows compact transverse profile while maintaining effective beam control.

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

3Device complexity

If fixed beam shaping optics are used, then device simplicity is improved, but adaptability during processing is reduced

Engineering Contradiction:
Improveoptics design simplicityVSAvoidbeam shape change capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The optical wedges are equipped with rotation drives that allow them to be rotated about the optical axis during processing. This dynamic capability enables the system to change spot shapes on-the-fly while maintaining the simplicity of the basic optical wedge design. The drives can be controlled to achieve different spot shapes as needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The spot shape is controlled by changing the rotation angle parameter of the optical wedges rather than by physically replacing optical elements. This parameter-based control maintains device simplicity while providing full adaptability for different beam shapes during processing.

Inventive Principle:
Principle #35Parameter changes

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 solution allows for quick changes in spot shapes during processing, achieving a simple and adaptive beam shape suitable for various applications while maintaining a slim and mobile processing head, essential for efficient laser machining.

Implementation Method 1

at least two optical elements arranged one behind the other in the direction of the collimated laser beam, which are formed by wedges with a wedge angle

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3938137B1Beamforming and deflection lens for a laser processing device and method for machining a workpiece by means of a laser beam
Publication Date: 2022.11.09 FRONIUS INT GMBH
  • EP3938137B1 patent drawingFigure 1
  • EP3938137B1 patent drawingFigure 2~3
  • EP3938137B1 patent drawingFigure 4A~4D

AI summary

The invention relates to a beam-forming and deflecting optical system (1) for a laser machining device, comprising at least two optical elements (2, 3) which are arranged one behind the other in the direction (z) of the laser beam (L) and which are formed by wedges (5, 6) with respective wedge angles (αi), at least one optical element (2) being connected to a drive for rotating the optical element (2) about the optical axis (c), whereby one optical wedge (5) can be rotated relative to the at least one other optical wedge (6). The invention also relates to a method for machining a workpiece (W) using a collimated laser beam (L). In order to achieve different shapes of the laser beam (L) on the workpiece (W), each of the optical wedges (5, 6) arranged one behind the other cover only one part of the laser beam (L).