Multiplexed Laser Beam Control for Responsive Fiber Power Distribution

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Solution Overview

Problem

Existing laser processing technologies face challenges in quickly adjusting the power distribution of combined laser light with different wavelengths to match changing workpiece shapes, leading to responsiveness issues and potential defects due to scattered laser light and damage to the laser resonator.

Innovation Solution

A laser processing device with a beam control mechanism that includes a first and second condenser lens, an optical combining member, and an optical path changing mechanism, allowing for precise control of the power distribution of multiplexed laser light by adjusting the incident positions of laser light with different wavelengths on an optical fiber, ensuring accurate power distribution and improved processing quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the reflector or condenser lens is moved by a piezo actuator to change the incident position of laser light, then the beam profile of the laser light can be adjusted, but the responsiveness is poor and it is difficult to quickly change the optical path when the workpiece shape changes

Engineering Contradiction:
Improvebeam profile adjustment capabilityVSAvoidresponsiveness
Core Design Contradiction:
Adaptability or versatilityVSSpeed

Solution Approach 1:

The patent divides the optical path into multiple independent segments, each with its own actuator for positioning optical elements. This allows individual segments to be adjusted independently and quickly, improving responsiveness while maintaining beam profile control capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces the piezo actuator mechanism with a faster positioning system that can quickly adjust the incident position of laser light on the optical fiber, enabling rapid optical path changes without the mechanical limitations of piezo actuators.

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

2Measurement precision

If the condenser lens is moved on a straight line by an actuator to change the incident position, then positional accuracy can be achieved, but responsiveness is compromised and scattered laser light may damage the laser resonator

Engineering Contradiction:
Improvepositional accuracyVSAvoidresponsiveness
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The patent introduces an intermediary optical element or mechanism that decouples the positioning function from the movement mechanism, allowing accurate positioning to be achieved without directly moving the condenser lens on a straight line, thereby improving responsiveness and preventing laser light scattering.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Use of energy by moving object

If laser light with different wavelengths is combined to process metal workpieces, then light absorptance can be improved, but the power distribution control becomes complex when workpiece shapes change

Engineering Contradiction:
Improvelight absorptanceVSAvoidpower distribution control complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent applies different wavelengths to different spatial regions or processing stages independently, allowing localized optimization of light absorptance for different workpiece features while simplifying overall power distribution control through region-specific management.

Inventive Principle:
Principle #3Local quality

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 solution enables reliable formation of molten pools and keyholes during welding, enhancing the overall welding quality by controlling the power distribution of combined laser light, reducing defects and maintaining high processing quality.

Implementation Method 1

a first condenser lens that receives the first laser light, and condenses the first laser light at a predetermined magnification, a second condenser lens that receives the second laser light, and condenses the second laser light at a predetermined magnification

Methodology Applied
Scientific EffectCondensation: Lens

Implementation Method 2

an optical fiber that includes at least a core, a first cladding provided coaxially with the core on an outer peripheral side of the core, and a second cladding provided coaxially with the core on an outer peripheral side of the first cladding, and includes an incident end face and an emission end opposite to the incident end face

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 3

a first laser oscillation unit that generates first laser light having a first wavelength, and a second laser oscillation unit that generates second laser light having a second wavelength different from the first wavelength

Methodology Applied
Scientific EffectStimulated emission: Laser

Data Source

PatentEP3978183B1Laser machining device and laser machining method using same
Publication Date: 2024.03.06 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3978183B1 patent drawingFigure 1
  • EP3978183B1 patent drawingFigure 2
  • EP3978183B1 patent drawingFigure 3

AI summary

A laser processing device includes a laser oscillator, optical fiber (90), beam control mechanism (20), and a laser light emitting head. The laser oscillator includes first and second laser oscillation units that generate first and second laser light rays (LB1) and (LB2), respectively. Beam control mechanism (20) includes optical path changing and holding mechanism (40) that is disposed between second condenser lens (32) that condenses second laser light (LB2) and dichroic mirror (33) that multiplexes first and second laser light rays (LB1) and (LB2) and causes the multiplexed light to be incident on optical fiber (90). Beam control mechanism (20) changes an incident position of second laser light (LB2) on optical fiber (90).