Laser Pulse Width Control for Target Fracture Length in Cutting

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Solution Overview

Problem

Laser processing devices face challenges in generating a fracture of desirable length from the modified region, affecting cut surface quality and processing speed.

Innovation Solution

The laser processing device adjusts the pulse width of the laser light based on the desired fracture length and object thickness, utilizing a correlation between pulse width and fracture length to control the generation of fractures from the modified region.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If the pulse width of the laser light is increased, then the length of the fracture generated from the modified region increases, but the processing speed decreases

Engineering Contradiction:
Improvefracture lengthVSAvoidprocessing speed
Core Design Contradiction:
Length of moving objectVSSpeed

Solution Approach 1:

The patent applies dynamics by making the pulse width adjustable and variable during the laser processing operation. The control unit dynamically changes the pulse width based on real-time feedback about the fracture length, allowing the system to adapt the pulse width to achieve desired fracture lengths while optimizing processing speed. This transforms a static parameter into a dynamic control variable that can be optimized during operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control by measuring the actual fracture length generated from the modified region and using this information to adjust the pulse width for subsequent processing. The control unit receives feedback about fracture length and automatically modifies the pulse width parameter to achieve the target fracture length, creating a closed-loop control system that resolves the contradiction between fracture length and processing speed.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If the pulse width of the laser light is increased to generate longer fractures, then the cut surface quality improves, but the energy consumption increases

Engineering Contradiction:
Improvecut surface qualityVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts pulse width based on the specific requirements of each processing location and the desired fracture length. Rather than using a consistently high pulse width that would maximize energy consumption, the control unit varies the pulse width to the minimum necessary value to achieve the required cut surface quality and fracture length, thereby optimizing energy efficiency while maintaining precision.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the pulse width parameter adaptively based on processing conditions, object material properties, and desired fracture characteristics. By optimizing the pulse width parameter for each specific situation rather than using a fixed high value, the system achieves the required cut surface quality with minimal energy consumption, resolving the contradiction between manufacturing precision and energy use.

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 approach allows for the generation of fractures with specific lengths, enhancing cut surface quality and processing speed by dynamically adjusting pulse width according to input values for fracture length and object thickness.

Implementation Method 1

a laser light source which emits a laser light

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 2

irradiates an object to be processed with a laser light while locating a converging point within the object, so as to form a modified region in the object

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP2418041B1Laser machining device and laser machining method
Publication Date: 2024.09.18 HAMAMATSU PHOTONICS KK
  • EP2418041B1 patent drawingFigure 1
  • EP2418041B1 patent drawingFigure 2
  • EP2418041B1 patent drawingFigure 3

AI summary

A laser processing device (100) comprises a laser light source (101) for emitting a laser light (L) and a laser light source controller (102) for controlling the pulse width of the laser light (L) and irradiates an object to be processed (1) with the laser light (L) while locating a converging point (P) within the object (1), so as to form a modified region along a line to cut (5) of the object (1) and generate a fracture extending in a thickness direction of the object (1) from the modified region as the modified region is formed. In the laser processing device (100), the laser light source controller (102) changes the pulse width of the laser light (L) according to a data table in which the fracture length, the thickness of the object (1), and the pulse width of the laser light (L) are associated with each other. That is, the pulse width is changed according to the fracture length generated from the modified region. Therefore, the laser processing device (100) can generate a fracture having a desirable length from the modified region.