Laser Roller Structuring with Expanded Multi-Beam Ablation Fields

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Solution Overview

Problem

Current methods for structuring rollers using pulsed lasers are limited by high repetition rates, which lead to technical control restrictions, accuracy issues, and mechanical limitations, preventing the effective use of maximum average power for shortening processing time and achieving precise deterministic structures.

Innovation Solution

The use of an optical element to modify the spatial intensity pattern of laser pulses, allowing for an enlarged processing field and optimal ablation fluence, enabling better utilization of maximum average power and maintaining structural resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the repetition rate of laser pulses is increased to shorten processing time, then productivity is improved, but technical control restrictions and accuracy issues worsen

Engineering Contradiction:
Improveprocessing timeVSAvoidaccuracy of deterministic structures
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The laser beam is segmented into multiple sub-beams arranged in a matrix pattern, allowing parallel processing of multiple locations simultaneously. This segmentation enables the system to maintain high repetition rates for productivity while distributing the processing load across multiple beams, thereby preserving accuracy through controlled spatial arrangement of each sub-beam.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from single-beam sequential processing to multi-beam parallel processing by adding a spatial dimension to the laser pulse delivery. The matrix arrangement of sub-beams enables simultaneous processing across the roller surface, effectively multiplying the processing throughput without compromising the precision of individual structuring locations.

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

2Productivity

If the repetition rate of laser pulses is increased to utilize maximum average power, then productivity is improved, but mechanical limitations worsen

Engineering Contradiction:
Improveprocessing timeVSAvoidmechanical limitations
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The invention replaces mechanical scanning systems with an optical approach using diffractive optical elements to generate and position multiple sub-beams. This substitution eliminates the need for high-speed mechanical scanners and complex moving parts, allowing the system to operate at high repetition rates without being constrained by mechanical inertia and acceleration limits.

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

Solution Approach 2:

The system adds optical dimensionality through a matrix of sub-beams, enabling parallel processing that multiplies productivity without increasing mechanical complexity. The diffractive optical element creates multiple beam paths simultaneously, effectively bypassing mechanical bottlenecks by using optical field manipulation instead of mechanical motion.

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

3Productivity

If the processing field size is increased to improve productivity, then area covered per pulse is improved, but structural resolution worsens

Engineering Contradiction:
Improvearea covered per pulseVSAvoidstructural resolution
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The processing field is segmented into multiple discrete sub-beams, each maintaining a small focal spot size for high resolution. By arranging these fine-resolution sub-beams in a matrix pattern, the system covers a larger total area per pulse while each individual sub-beam preserves the structural resolution required for deterministic structuring.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple high-resolution sub-beams are merged into a composite processing pattern that covers a larger area. Each sub-beam individually maintains small spot size for precision, but their combined effect achieves the productivity gain of processing larger areas simultaneously through parallel action of multiple beams.

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 allows for a shorter processing time while ensuring the accuracy and precision of deterministic structures on the roller surface, effectively utilizing the maximum average power of the laser.

Implementation Method 1

laser pulses are directed onto the surface of a roller to be structured using an optical system, so that the roller is structured by laser ablation

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP3172006B1Method for structuring a roller by means of laser removal
Publication Date: 2021.06.16 THYSSENKRUPP AG
  • EP3172006B1 patent drawingFigure 1~4
  • EP3172006B1 patent drawingFigure 5~6(c)
  • EP3172006B1 patent drawingFigure 7(a)~8(b)

AI summary

The invention relates to a device (20) for structuring a roller (22) by means of laser removal, comprising a roller-holding apparatus, which is designed to hold a roller (22) to be structured, a laser source (24), which is designed to produce a series of laser pulses, and an optical system (26), which is designed to direct laser pulses produced by the laser source (24) toward the surface of a roller (22) held in the roller-holding apparatus, wherein the optical system (26) comprises an optical element (28), which is designed to modify the spatial intensity pattern of a laser pulse and to enlarge the processing field (42, 44, 48, 50) irradiated by the laser pulse on the surface of the roller (22). The invention further relates to a method for structuring a roller (22) by means of laser removal, in which laser pulses are directed by means of an optical system (26) toward the surface of a roller (22) to be structured such that the roller (22) is structured by laser removal in processing fields (42, 44, 48, 50) irradiated by the laser pulses, wherein by means of an optical element (28), in particular a diffractive optical element or a spatial modulator for light, the spatial intensity pattern of a laser pulse is modified and the processing field (42, 44, 48, 50) irradiated by the laser pulse on the surface of the roller (22) is enlarged in dependence on the maximum mean power Pm and/or adapted in such a way that the optimal removal fluence Φο results.