Counter-Moving Lens Units for Fast, Vibration-Free Laser Focus

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Solution Overview

Problem

In laser material processing, rapid and vibration-free focus adjustment is necessary to accommodate non-flat surfaces and system fluctuations, but existing solutions either require complex constructions to avoid vibrations or are inefficient in achieving quick beam size and focus changes.

Innovation Solution

A device with a movably arranged first and second lens unit, where the lenses are moved in opposite directions by an adjusting device to adjust the distance between them, using actuators and sensors to control the movement, ensuring equal but opposite forces are applied to cancel out vibrations and allow for rapid focus adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a single lens is moved for focus adjustment, then the device structure is simple, but vibrations are generated and focus adjustment speed is limited

Engineering Contradiction:
Improvefocus adjustment speedVSAvoiddevice structure complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The optical system is segmented into multiple lens units (first lens unit and second lens unit) that can be independently actuated. This segmentation allows each lens unit to be controlled separately by independent actuators, enabling rapid focus adjustment without requiring movement of a single heavy lens assembly, thus improving speed while managing complexity through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs a counterbalancing mechanism where the first and second lens units are moved in opposite directions with equal force. This creates a counterweight effect that cancels out vibrations generated during focus adjustment, allowing for faster movement without compromising system stability or requiring complex vibration damping structures.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

2Speed

If lens units are moved quickly for rapid focus adjustment, then focus adjustment speed improves, but vibrations are generated that can stimulate the device

Engineering Contradiction:
Improvelens movement speedVSAvoidvibrations
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The first and second lens units are actuated in opposite directions with equal force, creating a counterbalancing effect that eliminates vibrations. The opposing movements generate equal and opposite impulses that cancel each other out, preventing vibration transmission to the device housing and enabling rapid lens movement without harmful vibrations.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The patent uses asymmetric actuation where lens units are moved in opposite directions rather than moving a single lens unit. This asymmetric movement pattern transforms the harmful vibration-generating single-direction impulse into a balanced dual-directional system that cancels vibrations while maintaining rapid adjustment capability.

Inventive Principle:
Principle #4Asymmetry

3Object-affected harmful factors

If complex constructions are used to prevent vibrations, then vibration prevention is effective, but the device becomes more complex and less efficient

Engineering Contradiction:
ImprovevibrationsVSAvoidconstruction complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Instead of adding complex vibration damping components or isolation mechanisms, the patent uses the optical elements themselves (lens units) as counterweights. By moving these lens units in opposite directions with equal force, the system inherently cancels vibrations through the counterweight effect, achieving vibration prevention without additional complex construction.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The lens units serve dual functions: they perform the optical focusing function and simultaneously act as counterweights for vibration cancellation. This self-service approach means the optical elements themselves provide the vibration compensation, eliminating the need for separate vibration damping components and reducing overall device complexity.

Inventive Principle:
Principle #25Self-service

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 enables quick and vibration-free focus adjustment in laser material processing, enhancing the precision and efficiency of beam size and focus changes, eliminating the need for complex constructions to prevent vibrations.

Implementation Method 1

a movably arranged first lens unit, which comprises a first lens, and a movably arranged second lens unit, which comprises a second lens... adjust the distance between the first lens and the second lens for the focus adjustment

Methodology Applied
Scientific EffectLens focusing: Lens

Implementation Method 2

moving the first lens unit in a first direction and the second lens unit in a second direction opposite the first direction in order to adjust a distance between the first lens and the second lens for the focus adjustment

Methodology Applied
Scientific EffectVibration cancellation: Vibration

Data Source

PatentEP3850413B1Apparatus and method for focus adjustment for a material processing device, and device for laser material processing
Publication Date: 2023.11.01 JENOPTIK OPTICAL SYSTEMS GMBH
  • EP3850413B1 patent drawingFigure 1~3
  • EP3850413B1 patent drawingFigure 4~5
  • EP3850413B1 patent drawingFigure 6~7

AI summary

The invention relates to an apparatus (112) for focus adjustment for device (100) for laser material processing having a movably arranged first lens unit (124) comprising a first lens (108), and a movably arranged second lens unit (126) comprising a second lens (110). Said apparatus has an adjustment device (114) designed to move the first lens unit (124) into a first direction (116) and the second lens unit (126) into a second direction (118) that is opposite the first direction (118) in order to adjust a distance between the first lens (108) and the second lens (110) for the focus adjustment.