UV Laser Lens Marking With Minimal Thermal Deformation
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Solution Overview
Problem
Existing methods for marking ophthalmic lenses, such as thermal and ultrashort laser processes, face challenges with material deformation and environmental impact, and are either expensive or require multiple devices for different materials.
Innovation Solution
A device using a solid-state laser emitting a focused pulsed beam of ultraviolet radiation with specific parameters (wavelength between 200 nm and 300 nm, pulse duration between 0.1 ns and 5 ns, and energy per pulse between 5 μJ and 100 μJ) for marking ophthalmic lenses, allowing for both technical and commercial markings on various materials with minimal thermal affected zones and adaptable fluence settings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If thermal processes with CO2 lasers are used for marking, then material removal is achieved, but the thermally affected zone is large and material deformation occurs
Solution Approach 1:
The patent changes the laser wavelength parameter from infrared (CO2 laser at 10.6 μm) to ultraviolet (200-400 nm), which fundamentally alters the interaction mechanism with the material. UV photons have higher energy that enables direct bond breaking through photoablation, avoiding thermal diffusion and creating a minimal thermally affected zone while achieving precise markings.
2Manufacturing precision
If ultrashort laser processes are used for marking, then marking quality is improved with minimal thermal effects, but the equipment cost is high and environmental impact is significant
Solution Approach 1:
The patent uses nanosecond-pulsed UV laser parameters (pulse duration 0.1-10 ns, wavelength 200-400 nm) instead of ultrashort femtosecond or picosecond pulses. This parameter selection achieves photoablation with minimal thermal diffusion while using more affordable nanosecond-pulsed UV laser equipment, reducing both equipment cost and environmental impact compared to ultrashort laser systems.
3Adaptability or versatility
If multiple laser devices are used for different materials, then marking capability across various materials is achieved, but device complexity increases
Solution Approach 1:
The patent employs a single nanosecond-pulsed UV laser device that can mark multiple materials including glass, plastics, and varnished surfaces. The UV radiation's high photon energy enables direct photoablation across different material types, and the controllable pulse parameters (0.1-10 ns duration, adjustable energy) allow adaptation to various materials without requiring multiple specialized laser systems.
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 precise, cost-effective, and environmentally friendly marking of ophthalmic lenses with reduced material deformation, allowing for markings on both finished and unfinished surfaces, and various materials, including those with functional treatments, using a single device.
Implementation Method 1
the interaction of ultraviolet (UV) laser radiation with an absorbing material (generally a polymer) of the lens drives a chemical decomposition mechanism. In contrast to an infrared photon (IR), the energy of an ultraviolent (UV) photon is high enough to break a covalent bond.
Implementation Method 2
Other example processes for marking by ablation, and in particular photo-ablation, referred to as photochemical processes, such as Excimer laser processes, are also known.
Implementation Method 3
the interaction between continuous-wave or pulsed infrared (IR) or near-infrared laser radiation emitted by the laser and a constituent material of the lens absorbing the rays gives rise to the following thermal effects: absorption of the rays by the material, diffusion of heat into the material, melting of the material then vaporization of the material.
Implementation Method 4
absorption of the rays by the material
Data Source
AI summary
A device for marking an ophthalmic lens (3), the lens (3) being made of at least one preset material, includes a laser (1) configured to produce permanent engravings on the lens (3) and configured to emit a focused beam of pulsed ultraviolet laser radiation that includes at least one radiation wavelength ranging between 200 nm and 300 nm, has a pulse length ranging between about 0.1 ns and about 5 ns, and has an energy per pulse ranging between about 5 μJ and about 100 μJ. A laser marking process configured to produce permanent engravings on an ophthalmic lens (3) via this device is also described.