Sapphire Watch Crystal Laser Marking Without Dust Contamination
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Solution Overview
Problem
Existing methods for marking sapphire watch crystals, such as laser etching, face issues with dust contamination and uncontrollable star-shaped internal defects, limiting the precision and visibility of markings.
Innovation Solution
A method involving a laser beam focused inside the sapphire crystal to create rectilinear opaque areas parallel or perpendicular to the upper surface, using controlled scanning speeds and parameters to produce precise hatching or perforation markings, allowing for adjustable dimensions and efficient control over marking placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If laser etching is used to mark sapphire crystals by removing material, then markings can be created on the crystal surface, but dust is generated that contaminates the marking
Solution Approach 1:
The harmful dust generation is eliminated by extracting the material removal step from the marking process. Instead of ablating material to create markings, the invention focuses the laser inside the crystal to create opaque areas through controlled internal defects, completely avoiding dust generation at the surface.
Solution Approach 2:
The invention converts the typically harmful uncontrolled star-shaped defects into a beneficial feature by deliberately creating controlled internal opaque areas. These controlled defects serve as the marking mechanism itself, transforming what was previously a quality issue into the core marking mechanism.
2Object-generated harmful factors
If laser impacts are used to create markings inside sapphire crystals, then markings can be formed without surface dust, but the star-shaped internal defects have uncontrollable cross-sections that limit minimum distance between impact areas
Solution Approach 1:
The invention changes the critical parameters of the laser interaction: using specific wavelengths (1064nm or 532nm), controlling pulse duration (nanosecond to femtosecond range), and adjusting focal depth within the crystal. These parameter changes transform the uncontrolled star-shaped defects into precise, controllable rectilinear opaque areas with predictable dimensions.
Solution Approach 2:
The marking is achieved through periodic laser pulses delivered in controlled sequences. By using pulsed laser action with specific frequencies and duty cycles, the invention creates uniformly spaced opaque areas that form precise patterns, replacing the uncontrolled single-impact approach.
3Manufacturing precision
If laser beam is scanned over crystal surface to remove material, then markings can be created, but the removed material must be evacuated which complicates the process
Solution Approach 1:
The invention extracts and eliminates the material removal step entirely from the marking process. By creating markings through controlled internal opaque areas rather than surface ablation, the harmful dust generation and complex evacuation systems are completely removed from the process.
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 eliminates dust contamination and provides precise, controllable markings with adjustable dimensions, enhancing the visibility and quality of markings on sapphire watch crystals.
Implementation Method 1
The beam is focused on a point inside the crystal and the interaction is such that it produces a rectilinear opaque area
Implementation Method 2
creating a break in the crystal lattice and making the material opaque
Data Source
AI summary
A method for marking a sapphire watch crystal, through the interaction between a laser beam and the sapphire. The beam is focused on a point inside the crystal and the interaction is such that it produces a rectilinear opaque area, which is parallel to the upper surface of the crystal or perpendicular to the surface. The orientation of the opaque area depends on the mode of operation applied. According to the hatching mode of operation, the beam is scanned along one or more linear paths, producing opaque lines inside the crystal, which are parallel to the upper surface. The perforation mode of operation produces distinct opaque areas, obtained by discontinuous operation of the beam on a number of juxtaposed points. According to this latter mode of operation, the opaque areas extend in the direction perpendicular to the upper surface of the crystal.