Galvanometric Laser Etching for Lenticular Grating Image Registration
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Solution Overview
Problem
Existing methods for producing images that can be selectively viewed by varying the angle of observation under a lenticular grating, such as through laser etching, face mechanical complexity and difficulties in adjusting deflection mirrors, leading to issues with image registration and laser density variations, especially when producing color images.
Innovation Solution
A method involving a laser etching setup with a galvanometric head and scanning lens, where the etching zone is placed at the periphery of the working zone at right angles to the optical axis, allowing for high-angle incidence and simple translational movement between locations to etch distinct images, with the option to subdivide large images into parts and use a cylindrical lenticular grating for enhanced image production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an image deflection mirror is used to deflect the laser beam for obtaining different mean etching angles, then different viewing angles can be achieved, but the adjustment of the deflection mirror becomes complex and dependent on the position of the etching zone, making it difficult to change positions and causing variations in laser density
Solution Approach 1:
The patent replaces the mechanical deflection mirror system with a galvanometric head that uses electromagnetic fields to deflect the laser beam. The galvanometric head provides electronic control of beam direction through coil and magnet interactions, eliminating the mechanical adjustment complexity of mirrors while achieving the same angle separation function.
Solution Approach 2:
The patent changes the control parameter from manual mechanical mirror adjustment to electronic galvanometric coil current control. By varying the current parameters in the galvanometric coils, the laser beam angle can be precisely controlled without mechanical intervention, enabling easy position changes and consistent laser density.
2Adaptability or versatility
If the etching zone is placed at the center of the working zone, then the optical path is shortest, but high-angle separation for multiple images cannot be achieved
Solution Approach 1:
The patent moves the etching zone from the central optical axis to the periphery of the working zone in a radial dimension. This peripheral positioning allows the laser beam to strike the etching zone at high angles relative to the optical axis, enabling multiple images to be etched at different angular positions around the periphery, thus achieving angle separation without excessively lengthening the optical path.
3Adaptability or versatility
If a tiltable plate is used to orient the device relative to the laser etching setup, then different etching angles can be obtained, but mechanical complexity increases and translational mobility is required to correct defocusing
Solution Approach 1:
The patent replaces the mechanical tiltable plate system with a galvanometric head that achieves angle variation through electromagnetic deflection of the laser beam. This substitution eliminates the need for mechanical tilting and associated translational adjustment mechanisms, simplifying the overall system while maintaining the capability to vary etching angles.
Solution Approach 2:
The patent introduces dynamic electronic control through the galvanometric head, allowing rapid and precise adjustment of laser beam angles without mechanical movement of the etching zone or device. The galvanometric coils enable dynamic repositioning of the beam angle in response to control signals, providing flexibility without mechanical complexity.
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 simplifies the production of images with high-angle separation, ensures image registration, and allows for larger image sizes without mechanical complexity, enabling efficient production of customizable identity documents and 3D effects.
Implementation Method 1
a laser etching is conventionally performed by means of a setup 1 comprising a laser 2, capable of emitting a laser beam 12
Implementation Method 2
a lens 4 cable of focusing the laser beam 12
Implementation Method 3
a galvanometric head 3 comprising two mirrors that are mobile in order to be able to deflect the laser beam 12 in space
Implementation Method 4
arranging the resulting interleaving under a lenticular grating
Data Source
AI summary
A process for producing, under a lenticular grating, in an etching zone, by laser etching, using a tool, a first image and at least one second image that may be selectively viewed by varying angle of observation, the tool including a laser, a galvanometric head and a lens, and defining an optical axis and a working zone, which includes steps of: placing the etching zone in a first location included in the working zone and on the periphery of the working zone, and, perpendicularly to the optical axis, etching the first image; and then placing the etching zone in a second location, which is different from the first location, included in the working zone and on the periphery of the working zone, and, perpendicularly to the optical axis, etching the second image.