Process for producing, by etching through a lenticular grating, images that may be selectively viewed by varying angle of observation

A method for producing a first image and at least one second image, that can be selectively viewed by varying an angle of observation, under a lenticular grating (9), in an etching zone (6), by laser etching, by means of a setup (1) that includes a laser (2) capable of emitting a laser beam (12), a galvanometric head (3) capable of deflecting the laser beam (12), and a lens (4) capable of focusing the laser beam (12) and defining an optical axis (Z) and a working zone (5), the method comprising:

• placing of the etching zone (6) at a first location (7), included in the working zone (5), in a periphery of the working zone (5), and at right angles to the optical axis (Z), the first location (7) being at a first distance from the optical axis (Z) such that a mean angle of the laser beam (12) relative to the optical axis (Z) is greater than or equal to 15°;
• etching of the first image by the laser (2) in the etching zone (6);
• placing of the etching zone (6) at a second location (8) different from the first location (7), by a translational movement, by a plate bearing a device (11) during etching, from the first location (7) in a same plane, the second location (8) being inside the working zone (5), in the periphery of the working zone (5), and at right angles to the optical axis (Z), and the second location (8) being at a second distance from the optical axis (Z) such that the mean angle of the laser beam (12) relative to the optical axis (Z) is greater than or equal to 15°;
• and
• etching of the second image by the laser (2) in the etching zone (6).