SYSTEM FOR LASER MARKING AND METHOD FOR DETERMINING AUTHENTICITY OF MARKING Russian patent published in 2003 - IPC

FIELD: forming legends on precious stones. SUBSTANCE: laser system for making microlegends includes laser on base of Nd : YLF crystal with modulation of Q-factor and with harmonic converter for generating irradiation with wave length about 530 nanometers; optical system including focusing lens; holder designed for mounting precious stone and movable along three axes in order to move blank relative to optical system for directing laser energy to necessary portions; device for forming image in order to observe precious stone at large number of observation points. System includes upper chamber on base of charge coupled devices and lateral chamber on base of charge coupled device; processor controlling position of holder by marking commands according to preset program and system for storing information related to images of large number of blanks. Rigid framework supports laser, optical system and holder for enhancing stability to errors caused by vibration. Method for determining authenticity of marking comprises steps of marking blank by means of ablation picture; storing image and then reproducing it on authenticity certificate. Novelty is storing image of marking in data base with possibility of comparison and further detecting authenticity of blank. EFFECT: prevention of inadvertent or undesired doubled marking, versatility of system. 96 cl, 14 dwg