Patent ID: 6649863
Filing Date: 2003-11-18
Classification: B23K

Abstract:
A gemstone marking system, comprising:(a) a laser, said laser generating a laser beam having a focal plane and directed to a marking surface of a gemstone; (b) means for translating the gemstone relative to said focal plane of said laser beam; (c) a focus sensing unit sensing relative disposition between said marking surface of the gemstone and said focal plane of said laser beam, said focus sensing unit including: a light source emitting a collimated optical beam directed in substantially coinciding fashion with said focal plane of said laser beam and overlapping regions positioned in close proximity to said focal plane of said laser beam, and an optical detector measuring the power of said optical beam, the power of said optical beam depending on a relative disposition between said marking surface of the gemstone and said focal plane of said laser beam; and (d) a signal processing unit operationally coupled to an output of said optical detector for receiving therefrom and processing data corresponding to the relative disposition of said marking surface of the gemstone and said focal plane of said laser beam.