The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 19, 2002
Filed:
Feb. 09, 2000
Applicant:
Inventors:
James Gordon Charters Smith, Buckinghamshire, GB;
Keith Barry Guy, Middlesex, GB;
Graham Ralph Powell, Buckinghamshire, GB;
Michael Peter Gaukroger, Hampshire, GB;
Assignee:
Gersan Establishment, Liechtenstein, LI;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B44C 1/22 ;
U.S. Cl.
CPC ...
B44C 1/22 ;
Abstract
An invisible information mark is provided on a facet of a diamond gemstone by applying a plasma resist to the exposed surface of the gemstone, applying an electrically conducting layer of metal to the region where the information mark is to be formed, ablating a selected zone of the metal and resist layers by ultraviolet laser thus forming a mask on the surface of the facet, electrically connecting the metal layer and plasma etching the facet through the mask, thus forming a mark of appropriate depth on the surface of the gemstone.