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:
Aug. 21, 2007
Filed:
Oct. 12, 2000
Ilene M. Reinitz, New York, NY (US);
Mary L. Johnson, San Diego, CA (US);
James E. Shigley, Temecula, CA (US);
Thomas S. Hemphill, Lexington, MA (US);
Ilene M. Reinitz, New York, NY (US);
Mary L. Johnson, San Diego, CA (US);
James E. Shigley, Temecula, CA (US);
Thomas S. Hemphill, Lexington, MA (US);
Gemological Institute of America, Inc., Carlsbad, CA (US);
Abstract
Of the 'four C's,' cut has historically been the most complex to understand and assess. This application presents a three-dimensional mathematical model to study the interaction of light with a fully faceted, colorless, symmetrical round-brilliant-cut diamond. With this model, one can analyze how various appearance factors (brilliance, fire, and scintillation) depend on proportions. The model generates images and a numerical measurement of the optical efficiency of the round brilliant—called DCLR—which approximates overall fire. DCLR values change with variations in cut proportions, in particular crown angle, pavilion angle, table size, star facet length, culet size, and lower girdle facet length. The invention describes many combinations of proportions with equal or higher DCLR than 'Ideal' cuts, and these DCLR ratings may be balanced with other factors such as brilliance and scintillation to provide a cut grade for an existing diamond or a cut analysis for prospective cut of diamond rough.