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:
Apr. 21, 1992
Filed:
Nov. 07, 1990
Tami Isobe, Yokohama, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A method for measuring an unknown parameter, such as a refractive index, absorption coefficient and film thickness of the uppermost layer of a multi-layered film formed on a substrate whose refractive index and absorption coefficient are known, the refractive index, absorption coefficient, and film thickness of the other layer or layers than the uppermost layer on the multi-layered film being known, and at least one of the refractive index n.sub.1, absorption coefficient k.sub.1 and film thickness d.sub.1 of the uppermost layer being unknown, includes the step of measuring the reflectances, the step of specifying the functions containing unknown parameters, and the step of numerically solving the equation.