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:
Jan. 08, 1991
Filed:
Jan. 19, 1990
Tami Isobe, Yokohama, JP;
Ricoh Company Ltd., Tokyo, JP;
Abstract
A method for determining a measured incident angle of a monochromatic light for measurement is applied in the measurement of a refractive index and a thickness of a thin film of a single layer formed on a substrate having a known complex refractive index. This method comprises the steps of measuring a first energy reflection ratio of an S-polarized light or a P-polarized light by a measured sample at various angles of incident of the monochromatic light having a certain wavelength used in the measurement; calculating a second energy reflection ratio of the S-polarized light or the P-polarized light when the monochromatic light is incident to the substrate within an incident medium having a certain refractive index, the second energy reflection ratio being calculated by using the complex refractive index and the refractive index of the incident medium as a function of the incident angle; calculating a second angle satisfying an equation in which the first and second reflection ratios are equal to each other with respect to the S-polarized light or the P-polarized light; and setting an angle except for this second angle as the measured incident angle. The other two incident angle determining methods are shown.