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. 31, 1992
Filed:
Sep. 22, 1989
William H Southwell, Thousand Oaks, CA (US);
Kirkpatrick W Norton, San Diego, CA (US);
Rockwell International Corporation, El Segundo, CA (US);
Abstract
A method is provided for monitoring the refractive index of an optical film as it is being deposited on a substrate. The film is illuminated by a source of light at a wavelength that is outside and less than the reflectance band of the coating. If the refractive index of the film is initially matched to the refractive index of the substrate and has no abrupt changes in its gradient-index profile, reflectance from the surface of the film can be detected and measured. In the absence of interference fringing from internal reflections, surface reflectance of the interface of the film with the surrounding air or vacuum is closely related to the refractive index of the film at its surface. Thus, surface reflection is monitored to provide a control signal to the deposition apparatus to conform the refractive index of material being deposited to a predetermined refractive index profile specified for the desired optical film.