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. 24, 1998
Filed:
Sep. 17, 1996
Shalini Venkatesh, Santa Clara, CA (US);
Brian L Heffner, Los Altos, CA (US);
Wayne V Sorin, Mountain View, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An apparatus and method for measuring the thickness of a film having top and bottom surfaces. The apparatus includes low coherence light source that generates a probe light signal. The film is positioned against a roller having a partially reflecting surface that is positioned at a fixed distance from the film. The probe light signal is applied to the film and is then reflected back through the film by the partially reflecting surface. The light leaving the film is collected to form the input to a receiver that determines the time delay between light reflected from the top and bottom surfaces of the film. The receiver output may also be used to determine the thickness of the various layers in a multi-layer film.