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:
May. 05, 1998
Filed:
Apr. 14, 1994
Adam E Norton, Palo Alto, CA (US);
Chester L Mallory, Campbell, CA (US);
Hung V Pham, San Jose, CA (US);
Paul Rasmussen, Livermore, CA (US);
KLA-Tencop. Corporation, San Jose, CA (US);
Abstract
An improved method and apparatus for measuring the relative reflectance spectra of an observed sample (3) and method and apparatus for autofocussing the sample (3). A broadband visible and ultraviolet beam (42) is split into a sample beam (46) and a reference beam (48). The sample beam (46) is reflected off the surface of the sample (3), and the spectrum of the reflected sample beam (46) is compared to the spectrum of the reference beam (48) to determine the relative reflectance spectrum of the sample (3). A video camera (96) is provided for viewing the sample (3). The autofocus system has a course-focus mode and a fine-focus mode. In the course-focus mode, the sample (3) is focused when the centroid of the sample image is centered on a position sensitive detector (99). In the fine-focus mode, the sample is focused when the intensity of light reaching the detector (99) is minimized.