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. 19, 1988
Filed:
Oct. 27, 1986
Applicant:
Inventor:
Herbert G Drake, Jr, San Rafael, CA (US);
Assignee:
Tegal Corporation, Novato, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01J / ;
U.S. Cl.
CPC ...
2502 / ; 356224 ;
Abstract
An improved optical endpoint detector is disclosed in which two photocells are used in conjunction with analog multipliers and variable voltage sources, all under microprocessor control. The combination enables one to measure the ratio of intensity of different emission lines, as well as their individual outputs and alternative process monitoring signals.