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:
Oct. 06, 2015
Filed:
Jan. 31, 2007
Hendrik Nicolaas Slingerland, Venlo, NL;
William Ralph Knowles, Newbury, MA (US);
Hendrik Nicolaas Slingerland, Venlo, NL;
William Ralph Knowles, Newbury, MA (US);
FEI Company, Hillsboro, OR (US);
Abstract
The invention relates to a particle-optical apparatus with a predetermined final vacuum pressure. To that end a vacuum chamber of said apparatus is via a first restriction connected to a volume where vapor or gas is present at a known pressure and via a second restriction to a vacuum pump. By making the ratio of the two conductances, associated with said restrictions, a calibrated ratio, the final pressure of the vacuum chamber is a predetermined final pressure. This eliminates the need for e.g. vacuum gauges and control systems, resulting in a more compact design of such apparatus.