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:
Jun. 09, 2009
Filed:
Jan. 15, 2008
Bernhard Gellrich, Aalen, DE;
Jens Kugler, Aalen, DE;
Thomas Schletterer, Stadtroda, DE;
Guido Limbach, Aalen, DE;
Julian Kaller, Koenigsbronn, DE;
Hans-juergen Scherle, Aalen, DE;
Detlev Mueller, Ellwangen, DE;
Dieter Schmerek, Huettlingen, DE;
Bernhard Gellrich, Aalen, DE;
Jens Kugler, Aalen, DE;
Thomas Schletterer, Stadtroda, DE;
Guido Limbach, Aalen, DE;
Julian Kaller, Koenigsbronn, DE;
Hans-Juergen Scherle, Aalen, DE;
Detlev Mueller, Ellwangen, DE;
Dieter Schmerek, Huettlingen, DE;
Carl Zeiss SMT AG, Oberkochen, DE;
Abstract
An optical element unit is provided comprising an optical element group; a housing receiving said optical element group and having an inner housing part and an exit end; and a purge unit connected to said housing and providing a purge medium to said inner housing part. The optical element group comprises an ultimate optical element. The ultimate optical element is located at the exit end of housing and separates the inner housing part from an environment external to the housing. The ultimate optical element and the housing define a sealing gap. The purge unit provides purge medium to the sealing gap to prevent intrusion of contaminants into the inner housing part.