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:
Dec. 03, 2002
Filed:
Mar. 03, 2000
Applicant:
Inventor:
Yuuji Yada, Iwata, JP;
Assignee:
NTN Corporation, Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01S 3/22 ;
U.S. Cl.
CPC ...
H01S 3/22 ;
Abstract
When an excimer laser device is stopped from operating, an alternating current is applied to a coil of an electromagnet of a magnetic bearing for a fan so as to erase a residual magnetic field and thus weaken the adhesiveness of dust to the electromagnet. A dust sucking unit sucks to remove the dust attaching to the electromagnet together with a gas introduced into a chamber. In this way, accumulation of the dust on the magnetic bearing for the fan can be prevented.