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:
Apr. 20, 1999
Filed:
Dec. 16, 1997
Applicant:
Inventors:
Assignee:
Advantest Corporation, Gyoda, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G21K / ; H01J / ;
U.S. Cl.
CPC ...
2503 / ; 2503 / ; 3133611 ; 3133631 ;
Abstract
The invention relates to a gun lens for generating a particle beam with a cathode, an extraction electrode, an anode and a condenser lens, wherein a deceleration field is generated between the extraction electrode and the anode and the condenser lens produces a magnetic field which is superimposed on both the cathode, the extraction electrode and the anode.