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. 11, 2012
Filed:
Sep. 28, 2009
Hiroshi Yasuda, Tokyo, JP;
Takeshi Haraguchi, Tokyo, JP;
Hiroshi Shimoyama, Nagoya, JP;
Hidekazu Murata, Nagoya, JP;
Hiroshi Yasuda, Tokyo, JP;
Takeshi Haraguchi, Tokyo, JP;
Hiroshi Shimoyama, Nagoya, JP;
Hidekazu Murata, Nagoya, JP;
Advantest Corp., Tokyo, JP;
Abstract
An electron gun includes: an electron source; an accelerating electrode; an extraction electrode for extracting electrons from an electron emission surface of the electron source; a suppressor electrode for suppressing emission of electrons from a side surface of the electron source; and an electron beam converging unit for converging an electron beam of thermal field emission electrons emitted from the electron emission surface by applying an electric field to the electron emission surface. The electron beam converging unit is an electrostatic lens electrode which is placed between the extraction electrode and the accelerating electrode and having an opening portion in its center. A voltage is applied to the electrostatic lens electrode to converge the electron beam.