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:
Mar. 11, 2014
Filed:
Apr. 14, 2010
Mikio Ichihashi, Kodaira, JP;
Takashi Onishi, Mito, JP;
Shunichi Watanabe, Hitachinaka, JP;
Keiji Tamura, Hitachinaka, JP;
Mikio Ichihashi, Kodaira, JP;
Takashi Onishi, Mito, JP;
Shunichi Watanabe, Hitachinaka, JP;
Keiji Tamura, Hitachinaka, JP;
Hitachi High-Technologies Corporation, Tokyo, JP;
Abstract
The present invention has an object to provide a cold cathode field-emission electron gun with low aberration, to thereby provide a high-brightness electron gun even in the case of a large current. The present invention provides a field-emission electron gun which extracts an electron beam from a cathode and converges the extracted electron beam, the field-emission electron gun including: a magnetic field lens which is provided such that the cathode is disposed inside of a magnetic field of the lens; and an extraction electrode for extracting electrons from the cathode, the extraction electrode being formed into a cylindrical shape without an aperture structure. The present invention can provide an electron gun having a function of converging an electron beam using a magnetic field, the electron gun which is capable of reducing an incidental electrostatic lens action and has small aberration and high brightness.