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.

Date of Patent:
Jan. 03, 1984

Filed:

Dec. 16, 1980
Applicant:
Inventors:

Tadahiro Takigawa, Inagi, JP;

Isao Sasaki, Sodegaura, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ; H01J / ;
U.S. Cl.
CPC ...
250397 ; 2504942 ;
Abstract

An electron beam apparatus comprises an electron gun having a cathode consisting of single-crystal lanthanum hexaboride and a plurality of electron lenses for projecting the cross-over image of an electron beam emitted from the electron gun as a reduced-scale image onto a sample. It further comprises a circuit for measuring the brightness and shape of the cross-over image projected onto the sample and the emission pattern of the electron beam emitted from the electron gun, and a circuit for applying a bias voltage, with which the cross-over image has a desired brightness and is round and the emission pattern is anisotropic, to the electron gun.


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