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:
Jun. 22, 2004
Filed:
Nov. 04, 2002
Applicant:
Inventor:
Masaaki Mita, Tokyo, JP;
Assignee:
JEOL Ltd., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J 3/1256 ;
U.S. Cl.
CPC ...
H01J 3/1256 ;
Abstract
An electron beam apparatus is offered which is capable of being used optimally over a wide range of electron beam currents. A method of controlling this apparatus is also offered. The apparatus has an electron emitter for producing an electron beam. The beam is collimated or slightly converged (made a real-image mode beam) by the first condenser lens. As a result, the amount of the electron beam limited by the anode electrode can be reduced to a minimum. The excitation of the first condenser lens is fixed to parallel beam conditions and so movement of the virtual electron source is prevented. This can enhance the axial accuracy.