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:
Nov. 17, 2009
Filed:
Dec. 10, 2007
Naomasa Suzuki, Hitachinaka, JP;
Hiroyuki Ito, Hitachinaka, JP;
Ichiro Tachibana, Hitachinaka, JP;
Hitachi High - Technologies Corporation, Tokyo, JP;
Abstract
The present invention was made in view of a problem of an electron microscope in which a reduction in detection efficiency of electrons detected by a detector should be prevented by eliminating any influence of a leakage magnetic field through a gap in an objective lens onto the electrons emitted from a specimen. To solve the problem, the present invention provides an electron microscope having a configuration with: a pole piece electrode for accelerating primary electrons emitted at an electrons source; and an objective lens including the pole piece electrode. In the objective lens, an electrically and magnetically insulated gap is formed between the pole piece electrode and other pole piece, and an auxiliary coil is concentrically disposed with the objective lens at a middle position between the gap and a detection surface of the electron detector, with an electric current flowing through the auxiliary coil in the opposite direction from that of an electric current flowing through the objective lens coil.