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:
Apr. 29, 2008
Filed:
Feb. 15, 2006
Tomohisa Ohtaki, Hitachinaka, JP;
Kenichi Hirane, Hitachi, JP;
Ryoichi Ishii, Hitachinaka, JP;
Haruhisa Takahata, Naka, JP;
Tomohisa Ohtaki, Hitachinaka, JP;
Kenichi Hirane, Hitachi, JP;
Ryoichi Ishii, Hitachinaka, JP;
Haruhisa Takahata, Naka, JP;
Hitachi High-Technologies Corporation, Tokyo, JP;
Abstract
In an environmental scanning electron microscope in which differential pumping for maintaining the pressure ratio between an electron optical system and a specimen chamber at a predetermined value is effected and a probe electric current is conditioned to meet a predetermined or more value so as to permit observation of uncooked food and moist specimens in low vacuum, there are provided three stages of objective apertures used as apertures for an objective lens for an electron beam in the electron optical system and used also as orifices for differential pumping for maintaining the pressure ratio between the electron optical system and the specimen chamber at a predetermined value. Then, a deflection fulcrum of the electron beam in the electron optical system is set at a mid stage of the three-stage objective aperture.