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:
Feb. 28, 1984
Filed:
Jul. 28, 1981
Akira Yonezawa, Fussa, JP;
International Precision Incorporated, Tokyo, JP;
Abstract
An electron microscope comprises an objective lens, at least an intermediate lens and a projector lens arrayed in this order on an optical axis. A movable aperture element is disposed between the objective lens and the intermediate lens whose disposition and magnetic excitation are so selected that electron beam diverging from a crossover produced at a back focal plane of the objective lens is focused on a plane of the movable aperture element. In the case of an electron microscope comprising an objective lens, an objective aperture element, a selected area aperture element, at least an intermediate lens and a projector lens arrayed in this order along an optical axis, an additional lens is disposed between the objective aperture element and the selected area aperture element. Disposition and magnetic excitation of the additional lens are so selected that electron beam diverging from a crossover produced at a back focal plane of the objective lens is focused at a plane of the selected area aperture element. In both electron microscopes, divergence angle of the electron beam scattered by a specimen is restricted by the movable aperture element or the selected area aperture element.