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:
Jan. 31, 1984
Filed:
Jan. 08, 1981
Akira Yonezawa, Fussa, JP;
International Precision Incorporated, Tokyo, JP;
Abstract
A transmission electron microscope comprises an objective lens and a condenser lens which are so arranged that excitation of the condenser lens can be varied in association with variation in excitation of the objective lens. A cross-over point which is produced by the condenser lens of the last stage in the non-excited state of the objective lens is caused to coincide with a preselected position on the optical axis of the microscope, which position is determined in accordance with magnitude of excitation of the objective lens. The position of a convergence point of the electron beam produced downstream of a specimen to be observed is maintained substantially constant independently from variations in excitation of the objective lens. The direction in which the electron beam impinges on specimen at a point to be observed is maintained substantially constant independently from variation in excitation of the objective lens. An image of improved quality is obtained without the field of view being narrowed, while observation can be made with constant magnification independently from different focus states. Aberrations are significantly decreased.