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. 19, 1980
Filed:
Sep. 01, 1977
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01M / ;
U.S. Cl.
CPC ...
250311 ; 250306 ; 2504 / ;
Abstract
An electron beam emitted from an electron beam source is applied to a sample and when it produces an magnified image of the sample on a fluorescent plate, the amount of the electron beam is detected. When the accumulation of the electron beam radiation reaches a predetermined value with lapse of the time, the beam density on the surface of the sample is so controlled as to be reduced to zero or below a certain preset level, whereby the sample is prevented from damage due to excessive exposure to the electron beam.