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:
Oct. 24, 2006
Filed:
Sep. 29, 2004
Hiromi Inada, Hitachinaka, JP;
Hiromi Inada, Hitachinaka, JP;
Hitachi High-Technologies Corporation, Tokyo, JP;
Abstract
In an electron microscope, focus correction is carried out automatically, an astigmatic difference amount is displayed and astigmatism correction is executed quantitatively. Enlarged specimen images obtained by irradiating an electron beam on a specimen while changing excitation currents of an objective lens and of a stigmator coil are picked up by a capturing unit comprised of an optical lens and a capturing device and image sharpness coefficients are calculated by means of an arithmetic logic unit. A suitable astigmatism correction direction is chosen on the basis of an angular component value of the obtained image sharpness coefficients and then, a correction excitation current is supplied to a stigmator coil to correct astigmatism and a correction excitation current is supplied to an objective lens coil to perform focus correction.