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:
Mar. 01, 2005
Filed:
Jan. 12, 2001
Harald Rose, Darmstadt, DE;
Harald Rose, Darmstadt, DE;
Carl Zeiss NTS GmbH, Oberkochen, DE;
Abstract
The invention relates to an electron-optical corrector for eliminating third-order aberrations, such as spherical aberrations, field curvature and off-axis astigmatism; said corrector being devoid of third-order off-axis coma, third-order distortion and first-order chromatic aberration of the first degree. The corrector has a construction which is symmetrical about the central plane in the direction of the linear optical axis. A hexapole Sof length lis first positioned in the direction of the beam path, followed by a circular lens R, a hexapole Sof length land subsequently a circular lens Rwhich is followed by a third hexapole Swith the same strength with the same strength of the hexapole Sand double the length of the latter l=21. The separation of the two circular lenses R, Rand the distance from the circular lens to the first hexapole Sis chosen in such a way that the internal plane of Scomes to rest in the front principal focus of the circular lens that is positioned downstream and the center of the hexapoles Sand Sis located on the focal plane. Additional elements of the corrector also follow in sequence, said elements being symmetrical about the central plane Zof the hexapole S.