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:
Sep. 28, 2004
Filed:
Jan. 09, 2003
Gerd Benner, Aalen, DE;
Leo Elektronenmikroskopie GmbH, Oberkochen, DE;
Abstract
In a transmission electron microscope with phase contrast imaging, the illumination of the object to be imaged takes place with an annular illuminating aperture. An annular phase-shifting element with a central aperture is arranged in a plane Fourier transformed with respect to the object plane. The annular phase-shifting element confers a phase shift of &pgr;/2 on a null beam, while the radiation of higher diffraction orders diffracted at the object in the direction of the optical axis passes through the central aperture of the annular phase-shifting element and consequently is not affected, or only slightly affected, by the phase-shifting element. The annular illuminating aperture is preferably produced sequentially in time by a deflecting system, which produces a beam tilt in a plane conjugate to the object plane.