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. 29, 1981
Filed:
Nov. 30, 1979
Dietmar Wagner, Sindelfingen, DE;
International Business Machines Corporation, Armonk, NY (US);
Abstract
Apparatus for dark field illumination consisting of light conducting fibers having end faces arranged within an annular region which is coaxial with the optical axis of an optical assembly, such as a microscope objective. The annular region is within the numerical aperture of the optical assembly and is positioned in the rear focal plane thereof so that light emitted by the fibers becomes dark field illumination for the object plane of the optical assembly when viewed through the central aperture of the annular region. Illumination of the object plane through the central aperture also dark field illuminates the object plane when viewed through the fibers. This is true even when the object plane is illuminated in only a small area by forcussing an illumination source through the central aperture and onto the object plane.