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:
Apr. 24, 1990
Filed:
Jan. 22, 1988
Gerhard Hohberg, Aalen-Dewangen, DE;
Hermann Gerlinger, Aalen-Ebnat, DE;
Carl-Zeiss-Stiftung, Heidenheim, DE;
Abstract
The invention is directed to a reflectance measuring apparatus for making contactless measurements on structured test objects wherein the measuring result is independent of the distance of the test object within a difference range (d). The illumination arrangement and the measuring arrangement have a common center axis (z) which extends perpendicularly to the surface of the test object. At least the illumination arrangement or the measuring arrangement includes at least three radiation transmitters or three radiation receivers having optical axes arranged on at least one cone (c) concentric with respect to the common center axis (z). Of the set of radiation transmitters and the set of radiation receivers, one of the sets is configured to have a parallel ray bundle with a core area (k) and the other one of the sets is configured to have a bundle having a limited aperture with the area (m) covered by the limited aperture or apertures being smaller than the core area (k) within a distance range (d).