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. 30, 1996
Filed:
Apr. 29, 1994
Joseph L Horijon, Eindhoven, NL;
Christiaan H Velzel, Eindhoven, NL;
Cornelis S Kooijman, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
The height of a surface (25) along an axis (4) is determined by measuring the axial position of an irradiated spot (31) formed on the surface at the intersection of the surface and the axis. Radiation reflected by the surface and collected by a lens (8) forms an image spot (32) on the axis (4). The position of the image spot is determined by measuring the intensity of the radiation at at least three positions along the axis by means of a detection unit (35). The output signals (44, 44') of the detection unit are processed in an electronic means (43) for determining the position of the highest radiation intensity and for supplying a signal (43') whose magnitude represents the axial position of the image spot (32), hence, of the irradiated spot (31 ).