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:
Jul. 20, 1993
Filed:
Dec. 23, 1991
Willem D Van Amstel, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A device for optically measuring the height of surface irregularities of an object. A scanning spot of radiation (11) is formed on such surface, and a first optical imaging system (20) forms a reflected image (31) of the scanning spot on a diffusely reflective or transmissive screen (30). A second imaging system (40) forms from the imaged scanning spot (31) a re-imaged scanning spot (51) on the photosensitive surface of a position-sensitive radiation detection system (50). The screen is arranged so that the radiation from scanning spot (11) is incident thereon at a small grazing angle, and is adapted to diffuse the radiation from the imaged scanning spot (31) to produce radiation directed substantially normally on the photosensitive surface of the radiation detection system. A high degree of correlation between the position of the re-imaged scanning spot (51) on the photosensitive surface and the height (.DELTA.Z) of the surface of the object being measured is thereby achieved. The substantially normal direction of incidence of radiation on the photosensitive surface minimizes reflection therefrom and so improves the efficiency of the radiation detection system.