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:
Jun. 18, 1991
Filed:
Sep. 22, 1988
Ernst Leitz Wetzlar, GmbH, Wetzlar, DE;
International Business Machines Company, Armonk, NY (US);
Abstract
In an apparatus for sensing a distance between a sensor and a surface of a body being measured, a sensor body of the sensor is formed as a light waveguide for laser light. A light exit site for light diffracted within the sensor body is located at a surface thereof which faces away from the measured body. A detection particle is located at the surface of the sensor body, which faces the measured body. The detection particle has a substantially convex and rounded off form and a major dimension which is smaller than the wavelength of the light. The measured body is located in the optical near field of the detection particle. A detector device converts the optical energy of the diffracted light into an electrical detector signal. A continuous thin film is provided as a coating on the sensor. It substantially covers the detection particle and at least a part of the surface of the sensor body in the vicinity of the detection particle. The film has a thickness which is smaller than one half of a predetermined wavelength. The sensor is used to finally convert a distance value into an electrical value.