Accession Number : ADD017274

Title :   Secret Optical Marking.

Descriptive Note : Patent, Filed 1 Nov 69, patented 1 Nov 94,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Drummeter, Louis F ; Stamm, Gordon L ; Rohl, Gerald E ; Rockman, Alfred G

Report Date : 01 Nov 1994

Pagination or Media Count : 4

Abstract : An optical marking system in which objects are coated with materials for the purposes of applying secretly coded marks on the objects. The coating materials are transparent in daylight and have the property of absorbing ultraviolet light. When such materials are applied to a portion of the surface of an object which is a good ultraviolet reflector, only the uncoated portion reflects ultraviolet. Thus, the marked object is therefore seen as having the coated portion blocked-out when viewed through a device which filters out all but ultraviolet wavelengths but appears to be unmarked when observed without the viewing device. Similar coding of objects may be achieved by appropriately selected paints, papers and other materials. (MM)

Descriptors :   *OPTICAL PROPERTIES, *CODING, *COATINGS, *IDENTIFICATION SYSTEMS, *PATENTS, *ULTRAVIOLET OPTICAL MATERIALS, MARKERS, REFLECTORS, OPTICAL FILTERS

Subject Categories : Coatings, Colorants and Finishes
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE