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. 18, 1989
Filed:
Jun. 02, 1988
Chester W Newell, San Jose, CA (US);
Arthur D Bates, Menlo Park, CA (US);
Newell Research Corporation, Campbell, CA (US);
Abstract
A method of making and of reading markers at control positions on a length of magnetic tape having light-impeding coatings on opposed sides of a transparent tape substrate. Markers are recorded by directing focused beams to control positions along longitudinal areas of the magnetic tape. The beams have an energy sufficient to ablate the coatings, but to leave the tape substrate intact. Raster scanning of the control position provides rectangular markers at prescribed positions. An optical splitting element is used in reading the markers. The element is a heptagonal prism which receives light from a tape drive and forms two parallel, spaced apart beams which are first directed at separate elevations through the markers in the magnetic tape, then converged to the light sensors in the drive. Preferably the optical path through the prism is a path formed by folding a hexagonal prism, with the fold being a reflective surface.