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:
Sep. 19, 1995
Filed:
Dec. 17, 1993
Bruce G Kolloff, Sussex, NJ (US);
Jeffrey S Schoenwald, Thousand Oaks, CA (US);
Steve Beccue, Oxnard, CA (US);
Mohsen Khoshnevisan, Newbury Park, CA (US);
Rockwell International Corporation, Seal Beach, CA (US);
Abstract
An interferometrically readable optical encoder for sensing linear position includes an optical medium movable in a linear direction and having a data storage layer, a plurality of uniformly sized sectors being defined in the layer. A linear absolute track is defined in the layer parallel to the linear direction and a plurality of absolute marks is formed in the layer in sequence along the absolute track within each sector, each such absolute mark being detectable by interferometric reflection of coherent light as representative of a binary 1 or a binary 0 and each such plurality of absolute marks defining a binary word. A linear incremental track is defined in the layer parallel to the linear direction with a series of incremental marks formed in the layer and evenly spaced along the first incremental track, each such incremental mark being detectable by interferometric reflection of coherent light. The binary word in a sector is read to identify the position of that sector in the linear direction and indicate the approximate position of the medium. The incremental marks refine the approximate position indication to provide a more precise position of the medium.