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:
Feb. 16, 1993
Filed:
Oct. 18, 1991
James S Johnston, West Sussex, GB;
Rosemount Limited, West Sussex, GB;
Abstract
Displacement measurement apparatus (1) shown in FIG. 1 measures the position of a reading means (4) relative to a coded track (2) which carries a sequence of code elements (5). The track is encoded with a binary sequence such that reading a binary word at any position along the track uniquely identifies its position. The binary word is remotely sensed by a decoding means (18) via a fibre optic link (12). Position information is encoded optically by the reading means using an interferometer to frequency modulate the transmitted light and the decoding means has a second interferometer to analyse received light and produce an electrical output representing the binary word.