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. 01, 1981
Filed:
Sep. 04, 1979
Daniel E Altman, San Diego, CA (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
A method and apparatus for sensing motion relies upon the total light traitted by an optical fiber. The fiber is wound in a spiral coil and cemented to a rigid base and a portion of the fiber's cladding is removed exposing its core. A highly refractive plate is placed closely adjacent the exposed core. When the plate is displaced, it intercepts at least a portion of the evanescent field that is adjacent to the spiral core. The intercepted portion reduces the total amount of light otherwise projected through the coiled optic fiber so that a detector can provide representations of the amplitude and frequency of the plate motion. The plate only penetrates the fiber's evanescent optical field which is associated with the total internal reflection at the glass-to-air interface at the fiber's surface. Adjusting devices and pressure compensation optionally are employed making this device suitable for use has a hydrophone.