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:
May. 21, 1991
Filed:
Nov. 20, 1989
Richard D Bartholomew, Huntsville, AL (US);
Stephen K Pitalo, Huntsville, AL (US);
James R Schaffer, Jr, Madison, AL (US);
The Boeing Company, Seattle, WA (US);
Abstract
An optical position sensor is provided for sensing the position of an object movable along a motion axis. The sensor comprises a light source, a support member, a beamsplitter, a variable filter, and a processor. The light source produces an optical beam that is directed to the beamsplitter. The beamsplitter is fixedly coupled to the support member and optically coupled to the light source, and converts the optical beam into a reference beam and a subject beam. The beamsplitter projects the subject beam along a beam axis fixed relative to the support member. The variable filter is positioned along the beam axis, it is coupled to the object, and it is movably coupled to the support member to be movable along the motion axis in coordination with movement of the object for modulating the subject beam. The transmissivity of the variable filter is nonuniform along the motion axis to attenuate the subject beam in accordance with the position of the object. The processor is optically coupled to the beamsplitter to receive the reference beam and optically coupled to the variable filter to receive the subject beam. The processor compares the subject beam to the reference beam to determine the position of the object.