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:
Jun. 15, 1982
Filed:
Sep. 01, 1977
Fritz Bien, Billerica, MA (US);
Morton Camac, Lexington, MA (US);
Aerodyne Research, Inc., Bedford, MA (US);
Abstract
Methods and apparatus are disclosed for studying motion of an object or element, to determine not only quantities of motion but also direction of motion. A laser beam or the like is circularly polarized and directed to two or more retroreflectors and then to a detector. Beams of different frequencies are established and determination of relative direction of motion of the retroreflectors is made from the increase or decrease of frequency of beats of one beam against the other. In one embodiment, left and right circularly polarized light is reflected, and one of the beams is frequency-shifted. The light, being circularly polarized, is insensitive to rotational orientation of the test object, while maintaining directional and motion information.