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:
Aug. 14, 1990
Filed:
May. 12, 1989
Michio Kondo, Nagoya, JP;
Brother Kogyo Kabushiki Kaisha, Aichi, JP;
Abstract
An optical heterodyne apparatus wherein two linearly polarized reference beams having different frequencies, and two linearly polarized measuring beams identical with the reference beams are obtained from a laser beam or beams which is/are transmitted from a laser source to a measuring portion of the apparatus through an optical fiber. The apparatus includes an optical device for obtaining two reference beams whose beat phases are different from each other by 180.degree., and two measuring beams whose beat phases are different from each other by 180.degree., a first pair of photosensors receiving the two reference beams and producing two reference beat signals; a second pair of photosensors receiving the two measuring beams and producing two measuring beat signals, a first differential amplifier receiving the reference beat signals and producing a differentially amplified output; and a second differential amplifier receiving the measuring beat signals and producing a differentially amplified output. A parameter of a subject is measured based on the outputs of the first and second differential amplifiers.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile