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:
Mar. 31, 1987
Filed:
Oct. 05, 1984
Applicant:
Inventors:
Wataru Kitaura, Hitachi, JP;
Tetsuo Ito, Hitachi, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01B / ; G01S / ;
U.S. Cl.
CPC ...
324208 ; 3312 / ;
Abstract
A plurality of permanent magnets are disposed on a movable object with predetermined spacings between them, and a fixed permanent magnet or magnets are disposed at positions spaced apart by a predetermined distance from the detection portion of a waveguide disposed along the movable object. Magnetostrictive ultrasonic waves generated on the waveguide are detected at the positions of these permanent magnets, and the position of the movable object is detected from the number of ultrasonic wave signals and the propagation time.