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, 1992
Filed:
Oct. 12, 1990
Applicant:
Inventors:
Patrick C Brownrigg, Long Beach, CA (US);
David B Chang, Tustin, CA (US);
Victor Vali, Laguna Hills, CA (US);
Assignee:
Hughes Aircraft Company, Los Angeles, CA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G01P / ; G01B / ;
U.S. Cl.
CPC ...
356 28 ; 356349 ; 356354 ;
Abstract
A speed sensor for a moving vehicle. A transmissive grating is used in conjunction with an electromagnetic wave source and beam combining waveguide to mix two beams of frequency f and f+.DELTA.f, where .DELTA.f is proportional to the speed of the grating relative to the ground. The source energy is reflected off the road to the grating. The zeroth and first order transmission from the grating are mixed to give the beat frequency .DELTA.f proportional to the ground speed. The sensor has no moving parts, and is independent of any gear ratios.