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:
Feb. 01, 1994
Filed:
Mar. 13, 1992
Applicant:
Inventor:
Satoshi Odagawa, Saitama, JP;
Assignee:
Pioneer Electronic Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ; G01C / ;
U.S. Cl.
CPC ...
364457 ; 364449 ; 36457105 ; 340990 ;
Abstract
Central coordinate data located on a circle of magnetism obtained from the X-Y coordinate data detected by a terrestrial magnetism sensor are calculated in correspondence with the direction of the road, calculated using map data or by a GPS device, and a present declination correction value each time the direction of the road is obtained. The declination correction value is automatically updated in such a manner as to decrease the radius of the circle of magnetism.