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:
Oct. 07, 2003
Filed:
Oct. 20, 2000
Applicant:
Inventors:
Masami Shirai, Saitama, JP;
Katsuhiko Kenjo, Tokyo, JP;
Assignee:
Other;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01C 1/500 ;
U.S. Cl.
CPC ...
G01C 1/500 ;
Abstract
A surveying instrument which incorporates a magnetic incremental rotary encoder includes a rotary magnetic drum provided on an outer peripheral surface thereof with a multi-pole magnetized layer having a plurality of equally-divided magnetized divisions, a pair of magnetic sensors located on opposite sides of said rotary magnetic drum so that each of said pair of magnetic sensors faces said multi-pole magnetized layer, and at least one magnet, positioned in the vicinity of at least one of said pair of magnetic sensors, for reducing an error in detection of said magnetic incremental rotary encoder.