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:
Apr. 22, 2003
Filed:
Oct. 20, 2000
Masami Shirai, Saitama, JP;
Katsuhiko Kenjo, Tokyo, JP;
Other;
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; and at least two magnetic sensors, each of which detects a magnetic field generated by the multi-pole magnetized layer therefrom. Each of the at least two magnetic sensors detects a variation in the magnetic field due to a rotation of the rotary magnetic drum to measure an angle of rotation of the rotary magnetic drum, and the at least two magnetic sensors are arranged so that two of the at least two magnetic sensors are offset from each other to have a phase angle of an odd-numbered pitch angle therebetween.