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:
Jan. 25, 2011
Filed:
Jul. 29, 2008
Ichiro Tokunaga, Miyagi-ken, JP;
Ichiro Tokunaga, Miyagi-ken, JP;
Alps Electric Co., Ltd., Tokyo, JP;
Abstract
A magnetic encoder is provided, in which a large output voltage (a large amplitude) is obtained so that the magnetic encoder can have a strong resistance to external noise and so that malfunction can be prevented. Each of first to fourth magnetoresistance elements A, A, A, and Ahas at least a pinned layer, and a free layer in which an internal magnetization direction changes in accordance with external magnetic fields emitted by a magnetic body. A magnetization direction α of the pinned layer is set to be in a first direction (a direction Z) that is parallel to an outer peripheral side surfaceA and that is perpendicular to rotation directions ra-ra, or is set to be in a second direction (a direction Z) that is opposite to the first direction. Additionally, an initial magnetization direction β of the free layer is set to be in the first direction (the direction Z) or the second direction (the direction Z). When a pitch of N and S poles adjacent to one another in the rotation direction is denoted by λ, a pitch of the magnetoresistance elements A, A, A, and Ais set to a pitch of λ/2.