Rotation-angle-detecting apparatus, rotating machine, and rotation-angle-detecting method
US8115479B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 2007 |
| Grant date | Feb 14, 2012 |
| Priority date | — |
| Expiry date | Oct 27, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/2451
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A rotation-angle-detecting apparatus comprising a magnet rotor having 4 or more magnetic poles on the surface, and sensor device for detecting magnetic flux from the magnet rotor, and an electronic circuit for outputting a signal representing the rotation angle of the magnet rotor using pluralities of signals obtained from the sensor device, the sensor device having pluralities of spin-valve, giant-magnetoresistive devices for outputting two or more different phase signals from a rotating magnetic field near the rotating magnet, each spin-valve, giant-magnetoresistive device having a pinned layer and a free layer, the magnetization direction of the pinned layer being fixed, and the magnetization direction of the free layer rotating depending on a magnetic field direction, pluralities of the spin-valve, giant-magnetoresistive devices comprising a first spin-valve, giant-magnetoresistive device having a reference magnetic-field-sensing direction, and a second spin-valve, giant-magnetoresistive device having a magnetic-field-sensing direction different from that of the first spin-valve, giant-magnetoresistive device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.