Magnetic encoder with a plurality of magnetic signal-generating means having different magnetic pole pitches
US5325056A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 1991 |
| Grant date | Jun 28, 1994 |
| Priority date | — |
| Expiry date | Aug 29, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnetic encoder containing a magnetic drum having on its side surface a plurality of magnetic signal-generating means having different magnetic pole pitches, and a plurality of magnetoresistance elements each disposed opposite to each of the magnetic signal-generating means. The magneto resistance elements include a plurality of series-connected thin, ferromagnetic layer patterns having a magnetoresistance effect so that an output signal of each magnetoresistance element is in the form of a substantially sinusoidal curve. The magnetic pole pitch of one magnetic signal-generating means is 5 times or more the magnetic pole pitch of other magnetic signal-generating means, and the magnetoresistance element opposite to the magnetic signal-generating means having a larger magnetic pole pitch includes by 5 or more series-connected thin, ferromagnetic layer patterns within the range of one-fourth the larger magnetic pole pitch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.