Magnetically coded device and method of manufacture
US5091021A · kind A · utility
9Cited by
2References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1990 |
| Grant date | Feb 25, 1992 |
| Priority date | — |
| Expiry date | Sep 28, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12465
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Nonmagnetized permanent magnet material is heated in a pattern by a laser beam to a localized temperature above the Curie point or a temperature sufficient to reduce the coercivity sufficiently for an external field to magnetize the pattern in the direction of the field. Magnets so produced can have very high pole density, digital encoding and analog patterns having gradually varying local field strength. Alternating pole magnets of this type can be used for stepper motor magnets.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.