Linear motor, stage device, and exposing device
US6043572A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 1998 |
| Grant date | Mar 28, 2000 |
| Priority date | — |
| Expiry date | Oct 14, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K41/03
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A linear motor includes a coil for receiving an electrical current and a first plurality of permanent magnets. The coil and the first plurality of permanent magnets move relative to each other in a direction of relative movement when an electrical current flows through the coil. The permanent magnets are arrayed in the direction of relative movement to form a first array. The direction of polarity of each permanent magnet in the first plurality of permanent magnets is oriented 90.degree. relative to the direction of polarity of an adjacent permanent magnet in the first plurality of permanent magnets. The first plurality of permanent magnets has a main portion and an end portion comprising plural corrective permanent magnets. Each of the plural corrective permanent magnets is smaller than the permanent magnets in the main portion having the same or opposite direction of polarity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.