Drive apparatus having drive unit using magnetic circuit
US11165325B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 22, 2018 |
| Grant date | Nov 2, 2021 |
| Priority date | — |
| Expiry date | Jun 3, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B2205/0069
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A drive apparatus comprising a stationary frame with a coil, a movable frame with a magnetic circuit held movably in a direction orthogonal to a first direction, and a drive unit that moves the movable frame by applying electric current to the coil. The magnetic circuit is constituted by aligning a first magnet having a magnetization direction parallel to the first direction, a second magnet having a magnetization direction opposite to the first magnet, and a third magnet between the first and second magnets in a direction orthogonal to the first direction. The third magnet has a magnetization direction that has a pole in the same direction of the poles of the first and second magnets when viewed from the coil side. The side spaces of the first and second magnets opposite to the third magnet are occupied by material whose magnetic permeability is lower than the magnets.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.