摘要 |
A movable coil-type actuator including (a) a permanent magnet assembly constituted by a flat permanent magnet and a lower yoke element made of ferromagnetic material, the permanent magnet assembly including a recess in a central portion; (b) an upper yoke element made of a ferromagnetic material, the upper yoke element having such a shape that an edge of the permanent magnet does not extend from a periphery of the upper yoke element when viewed from above; (c) a unitary base member made of a thermoplastic resin and integrally including a hold portion for receiving the permanent magnet assembly and support portions for supporting the upper yoke element, a magnetic gap being defined by the permanent magnet and the upper yoke element; and (d) a movable coil fixed to an end of a swingable arm and movable in the magnetic gap.
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