| 摘要 |
PCT No. PCT/SE98/00147 Sec. 371 Date Sep. 27, 1999 Sec. 102(e) Date Sep. 27, 1999 PCT Filed Feb. 2, 1998 PCT Pub. No. WO98/35268 PCT Pub. Date Aug. 13, 1998Apparatus is disclosed for cyclic displacement of a camera shutter mechanism or the like between first and second end positions comprising an electromagnet displacing the shutter mechanism, the electromagnet comprising a pivotable armature pivotable between first and second positions, a plurality of blades, a rocker arm connected to the armature, a linkage connecting the rocker arm to the blades whereby pivoting of the armature can be translated into rotary movement of the blades, a biasing spring for biasing the armature towards a neutral position between the first and second end positions, a driver for ensuring that the armature reaches the first and second end positions, the driver comprising a permanent magnet for holding the armature in either of the first and second end positions and counteracting the biasing spring, and at least one coil for exerting a force on the armature upon activation of the coil, the force being sufficient to overcome the permanent magnet and the biasing spring. |
