| 摘要 |
PROBLEM TO BE SOLVED: To prevent the positional shifting of a permanent magnet caused by vibrations or shocks by highly accurately fixing the permanent magnet to a yoke plate. SOLUTION: This device is provided with: a pair of yoke plates 40 facing each other; a permanent magnet 31 fixed to at least one of the opposing surfaces of the yoke plates 40; and a driving coil 30 arranged to move between the opposing surfaces of the yoke plates 40. The permanent magnet 31 is formed into a flat plate shape having at least outer and inner periphery circular-arc projected and recessed surfaces 32 and 33 and two side faces 34 and 35. The yoke plate 40 has projections 40a to 40c for positioning the permanent magnet 31 in a normal position. The projections are disposed to abut only on parts which include the outer periphery circular-arc projected surface 32 and an extending surface 36 extended from the projected surface 32, but excludes the inner periphery circular-arc recessed surface 33 and the two side faces 34 and 35. COPYRIGHT: (C)2007,JPO&INPIT
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