Patent attributes
An autofocus actuator 1 is provided with a yoke 300 that comprises an inner cylindrical portion 301 defining an insertion bore through which a hollow body portion of a holder is adapted to be received and an outer cylindrical portion 302 provided outside of the inner cylindrical portion 301 with a predetermined spacing left between the inner cylindrical portion 301 and the outer cylindrical portion 302 by a connecting portion, and the yoke 300 is constructed so as to receive a coil 20 in the space of a predetermined gap. The outer cylindrical portion 302 is formed into a generally polygonal cylindrical shape and inner surfaces of the outer cylindrical portion 302 define a plurality of magnet mounting surfaces each having a planar shape. A generally flat plate shape permanent magnet 41 is mounted on each of these magnet mounting surfaces 303. By the use of such a flat plate shape permanent magnet 41, it becomes possible to reduce a manufacturing cost and also possible to easily align and assemble the permanent magnets 41.
