Patent ID: 7227285
Filing Date: 2007-06-05
Classification: H02K

Abstract:
1. An autofocus actuator, comprising: a holder including a cylindrical portion having one end to which a lens unit is attached and a flange portion provided on the outer periphery of the other end of the cylindrical portion; a coil fixedly secured to the flange portion of the holder in such a manner as to surround the cylindrical portion of the holder; a yoke including an inner cylindrical portion having an insertion bore into which the cylindrical portion of the holder is inserted, an outer cylindrical portion provided outside the inner cylindrical portion with a predetermined spacing left therebetween, and a connecting portion for integrally interconnecting the ends of the inner cylindrical portion and the outer cylindrical portion at opposite side from the flange portion of the holder, the yoke adapted to accommodate the coil within the space of a predetermined gap size between the inner cylindrical portion and the outer cylindrical portion; a plurality of permanent magnets disposed on a magnet mounting surface of the inner periphery of the outer cylindrical portion of the yoke in a spaced-apart confronting relationship with the coil; a pair of leaf springs including an upper leaf spring and a lower leaf spring provided on opposite end sides in an optical axis direction of the cylindrical portion of the holder, respectively, for supporting the holder displaceably in the optical axis direction with the holder being positioned in a radial direction thereof; and a stopper attached to the one end of the cylindrical portion of the holder which protrudes from the inner cylindrical portion of the yoke for supporting the upper leaf spring between the holder and the stopper in a sandwich manner, wherein the holder in which the lens unit is incorporated being capable of adjusting its position in the optical axis direction by supplying electrical power to the coil; wherein the autofocus actuator further comprising light transmission means for confirming the space between the inner peripheral surface of the inner cylindrical portion and the outer peripheral surface of the cylindrical portion of the holder, the light transmission means being provided at predetermined positions of the flange portion and the stopper, respectively, so that light can pass therethrough.