Patent ID: 7924665
Filing Date: 2011-04-12
Classification: G11B

Abstract:
1. A pickup device comprising: a fixed portion; a movable portion holding an objective lens and adapted to move in at least one direction of a focus direction along an optical axis of a light beam incident on the objective lens and a tracking direction substantially orthogonal to the focus direction; a linear resilient member with ends connected to the movable portion and the fixed portion; a coil, wherein only one lateral side of the movable portion is attached to the coil; and a flux providing unit providing a magnetic flux that applies respective driving forces to a plurality of driven coil portions located at respective positions located away from a center of gravity of the movable portion, the directions of the driving forces being non-parallel and crossing with each other such that respective torques generated on the movable portion by driving the driven coil portions counteract one another; wherein the plurality of driven coil portions are located on the same side of a plane passing through the center of gravity of the movable portion and extending, parallel to the one lateral side, in a direction in which the movable portion is driven; and wherein the flux providing unit includes: a first magnet having a first pole and a second pole with different polarities and disposed opposite to the coil, the first magnet being spaced apart from the coil; and a second magnet disposed adjacent to the first magnet in such a manner that a second pole thereof is positioned close to the first pole of the first magnet opposing the coil and a first pole thereof is positioned close to the second pole of the first magnet opposing the coil, the coil including a tracking coil and being provided on the one lateral side of the movable portion, facing the fixed portion; wherein the first magnet has a first opposing surface facing the one lateral side of the movable portion and the second magnet has a second opposing surface facing a side of the movable portion that is perpendicular to the one lateral side of the movable portion, and wherein the first magnet and the second magnet are disposed with the first opposing surface and the second opposing surface being perpendicular to each other.