Patent ID: 7911888
Filing Date: 2011-03-22
Classification: G11B

Abstract:
1. An actuator for a pickup, comprising: a fixed portion; a movable portion designed to be movable in each of a focusing direction extending along an optical axis of an objective lens and a tracking direction substantially perpendicular to the focusing direction, due to a driving force transmitted from a drive portion, for holding the objective lens; and a plurality of linear elastic members of five or more each having ends connected to the movable portion and the fixed portion, respectively, wherein the plurality of the linear elastic members is equal to one another in length dimension between the fixed portion and the movable portion, the ends of the plurality of the linear elastic members are located on a virtual circle formed on a plane by being projected onto a plane including both the focusing direction and the tracking direction, the virtual circle has a center defined as a rolling center with which a center of translational forces of the linear elastic members coincides, and at least one of a center of gravity of the movable portion and a center of a driving force of the movable portion coincides with the rolling center.