Patent ID: 7640559

Claim:
An objective lens actuator which is mounted on an optical head that concentrates a light beam on an optical disk, comprising: a movable body including a first objective lens used for concentrating the light beam on a recording surface of a high-density optical disk having a recording density higher than a DVD, a second objective lens used for concentrating the light beam on a recording surface of a CD or a DVD, and a lens holder holding both objective lenses; a base; and a support member supporting the movable body on the base so that the movable body can move in a focusing direction and in a tracking direction, wherein: when a light beam is concentrated and focused on the high-density optical disk, D 1 represents a distance between a disk surface and a part of the movable body in a closest position to the disk; when a light beam is concentrated and focused on the CD, D 2 represents a distance between a disk surface and the part of the movable body in the closest position to the disk; when a light beam is concentrated and focused on the DVD, D 3 represents a distance between a disk surface and the part of the movable body in the closest position to the disk; and the following relational expression (1) is satisfied, D1<D2<D3 (1).