Patent ID: 7304917
Filing Date: 2007-12-04
Classification: G11B

Abstract:
1. An actuator comprising: a holder for integrally holding an objective lens through which a light beam from an optical pickup passes, and an aberration-correcting element disposed on the optical axis of the objective lens to be driven by the supply of an aberration-correcting driving signal and mounted on a lower surface of the holder; a suspension base opposing the holder; and at least six suspension members disposed between the holder and the suspension base to support the holder movably in a focusing direction and/or a tracking direction, wherein two of the suspension members are respectively disposed below the other four suspension members on opposite sides of said objective lens, three of the suspension members are provided on one side of the objective lens and the other three of the suspension members are provided on the other side of the objective lens, one of said two suspension members being on one side of the objective lens, the other of said two suspension members being on the other side of said objective lens; wherein the aberration-correcting driving signal is supplied to the aberration-correcting element through said two of the suspension members, wherein the holder includes a bobbin for holding the objective lens, the aberration-correcting element is provided at an end of the bobbin through which the light beam passes, and the two suspension members through which the aberration-correcting driving signal is supplied to the aberration-correcting element are directly attached to the two ends of the aberration-correcting element and the suspension base at a position lower than the other four of the suspension members, and wherein, when an imaginary axis extending in the tracking direction is designated as an X-axis, an imaginary axis extending in the focusing direction is designated as a Y-axis, and an imaginary axis orthogonal to the X-axis and the Y-axis is designated as a Z-axis, the first and second suspension members are provided between the holder and the suspension base on both sides of the objective lens and on a first single plane parallel to an XZ-plane including the X-axis and the Z-axis, the third and fourth suspension members are provided between the holder and the suspension base on both sides of the objective lens and on a second single plane spaced in parallel from the first plane along the Y-axis and in a traveling direction of the light beam, and the fifth and sixth suspension members are provided between the aberration-correcting element and the suspension base on both sides of the objective lens and on a third single plane spaced in parallel from the second plane along the Y-axis and the traveling direction of the light beam, wherein the aberration-correcting driving signal is supplied to the aberration-correcting element through the fifth and sixth suspension members, and wherein the first, third, and fifth suspension members extend apart and parallel to one another on a single plane orthogonal to the XZ-plane, and the second, fourth, and sixth suspension members extend apart and parallel to one another on a single plane orthogonal to the XZ-plane.