A cross section of a luminous flux of returning light from a disc is split into a plurality of regions, and an operation is performed so that a weighting of a light amount of a region which has favorable symmetry in a radial direction and is formed on a circumference of an ellipse among the split regions is increased. Further, a lens shift detection signal is formed, and a lens shift detection signal is canceled from a push-pull signal.

A cross section of a luminous flux of returning light from a disc is split into a plurality of regions, and an operation is performed so that a weighting of a light amount of a region which has favorable symmetry in a radial direction and is formed on a circumference of an ellipse among the split regions is increased. Further, a lens shift detection signal is formed, and a lens shift detection signal is canceled from a push-pull signal.

A linear actuator for linearly positioning a recording head in a data storage mechanism. The disclosed linear actuator includes an electrically conductive coil having first and second parts that are both wound in the same rotary direction about an axis, and a magnet spaced from the electrically conductive coil by an air gap. Transmission of an electric current through the first part of the electrically conductive coil in a first current flow direction about the axis and through the second part of the electrically conductive coil in an opposite second current flow direction about the axis induces linear movement of one of the electrically conductive coil and magnet relative to the other of the electrically conductive coil and magnet.

A linear actuator for linearly positioning a recording head in a data storage mechanism. The disclosed linear actuator includes an electrically conductive coil having first and second parts that are both wound in the same rotary direction about an axis, and a magnet spaced from the electrically conductive coil by an air gap. Transmission of an electric current through the first part of the electrically conductive coil in a first current flow direction about the axis and through the second part of the electrically conductive coil in an opposite second current flow direction about the axis induces linear movement of one of the electrically conductive coil and magnet relative to the other of the electrically conductive coil and magnet.

A linear actuator for linearly positioning a recording head in a data storage mechanism. The disclosed linear actuator includes an electrically conductive coil having first and second parts that are both wound in the same rotary direction about an axis, and a magnet spaced from the electrically conductive coil by an air gap. Transmission of an electric current through the first part of the electrically conductive coil in a first current flow direction about the axis and through the second part of the electrically conductive coil in an opposite second current flow direction about the axis induces linear movement of one of the electrically conductive coil and magnet relative to the other of the electrically conductive coil and magnet.

A linear actuator for linearly positioning a recording head in a data storage mechanism. The disclosed linear actuator includes an electrically conductive coil having first and second parts that are both wound in the same rotary direction about an axis, and a magnet spaced from the electrically conductive coil by an air gap. Transmission of an electric current through the first part of the electrically conductive coil in a first current flow direction about the axis and through the second part of the electrically conductive coil in an opposite second current flow direction about the axis induces linear movement of one of the electrically conductive coil and magnet relative to the other of the electrically conductive coil and magnet.

A linear actuator for linearly positioning a recording head in a data storage mechanism. The disclosed linear actuator includes an electrically conductive coil having first and second parts that are both wound in the same rotary direction about an axis, and a magnet spaced from the electrically conductive coil by an air gap. Transmission of an electric current through the first part of the electrically conductive coil in a first current flow direction about the axis and through the second part of the electrically conductive coil in an opposite second current flow direction about the axis induces linear movement of one of the electrically conductive coil and magnet relative to the other of the electrically conductive coil and magnet.