Fringing field focus motor and mechanism for optical disk drive
AssigneeDPHI Acquisitions, Inc.
InventorsPeter J. Raymond, Thomas E. Berg
Life of this patent
Estimating the term…
Abstract
A system for controlling a distance between an optical head and the surface of a rotating optical disk comprising: an actuator arm having a first and second surface, the first surface facing the optical disk, the second surface facing away from the optical disk; an electromagnetic coil having an inner void, said coil adjacent to the second surface of the arm; and at least one permanent magnet producing a magnetic field that passes through the coil such that when an electric current is applied to the coil, a force is created at two or more segments of the coil.
Claims24
A system for controlling a distance between an optical head and the surface of a rotating optical disk comprising:
- an actuator arm including an optical head and having first and second surfaces, the actuator arm positioned between the optical disk and a magnet assembly, the first surface facing the optical disk, the second surface facing the magnet assembly;
- an electromagnetic coil having an inner void, said coil substantially parallel and adjacent to the second surface of the arm;
- the magnet assembly comprising three magnetized zones, a central zone and two outer zones, said zones having alternating magnetic fields wherein the transitions between the alternating zones are aligned with two or more active portions of the electromagnetic coil;
- and
- wherein the magnetic field from each of the outer zones passes through the electromagnetic coil and into the central zone.
A system for controlling a distance between an optical head and the surface of a rotating optical disk comprising:
- an actuator arm having a first and second surface, the first surface facing the optical disk, the first surface of the arm including the optical head, the second surface facing away from the optical disk;
- an electromagnetic coil having an inner void, said coil adjacent to the second surface of the arm;
- and
- at least one permanent magnet producing a magnetic field that passes through the coil such that when an electric current is applied to the coil a force is created at two or more segments of the coil.
A method for positioning an optical pickup element relative to an optical disk comprising:
- applying current to an electromagnetic coil positioned in a magnetic field causing a force which moves the optical pickup unit in a direction generally perpendicular to the surface of the optical disk, the coil having two or more portions aligned with a transition between alternating magnetic fields or the edge of a magnet;
- and
- altering the current in the coil to reposition the optical pickup unit in a direction generally perpendicular to the surface of the optical disk.
A system for maintaining a distance between an optical head and the surface of a rotating optical disk comprising:
- means for locating and positioning an optical head;
- means attached to the means for locating and positioning an optical head for creating a variable magnetic field;
- and
- means for creating a permanent magnetic field having two or more transitions between alternating magnetic zones, said transitions aligned with two or more segments of the means for creating a variable magnetic field such that altering the variable magnetic field positions the optical head closer to or further away from the surface of the rotating optical disk.
Dependencies are inferred from the claim text.