Two-axis moving coil actuator

A driven unit for an actuator for adjusting the position of an objective lens in an optical data storage system, comprising:

• an objective lens having an optical axis;
• a lens holder to which said objective lens is mounted;
• a first coil wrapped around said lens holder having an axis substantially parallel to said optical axis of said objective lens;
• a second coil affixed to said first coil having an axis substantially perpendicular to said axis of said objective lens;
• and
• a third coil affixed to said first coil having an axis substantially perpendicular to said axis of said objective lens, wherein said second coil and said third coil have inside portions which define a hollow center, and said inside portions are positioned around and against said first coil.

An actuator for adjusting the position of an objective lens in an optical data storage system, comprising:

• an objective lens having an optical axis;
• a first pair of permanent magnets, comprising a generally rectangular first permanent magnet defining a face and having a north pole and a south pole, and a generally rectangular second permanent magnet defining a face and having a north pole and a south pole, wherein said north pole of said first permanent magnet is positioned adjacent said south pole of said second permanent magnet and said south pole of said first permanent magnet is positioned adjacent said north pole of said second permanent magnet, said first permanent magnet and said second permanent magnet adjoining along a planar interface perpendicular to said optical axis of said objective lens;
• a second pair of permanent magnets, comprising a generally rectangular third permanent magnet having a north pole and a south pole, and a generally rectangular fourth permanent magnet having a north pole and a south pole, wherein said north pole of said third permanent magnet is positioned adjacent said south pole of said fourth permanent magnet and said south pole of said third permanent magnet is positioned adjacent said north pole of said fourth permanent magnet, said third permanent magnet and said fourth permanent magnet adjoining along a planar interface perpendicular to said optical axis of said objective lens;
• a lens holder to which said objective lens is mounted positioned between said first pair of permanent magnets and said second pair of permanent magnets;
• a first coil secured to said lens holder having an axis generally coaxial with said optical axis of said objective lens, wherein, in response to a flow of electrical current through said first coil, said first coil cooperates with said first pair of permanent magnets and said second pair of permanent magnets to exert a resultant force perpendicular to said axis of said objective lens;
• a second coil having an axis generally perpendicular to said axis of said objective lens;
• and,
• a third coil having an axis generally perpendicular to said axis of said objective lens and generally coaxial with said axis of said second coil, wherein, in response to a flow of electrical current through said second coil and said third coil, said second coil cooperates with said first pair of permanent magnets and said third coil cooperates with said second pair of permanent magnets to exert a resultant force parallel to said axis of said objective lens.

An actuator for adjusting the position of an objective lens in an optical data storage system so that an optical beam can be focused on an optical spot, comprising:

• an objective lens having an optical axis;
• a lens holder to which said objective lens is mounted;
• a first pair of permanent magnets positioned to one side of said lens holder, comprising a first permanent magnet having a north pole and a south pole and a second permanent magnet having a north pole and a south pole, wherein said north pole of said first permanent magnet and said south pole of said second permanent magnet are positioned adjacent said lens holder, and wherein further said first permanent magnet is positioned closer to said optical spot than said second permanent magnet;
• a second pair of permanent magnets positioned to a side of said lens holder opposite said first pair of permanent magnets, said second pair of permanent magnets comprising a third permanent magnet having a north pole and a south pole and a fourth permanent magnet having a north pole and a south pole, wherein said south pole of said third permanent magnet and said north pole of said fourth permanent magnet are positioned adjacent said lens holder, and wherein further said third permanent magnet is positioned closer to said optical spot than said fourth permanent magnet;
• a first coil secured to said lens holder having an axis substantially parallel to said optical axis of said objective lens, wherein, in response to a flow of electrical current through said first coil, said first coil cooperates with said first pair of permanent magnets and said second pair of permanent magnets to exert a resultant force perpendicular to said axis of said objective lens;
• a second coil secured to said first coil having an axis generally perpendicular to said axis of said objective lens;
• and,
• a third coil secured to said first coil having an axis substantially perpendicular to said axis of said objective lens and generally coaxial with said axis of said second coil, wherein, in response to a flow of electrical current through said second coil and said third coil, said second coil cooperates with said first pair of permanent magnets and said third coil cooperates with said second pair of permanent magnets to exert a resultant force parallel to said axis of said objective lens.