Patent ID: 7872951
Filing Date: 2011-01-18
Classification: G11B

Abstract:
1. An actuator for an optical pickup, for moving an object in a first direction, a second direction, and a third direction, said actuator comprising: a first permanent magnet set having a first middle yoke sandwiched between two magnets with two S-poles located immediately adjacent to said first middle yoke, and a top N-pole and a bottom N-pole located respectively at two opposite ends of said first permanent magnet set; a second permanent magnet set having a second middle yoke sandwiched between two magnets with two N-poles located immediately adjacent to said second middle yoke, and a top S-pole and a bottom S-pole located respectively at two opposite ends of said second permanent magnet set; a focusing coil, connected to said object and placed on an outer circumference of said first and second permanent magnet sets, for moving said object in said first direction by controlling an amplitude and direction of electrical current flowing through said focusing coil; a tilting coil, connected to said object and placed on the outer circumference of said first and second permanent magnet sets, for moving said object in said second direction by controlling an amplitude and direction of electrical current flowing through said tilting coil; and a tracking coil, connected to said object and placed on the outer circumference of said first and second permanent magnet sets, for moving said object in said third direction by controlling an amplitude and direction of electrical current flowing through said tracking coil; wherein said first and second permanent magnet sets are placed on a bottom yoke and positioned next to each other with a small space in between, and said top and bottom N-poles of said first permanent magnet set are next to said top and bottom S-poles of said second permanent magnet set for generating magnetic fields, and said actuator generates repelling and attracting forces to move said object in said first direction, said second direction, and said third direction independently.