Optical pick-up actuator using a concentrated magnetization

摘要

An actuator for optical pick-up using the concentrated magnetization method that is capable of moving an objective lens converging a laser light beam onto an optical disc. In the actuator, a lens holder is attached to the objective lens. Coils are wound around the lens holder to receive a current. A permanent magnet constructs a magnetic circuit along with the coils to generate a driving force for the objective lens and is magnetized to concentrate a magnetic flux toward the coils. The actuator can improve a driving sensitivity in a wide frequency band with the aid of the permanent magnet in which a magnetic flux density concentrates on the effective surfaces of the coils.