Abstract
An objective lens actuator using inner magnets for optical pickups was developed. The main magnets are paced outside the focusing coils, and the inner magnets are placed inside the coils. The inner magnets produce magnetic flux density in the tracking direction. Subsidiary driving forces generated in the focusing coils by the inner magnets when the moving part is moved in the tracking direction cancel the rolling moment caused by the main driving forces generated by the main magnets. The tilting of the actuator caused by the rolling moment is 90% less than with a conventional actuator without inner magnets.
