PURPOSE: To decrease number of components and to attain miniaturization and light weight by arranging the position of a parallel plate spring, a magnetic circuit, a focus direction drive coil and a track direction drive coil to a nearly symmetrical position to an objective lens.
CONSTITUTION: It is supposed that a current flows to the track direction drive coil 108 in the direction of th arrow in solid lines. The direction of the magnetic flux is a direction shown in the arrow, the track direction drive coil 108 is in the relation of position with a yoke 110 as shown in the figure, and an electromagnetic force explained as th Fleming's left-hand rule produced by the current flowing to the arrow is acted on the track direction drive coil 108 in the right direction. The direction of the flow of magnetic flux is set in the arrow shown in broken lines or oppositely depending on the direction of a magnet 109, and the direction and amount of the current flowing to the track direction drive coil 108 are supplied properly to the objective lens 105 in a direction correcting the track direction error. Furthermore, the miniaturization is also attained by bending the track direction drive coil 108 at right angles.
INAGAKI SHIGERU
NAKAJIMA ATSUYOSHI
HOSHI SEIJI
TAKEMURA YASUHIRO
