Method and apparatus for initializing intermediate region between tracks on magnetooptical recording medium

An apparatus for initializing a magnetooptical recording medium having a plurality of information tracks onto which information is recorded and having a plurality of intermediate regions, free from having information recorded thereon, alternately arranged, said apparatus comprising:

• means for applying to the recording medium a magnetic field having a predetermined direction;
• scanning means for scanning the recording medium by a light beam having sufficient power to align a magnetizing direction;
• tracking means for selectively effecting a first tracking control operation in which the light beam is tracking-controlling to an information track so as to trace the track and a second tracking control operation in which the light beam is tracking-controlled to an intermediate region so as to trace the intermediate region;
• and
• switching means for switching the tracking operation of said tracking means between the first tracking control operation and the second tracking control operation.

An apparatus for initializing a magnetooptical recording medium having a plurality of information tracks onto which information is recorded and having a plurality of intermediate regions, free from having information recorded thereon, alternately arranged, said apparatus comprising:

• a magneto for applying to the recording medium a magnetic field having a predetermined direction;
• an optical head for irradiating the recording medium with a light beam having sufficient power to align a magnetizing direction;
• a motor for relatively moving the recording medium and the light beam;
• a photodetector for receiving light reflected from the recording medium and for generating a tracking error signal;
• a tracking actuator for changing an applied position of the light beam on the recording medium in accordance with the tracking error signal;
• and
• a switching circuit for switching between a first tracking operation in which the light beam is tracking-controlled to an information track so as to trace the track and a second tracking operation in which the light beam is tracking-controlled to an intermediate region so as to trace the intermediate region, by selectively reversing a polarity of the tracking error signal input to the tracking actuator.

A method of producing an initialized magnetooptical recording medium having a plurality of information tracks onto which information is recorded and a plurality of intermediate regions, free from having information recorded thereon, alternately arranged, said method comprising the steps of:

• providing a magnetic film having a random magnetizing direction on a substrate on which a plurality of grooves are formed;
• tracing a central portion of an information track, which includes a region in between the grooves, with a coincident central portion of light beam which is tracking-controlled to the track and has sufficient power to align a magnetizing direction while applying to the magnetic film, a magnetic field having a predetermined direction, thereby aligning the magnetizing direction of the magnetic film of the track in a uniform direction;
• and
• tracing a central portion of an intermediate region, which includes a groove, with a coincident central portion of the light beam which is tracking-controlled to the intermediate region and has sufficient power to align a magnetizing direction while applying a magnetic field having a predetermined direction to the magnetic film, thereby aligning the magnetizing direction of the magnetic film of the intermediate region in a uniform direction.