Magneto-optical recording utilizing signal phase adjustment

A magneto-optical recording apparatus comprising:

• clock generating means for generating a recording fundamental clock synchronized with a reference clock that is recorded in advance on a magneto-optical recording medium;
• magnetic field generating means for generating an alternating field having the same frequency as that of the recording fundamental clock and applying the alternating field to the magneto-optical recording medium;
• phase control means for changing a phase of the recording fundamental clock to generate a changed phase clock in response to data to be recorded;
• and
• light irradiating means for irradiating a spot of a predetermined intensity necessary for thermo-magnetic recording at a particular recording position of the magneto-optical recording medium on the basis of the changed phase clock.

A magneto-optical recording apparatus comprising:

• clock generating means for generating a recording fundamental clock synchronized with a reference clock that is recorded in advance on a magneto-optical recording medium;
• magnetic field generating means for generating an alternating field having the same frequency as that of the recording fundamental clock and applying the alternating field to a particular recording position of the magneto-optical recording medium, wherein the magnetic
• field generating means includes a tank circuit formed of a coil provided on a magnetic head and a capacitor connected in parallel to the coil;
• phase control means for changing a phase of the recording fundamental clock in response to data to be recorded;
• and
• light irradiating means for irradiating a spot of a predetermined intensity necessary for thermomagnetic recording at a particular recording position of the magneto-optical recording medium on the basis of the changed phase clock.

A magneto-optical recording apparatus comprising:

• clock generating means for generating a recording fundamental clock synchronized with a reference clock that is recorded in advance on a magneto-optical recording medium, wherein the reference clock is recorded by a clock pit formed of a concave or convex portion formed on a reflection surface of the magneto-optical recording medium, and the clock generating means detects the clock pit on the basis of a change of an amount of a reflected laser light continuously radiated on the magneto-optical recording medium to thereby generate the recording fundamental clock synchronized with the reference clock;
• magnetic field generating means for generating an alternating field having the same frequency as that of the recording fundamental clock and applying the alternating field to a particular recording position of the magneto-optical recording medium;
• phase control means for changing a phase of the recording fundamental clock in response to data to be recorded;
• and
• light irradiating means for irradiating a spot of a predetermined intensity necessary for thermomagnetic recording at a particular recording position of the magneto-optical recording medium on the basis of the changed phase clock.

A magneto-optical recording apparatus comprising:

• clock generating means for generating a recording fundamental clock synchronized with a reference clock that is recorded in advance on a magneto-optical recording medium, wherein the reference clock is recorded by a pregroove formed of a groove wobbled on a reflection surface of the magneto-optical recording medium at a constant period and the clock generating means generates the recording fundamental clock synchronized with the reference clock on the basis of a change of an amount of a reflected laser light continuously radiated on the magneto-optical recording medium;
• magnetic field generating means for generating an alternating field having the same frequency as that of the recording fundamental clock and applying the alternating field to a particular recording position of the magneto-optical recording medium;
• phase control means for changing a phase of the recording fundamental clock in response to data to be recorded;
• and
• light irradiating means for irradiating a spot of a predetermined intensity necessary for thermomagnetic recording at a particular recording position of the magneto-optical recording medium on the basis of the changed phase clock.

A magneto-optical recording apparatus comprising:

• clock generating means for generating a recording fundamental clock synchronized with a reference clock that is recorded in advance on a magneto-optical recording medium;
• magnetic field generating means for generating an alternating field having the same frequency as that of the recording fundamental clock and applying the alternating field to a particular recording position of the magneto-optical recording medium;
• phase control means for changing a phase of the recording fundamental clock in response to data to be recorded;
• and
• light irradiating means for irradiating a spot of a predetermined intensity necessary for thermomagnetic recording at a particular recording position of the magneto-optical recording medium on the basis of the changed phase clock, wherein a pit in which an edge position thereof is shifted stepwise from a predetermined reference position in response to data to be recorded is recorded by the light irradiating means on the magneto-optical recording medium by irradiating a spot of a predetermined intensity necessary for thermomagnetic recording on a particular recording position which corresponds to the shifted edge position each time the magnetic field generating means alternately applies a magnetic field of a positive direction or negative direction to the magneto-optical recording medium.

A magneto-optical recording and reproducing apparatus for reproducing information from a magneto-optical recording medium in which information is recorded by stepwise shifting an edge position of a pit from a predetermined reference position, comprising:

• clock generating means for generating a recording fundamental clock synchronized with a reference clock recorded in advance on the magneto-optical recording medium;
• an optical detection system for irradiating the magneto-optical recording medium with a laser light to detect a reproduced signal corresponding to the pit on the basis of a direction of a Kerr rotational angle of a reflected light;
• level detecting means for detecting a reproducing level of the reproduced signal at a sample timing synchronized with the recording fundamental clock;
• and
• judging means for reproducing a recording information associated with an edge position shift amount of the pit on the basis of the reproducing level.

A magneto-optical recording method comprising the steps of:

• generating a recording fundamental clock synchronized with a reference clock that is recorded in advance on a magneto-optical recording medium;
• generating an alternating field having the same frequency as that of the recording fundamental clock and applying the alternating field to a particular recording position of the magneto-optical recording medium;
• changing a phase of the recording fundamental clock in response to data to be recorded;
• and
• irradiating a spot of a predetermined intensity necessary for thermomagnetic recording at a particular recording position of the magneto-optical recording medium on the basis of the changed phase clock, wherein a pit in which an edge position thereof is shifted stepwise from a predetermined reference position in response to data to be recorded is recorded on the magneto-optical recording medium by irradiating a spot of a predetermined intensity necessary for thermo-magnetic recording on a particular recording position which corresponds to the shifted edge position each time a magnetic field of a positive direction or negative direction is alternately applied to the magneto-optical recording medium.

A magneto-optical recording and reproducing method for reproducing information from a magneto-optical recording medium in which information is recorded by stepwise shifting an edge position of a pit from a predetermined reference position, comprising the steps of:

• generating a recording fundamental clock synchronized with a reference clock recorded in advance on the magneto-optical recording medium;
• irradiating the magneto-optical recording medium with a laser light to detect a reproduced signal corresponding to the pit on the basis of a direction of a Kerr rotational angle of a reflected light;
• detecting a reproducing level of the reproduced signal at a sample timing synchronized with the recording fundamental clock;
• and
• reproducing a recording information associated with an edge position shift amount of the pit on the basis of the reproducing level.