Magneto-optical disk apparatus capable of reproducing while enlarging magnetic domains using dc magnetic field, reproducing method, and recording/reproducing method

A record and reproduction method of reproducing a signal by applying a DC magnetic field to a magneto-optical recording medium (10) and recording a signal by applying an alternating magnetic field to said magneto-optical recording medium (10), comprising:

• a first step of recording the signal by irradiating said magneto-optical recording medium (10) with a laser beam, and applying an alternating magnetic field modulated with a predetermined recording pattern to said magneto-optical recording medium (10);
• a second step of irradiating said magneto-optical recording medium (10) with a laser beam of an intensity raising a temperature of a portion of a reproduction layer (3) of said magneto-optical recording medium (10) to or above a compensation temperature;
• a third step of detecting a reproduced signal of the predetermined recording pattern by changing the intensity of said DC magnetic field;
• and
• a fourth step of detecting an error rate based on said reproduced signal and determining the appropriate intensity of said DC magnetic field to keep said error rate within a predetermined range.

A record and reproduction method in a magneto-optical disk device (100, 200, 300, 400, 500, 600) for reproducing a signal by applying a DC magnetic field to a magneto-optical recording medium (10) and recording a signal by applying an alternating magnetic field to said magneto-optical recording medium (10),

• said magneto-optical disk device (100, 200, 300, 400, 500, 600) including:
• a permanent magnet (125) producing said DC magnetic field, and
• a magnetic head (11, 11A) producing said alternating magnetic field,
• said method comprising:
• a first step of recording the signal by irradiating said magneto-optical recording medium (10) with a laser beam, and applying the alternating magnetic field modulated with a predetermined recording pattern to said magneto-optical recording medium (10);
• a second step of irradiating said magneto-optical recording medium (10) with a laser beam of an intensity raising a temperature of a portion of a reproduction layer of said magneto-optical recording medium (10) to or above a compensation temperature;
• a third step of detecting a reproduced signal of the predetermined recording pattern by changing the intensity of said DC magnetic field;
• and
• a fourth step of detecting an error rate based on said reproduced signal and determining the appropriate intensity of said DC magnetic field to keep said error rate within a predetermined range, wherein
• said first step is configured to locate said permanent magnet (125) in an escape position providing substantially equal two peak intensities in said alternating magnetic field emitted from said magnetic head.

A record and reproduction method of reproducing a signal by applying a DC magnetic field to a magneto-optical recording medium (10), and recording a signal, comprising:

• a first step of recording the signal by emitting a laser beam modulated with a predetermined recording pattern, and applying the DC magnetic field;
• a second step of irradiating said magneto-optical recording medium (10) with a laser beam of an intensity raising a temperature of a portion of a reproduction layer (3) of said magneto-optical recording medium (10) to or above a compensation temperature;
• a third step of detecting a reproduced signal of the predetermined recording pattern by changing the intensity of said DC magnetic field;
• and
• a fourth step of detecting an error rate based on said reproduced signal and determining the appropriate intensity of said DC magnetic field to keep said error rate within a predetermined range.