Other

Michio Matsuura

Shigemi Maeda

Minoru Tobita

Toshiaki Hioki

Takeshi Maeda

Hitoshi Watanabe

Tetsu Watanabe

Satoshi Sumi

Masaaki Kurebayashi

Yasuhito Tanaka

Nobuhide Matsubayashi

An optical disc and an optical disc drive for the optical disc are provided which are suitable for recording data with a high density. The optical disc D uses both lands and grooves as recording tracks. Each of the tracks consists of one address segment and forty five data segments. The address segment is wobbled at one side thereof. Each of the data segments is a DC groove. The address segment records an address information including a sync signal, frame address, track address and CRC, a tilt pattern and a clock mark. The clock mark is adapted to reflect laser beam in one amount before the mark and in another amount after the mark. The tilt pattern has a different track pitch from those in other areas. The data segments record data magneto-optically.

Optical disc and optical drive

Optical disc and optical disc drive

A magneto-optical information recording/reproducing apparatus in which a magneto-optical information recording medium at least including a first magnetic film having perpendicular magnetic anisotropy, and a second magnetic film to which information recorded on the first magnetic film is transferred by irradiation of a laser beam, is used so that a readout laser beam is irradiated onto the second magnetic film to thereby readout the information transferred to the second magnetic film. The apparatus includes a 2-split detection circuit for receiving the readout laser beam reflected from the second magnetic film of the recording medium, and a subtraction circuit in which output signals of the two detection elements of the 2-split detection circuit are subtracted from each other to generate a differential signal. The apparatus further comprises a circuit for making a spot of the laser beam jump one track before readout of the information from the magneto-optical information recording medium, a positive/negative balance correction circuit for detecting an amplitude ratio between positive and negative side amplitudes in a track jump signal generated in the differential signal from the subtraction circuit in response to the track jump to thereby output a correction signal in accordance with the amplitude ratio, and an addition circuit for adding the correction signal to the differential signal to thereby generate a tracking error signal for tracking control used in readout of the magneto-optical information from the magneto-optical information recording medium.

Apparatus and method for recording/reproducing magneto-optical information

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Hyogo, Japan

Michio Matsuura