Patent Number: 6,169,714

Title: Apparatus and method for recording/reproducing magneto-optical information

Abstract: 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.

Inventors: Tanaka; Yasuhito (Tokyo, JP), Kurebayashi; Masaaki (Ebina, JP), Maeda; Takeshi (Kokubunji, JP), Watanabe; Hitoshi (Ibaraki-ken, JP), Watanabe; Tetsu (Tokyo, JP), Maeda; Shigemi (Yamatokooriyama, JP), Sumi; Satoshi (Gifu, JP), Matsubayashi; Nobuhide (Hachioji, JP), Matsuura; Michio (Akashi, JP)

Assignee: Hitachi, Ltd.

International Classification: G11B 11/00 (20060101); G11B 11/105 (20060101); G11B 7/125 (20060101); G11B 7/095 (20060101); G11B 7/09 (20060101); G11B 007/09 ()

Expiration Date: 01/02/2018