Hitachi Maxell, Limited

Hitachi Maxwell, Ltd.

Susumu Imai

Katsusuke Shimazaki

Hiroyuki Awano

Masafumi Yoshihiro

Hiroki Takao

Hitoshi Watanabe

Norio Ohta

Toshinori Sugiyama

Osamu Ishizaki

Yuji Yamazaki

A magnetic recording medium comprises, on a substrate, a recording auxiliary layer, a recording holding layer, recording control layer, and a recording layer. The recording layer is constructed by using a ferri-magnetic material having perpendicular magnetization. The data can be recorded at a super high density by using the recording and reproducing head of the present invention, because the recording layer has the perpendicular magnetization. The disappearance of data, which would be otherwise caused by the thermomagnetic relaxation phenomenon, is suppressed after recording the data, because the recording layer has large coercive force at the room temperature. The data, which is recorded at the super high density on the magnetic recording medium, can be reproduced by using a magnetic resistance element carried on the recording and reproducing head.

Magneto-optical recording and reproducing method, using reproducing layer with high saturation magnetization

External magnetic fields H(x) or reproducing light beams L(x) having different intensity patterns are applied to an identical recording position on a magneto-optical recording medium so that different pieces of information corresponding to the patterns are reproduced from the identical recording position. A function H(x) or L(x) is a password for obtaining the information. Only a person, who knows the function, can access specified information recorded on the magneto-optical recording medium. The function H(x) or L(x) is a function in which the magnetic field intensity or the light intensity is modulated with respect to the recording position x so that magnetic domains may be thinned out to perform reproduction at a specified cycle from continuous magnetic domains in a recording area. Other than the use for the purpose of security, reproduced C/N can be remarkably improved by performing reproduction n times while radiating a reproducing light beam P /P which is power-modulated so that the high power P is applied at every cycle which is not less than n times the recording clock, to a specified magneto-optical recording medium capable of magnetic domain-magnifying reproduction.

Reproducing method and reproducing apparatus for magneto-optical recording medium

Reproducing method and reproducing apparatus for magneto-optical recording medium using different radiation patterns

Magnetic recording medium, recording and reproducing head, and magnetic recording and reproducing method

A compact recording and reproducing apparatus includes a floating-type head movable in a fan shape in parallel with the surface of a disk recording medium in order to make faster access to the tracks and to record information at a higher density. A slider and a head are secured to the tip of a swing arm capable of fan-shaped swing movement, and a solid immersion lens is used for the head, so that the light beam can be passed along the arm from the fulcrum at the rotating pivot of the swing arm member.

Recording and reproducing apparatus having a magneto-optical head with an objective lens and laser-beam-permeable member

Recording and reproducing apparatus having a magneto-optical head with

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Toride, Japan

Susumu Imai