Sharp Kabushiki Kaisha Corporation

Shinzo Sawamura

Hiroyuki Katayama

Kunio Kojima

Junichi Sato

Yasushi Ogimoto

Masaki Hamamoto

A magnetic storage medium includes a magnetic storage medium that exhibits a magnetic compensation temperature specified higher than room temperature to minimize effects of heat generated by a head using magneto-resistance effect. In a heat assisted recording and reproduction method using such a magnetic storage medium, during reproduction, the S/N ratio in a reproduction signal is enhanced by optimizing the bias current applied to the head using magneto-resistance effect. A magnetic storage medium and a heat assisted recording and reproduction method using such a magnetic storage medium whereby information is magnetically recorded and reproduced by heating a read-out domain are offered that enables signal reproduction with a good S/N ratio despite possible use of a head exhibiting magneto-resistance effect.

Magnetic storage medium and heat assisted recording and reproduction method

A magnetic recording medium of the present invention comprises a first magnetic layer and a second magnetic layer each having different magnetization, coercive force, and temperature characteristics. By magnetically coupling the first and second magnetic layers to each other, gradual temperature dependence of magnetization can be realized.

Magnetic recording medium

A magnetic layer includes a first magnetic film and a second magnetic film which are coupled to each other by means of exchanged coupling of magnetic materials, and one of the magnetic films is made of a ferrimagnetic material having a magnetic compensation temperature. When information is reproduced by heating a magnetic reproducing track portion to a magnetically reproducible temperature by a light beam, the magnetization directions of the two magnetic films are opposite in a peripheral track portion having approximately room temperature, and the same in the magnetic reproducing track portion heated to the magnetically reproducible temperature. Consequently, crosstalk from the peripheral track portion is reduced, and a reproducing signal from the magnetic reproducing track portion is increased, thereby improving the S/N of the reproducing signal significantly. Consequently, it has become possible to provide a magnetic recording medium which can realize high-density recording and reproducing with less crosstalk while producing a reproducing signal with excellent S/N.

Magnetic recording medium and magnetic reproducing method

The present magnetic recording and reproducing device is provided with a magnetic head ( ), which, during recording, applies an external magnetic field to a recording medium ( ) having a recording layer made of a ferrimagnetic material, and with a laser light source, which increases the temperature of the recording medium ( ) in domains (Tr and Tr ) which are opposite the magnetic head ( ), but exclude a track to be recorded (Tr), which is a domain for recording. Consequently, a magnetic recording and reproducing device can be provided which is capable of suppressing crosstalk and realizing higher recording density than conventionally.

Magneto-optical recording and reproducing device capable of suppressing cross talk

The present invention provides a thermally assisted magnetic recording medium consists of a recording region for recording information including a recording layer and a carbon nitride film provided on a side from which light is incident with respect to the recording layer, wherein the recording region is locally heated using light as a heat source for magnetically recording and reproducing information.

Thermally assisted magnetic recording medium

The present invention is a magnetic signal reproducing device for reproducing information from a magnetic recording medium in which a polarity of magnetization is inverted at a first temperature during temperature change. The device includes local temperature raising device for locally raising the temperature of the magnetic recording medium, and reproducing device for magnetically detecting information recorded on the magnetic recording medium. In the device, during a reproducing operation, the local temperature raising device forms an area having a lower temperature than the first temperature and an area having a higher temperature than the first temperature within an area in the magnetic recording medium, thereby reducing contribution to reproduced signal from magnetization of an area other than a reproduction target area.

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Nishinomiya, Japan

Shinzo Sawamura