Fuji Photo Film Company, Limited

Fujifilm Corporation

Makoto Nagao

Akira Nahara

Masakazu Nishikawa

Kazunori Komatsu

Fusao Yamanaka

Goro Akashi

Ryuji Sugita

Kunihiko Sano

Tadashi Yasunaga

Yoshihiro Arai

Satoshi Wakamatsu

Takashi Komine

Kazuyuki Usuki

Kazuhiko Morita

Minoru Araki

Yoichi Nishida

Hideyuki Kubota

Toshihide Ishioka

Yoshihisa Usami

Yasuyuki Yamada

Hiroyuki Iwasaki

Seiichi Watanabe

Yasuo Nishikawa

Kazuo Tsubouchi

Nobuo Mikoshiba

Satoru Honjo

Kazuhiro Niitsuma

Akito Kamatani

Akio Yanai

Koji Sasazawa

Kazutoshi Katayama

Kiyotaka Fukino

Kenji Ichikawa

Eiichi Mizuki

Naoto Fujiwara

Tsuneo Inui

Hisashi Tsubata

Atsushi Morooka

Takuji Kaneda

The present invention provides a magnetic transfer master carrier which forms a magnetic pattern corresponding to a pattern of information to be recorded on a perpendicular magnetic recording medium when a magnetic field is applied to the perpendicular magnetic recording medium, with the magnetic master carrier and the perpendicular magnetic recording medium closely attached to each other, the carrier including: a base material having convex portions on its surface, the convex portions being provided corresponding to the pattern of information; a magnetic layer deposited on at least top surfaces of the convex portions, and having perpendicular magnetic anisotropy; and a soft magnetic layer deposited on the surface of the magnetic layer.

Magnetic transfer master carrier, magnetic transfer method, and magnetic recording medium

A magnetic transfer master carrier of the present invention includes a base material having convex portions on its surface, the convex portions being provided corresponding to a pattern of information to be recorded on a perpendicular magnetic recording medium, and a magnetic layer deposited at least on top surfaces of the convex portions, wherein when a magnetic field is applied to the magnetic transfer master carrier, the magnetic layer absorbs a magnetic flux so as to form a pattern of the magnetic field, wherein the magnetic layer includes at least two perpendicular magnetic anisotropic layers, and an antiferromagnetic coupling induction layer which is provided so as to be sandwiched in between two neighboring layers of all the perpendicular magnetic anisotropic layers, and to induce antiferromagnetic coupling therebetween.

Magnetic transfer master carrier and magnetic transfer method

An electrode master for ferroelectric recording records information on a ferroelectric recording medium in which the direction of polarization of a ferroelectric material has been unified in one direction by applying a voltage thereto, based on the direction of polarization of the ferroelectric material, by applying voltage pulses to the ferroelectric recording medium. The electrode master includes an electroconductive base material; a plurality of electrode convexes provided on a surface of the electroconductive base material so as to correspond to information to be recorded on the ferroelectric recording medium; and an electrode terminal conducted to each of the electrode convexes and provided on the electroconductive base material.

Electrode master for ferroelectric recording and method for recording on ferroelectric recording medium

The present invention provides a magnetic transfer method comprising: a magnetic transfer step of applying a magnetic field for transfer parallel to the plane of a disk shaped substrate having formed on the surface thereof a pattern composed of magnetic layer arrangement corresponding to information to be transferred to a perpendicular magnetic recording medium while a master recording medium for perpendicular magnetic transfer being the substrate is brought into close contact with the perpendicular magnetic recording medium, and thereby transferring the magnetic pattern of the master recording medium for perpendicular magnetic transfer to the perpendicular magnetic recording medium; and a servo correction information writing step of writing by use of a magnetic head, servo correction signal information into a section adjacent to the information transferred to the perpendicular magnetic recording medium by the magnetic transfer step.

Magnetic transfer method for perpendicular magnetic recording medium, perpendicular magnetic recording medium, and magnetic recording apparatus

The present invention provides a method of initializing a perpendicular magnetic recording medium in which a magnetic field having a magnetic field strength Hex is applied to a perpendicular magnetic recording medium having a magnetic layer having a coercive force Hc to initialize the magnetic layer, the method comprising the steps of: controlling a magnetic field strength HexP in a direction parallel to the medium surface of the magnetic field so that HexP&#x3e;1.3&#xd7;Hc; and controlling a magnetic field strength HexV in a direction perpendicular to the medium surface of the magnetic field so that HexV&#x3c;Hc.

Method of initializing perpendicular magnetic recording medium, perpendicular magnetic recording medium and magnetic recording apparatus

A magnetic transfer method comprises the processes of: adhering a side having a perpendicular magnetic recording layer of a perpendicular magnetic recording medium in which a perpendicular magnetic recording layer is formed on a surface of a disk shaped substrate, to a surface of a master recording medium in which a magnetic layer is formed corresponding to information to be recorded for transferring information to the perpendicular magnetic recording medium and of the side having the magnetic layer formed; and performing magnetic transfer by relatively rotating a magnetic field application device about the center of the perpendicular magnetic recording medium as an axis with respect to the perpendicular magnetic recording medium and the master recording medium, while applying a magnetic field to the perpendicular magnetic recording medium and the master recording medium by the magnetic field application device, wherein the magnetic field application device is rotated two or more times.

Magnetic transfer method, magnetic transfer apparatus, magnetic recording medium and magnetic record reproduction system

The present invention provides a master disk for magnetic transfer which has a disk-like outer shape and in the surface of which a large number of fine magnetic layer patterns are formed, wherein the relationship between the outside diameter size d (mm) of the extreme outer circumference of the magnetic layer pattern and the master disk thickness t (mm) is given by 2.04&#xd7;10&#xd7;d+0.006&#x2266;t&#x2266;8.15&#xd7;10&#xd7;d+0.024, in order to exclude the effects of bows, strains and thickness deviations of a master disk in performing magnetic transfer and ensure that accurate transfer of magnetization patterns can be performed.

Master disk for magnetic transfer, magnetic recording medium and magnetic recording apparatus

An amplitude servo pattern capable of providing accurate servo control through reproduced amplitude with reduced noise is provided. The amplitude servo pattern has servo burst signals composed of burst bit strings adjacently disposed in a track width direction. The burst bit strings are disposed such that the servo burst signals adjacently disposed in the track width direction have a phase difference with each other in a track direction.

Amplitude servo pattern, magnetic recording medium and the manufacturing method, patterned magnetic transfer master substrate used in the manufacturing method, and magnetic recording/reproducing apparatus

Provided is a method of magnetic transfer. The method includes initially DC-magnetizing a transfer-recipient disc in a circumferential direction, by applying a magnetic field to the transfer-recipient disc in the circumferential direction thereof bringing initially DC-magnetized transfer-recipient disc and a master disc into close contact with each other, on the top side of the master disc a magnetic layer including a great number of protrusions that configure a magnetic pattern being formed; and executing magnetic transfer in such a way that a magnetic-field generation device is provided, and that, when a magnetic field is applied in a circumferential direction to the transfer-recipient disc and the master disc, transfer of the magnetic pattern of the master disc onto the transfer-recipient disc occurs.

Magnetic-transfer method, magnetic recording medium, and magnetic recording device

A master information carrier for magnetic transfer bears uneven signal patterns on its surface. When the minimum bit length in the uneven signal patterns is B, dummy uneven patterns are provided in a depression of the uneven signal patterns, which has a length of 4Bor longer in the direction along a track. When magnetic transfer is performed, magnetized patterns corresponding to the dummy uneven patterns are transferred onto a slave medium. The magnetized patterns are patterns which will not be recognized as reproduction signals at a drive, into which the slave medium after magnetic transfer will be loaded.

Master information carrier for magnetic transfer, magnetic transfer method, and magnetic recording medium

When signals are read out by a magnetic head from a magnetic recording medium on which magnetic bits corresponding to information are recorded along the tracks thereof by a magnetic transfer method, if a space which is longer than or equal to a length corresponding to three bits is present between consecutive magnetic bits, readout of signals from a sub-pulse generation area in the space is cancelled in readout of the magnetic bits by the magnetic head along the tracks. The signals are not read out at all, or even if the signals are read out, they are not processed as valid signals.

Signal processing method of magnetic recording medium and magnetic record reproduction apparatus

In an information recording method of the present invention by carrying out recording data while carrying out tracking servo accurately, high density recording of signals at a good S/N can be carried out, and high density recording by a vertical magnetic recording system can be carried out. A magnetic disk comprises a magnetic recording layer, and the magnetic recording layer is magnetized in advance such that magnetized regions A and B having different magnetization directions are formed. At a time of recording data, vertical magnetic recording is carried out by a magnetic head while carrying out accurate tracking servo by optically tracking by a magneto-optical effect utilizing a difference in the magnetization directions of the magnetized regions A and B. Therefore, high-density recording at a good S/N is possible.

Information recording method using a vertical magnetic system

A magnetic transfer device for bringing a master carrier with information and a slave medium into intimate contact with each other and then applying a transfer field to transfer the information to the slave medium. The master carrier has an inclined face on its radially outer end. After the magnetic transfer of the information, claws are inserted in the gas formed by the inclined face of the master carrier and the slave medium. The slave medium held in intimate contact with the master carrier is separated from the master carrier by lifting the slave medium with the claws.

Magnetic transfer device

In the magnetic transferring method for magnetically transferring an information signal such as a servo signal from the master medium to the slave medium, when magnetic transfer is performed by bringing a master medium and a slave medium into close contact with each other, the master medium bearing an information signal and the slave medium having a lubricating layer formed on the surface of its recording plane during use, and applying a transfer magnetic field, the magnetic transfer is performed by bringing the slave medium before the formation of the lubricating layer and the master medium into close contact with each other. Thus, the separation of the slave medium from the master medium after the magnetic transfer is facilitated, and the adsorption of dust on the slave medium is prevented.

Magnetic transferring method, and method and apparatus for cleaning magnetic transfer master medium

A magnetic recording medium, which comprises a flattening layer with a thickness of 0.1-5.0 &mgr;m, a seed layer, a nonmagnetic primer layer containing chromium with a chromium concentration of 77-100 atom %, a Co&mdash;Cr type alloy magnetic layer, a protective layer, and a lubricating layer coated sequentially on at least one of the surfaces of a flexible nonmagnetic support member, whereby the seed layer is designed in such a manner that the linear expansion coefficient (E ) of the seed layer and the linear expansion coefficient (E ) of the nonmagnetic primer layer satisfy the relation: &verbar;E &minus;E &verbar;/E <0.3, and the tensile strength (S ) of the seed layer and the tensile strength (S ) of the nonmagnetic primer layer satisfy the relation: S /S >1.

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Odawara, Japan

Makoto Nagao