Hitachi, Ltd.

Other

Hitachi Maxell, Limited

Hgst Netherlands, B.v.

Western Digital Technologies, Inc.

Hitachi Consumer Electronics Co., Ltd.

Hitachi Maxwell, Ltd.

Hitachi, Lt.

Akemi Hirotsune

Motoyasu Terao

Yumiko Anzai

Makoto Miyamoto

Yasushi Miyauchi

Harukazu Miyamoto

Tetsuya Nishida

Keikichi Andoo

Junko Ushiyama

Hiroyuki Minemura

Tsuyoshi Toda

Hideki Saga

Masatoshi Ohtake

Takeshi Maeda

Toshimichi Shintani

Takahiro Kurokawa

Nobuhiro Tokushuku

Yukio Fukui

Ikuko Takekuma

Keikichi Ando

Koichi Moritani

Takao Watanabe

Mitsuhide Miyamoto

Yotsuo Yahisa

Ichiro Tamai

Hiromi Kudo

Yoshiko Nishi

Tomonori Sekiguchi

Takashi Naito

Hiroki Yamamoto

Takeshi Shimano

Yoshitaka Bito

Hiroyuki Matsumoto

Kiwamu Tanahashi

Takashi Namekawa

Takeshi Hoshino

Shigeharu Kimura

Hiroaki Nemoto

Yoshinori Ishikawa

Youichi Horii

Hiroko Sukeda

Oleksandr Mosendz

Reiji Tamura

Masaki Mukoh

Takehiko Yorozu

Rieko Otsuka

Yoshihiro Ikari

Junichi Sayama

Hisae Wakabayashi

A magnetic recording medium includes an amorphous buffer layer, a hybrid layer including a barrier layer, and a texture control layer. The magnetic recording medium also includes a heat sink layer, an under layer, and a perpendicular recording layer.

Perpendicular magnetic recording medium

A magnetic medium for perpendicular magnetic data recording having improved corrosion characteristics and reduced surface roughness. The magnetic medium includes an under-layer and a perpendicular magnetic recording layer formed over the under-layer. The under-layer can be formed of MgO and has an oxygen concentration that is greater at the perpendicular magnetic recording layer than it is away from the perpendicular magnetic recording layer.

Perpendicular magnetic recording media having novel magnetic under-layer structure

A magnetic medium for perpendicular magnetic data recording, having improved magnetic properties through use of a novel seed layer. The magnetic medium includes a substrate having a seed layer, a magnetic under-layer and a magnetic recording layer formed there-over. The seed layer includes an element selected from a first group of Cr, Co, Fe and Ni, and at least one element that is selected from the other elements of the first group or from a second group consisting of W, Mo and Ru. A buffer layer may be included between the substrate and the seed layer.

Perpendicular magnetic recording media having novel seed layer

According to one embodiment, a perpendicular magnetic recording medium includes a soft magnetic underlayer formed above a substrate, a lower seed layer formed above the soft magnetic underlayer, at least one upper seed layer formed above the lower seed layer, an interlayer formed above the at least one upper seed layer, a perpendicular recording layer formed above the interlayer, and a protective layer formed above the perpendicular recording layer, wherein the at least one upper seed layer comprises Ni or a Ni based alloy including N, and wherein the lower seed layer includes Ni and at least one element selected from a group consisting of: W and Cr. Other embodiments are described herein regarding perpendicular magnetic recording systems and methods of producing perpendicular magnetic media.

Perpendicular magnetic recording medium and magnetic storage apparatus using the same

In one embodiment, a perpendicular magnetic recording medium includes a substrate, a soft-magnetic underlayer above the substrate, a seed layer above the soft-magnetic underlayer, a first intermediate layer above the seed layer, a second intermediate layer above the first intermediate layer, a recording layer above the second intermediate layer, and a protective layer above the recording layer. The second intermediate layer includes an Ru alloy having an element selected from a group consisting of: Ti in a range from about 20 at. % to about 50 at. %, Nb in a range from about 20 at. % to about 50 at. %, Al in a range from about 20 at. % to about 40 at. %, Ta in a range from about 30 at. % to about 50 at. %, and Si in a range about 20 at. % to about 40 at. %. Other magnetic media and systems using this media are described according to more embodiments.

Perpendicular magnetic recording media having low medium noise and systems using the same

A multilayer optical disc which has three or more recording layers and enables easy positioning of a focused beam spot onto a particular recording layer in which a BCA is disposed. An inter-layer distance between a particular recording layer and a recording layer adjacent to the particular recording layer is larger than the other inter-layer distances in which, at the focused beam spot positioning, the focused beam spot traverses the said adjacent recording layer earlier than the other recording layer adjacent to the particular recording layer.

Multilayer optical disc for easy positioning of a focused beam

In a multilayer optical recording medium having at least three recording layers, an influence of interlayer crosstalk due to unnecessary light is suppressed. Each of the recording layers includes an information recording area, and the recording layers other than the nearest recording layer and the farthest recording layer when viewed from a light incident side include a first annular area having uneven patterns formed thereon, and a second annular area having uneven patterns formed thereon, the first annular area being adjacent to an inner side of the information recording area, the second annular area being adjacent to an outer side of the information recording area.

Multilayer optical recording medium having three or more recording layers with reduced interlayer crosstalk

In an information memory apparatus having minute areas for storing information arranged in x, y and z directions three-dimensionally, parallel rays are irradiated to a memory area MA in a direction perpendicular to a z-axis to take projection images of the memory area MA while rotating the memory area MA around the z-axis little by little. The light rays irradiated at this time have a size which covers at least a direction of an x-y plane of the memory area. A computation unit PU finds data and addresses of minute areas distributed three-dimensionally by performing computation based upon the principle of computer tomography on the projection images. As for data writing, a change is given to optical transmissivity or light emission characteristics by irradiating laser light focused by a lens OL placed outside the memory area to a desired minute area and causing heat denaturation within the pertinent minute area.

Information storage device and storage media

Regarding a signal recorded with a first frequency in a recording area on a specific first recording layer and a signal recorded with a second frequency different from the first frequency in a recording area on a second recording layer which might cause interlayer crosstalk in relation to the first recording layer, a reproducing signal measurement method for a multilayer optical recording medium having at least three recording layers includes reproducing the signal recorded in the recording area on the first recording layer, separating signals recorded respectively with the first and second frequencies, discriminating signal amplitude of the first frequency and a maximum value in signal amplitude of the second frequency, and calculating a signal amplitude ratio between them to measure interlayer crosstalk contained in the signal reproduced from the recording area on the first recording layer. Thus, the interlayer crosstalk quantity caused by unnecessary light can be measured quantitatively.

Reproducing signal measuring method, signal reproducing apparatus, and optical recording medium

An information memory device using an electromagnetic-wave resonance phenomenon is provided to achieve both high density and long-period storage of stored data. Memory cells are three-dimensionally arranged in the inside of a solid-like medium which is not contacted with a surface of the medium, and the memory cell has resonance characteristics to electromagnetic waves depending on the space coordinates of the memory cell. For the medium, a material is selected so that an electromagnetic wave having the resonance frequency of the memory cell. By observing absorption spectra of the irradiated electromagnetic wave or emission spectra after the absorption, three-dimensional space coordinates of the memory cell are calculated.

Information memory device and memory medium

Multicolor characters or pictures are written in an optical disk in a visible manner. The optical disk comprises a figure writing layer for writing a visible figure in addition to a data recording layer for recording data. Recording of user data in the data recording layer and the writing of a visible figure in the figure writing layer are performed using the same optical disk drive. In one example, the figure writing layer comprises phase change layers that are formed via protection layers in a region sandwiched between a pair of reflective layers. By writing figure data separated into individual basic colors in the phase change layers individually, a multicolor figure can be made visible.

Optical disk and recording method of visible figures into optical disk

An information recording medium includes a plurality of layers for recording or reproduction of information by irradiation, wherein each of the layers includes an emboss portion and wobble portion including wobbles of a first frequency and a second frequency that is different from the first frequency. The first frequency is constant in each of the plurality of layers, and a different signal is obtained from the wobbles of the first and second frequencies in each of the plurality of layers.

Information recording media, a method for recording/reproducing information, an apparatus for recording/reproducing information

Recording information is disclosed in which an information recording medium is irradiated with a recording energy beam that is power-modulated into at least a record power level and a record-ready power level lower than the record power level. The information is recorded on the recording medium in the form of length and interval of a mark portion. When forming a mark portion of a predetermined length, the radiation energy of the energy beam is increased as compared with when forming a mark portion of a different length before or after the first pulse of an energy beam pulse train including at least a pulse for forming the mark portion.

Information recording method and apparatus with suppressed mark edge jitters

Growing community of inventors

Saitama, Japan

Akemi Hirotsune