Other

Hitachi, Ltd.

Hiroki Kuramoto

Motoyasu Terao

Hiroki Yamamoto

Ken Takahashi

Sumio Hosaka

Fumiyoshi Kirino

Eiji Koyama

Nobuyuki Inaba

Takashi Naitou

Takashi Naito

Yoshie Kodera

Makoto Iida

Tatsumi Hasebe

Aki Nakajo

Sadayauki Nishimura

An information recording medium capable of high-density recording and accurate reproduction and also capable of repeated recording and reproduction, an information recording device that employs the information recording medium has a Co&#x2014;Si oxide thin filmconstructed such that columnar crystalsare separated by an intergranular phasewhich contains SiOhaving a lower coefficient of thermal conductivity than the columnar crystals. Therefore, the intergranular phaseprevents heat transfer from one columnar crystalto another. In addition, the intergranular phaseseparates columnar crystalsfrom each other, so that the crystalline structure of each columnar crystalis not affected by its adjacent columnar crystal. The advantage of such construction is that the columnar crystalsdo not undergo phase transformation except for those which were given energy necessary for phase transformation directly from the laser beam, and hence columnar crystalsoverheated by the laser beam do not affect their adjacent columnar crystals. Thus it is possible to accurately form recording pits whose mark length is smaller than the laser beam diameter.

Information recording medium and information recording device

An ultra-high density information recording media has an inorganic compound layer on a substrate , and in the inorganic compound layer , an oxide of at least one kind selected from silicon oxide, aluminum oxide, titanium oxide, tantalum oxide, and zinc oxide exists in an amorphous state at a grain boundary of crystal grain of an oxide of at least one kind selected from cobalt oxide, iron oxide, and nickel oxide. The media has a magnetic layer made of an artificial lattice multilayer obtained by alternately laminating a Co layer or an alloy layer consisting of Co as a main phase and a metal element layer of at least one kind selected from Pt and Pd onto the layer . Thus, a distribution of magnetic properties serving as a pinning site of the movement of a magnetic wall in case of recording information to the magnetic layer is formed in the magnetic layer

Information recording media and information recording drive

The magnetic recording medium includes an underlayer formed of an inorganic compound layer, and a magnetic layer formed over the underlayer . The inorganic compound layer as the underlayer has crystal grains and at least one kind of oxide, the crystal grains having as main elements at least one of cobalt oxide, chromium oxide, iron oxide and nickel, the at least one kind of oxide lying as a non-crystalline phase in grain boundaries between the crystal grains and selected from among silicon oxide, aluminum oxide, titanium oxide, tantalum oxide and zinc oxide.

Magnetic recording disk

An information recording medium capable of high-density recording and accurate reproduction and also capable of repeated recording and reproduction, an information recording device that employs the information recording medium has a Co&mdash;Si oxide thin film constructed such that columnar crystals are separated by an intergranular phase which contains SiO having a lower coefficient of thermal conductivity than the columnar crystals . Therefore, the intergranular phase prevents heat transfer from one columnar crystal to another. In addition, the intergranular phase separates columnar crystals from each other, so that the crystalline structure of each columnar crystal is not affected by its adjacent columnar crystal . The advantage of such construction is that the columnar crystals do not undergo phase transformation except for those which were given energy necessary for phase transformation directly from the laser beam, and hence columnar crystals overheated by the laser beam do not affect their adjacent columnar crystals. Thus it is possible to accurately form recording pits whose mark length is smaller than the laser beam diameter.

Information recording medium with recording film with cobalt oxide crystalline particles, and information recording device including the same

In a projector, the precision of color synthesis is improved and the generation of vertical stripes in the projected image is suppressed by a dichroic prism used for color synthesis that employs at least the following aspects. (1) The dichroic prism is formed using triangular prisms, in which projections or grooves are provided that have two faces parallel to two pasted faces of the triangular prisms, the projections or grooves being integrally injection-molded on faces of the triangular prisms that are substantially perpendicular to the light beam (i.e., the faces through which no light beam passes); (2) the dichroic prism is positioned using marks on the pasted faces of the triangular prisms; or (3) the dichroic prism is formed by engaging triangular prisms in which recesses or projections are formed.

Projector

A magneto-optical storage apparatus including an ultra-high density information recording media having an inorganic compound layer on a substrate and in the inorganic compound layer an oxide of at least one kind selected from silicon oxide, aluminum oxide, titanium oxide, tantalum oxide, and zinc oxide exists in an amorphous state at a grain boundary of crystal grain of an oxide of at least one kind selected from cobalt oxide, iron oxide, and nickel oxide. The media has a magnetic layer made of an artificial lattice multilayer obtained by alternately laminating a Co layer or an alloy layer consisting of Co as a main phase and a metal element layer of at least one kind selected from Pt and Pd onto the layer Thus, a distribution of magnetic properties serving as a pinning site of the movement of a magnetic wall in case of recording information to the magnetic layer is formed in the magnetic layer

The magnetic recording medium includes an underlayer formed of an inorganic compound layer, and a magnetic layer formed over the underlayer . The inorganic compound layer as the underlayer has crystal grains and at least one kind of oxide, the crystal grains having as main elements at least one of cobalt oxide, chromium oxide, iron oxide and nickel oxide, the at least one kind of oxide lying as a non-crystalline phase in grain boundaries between the crystal grains and selected from among silicon oxide, aluminum oxide, titanium oxide, tantalum oxide and zinc oxide.

A magnetic recording medium includes a non-magnetic substrate, an inorganic compound layer that is formed on the substrate and which contains a crystalline first oxide and a second oxide, and a magnetic layer that is formed on the inorganic compound layer. The crystalline first oxide comprises at least one oxide selected from cobalt oxide, chromium oxide, iron oxide and nickel oxide. The second oxide comprises at least one oxide selected from silicon oxide, aluminum oxide, titanium oxide, tantalum oxide and zinc oxide. The second oxide is present at a grain boundary of crystal grains of said first oxide. According to the present invention, magnetic recording media low in noise and diminished in thermal fluctuation and thermal decay can be obtained by making fine the crystal grains of a magnetic layer and controlling the dispersion of the grain size. Thus, magnetic recording apparatuses can be realized which can perform an ultrahigh density magnetic recording of higher than 20 Gb/in .

Growing community of inventors

Yokohama, Japan

Hiroki Kuramoto