Fujitsu Corporation

Other

Ken Tamanoi

Keiji Shono

Motonobu Mihara

Koji Matsumoto

Tsutomu Tanaka

Toshio Sugimoto

Sumio Kuroda

Masakazu Taguchi

Haruhiko Izumi

Masaharu Moritsugu

Miyozo Maeda

Tomonori Ikeya

Takuya Kamimura

Toru Maniwa

Yasunobu Hashimoto

Kazuyuki Ozaki

Akihiro Itakura

Mineo Moribe

Yuzuru Yamakage

Shingo Hamaguchi

Takeshi Morikawa

Yoshihiro Muto

Ryo Kurita

Shoyu Ito

Kenji Shono

A power amplifier includes a first matching circuit configured to perform harmonic processing of an input signal, and a second matching circuit configured to perform the harmonic processing of an output signal, the output signal being generated by amplifying a power of the input signal. The power amplifier rotates a phase of output impedance at a matching point of the harmonic included in the generated output signal when the power of the input signal is decreased from a value higher than a certain value to a value lower than the certain value.

Power amplifier

A recording medium includes a substrate, a recording layer provided with perpendicular magnetic anisotropy for recording of information, a foundation layer disposed between the substrate and the recording layer, an initial layer which is greater in surface tension than the foundation layer and held in contact with a recoding-layer-side surface of the foundation layer, and a functional layer held in contact with a recoding-layer-side surface of the initial layer.

Recording medium and method of making the same

The present invention provides a magneto-optical recording medium including a recording layer, an intermediate layer and a reproducing layer stacked in this order. Information recorded in the recording layer is transferred to the reproducing layer through the intermediate layer so that the information is reproduced. The reproducing layer includes an upper reproducing layer, a coupling layer, and a lower reproducing layer formed in this order on the intermediate layer. Magnetic information in the upper reproducing layer in an area whose temperature is increased to a predetermined temperature is transferred to the lower reproducing layer through the coupling layer.

Magneto-optical recording medium

The invention is a magneto-optical recording medium characterized by containing at least a soft magnetic layer, a protective layer, a resin layer having a servo pattern formed thereon, a reflecting film, a lower dielectric material film, a recording film, an upper dielectric material film, and a cover layer, formed on a substrate in this order.

Magneto-optical recording medium including a soft magnetic layer, a protective layer and a silane coupling agent layer, in this order

A master medium for magnetic transfer includes a substrate having a concave portion formed in its surface corresponding to a pattern of recorded information to be transferred; a first perpendicular ferromagnetic layer deposited in the concave portion; and a second perpendicular ferromagnetic layer layered on the substrate surface and the first perpendicular ferromagnetic layer surface. The substrate surface and the first perpendicular ferromagnetic layer surface are flattened to form a single flat surface. In the master medium for magnetic transfer, a magnetic field change in a direction parallel to the substrate surface at a magnetization boundary of the first perpendicular ferromagnetic layer is steep. Since the influence of the change of an external magnetic field is reduced, it is possible to perform accurate transfer from the master medium for magnetic transfer to a slave medium for magnetic recording.

Master medium for magnetic transfer, magnetic transferring and recording method, slave medium for magnetic recording, and method for producing a master medium for magnetic transfer

A magneto-optical recording medium has a configuration such that information recorded can be read from a region smaller than a beam spot by applying an external magnetic field and directing a light beam in reproducing. The magneto-optical recording medium includes a magnetic recording layer for recording and holding information, a magnetic reproducing layer provided on one side of the magnetic recording layer on which the light beam is incident, a nonmagnetic layer provided on another side of the magnetic recording layer opposite to the magnetic reproducing layer, and a magnetic assist layer provided on the nonmagnetic layer. The magnetic assist layer has a coercive force smaller than an external magnetic field applied in recording or reproducing information.

Magneto-optical recording medium possessing a magnetic assist layer

A magneto-optical recording medium includes at least three magnetic layers of a first magnetic layer, a second magnetic layer and a third magnetic layer, in which a recording mark recorded in the third magnetic layer by irradiation of a light beam is transferred through the second magnetic layer formed above the third magnetic layer to the first magnetic layer formed above the second magnetic layer for reproduction, wherein the first magnetic layer is provided with a high temperature mask having no spontaneous magnetization in a region where its temperature becomes a predetermined temperature or higher.

Magneto-optical recording medium with first and second magnetic layers with almost equal Curie temperatures

A magneto-optical recording medium comprising four magnetic layers including a mask layer, a reproduction layer, an intermediate layer and a recording layer, wherein the reproduction layer and the recording layer each have a direction of easy magnetization extending in a layer stacking direction at room temperature, the mask layer and the intermediate layer each have a direction of easy magnetization extending in an in-plane direction at room temperature, the mask layer, the reproduction layer, the intermediate layer and the recording layer have Curie temperatures Tc1, Tc2, Tc3 and Tc4, respectively, which satisfy relationships of Tc3<Tc2, Tc3<Tc4 and Tc3<Tc1, and the intermediate layer is a rare-earth-rich magnetic layer.

Magneto-optical recording medium and method of reproducing the same

A magneto-optical recording medium capable of perfectly masking a mark adjacent to a mark to be reproduced thereby improvng reproduction output. The magneto-optical recording medium includes a transparent substrate, a magnetic reproducing layer laminated on the transparent substrate, a nonmagnetic intermediate layer laminated on the magnetic reproducing layer, and a magnetic recording layer laminated on the nonmagnetic intermediate layer. The reproducing layer has an easy direction of magnetization in a plane at room temperature, and has an easy direction of magnetization perpendicular to a film surface at a given temperature or higher. The nonmagnetic intermediate layer is thin enough to allow magnetostatic bond between the recording layer and the reproducing layer at the given temperature or higher. Instead of the nonmagnetic intermediate layer, a magnetic intermediate layer having an easy direction of magnetization in a plane from room temperature to its Curie temperature may be interposed between the reproducing layer and the recording layer.

Magneto-optical recording medium and reproducing method for information recorded on the medium

A magneto-optical recording medium having a magnetic film stack structure includes a recording layer, a reproducing layer, and an intermediate layer formed between the recording layer and the reproducing layer. The intermediate layer has an easy magnetization characteristic along an in-plane direction at room temperature.

High density magneto-optical recording medium and production method thereof

A magneto-optical recording medium capable of perfectly masking a mark adjacent to a mark to be reproduced thereby improving a reproduction output. The magneto-optical recording medium includes a transparent substrate, a magnetic reproducing layer laminated on the transparent substrate, a nonmagnetic intermediate layer laminated on the magnetic reproducing layer, and a magnetic recording layer laminated on the nonmagnetic intermediate layer. The reproducing layer has an easy direction of magnetization in a plane at room temperature, and has an easy direction of magnetization perpendicular to a film surface at a given temperature or higher. The nonmagnetic intermediate layer is thin enough to allow magnetostatic bond between the recording layer and the reproducing layer at the given temperature or higher. Instead of the nonmagnetic intermediate layer, a magnetic intermediate layer having an easy direction of magnetization in a plane from room temperature to its Curie temperature may be interposed between the reproducing layer and the recording layer.

Magneto-optical recording medium and reproducing method for information recorder on the medium

An auxiliary magnetic layer for generating a reproduction magnetic field which can be positive or negative in accordance with the front and rear edges of a reproduction waveform is provided on the opposite side of the magnetic layer to the substrate for recording and reproducing data. Consequently, a magnetic field which has an advantageous polarity to each of the front and rear edges of the reproduction waveform functions and both edges can have steep inclinations, which enhances the quality of the reproduction signal.

A magneto-optical recording medium which is adapted to realize a partial ROM with remarkable facility in providing software. The magneto-optical recording medium comprises a transparent substrate, a volatile magnetic recording layer formed on the transparent substrate and having a Curie temperature approximately equal to or lower than a temperature raisable in a recording/reproducing apparatus of a user, and a nonvolatile magnetic recording layer formed on the volatile magnetic recording layer and having a Curie temperature higher than the temperature raisable in the recording/reproducing apparatus of the user; wherein the nonvolatile magnetic recording layer is not initialized and is retained in a state immediately after manufacture of the medium.

Magneto-optical recording medium and method of using same

A magneto-optical recording medium of a three-layered structure (consisting of a readout layer, an intermediate layer, and a recording layer), capable of double-mask magnetically-induced super-resolution readout, has magnetic properties such that the exchange coupled force between the readout layer (a GdFeCo film) and the intermediate layer (a GdFe film) decrease with increasing temperature, while the exchange coupled force between the intermediate layer and the recording layer (a TbFeCo film) increase with increasing temperature. The magnetic property of the readout layer is transition-metal magnetization dominant, and that of the intermediate layer is rare-earth magnetization dominant. When reading the medium, a region (an intermediate-temperature transfer region) where the magnetization in the readout layer is oriented in the direction of magnetization in the recording layer, and a region (a high-temperature rear mask) where the magnetization in the readout layer is oriented in a second specific direction, are simultaneously formed within a beam spot from a state (a low-temperature front mask) in which the magnetization in the readout layer is oriented in a first specific direction, thus achieving a double mask condition in a single step. Overwrite recording and magnetically-induced super-resolution readout are realized on the same magneto-optical recording medium.

Magneto-optical recording medium capable of double mask readout

A magneto-optical recording medium, and a method of its production, a method of reading and an apparatus of reading the same capable of decreasing the magnetic field to be applied during MSR readout, or reading without applying magnetic field, by including first, second and third magnetic layers having specified magnetic characteristics.

Growing community of inventors

Kawasaki, Japan

Ken Tamanoi