Matsushita Electric Industrial Co., Ltd.

Hidetsugu Kawabata

Norio Miyatake

Motoyoshi Murakami

Keizo Ishiwatari

Tohru Nakamura

Yasumori Hino

Teruyuki Takizawa

Masahiro Birukawa

Yoshihiko Kudoh

Kiyoshi Uchida

Hideaki Inoue

Hiroshi Takeuchi

Yuji Nagata

Akira Muto

Noriaki Hara

Yoshihiko Kudo

Masakazu Yamamoto

Toshio Shimizu

A magneto-optical recording medium includes a magneto-optical layer, a reflection layer and an inorganic dielectric layer interposed therebetween. The dielectric layer is extremely thin so that it will exhibit almost no optical effect, thereby allowing a high CN ratio to be obtained. Thermal conductivity of the dielectric layer is so low that the magneto-optical and reflection layers are thermally isolated from each other. That is, if refractive index of the dielectric layer is n, thickness of the dielectric layer is T (nm), and the thermal conductivity of the dielectric layer is C (J (m sec K).sup.-1), then the thickness T is set within a range that satisfies the following equation:

Magneto-optical recording medium

A magneto-optical recording medium operable with a low external magnetic field intensity during recording and erasing and attenuating a variation in the external magnetic field intensity comprises a magneto-optical recording layer and protective and reflective layer provided adjacent to the magneto-optical recording layers, each of which has a size of microstructures (which are associated with the non-uniformity in composition, density, crystallizability, and the like and visible under a transmission electron microscope) less than the width of a magnetic domain wall in the magneto-optical recording layer.

Magneto-optical recording medium and method of manufacturing same

A sliding part of a magnetic-field generator is configured to slide above and spaced from a surface of a loaded magneto-optical disk in a floating manner. A magnetic-field generating part, which provides a magnetic field to the magneto-optical disk, includes a magnetic pole disposed on a side of the sliding part such that the magnetic pole and the sliding part are positioned adjacent to each other in a radial direction of the surface of the loaded magneto-optical disk and such that the magnetic pole is located closer to a periphery of the magneto-optical disk than the sliding part. An entire flat end surface of the magnetic pole confronting the surface of the magneto-optical disk is generally parallel to and recedes from a slide surface of the sliding part such that the entire flat end surface is spaced further from the surface of the magneto-optical disk than the slide surface of the sliding part.

Magnetic-field generator for use in a magneto-optical disk unit

A magneto-optical disk unit has a first magnetic-field generator for generating a magnetic field corresponding to a frequency in a recording signal frequency band and a second magnetic-field generator for generating DC magnetic fields of both north-seeking and south-seeking poles in a non-contact manner with a loaded magneto-optical disk. The first magnetic-field generator has a slider part for sliding over a loaded magneto-optical disk in a floating manner using an aerodynamic effect. The unit further has a transfer driver for moving the first and second magnetic-field generators in a direction parallel to the loaded magneto-optical disk and a rotary plate for vertically moving the first magnetic-field generator. The unit also has a disk judging circuit for judging whether the loaded magneto-optical disk is of a magnetic-field-modulation overwritable type (first type) or an erase-operation-required type (second type), and a controller for controlling the rotary plate to bring the first magnetic-field generator into contact with the loaded disk when this disk is of the first type and to keep it raised from the disk when this disk is of the second type. The second magnetic-field generator is used when the disk is judged to be of the second type.

Magneto-optical disk unit compatible with different two types of

In a method of producing a deposition film of a composite material, a plurality of sputtering targets each containing one of a plurality of different components are disposed separately in a vacuum chamber. A substrate is subjected to sputtering from the sputtering targets while being moved at an adequately high speed relative to a deposition rate from each sputtering target so that extremely thin layers of the respective components are sequentially stacked repeatedly a plurality of times to thereby form a deposition film of a composite material in which the plurality of different components are mixed uniformly.

Method of producing a deposition film of composite material

A magneto-optical recording medium comprising a layer of amorphous rare-earth-transition-metal alloy having a uniaxial magnetic anisotropy, the alloy containing germanium as additive, and the recording medium having high crystallization temperature, enough stability and good reading S/N ratio.

A speaker diaphragm of the present invention is prepared in a manner such that a boron layer is formed on one face of a dome-shaped metal foil by means of a physical vapor deposition method such as ion-plating, cathode sputtering, vacuum evaporation or the like, when necessary the metal foil is thinned by etching, and then, if necessary, another boron layer is formed on the other face of the metal foil. Alternatively, a metal layer is formed on the surface of the boron layer. The resultant speaker diaphragm is light in weight and high in modulus and also has appropriate internal mechanical resistance against vibration, thereby providing a speaker of high efficiency and satisfactory characteristics.

Method of making metal coated foil speaker diaphragm

A magnetic head having a high wear resistance and high workability such as by grinding, and a method for manufacturing the same. According to this method, at least a portion of that surface of the core forming the magnetic head or shielding case, which is to be brought into contact with a magnetic recording medium, is subjected to a boronizing treatment to form a boronized layer.

Method for manufacturing magnetic head using boronizing treatment

A composite diaphragm for a speaker comprises a boron layer formed on a metal foil such as titanium foil, in which a layer of a low melting point metal such as aluminum or magnesium is interposed between the metal foil and the boron layer to provide high rigidity, high elasticity and high bonding strength between the metal foil and the boron layer.

Growing community of inventors

Hirakata, Japan

Hidetsugu Kawabata