Matsushita Electric Industrial Co., Ltd.

Koichi Shinohara

Takashi Fujita

Takashi Suzuki

Masaru Odagiri

Shigeki Kawase

Hideki Kuwajima

Kaoru Matsuoka

Mikio Murai

Kunio Hibino

Shigeo Obata

Toshiaki Kunieda

Norimoto Nouchi

Yoshihiro Ueno

Hiromi Kita

Makoto Miyamoto

Tatsuhiko Inagaki

Kenichi Sakamoto

Yasuo Iijima

Masao Kawagishi

Hideki Yoshida

Nobuo Satoh

Takeshi Murakami

An information-recording/-reproducing device comprises a rotor assembly formed of a disc portion having information recording layer provided on the main surface and an axle portion, the disc portion being connected at the center of a surface opposite to the main surface with the rotating axle so that the rotating axis crosses at right angle with the main surface of disc portion at the center of rotation, a bearing for supporting the axle of disc portion freely rotatable, a rotating magnet fixed to a rotor yoke, a stator disposed opposing to the rotating magnet, and a motor for rotating the disc portion with the rotating axis of the axle as the center of rotation. Preferably, the disc portion with the rotating axle portion having a round column shape or a cylindrical shape, further may have a shallow hollow in the central part of the main surface which being a surface opposite to the surface having the rotating axle.

Rotor assembly, information-recording/-reproducing device using the rotor assembly and method of assembling the rotor assembly

A disk drive comprises a recording medium, spinning means, a head supporting device having a support arm disposed in a rotatable manner about a bearing unit in a radial direction as well as a perpendicular direction to a writing surface of the recording medium, and rotating means for rotating the support arm in the radial direction of the recording medium. A shape of the housing is defined based on a first straight line tangent to both an outermost rim of the rotating means and an outer periphery of the recording medium, and according to a quadrilateral comprised of the first straight line, a second straight line tangent to the outer periphery of the recording medium and perpendicular to the first straight line, a third straight line tangent to the outermost rim of the rotating means and perpendicular to the first straight line, and a fourth straight line tangent to the outer periphery of the recording medium and parallel with the first straight line, thereby realizing the disk drive that is compatible in external size with memory cards.

Disk drive with head supporting device

A tape cassette for a magnetic recording tape having metallic magnetic recording layer is provided with a gas trapping layer which is disposed on a portion of the cassette near the path of the magnetic recording tape stretched between a pair of reels. The trapping layer has a trapping tendency which is at least equivalent to that of the magnetic recording tape. Any corrosive gas components coming into the cassette is adsorbed by and made to react with the trapping layer so as to reduce the concentration of the corrosive gas reaching the metallic magnetic recording layer, thus preventing degradation of the magnetic recording layer and ensuring that recording is conducted with high recording density.

Tape cassette with a trapping layer having a corrosiveness which is

A thin film magnetic recording medium has a shape imparting substance disposed on a substrate, and a thin-film layer including at least a magnetic layer formed on the shape imparting substance. The area of each of the projecting portions of the thin-film layer which are formed by virtue of the shape imparting substance is set such as to be more than four times as large as the area of each of the particles of the shape imparting substance. The center line of each of the projecting portions of the thin-film layer may be made offset from the center line of the corresponding particle of the shape imparting substance. Thus, it is possible for the thin film magnetic recording medium to display excellent electromagnetic response properties and runability as well as durability even under a harsh environment.

Thin film magnetic recording media

A magnetic recording medium comprises steep mountain-shaped protrusions having heights ranging 50-600 .ANG. and distributed at a rate of 1.times.50.sup.5 -1.times.10.sup.8 protrusions/mm.sup.2 on a surface of ferromagnetic metal layer and further thereon a lubricant layer; the magnetic recording medium is suitable for VTR tape which has a satisfactory durability for repeated use and eliminates head clogging and squealing.

Magnetic recording medium

A thin film of a ferromagnetic metal or alloy and containing oxygen is formed over the surface of an elongated polyester film, said surface being formed with worm-like or particle-like projections consisting of cured high-molecular weight compounds.

Magnetic recording media and process for fabricating the same

A magnetic recording media, e.g. VTR tape is improved by providing an undercoating layer on a polyester film substrate, the undercoating layer being formed under a ferromagnetic thin film and being an even-scattering of a large number of inorganic or organic granules distributed at a rate of 1000/mm.sup.2 or more.

A magnetic recording media comprises a polyester substrate having 1000/mm.sup.2 or more protrusions of polyester oligomer, and a ferromagnetic thin film of 400 .ANG. or larger thickness both formed on the surface of the polyester substrate; the recording media has substantially no squealing even at 30.degree. C. at over 80% relative humidity.

Polyester substrate for magnetic recording medium having oligomer

The invention provides a method and a device for mass-producing a magnetic recording medium which has excellent wear and corrosion resistance and uniform quality along the longitudinal and transverse directions of an elongated base body, wherein the elongated base body in a vacuum chamber is fed to continuously deposit a ferromagnetic material thereon, while a gas is sprayed in the vicinity of an incident angle control section of a mask for controlling an angle of incidence of a vapor flow from a vapor source to the elongated base body. The angle of incidence is kept constant to prevent deposition of the vapor material on the incident angle control section, and simultaneously, a uniform oxide film is formed on the ferromagnetic layer using a gas containing oxygen.

Method and device for manufacturing magnetic recording medium

A method of vacuum depositing a layer on a plastic film in which the film is transported so as to pass along a metal surface moving with the film, which surface removes heat from the film, and vacuum depositing the vapor of an evaporant onto the surface of the plastic film while it is in contact with the metal surface. The film is in an electret state when it is located at the metal surface, whereby an electrostatic attractive force is produced between the film and the metal surface, thereby increasing the efficiency of heat conduction between the film and the metal.

Method of vacuum depositing a layer on a plastic film substrate

A method of making a magnetic recording medium including a step of continuously depositing a ferromagnetic layer with the use of electron beam for heating an evaporation source material. A container for retaining said source material in a heating position is made of a ceramics having a composition comprising 97 to 99 wt % of MgO, 0.2 to 0.5 wt % of Al.sub.2 O.sub.3 and 0.4 to 1 wt % of SiO.sub.2.

Method of making a magnetic recording medium

A blower and a dust collector are communicated through valves with an evacuated process chamber in which are disposed one or more sets of a film-substrate holder and an evaporation source in such a way that the blower, the dust collector and the process chamber constitute a closed circuit.

Vacuum evaporation system for deposition of thin films

A magnetic thin film deposited on a non-magnetic substrate consists substantially of Ni, Co and oxygen, the content of Ni being between 10 and 55% by weight based on the weight of Ni and Co, the atomic percent ratio of oxygen to Ni and Co being between 3 and 45%.

Metallic thin film magnetic recording medium

A magnetic recording medium wherein a ferromagnetic substance consisting of Fe, Co, Ni or alloy thereof is vacuum evaporated and deposited on a substrate made of a plastic film or a sheet of non-magnetic metal. The thin ferromagnetic film has the columnar crystal structure, and the columnar crystals are coated with a layer of oxide of the ferromagnetic substance.

Within the vacuum atmosphere containing oxygen a cylindrical rotary can and an evaporation source are disposed in opposed relationship and in such a way that the normal line constructed at the center of the evaporation surface of the evaporation source will not intersect the axis of the cylindrical rotary drum. The beam of the evaporating ferromagnetic substance is directed to and impinged against the substrate transported along the rotary drum at right angles to the direction of transport thereof.

Growing community of inventors

Kobe, Japan

Koichi Shinohara