Sony Corporation

Dexerials Corporation

Yoshimi Takahashi

Susumu Sato

Yutaka Soda

Seiji Onoe

Katsuhisa Orihara

Satoru Sugita

Masatoshi Hayakawa

Shuichi Goto

Tomio Kobayashi

Tatsuo Kumura

Heikichi Sato

Kiyotada Yokogi

Toshiaki Yokota

Kazushi Yamauchi

Makoto Kubota

Kenji Asakura

Shoichi Kano

Junichi Saito

An antenna device, capable of stable communications without increasing a space of the entire device by keeping a resonance frequency substantially constant even if the temperature changes, includes: an antenna circuit having an antenna coil with an electrically connected capacitor; the coil receiving a magnetic field transmitted from a reader/writer at a predetermined oscillation frequency; the circuit becoming communicable when inductively coupled to the reader/writer; and a magnetic sheet formed at a position superposed on the coil to change its inductance, wherein the coil has a temperature characteristic in which the inductance is changed with a temperature change, and the sheet has a temperature characteristic of changing the inductance to achieve a characteristic inverse to the inductance change with the temperature change in a predetermined use temperature range, and substantially matching a resonance frequency of the circuit with the oscillation frequency in the use temperature region.

Antenna device and communication device

An antenna for receiving electromagnetic waves in a desired frequency band, includes a radiating conductor and a ground conductor, a feeder part, a wavelength-shortening section, and a magnetic field applying section. The radiating conductor and a ground conductor resonate at a resonance point frequency. The feeder part is configured to feed the radiating conductor with electricity. The wavelength-shortening section in which a magnetic body having both a dielectric property and a magnetic property is disposed close to the radiating conductor shifts the resonance point frequency into a band lower than the desired frequency band by a wavelength-shortening effect obtained based on the dielectric property and the magnetic property. The magnetic field applying section is configured to apply a magnetic field to the magnetic body so as to reduce a magnetic loss due to the magnetic body.

Antenna structure including radiating conductor and magnetic material having dielectric property

A head substrate and a protective substrate are formed of an electrostatic-discharge resistant conductive material having an electrical resistivity of 10to 10&#x3a9;cm. These substrates are electrically connected to a base metal through the use of conductive paste and are set to a ground potential via the base metal and a rotating drum. This suppresses a discharge current flowing through an MR element when an electrostatically charged substance touches or approaches a magnetic reproducing head, a terminal, a conducting wire, etc. to generate an electrostatic discharge. The magnetic reproducing head including an MR element and the like is prevented against an electrostatic discharge damage. It is possible to provide the magnetic reproducing head, a head drum apparatus, and a magnetic recording-reproducing apparatus which can highly effectively prevent an electrostatic discharge damage.

Magnetic reproducing head having a structure to inhibit electrostatic discharge damage to a recording tape

Magnetic reproducing head having a structure to inhibit electrostatic discharge to a recording tape

A magnetic transducer head comprising a first magnetic core element and a second magnetic core element, each of the first and second core elements comprising a magnetic ferrite block and a magnetic metal thin film integrated with the magnetic ferrite block. These core elements having a first planar surface and a second planar surface. The magnetic metal thin film being provided on the second planar surface and having an edge thereof facing to the first planar surface, and the second planar surface being slantly provided with respect to said first planar surface. These core elements being bonded together to form an operating magnetic gap between the edge of the magnetic metal thin film on the first core element and the edge of the magnetic metal thin film on the second core element. The magnetic metal thin film on the first core element or the magnetic thin film on the second core element is formed in one common plane. The magnetic metal thin film may be formed of the ferromagnetic metals including Fe--Al--Si alloys, amorphous metal alloys or permalloy. And the magnetic metal thin film having substantially uniform columnar grain structure or uniform magnetic anisotropy, over entire area of the film.

Magnetic transducer head having an alloy thin film of high saturation

Growing community of inventors

Miyagi, Japan

Yoshimi Takahashi