Tokyo Shibaura Denki Kabushiki Kaisha

Kabushiki Kaisha Toshiba

Nippon Hoso' Kyokai

Norikazu Sawazaki

Shu Chiba

Junichi Akiyama

Hitoshi Iwasaki

Toshikazu Matsui

Yoshio Nishi

Soichi Iwamura

Yasushi Higashiyama

Norio Endo

Yasuaki Nishida

Masaharu Watanabe

Shigeru Yatabe

Toshimi Yamato

Jun-ichiro Ikeuchi

Shigeo Senzaki

An apparatus for reproducing a signal recorded, in the form of a perpendicular signal magnetization, on a perpendicular magnetic recording layer backed with a high permeability layer of a magnetic recording medium. A thin-film magnetic material is disposed to face the recording layer so that an enlarged magnetized region is formed in the high permeability layer, which includes the position at which the magnetic material faces the recording layer. In this region, magnetic variation occurs in response to the signal magnetization of the recording layer at the position the magnetic material faces the recording layer. A detecting member such as a coil is disposed in the proximity of the magnetic material so as to be magnetically coupled to the enlarged magnetized region of the high permeability layer. The detecting member is used as a tuning element of a tuning circuit supplied with high frequency energy. A resonance output voltage of the high frequency circuit varies in response to the detection of magnetic variation in the high permeability layer. A reproducing circuit detects the variation in the resonance output voltage of the high frequency circuit to reproduce the signal recorded on the recording layer.

Magnetic reproducing apparatus

A magnetic playback apparatus using ferromagnetic resonance of a magnetic material provided with a magnetic anisotropy to develop an anisotropic magnetic field. The magnetic material is disposed at a position influenced by a magnetic field resulting from a signal recorded on the magnetic recording medium. The magnetic material is coupled with a high frequency circuit to be supplied with a high frequency magnetic field. The high frequency characteristics of the magnetic material greatly vary depending on a ferromagnetic resonance. A ferromagnetic resonance magnetic field is set up, allowing for the magnitude of an anisotropic magnetic field and the frequency of the high frequency magnetic field, so that a great variation in the high frequency characteristics due to the ferromagnetic resonance may be obtained according to the signal magnetic field.

Magnetic resonance-type playback apparatus including a magnetic material

A magnetic recording head apparatus includes: a magnetic head body opposing a travelling magnetic tape; a tuning circuit having the head body as a variable inductance element; a high-frequency signal source for generating a high-frequency signal; and a detector connected to the tuning circuit. The inductance of the head body is changed in accordance with a change in the magnetic signal field applied from the magnetic tape. The high-frequency signal is amplitude-modulated in accordance with the high-frequency signal. A peak or envelope waveform of the modulated high-frequency signal is detected by a detector, thereby obtaining a reproduced information signal.

Magnetic head apparatus with variable inductance

A capacitance element includes as an interelectrode substance a magnetic body for detecting a magnetic field formed by a magnetic recording medium. A tuned circuit includes the capacitance element as a tuning element and receives a signal from a high-frequency oscillator. The magnetic characteristics of the magnetic body change with changes in the magnetic field formed by the magnetic recording medium. The high-frequency signal output from the tuned circuit changes with changes in the magnetic characteristics of the magnetic body. A detecting circuit detects the changes in the high-frequency signal output so as to reproduce signals recorded on the magnetic recording medium.

Magnetic reproduction system utilizing magnetic body as capacitor

A head for recording an information signal in and reproducing the same from a semiconductor recording medium comprises an electrode stylus for recording and reproducing recording information by relatively sliding on the semiconductor recording medium, the recording information being recorded and reproduced through the electrode stylus, and a nonconductive supporting substrate, provided on the side surface of the electrode stylus, for supporting the electrode stylus. A hardness of the electrode stylus is lower than a hardness of a surface medium which constitutes the semiconductor recording medium and is higher than a hardness of the supporting substrate.

Head for recording an information signal in and reproducing the same

Signals are recorded on a magnetic tape having a magnetic recording layer containing a magnetic material whose high frequency characteristic varies with a magnetic field produced therein. Changes in the coupling degree of a high frequency coupling circuit caused by a signal field allows to reproduce a recorded signal.

Magnetic recording and reproducing apparatus

Signals are recorded on a magnetic tape having a magnetic recording layer containing a magnetic material whose magnetic permeability or high frequency loss varies with a magnetic field produced therein. Changes in the permeability or high frequency loss produced according to the recording signals are converted into changes in the resonant frequency or Q of a resonant circuit, whereby a reproduced output is obtained.

An optical recording device for forming recording tracks of an indented pattern on a magnetic recording tape comprises a rotary drum which has at least two windows, the magnetic recording tape being driven obliquely on the windows along an outer surface of the drum, and an optical system, disposed inside the rotary drum, for converting a modulated laser beam incident on the optical system into two slit beams, major axes of sections of which form a predetermined angle and for emitting the slit beams on the magnetic recording tape through the windows, whereby the recording tracks of the indented pattern in correspondence with the signal are formed obliquely on the magnetic recording tape with respect to a longitudinal direction of the magnetic recording tape by the slit beams so as to form different azimuths between adjacent recording tracks.

Optical magnetic recording device

An electrostatic voltage detecting device includes a detecting electrode for detecting an electrostatic voltage generated by charge on a recording medium, a variable capacitance diode whose capacitance changes according to an output signal applied from the detecting electrode, a primary coil combined with the variable capacitance diode to form a resonance circuit, an oscillator for supplying an oscillating output signal of predetermined frequency to the primary coil, and a secondary coil inductively coupled with the primary coil. The capacitance of the variable capacitance diode changes according to an output voltage applied from the detecting electrode to vary a resonance frequency of the resonance circuit and consequently a voltage induced in the secondary coil.

Electrostatic voltage detecting device

A magnetic head includes a magnetic body, at least the permeability or high frequency loss of which is changed with changes of the record magnetic field on a magnetic tape, and a coil. A high frequency signal is supplied to a tuned circuit, which includes the coil and a capacitor, and a signal corresponding to the record magnetic field is taken out through the detection of the changes of the voltage of the high frequency signal supplied to the tuned circuit.

Magnetic reproducing system

Magnetic transcription-recording method

An information recording medium comprises a silicon substrate, a silicon dioxide film formed on one principal surface of the semiconductor substrate and a silicon nitride film formed on the silicon dioxide film. A recording electrode stylus is moved relative to and along the surface of the silicon nitride film while applying a recording signal voltage between the stylus and substrate, thus causing charges corresponding to the recording signal voltage to be passed through the silicon dioxide film by the tunnel effect and stored in the silicon nitride film.

Growing community of inventors

Yokohama, Japan

Norikazu Sawazaki