Kabushiki Kaisha Toshiba

The Furukawa Electric Co., Ltd.

Toshiba Computer Engineering Corporation

Masahiro Kusunoki

Hiroshi Ohashi

Hiroshi Okamura

Mitsuru Masuda

Susumu Kimura

Koji Osafune

Toshiyuki Fujioka

Shigeru Takekado

Yoshiaki Uchida

Hiroyuki Tamaoka

Yoichi Iso

Yoshihisa Nakamori

Toshiya Saito

[OBJECT] There is provided a wireless power transmission system capable of transmitting power efficiently even when it is rotated. [ORGANIZATION] A power transmission device has a first and a second electrode (a center electrodeand an annular electrode) each having a rotationally symmetrical shape with respect to a common center axis, a first and a second connection line (connection lines), and a first inductor to (inductor). A power reception device has a third and a fourth electrode (center electrodeand annular electrode) each having a rotationally symmetrical shape with respect to a common center axis, a third and a fourth connection line (connection lines), and a second inductor. The electrodes of the power transmission device and the power reception device are disposed to oppose each other across a distance of &#x3bb;/2&#x3c0; or less as a near field, and a resonance frequency of a coupler constituted of the first and the second electrode and the first inductor and a resonance frequency of a coupler constituted of the third and the fourth electrode and the second inductor (inductor) are set to be substantially equal.

Wireless power transmission system for transmitting alternating-current power wirelessly

[OBJECT] There is provided a wireless power transmission system capable of transmitting power efficiently even when there is an obstacle or the like. [ORGANIZATION] A power transmission device has a first and a second electrode (), a first and a second connection line (), and a first inductor (). A power reception device has a third and a fourth electrode (), a third and a fourth connection line (), and a second inductor (). At least one of the first to the fourth electrode is housed in a conductive casing () having an opening corresponding to an opposing electrode, and a resonance frequency of a power transmission coupler constituted of the first and the second electrode and the first inductor () and a resonance frequency of a power reception coupler constituted of the third and the fourth electrode and the second inductor () are set to be substantially equal.

A wireless power transmission system that transmits alternating-current power includes a power-transmitting device including first and second electrodes spaced apart and having a total width of &#x3bb;/2&#x3c0; or less, i.e., a near field range, and a first inductor between the first and second electrodes and a AC power-generating section, and a power-receiving device including third and fourth electrodes spaced apart and having a total width of &#x3bb;/2&#x3c0; or less, and a second inductor between the third and fourth electrodes and a load. A coupler including the first and second electrodes and the first inductor forms one resonant circuit and a coupler including the third and fourth electrodes and the second inductor forms another resonant circuit. Resonance frequencies of the couplers are substantially equal. The first and second electrodes and the third and fourth electrodes are spaced apart by &#x3bb;/2&#x3c0; or less.

Wireless power transmission system for transmitting power between a power transmitting device and a power receiving device

A magnetic recording/reproducing apparatus includes a control section, a recording section and a medium access section having a head. The control section sets a write mode in response to an input write access command, and outputs write data and density indication data to the recording section. In the write mode, the recording section generates dummy data in accordance with the density indication data and modulates a write current in accordance with the write data and the dummy data subsequent to the write data. The modulated write current is supplied to the medium access section. A value of the write current is determined in accordance with the density indication data, and the write current decays with a time constant while the write current is modulated in accordance with the dummy data. The medium access section write-accesses a medium in accordance with the modulated write current in the write mode.

Method of accurately executing read access and magnetic

A magnetic disk apparatus comprises an access section including a read/write head, for applying to a magnetic disk a recording magnetic field in a gap of the read/write head in accordance with input generation control data. A discriminator discriminates a recording density of the magnetic disk and outputs recording density data representing the recording density to a access controller. The access controller generates and outputs to the access section the generation control data in accordance with input write data and the recording density data from the discriminator.

Method of controlling recording magnetic field applied by gap of

Disclosed is a magnetic head apparatus, which comprises a pair of magnetic cores defining a magnetic gap for recording and reproducing information, and grooves in the lateral faces of the magnetic cores, extending at right angles to those faces of the cores which are opposed to a magnetic recording medium or which define the magnetic cores. The grooves determine the width of the magnetic gap. That face of at least one of the magnetic cores which is opposed to the recording medium, is recessed from the remaining portion of the core, so as to cover a width equivalent to the length of the grooves, at the maximum. In the magnetic head of the invention, moreover, a nonmagnetic portion is formed at least on an erase gap, so that the degree of magnetic coupling between the erase gap and the recording medium is lower than that between a read/write gap and the medium. Thus, magnetic induction, which is produced in the erase core when data is read from the medium, is reduced.

Low-noise magnetic read/write head

A magnetic recording apparatus capable of efficiently erasing data in accordance with a type of magnetic recording medium, comprises a current source, an erase head for erasing data recorded on a recording medium using a supplied erase current, and a current supplying section for supplying an erase current from the current source to the erase head in accordance with input erase current control data. The current supplying section comprises a selecting section for selecting a combination of a plurality of control elements in accordance with the input erase current control data, and a supplying section for supplying an erase current determined in accordance with the selected combination from the current source to the erase head.

Method of efficiently erasing data in accordance with type of magnetic

A magnetic head device for use with a high recording density, large memory capacity floppy disk, is disclosed. The slider of the magnetic head device has a contact surface for effecting contact with a disk, the lead/write gap is located at a predetermined position in the contact surface, and the width of the slider contact surface is 1 mm or less.

Magnetic head device

A magnetic recording/reproduction apparatus of the invention has a magnetic head for reading a vertical magnetically recorded signal, an inplane magnetic recorded signal or a magnetic recorded signal having both a vertical magnetic component and an inplane magnetic component and for supplying a reproduced signal, a first analog signal converting circuit for converting the reproduced signal into an analog inplane reproduced signal when the reproduced signal is a vertical reproduced analog signal, a second analog signal converting circuit for bypassing an inplane analog reproduced signal when the reproduced signal is the inplane reproduced analog signal, and a third analog signal converting circuit for converting the reproduced signal into an inplane reproduced analog signal when the reproduced signal is the inplane reproduced analog signal. The circuits are switched to operate selectively in accordance with the type of signals reproduced from a magnetic recording medium.

Magnetic recording/reproduction apparatus

Leaf spring is fixed at one end thereto to a carriage, and extended at a predetermined angle to the carriage. A part of the leaf spring has rigidity. A gimbal spring, which free from the carriage, is mounted on the rigid portion. Head is fixed to the gimbal spring. The head can move perpendicularly to the carriage by the operation of the leaf spring, and can roll and pitch by the operation of the gimbal spring. Thus, the head can follow to move elevationally upward and downward and incline to the disk-like recording medium and contact the medium with good contacting property.

Head supporting mechanism for maintaining close operative relationship

In a horizontal recording medium, new information can be overwritten upon old information at a low recording density without erasing the medium. In a perpendicular recording medium, on the other hand, new information is recorded at a high recording density after having erased the medium. On the basis of the above features of the horizontal and perpendicular recording mediums with different recording densities, the apparatus comprises first magnetic head with a long gap for the horizontal recording medium, a second magnetic head with a short gap for the perpendicular recording medium, and a heat selector, in order to provide a magnetic recording and reproducing apparatus compatible with both high and low recording density mediums.

Floppy disc magnetic head apparatus compatible with both horizontal and

In a magnetic head drive apparatus of this invention, a coil of an erasing head is connected to a center point of the coils of a read/write head, and a drive current from a constant-current source is alternately supplied to both terminals of the coil of the read/write head, according to the polarity of the write data. When the read/write head is driven to write data in a magnetic recording medium, the erasing head and the read/write head are driven at an identical timing. In this case, the drive currents for the read/write head and the erasing head are supplied from a single-current source. For this reason, separate constant-current sources are not necessary for the read/write head and the erasing head.

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Tokyo, Japan

Masahiro Kusunoki