Tdk Corporation

Takeshi Kamono

Noritaka Chiyo

Mitsunari Suzuki

Narutoshi Fukuzawa

Masayuki Kobayashi

Eiji Takegami

Toshinori Matsuura

Naoki Mukaida

Kazuyoshi Hanabusa

Yukio Terasaki

Tetsuya Nishiyama

Yasuhiro Terasaki

Masahide Ohnishi

Jun Kawakami

Takahiro Shiohara

A plasma generator capable of adjusting the amount of plasma generation in a simple configuration includes a control circuit controlling a frequency of an AC power supplied to a piezoelectric transformer and a control signal generation circuit providing a control signal to the control circuit. The plasma generator is configured so that the control signal output from the control signal generation circuit is appropriately adjusted. The control circuit controls the frequency of the AC power so as to bring a target value, which is set based on the control signal provided from the control signal generation circuit.

Plasma generator

A power transmission device, which is used for a contactless power transmission to a movable body moving on a travelling surface in a power transmission direction parallel to the travelling surface, including a power transmission coil and a shielding plate, wherein, the power transmission coil is installed so that a coil surface is approximately vertical to the travelling surface, and at least a part of the shielding plate is disposed inside the region on the travelling surface sandwiched between a plane surface defined by a coil surface of the power transmission coil and a plane surface defined by a coil surface of a power receiving coil mounted on the movable body.

Power transmission device

The present invention provides a contactless power transmission circuit which is capable of narrowing a fluctuation extent of an output voltage output by a power receiving coil via a rectifier circuit. The contactless power transmission circuit controls a period of an alternating voltage output from a driving circuit based on a smaller one of either of a first command value and a second command value. Here, the first command value is one based on a difference between a detected value of the output voltage from the rectifier circuit and a target value. The second command value is one calculated based on a difference between a detected value of a transmission current flowing through the power transmitting coil and a target value.

Contactless power transmission circuit

A power feeding coil unit includes a power feeding coil, and an auxiliary coil. The auxiliary coil is arranged not to interlink with a magnetic flux that interlinks with a power receiving coil that is arranged to face the power feeding coil during power feeding. An axial direction of the auxiliary coil is nonparallel to an opposing direction of the power feeding coil and the power receiving coil. A direction of circulation of a magnetic flux generated by the auxiliary coil is opposite to a direction of circulation of a magnetic flux generated by the power feeding coil.

Power feeding coil unit and wireless power transmission device

A power feeding coil unit includes a first power feeding coil and a second power feeding coil that generate a first magnetic flux, a first auxiliary coil that generates a second magnetic flux interlinking with the first power feeding coil, and a second auxiliary coil that generates a third magnetic flux interlinking with the second power feeding coil. An axial direction of the first auxiliary coil is nonparallel to an axial direction of the first power feeding coil, and an axial direction of the second auxiliary coil is nonparallel to an axial direction of the second power feeding coil. A direction of circulation of the second and third magnetic fluxes are opposite to a direction of circulation of the first magnetic flux.

A coil which maintains a balance of a parasitic capacitance and has a structure that can be multilayered. The coil is stacked with a structure which includes winding wire portions formed of a wire wound for several turns in a plane in each layer, wherein winding wire portions in each layer include a first winding portion formed by performing a single turn of winding in each layer in a same winding direction from a bottom layer to an uppermost layer, and a second winding portion formed by performing a single turn of winding in each layer in a same winding direction from the uppermost layer to the bottom layer, and the winding directions of the first and second winding portions are identical to each other and the first winding portion and the second winding portion are joined in the uppermost layer or the bottom layer.

Coil

A DC-DC converter is configured with a voltage-source power converter at a primary side of a transformer, a current-source power converter at a secondary side of the transformer, and a controller. First and second voltage detection circuits respectively detect first and second voltages of the voltage-source and the current-source power converters. A current detection circuit detects an input-output current of the current-source power converter. The controller controls the voltage-source and the current-source power converters to transfer power between the primary side and the secondary side of the transformer. The controller includes a calculation unit that performs calculations based on the first voltage, the second voltage and the input-output current, and a table unit that include a plurality of parameter sets. The calculation unit performs the calculations based on one of the plurality of parameter sets that is selected from the table unit.

DC-DC converter

First operations and second operations are performed in parallel. The first operations are operations to write first data to a first unit area which is any one of unit areas. The second operations are operations to read second data corresponding to the same logical page as first data from one or more flash memories and write the second data to a second unit area which is any one of the unit areas and different from the first unit area. Data transfer is performed between the first unit area and the second unit area so as to form data composed of the first data and a portion of the second data which is not replaced with the first data.

Memory controller, flash memory system with memory controller, and method of controlling flash memory

In the control of the number of program-erase cycles, physical blocks (PBs) are divided into plural groups on a basis of the number of program-erase cycles and a search for a free PB is performed in the groups when assigning a logical block (LB) to the free PB. In the search, a free PB among a group covering a small number of program-erase cycles precedes that among a group covering a large number of program-erase cycles. Further, when searching out a free PB in the search, data stored in a PB (source PB) included in a group covering a smaller number of program-erase cycles than that covered by a group including the free PB searched out are transferred to the free PB if there is the source PB. The source PB is a PB to which a LB is assigned earliest among a group including it.

Growing community of inventors

Tokyo, Japan

Takeshi Kamono