Tdk Corporation

Samsung Electronics Co., Ltd.

National Institute of Advanced Industrial Science and Technology

Narutoshi Fukuzawa

Takashi Kikukawa

Tatsuhiro Kobayashi

Hiroshi Take

Kazunori Oshima

Akira Gotani

Kazuki Kondo

Takashi Horai

Junji Tominaga

Hiroyuki Arioka

Hiroshi Kawahara

In-oh Hwang

Syuji Tsukamoto

Takayuki Shima

Takahiro Suwa

Jae-Cheol Bae

Toshinori Matsuura

Motohiro Inoue

Masashi Kuwahara

Kyung-geun Lee

Hajime Utsunomiya

Hyun-Soo Park

Kazuhiro Hattori

Minoru Fujita

Shuichi Okawa

Noritaka Chiyo

Kazuya Shimakawa

Mitsunari Suzuki

Daisuke Yoshitoku

Toshiki Aoi

Joo-Ho Kim

Tetsuya Nishiyama

Takashi Nakano

Takeshi Kamono

Joo-ho Kim

Yoshinori Uchiyama

Tsunehiro Saen

In-Oh Hwang

Shuji Tsukamoto

Ayako Sato

Hui Zhao

Akihiro Il

Hiroshi Saiwai

An object of the present invention is to suppress deterioration in detection accuracy during power feeding in the detection of the metallic foreign object using the antenna coil. A metallic foreign object detector includes: an antenna coil; a capacitor that constitutes a resonance circuit RC together with the antenna coil; a power supply that applies voltage to the resonance circuit to generate a vibration signal in the resonance circuit; a determination circuit that determines the presence/absence of a metallic foreign object based on the waveform of the vibration signal; a resonance capacitor switch inserted into the resonance circuit; and a control circuit that controls the open/close state of the resonance capacitor switch. The control circuit brings the resonance capacitor switch into a closed state responding to the power supply starting application of voltage to the resonance circuit.

Metallic foreign object detector, wireless power transmitting device, wireless power receiving device, and wireless power transmission system

An object of the present invention is to improve the accuracy of detection of the metallic foreign object. A metallic foreign object detector includes a sensor part having at least one antenna coil that receives a magnetic field or current to generate a vibration signal, an integration circuit that acquires the integral value of a waveform of a signal corresponding to the vibration signal, and a determination circuit that determines the presence/absence of a metallic foreign object approaching the antenna coil based on the integral value and a criterion integral value which is the integral value obtained in the absence of the approaching metallic foreign object. The integral value and the criterion integral value are obtained by integrating the waveform having the same wavenumber.

An object of the present invention is to reduce the possibility of failure in the detection of metallic foreign object. A metallic foreign object detector includes a sensor part having at least one antenna coil that receives a magnetic field or current to generate a vibration signal a vibration time length measurement circuit that measures a vibration time length indicating the length of time required for the vibration of the vibration signal output from the sensor part corresponding to a predetermined wavenumber larger than 1, and a determination circuit that determines the presence/absence of a metallic foreign object approaching the antenna coil based on the vibration time length and a criterion vibration time length which is the vibration time length obtained in the absence of the approaching metallic foreign object.

Wireless power transmitting device, wireless power receiving device, and wireless power transmission system

A metallic foreign object detector, used in a wireless power transmission system that transmits power using an alternating magnetic field, includes antenna coils that generate a vibration signal by receiving a magnetic field or current, one or more capacitors that constitute a resonance circuit together with each of the antenna coils, and a detection part that detects a metallic foreign object by sequentially using the antenna coils. The detection part has detection modes that detect the presence/absence of the metallic foreign object based on changes in mutually different characteristics of the resonance circuit. The detection part selects one mode from the detection modes in accordance with at least one of the power feeding state of the wireless power transmission system and the position of each of the plurality of antenna coils and performs the detection of the metallic foreign object in the selected detection mode.

An object of the present invention is to improve detection accuracy of a metallic foreign object between a feeding coil and a receiving coil during wireless power feeding. A wireless power transmitting device is a device that performs power transmission by wireless using an alternating magnetic field vibrating at a predetermined power transmission frequency and includes a feeding coil, an antenna coil, a capacitor that constitutes a resonance circuit RC together with the antenna coil, a noise detection part that detects noise vibrating at a frequency higher than the power transmission frequency, and a foreign object detection partthat detects the presence/absence of a metallic foreign object based on a change in voltage or current generated in the resonance circuit RC and a noise detection result from the noise detection part.

A coil device and a wireless power transmission device which can detect the happened open fault or short fault reliably in any one of the plurality of capacitor elements constituting the capacitor circuit. Coil device includes coil for power transmission, capacitor circuit connected to coil for power transmission and having a plurality of capacitor elements, conductive metal portion which is disposed close to coil for power transmission, and measuring portion for measuring a voltage or a current generated in metal portion.

Coil device and wireless power transmission device

A wireless power transmission device includes a power feeding unit and a power receiving unit. The power feeding unit and the power receiving unit are disposed so that a principal surface of a primary magnetic core and a principal surface of a secondary magnetic core face each other across a primary winding and a secondary winding. The distance from a surface of a feeding-side shield member which faces a feeding-side coil to a surface of the feeding-side coil which faces the feeding-side shield member, is longer than the distance from a surface of a receiving-side shield member which faces a receiving-side coil to a surface of the receiving-side coil which faces the receiving-side shield member.

Wireless power transmission device

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 coil unit in which impact resistance is ensured and that has a magnetic body for heating prevention. The coil unit (the power receiving coil unit) includes a winding wire (the winding wire portion) and a magnetic body, wherein in the magnetic body, a plurality of individual pieces with two principle surfaces opposing in a thickness direction are disposed in rows and columns in a direction substantially orthogonal to the thickness direction, and the two principle surfaces are in a polygonal shape and all interior angles forming a polygon are obtuse angles (except for a right angle).

Coil unit

A magnetic recording medium is provided in which recording elements and concave portions have a clear difference in terms of magnetism at the boundaries therebetween, and which has favorable production efficiency. The magnetic recording medium includes a substrate; a recording layer formed in a predetermined concavo-convex pattern over the substrate, convex portions of the concavo-convex pattern serving as recording elements; and a filler portion filling a concave portion between the recording elements. A center part of a bottom surface of the concave portion protrudes from edge parts of the bottom surface of the concave portion in a direction away from the substrate.

Magnetic recording medium and magnetic recording and reproducing apparatus

A magnetic recording medium is provided, which has recording layers having concavo-convex patterns formed on both sides of a substrate and can easily distinguish one face from the other face. A magnetic recording and reproducing apparatus having the magnetic recording medium is also provided. The magnetic recording medium includes a substrate, a first recording layer formed in a first concavo-convex pattern on a side of a first face, and a second recording layer formed in a second concavo-convex pattern on a side of a second face. The magnetic recording medium also includes a distinction element which can distinguish the first face from the second face. At least part of the distinction element is disposed in a non-recording area adjacent to at least one of an inner part and an outer part of a recording area in a radial direction.

Magnetic recording medium, magnetic recording and reproducing apparatus, method for manufacturing magnetic recording medium, and method for checking magnetic recording medium

A highly reliable magnetic recording medium is provided which has a recording layer formed in a concavo-convex pattern and wherein the recording layer is unlikely to cause a change in magnetic properties. The magnetic recording medium includes a substrate, a recording layer formed in a predetermined concavo-convex pattern over the substrate, convex portions of the concavo-convex pattern serving as recording elements; and a filler portion filling a concave portion between the recording elements. The filler portion comprises a metal-based main filler material and oxygen. Oxygen is unevenly distributed in the filler portion so that the ratio of the number of oxygen atoms to the total of the number of atoms of the main filler material and the number of oxygen atoms is greater in an upper surface portion of the filler portion than in a lower portion of the filler portion.

A method of determining an optimum reproduction condition of a first mark recorded on an optical recording medium that is smaller than a resolution of a pickup to reproduce the first mark. The method includes obtaining an optimum reproduction condition of a second mark having a length which closely approximates the resolution of the pickup, and determining the optimum reproduction condition of the first mark using the obtained optimum reproduction condition of the second mark.

Method and apparatus to determine an optimum reproducing condition on an optical recording medium

A super-resolution optical recording medium has at least a recording layer and a super resolution layer on a substrate. In the recording layer, a minimum recording mark is formed with spaces within a beam spot of a laser beam in recording. The minimum recording mark has a size of a resolution limit of a reproduction optical system or less, and can be reproduced by the reproduction optical system due to the existence of the super solution layer. The minimum recording mark in an AFM image takes the shape of a convex arc on a leading edge thereof and the shape of a concave arc on a trailing edge thereof (the AFM image is a plan view which can be observed on a surface when the light transmission layer is removed), and spaces have the similar shape to these.

Super-resolution optical recording medium and method for recording information on super-resolution optical recording medium

An optical recording medium includes a substrate, a first dielectric layer, a recording layer, a second dielectric layer, a super-resolution layer, and a third dielectric layer, which are provided in that order. The super-resolution layer is formed of a material configured such that voids are generated when the material is irradiated with DC light at a predetermined irradiation power for 1 to 300 seconds. Therefore, super-resolution reproduction can be made such that the irradiation power of a readout laser beam does not depend on the size of a recording mark.

Growing community of inventors

Tokyo, Japan

Narutoshi Fukuzawa