Other

Nippon Telegraph and Telephone Corporation

Ando Electric Company

Jx Nippon Mining & Metals Corporation

Ntt Electronics Corporation

Nippon Telephone and Telegraph Corporation

Nippon Telegraph & Telephone Co.

Mitsuru Shinagawa

Tadao Nagatsuma

Junzo Yamada

Katsushi Ohta

Akishige Ito

Jun Kikuchi

Yoshiki Yanagisawa

Toshiyuki Yagi

Nobuaki Takeuchi

Yoshio Endou

Tadashi Minotani

Fumio Akikuni

Nobukazu Banjo

Nobutarou Shibata

Kazuyoshi Matsuhiro

Hakaru Kyuragi

Katsuyuki Ochiai

Aiichirou Sasaki

Haruka Kyuragi

Kazuo Fujiura

Seiji Toyoda

Masahiro Sasaura

Ai-ichiro Sasaki

Hiroyoshi Togo

Ryusuke Kawano

Toshiaki Asahi

Noriyuki Toriyama

Nobutaro Shibata

Yuichi Kado

Ken Takeya

Makoto Yaita

Ryoichi Matsumoto

Nobukazu Banjou

Takuji Harada

Sanjay Gupta

Hideyuki Okamoto

Ai-Ichiro Sasaki

In an optical modulator capable of modulating incident laser beam L by a compound semiconductor single crystal having a property of generating an electro-optic effect, the attenuation of the signal strength in a low frequency band is prevented without lowering the carrier concentration of the compound semiconductor. The optical modulatorcomprises: incidence limiting meanswhich is provided on or near an incidence plane, on which the laser beam L can be incident, of the compound semiconductor single crystalso as to limit incidence of light other than the laser beam L on the incidence plane; and a shielding memberwhich is formed from a low-permittivity material having a light blocking effect, and covers a surfaceof the compound semiconductor single crystalextending along a traveling direction of the laser beam L that entered the compound semiconductor single crystal

Optical modulator and electric field sensor

A signal electrode (A) and a ground electrode (B) are disposed respectively on surfaces of a case (). In this way, the signal electrode (A) and the ground electrode (B) do not come into contact with any electric component, such as a transmission circuit (), disposed inside the case (), and thus a reduction in an electric field (Ec) induced in an electric-field transmission medium can be prevented. In addition, a certain distance between the signal electrode (A) and the ground electrode (B) is kept, and thus a reduction in the electric field (Ec) induced in the electric-field transmission medium can be prevented. Furthermore, the contactability between the signal electrode (A) and the electric-field transmission medium is improved, and thus the electric field (Ec) induced in the electric-field transmission medium can be increased.

Electric-field communication device

When a human hand () holds a transceiver (), the hand holds a bottom of an external wall surface and a side of the external wall surface of an insulating case (). Therefore, a transmitting and receiving electrode () and an insulating film () cover not only the bottom of the external wall surface but also the side of the external wall surface of the insulating case (). A first ground electrode (), a second ground electrode (), and a third ground electrode () are attached to upper portions of the internal wall surface of the insulating case () apart from the transmitting and receiving electrode (). An insulating foam member () is interposed between the insulating case () and a transceiver main body (), and an insulating foam member () is interposed between the transceiver main body () and a battery ().

Electric field sensor device, transceiver, positional information obtaining system and information input system

The present invention relates to an electric field sensor including: a light source (); an electro optic crystal () which is applied with an electric field based on a signal under test, in which a birefringent index changes according to the electric field, and which changes a polarization state of light incident from the light source according to the birefringent index and emits the light; and a detector () that detects an electric signal according to the change of the polarization state of the light emitted from the electro optic crystal (). Further, the electric field sensor includes: a signal electrode () for applying the electric field based on the signal under test to the electro optic crystal (); a counter electrode () that forms a pair with the signal electrode (); and an auxiliary electrode () that is electrically connected to the counter electrode (), and that forms a capacitance with ground.

Electric field sensor

A transmitter () modulates information to be transmitted with an alternating-current signal having a predetermined frequency and includes a variable reactance section () which produces resonance with a stray capacitance () between a circuit ground () in the transmitter () and an earth ground () which strays from the earth ground () and a stray capacitance () between the human body () and the earth ground (). A receiver () that receives the induced electric field from the transmitter () includes an electrode () that transmits/receives the electric field to/from the human body (); a detection signal source () that applies a detection signal to the electrode (); and a detecting section () which detects the detection signal, and further detects, based on an amplitude of the detection signal, a resonant state of the variable reactance section () in the transmitter () held by the human body () close to the electrode (), the stray capacitance () between the human body () and the earth ground (), and the stray capacitance () between the ground () of the transmitter () and the earth ground (), and outputs a signal when the resonant state is present.

Receiver, transceiver, and electric field communication system

A reactance adjuster includes an electrode () inducing an electric-field in an electric-field transmittable medium (), an adjusting signal generation section () outputting alternatingly a high level or a low level signal to a resonance section (), an electric-field detection section () generating an electric signal based on the electric-field in the medium (), a first electric-charge storing means (C) storing electric-charge according to the electric signal when the section () outputs a high level signal, a second electric-charge storing means (C) storing electric-charge according to the electric signal when the section () outputs a low level signal, a voltage comparator () outputting a predetermined signal based on a voltage difference between the storing means, a control section () outputting a constant voltage when the first and the second storing means (CC) are storing electric-charge and a voltage based on a predetermined signal when the storing ends.

Reactance adjuster, transceiver and transmitter using the reactance adjuster, signal processing circuit suitable for use in the reactance adjuster, the transceiver, and the transmitter, reactance adjusting method, transmitting method, and receiving method

There is provided a transmission means () configured to transmit a modulated signal obtained by modulating data, a transmission electrode () that induces an electric field based on the modulated signal in an electric field transmission medium (), a first reactance means () that is provided between the electric field transmission medium () and an earth ground () and configured to cause resonance with parasitic capacitance produced between a ground () the transmission means () and the earth ground (), parasitic capacitance produced between the electric field transmission medium () and the ground () of the transmission means () and parasitic capacitance produced between the electric field transmission medium () and the earth ground (), and a second reactance means () provided between an output of the transmission means () and the ground () of the transmission means () or between the transmission electrode () and the ground () of the transmission means ().

Transmission device, electric field communication transceiver, and electric field communication system

In a transceiver for inducing electric fields based on data to be transmitted in an electric field propagating medium and carrying out transmission and reception of data by using induced electric fields, having a transmission electrode and a transmission circuit, a transmission side switch is provided to disconnect the transmission circuit from the transmission electrode, when the transceiver is not in a transmission state in which the transmission circuit is supplying the transmission data to the transmission electrode.

Transceiver suitable for data communications between wearable computers

On one pair of opposed side faces () of electro-optic crystal (), grooves () are formed so as to make bottom faces of the grooves approach each other and make a distance between the bottom faces shorter than a predetermined distance, and the pair of electrodes () are formed in the grooves () so as to fill the grooves nearly completely.

Electrooptic modulation element

The button apparatus is an apparatus provided for, for example, a vending machine and to be touched and pressed with the body of a user who wants to purchase a commodity from the vending machine. By pressing down the button apparatus, the user can purchase a required commodity from the vending machine. The button apparatus has a conductive pusher, an insulator, a switch, and a transceiver. A user wearing a wearable computer and a user's transceiver touches and presses down the pusher, to separately establish communication between the transceiver and the user's transceiver through the conductive pusher and the body of the user, as well as communication of providing a press signal.

Sales apparatus and method of transmitting and receiving merchandise information by electric field induced in human body

A transceiver for inducing electric fields according to data to be transmitted in an electric field propagating medium, and carrying out at least data transmission by using induced electric fields, is formed by a transmission unit configured to modulate the data to be transmitted by generating alternating current signals having a prescribed frequency, and transmit modulated signals obtained by modulating the data to be transmitted, and a resonance causing unit configured to cause a series resonance with a parasitic capacitance appearing between a ground for the transmission unit and an Earth ground and a parasitic capacitance appearing between the electric field propagating medium and the Earth Ground.

Transceiver capable of causing series resonance with parasitic capacitance

An electro-optic sampling apparatus is provided to enable measurement on potentials of signals on the conductor of coaxial cable with high precision and with ease. Herein, an electric input connector inputs a measured electric signal, which is introduced to a conductive path such as a microstrip line. An electro-optic material (e.g., Bi SiO ) that provides electro-optic effect such as Pockel's effect is fixed to a bare portion of the conductive path and is varied in birefringence ratio in response to strength of electric field caused by the conductive path through which the measured electric signal transmits. The conductive path is then terminated by a terminal device. Now, a laser beam is radiated toward the electro-optic material, wherein it is varied in polarization in response to variations of the birefringence ratio. Then, the laser beam is reflected by a dielectric mirror and is separated into two beams by a polarization beam splitter. Photodiodes are provided to convert the two beams to electric signals representing potentials. Thus, the apparatus measures voltage of the measured electric signal based on the electric signals.

Electro-optic apparatus for measuring signal potentials

An electro-optic probe has a laser diode for emitting a laser beam in accordance with a control signal from a measuring instrument main body, an electro-optic or magneto-optic element provided with a reflection film on an end surface thereof, a separator provided between the laser diode and electro-optic or magneto-optic element which is pervious the laser beam emitted from the laser diode and separates a beam reflected from the reflection film and two photodiodes which transform the beam reflected by the separator. A member of weak dielectric material, such as a glass plate, overlies the electro-optic or magneto-optic element at the end of the probe to protect the element, or the element is at the end of the probe and is exposed.

Electro-optic probe and magneto-optic probe

Growing community of inventors

Isehara, Japan

Mitsuru Shinagawa