Fuji Electric Co., Ltd.

Uniden Corporation

Yokogawa Electric Corporation

Uniden America Corporation

Adv Antest Corporation

The University of Tokyo

Takahiro Kudo

Kimitada Ishikawa

Yujiro Kitaide

Kyoichi Ikeda

Hiroyuki Ishida

Masato Takahashi

Tetsuya Watanabe

Hiroyuki Yoshimura

Masami Kishiro

Hideo Hikuma

Kimihiro Nakamura

Ronald Lee Lipp

Hiroki Ohno

Junzo Tanaka

Hideo Tsukamoto

Takashi Odagiri

Nobuhisa Kato

Susumi Ohashi

Zhao Min

Kazuhiko Shimizu

Min Zhao

Daisuke Hayashi

Akira Miura

Koji Asami

Shinji Iio

Morio Wada

Takashi Mogi

Tsuyoshi Yakihara

Tatsuya Watanabe

Michihiko Tsuruoka

Masayuki Suehiro

Katsuya Ikezawa

Akio Fujita

Masayasu Fujino

Satoshi Fukuhara

Tohru Asami

Katsuhiko Otsuji

Toshimasa Umezawa

Makoto Ehara

Kunihiro Takahashi

Yuzo Ishida

Machio Dobashi

Shuji Tsukamoto

Yoshihiro Kawahara

Shoujirou Araki

Nobuaki Kohno

Haruki Kawakami

Hideaki Kuwayama

Kouji Nagai

Atsushi Kaneda

Hideo Hikiuma

Masanori Takebe

A front-end circuit is used to test an RF signal from an RF device. The RF signal is generated by modulating a carrier signal having a carrier frequency with a wideband baseband signal. A variable frequency oscillator generates a local signal having a variable local frequency. The first frequency mixer frequency mixes a local signal and an RF signal to generate an IF signal having a frequency. A band-pass type first filter filters the IF signal. The local frequency can be selected from a plurality of frequencies having a frequency interval equal to or narrower than a bandwidth of the first filter.

Front-end circuit

A transmitting device includes: a compressing unit configured to generate and output a compressed digital signal that has been compressed, by converting an input digital signal by use of a Walsh function and extracting a specific frequency component.

Transmitting device, receiving device, and transmitting and receiving system

An optical logic device performs a logic operation on a plurality of input light signals. The optical logic device has a photoelectric conversion portion, in which photoreceivers for receiving input light signals are provided in parallel, that outputs an electric signal obtained by adding up outputs of the photoreceivers, and a comparator that compares a voltage level of the electric signal outputted from the photoelectric conversion portion with a predetermined voltage level.

Optical logic device responsive to pulsed signals

An over-current protection device is constituted of a current detection unit for detecting a current from a power-supply source to a load having a magnetism detection element with a magnetic impedance (MI) effect, an AC-current supply device for supplying an AC current to the detection element, a bias-current supply device for supplying a bias current to a bias coil, a peak detection device for detecting a peak of impedance of the magnetism detection element as a variation of voltage, and a switch corresponding to a phase for selecting an output of the peak detection device. In the current detection unit, a holding device for holding a switch output and an amplifier are disposed in common for detecting the current in each phase, thereby expanding a current detectable range and reducing power consumption and cost.

Over-current protection device

An overload current protection device for cutting off power applied from a power supply to a load () such as a motor by means of a contactor (switch) () at overloading. With the configuration, an element () having a magnetic impedance effect as current detection units () is used to thereby expand a current detection range by eliminating magnetic saturation due to a core, a problem with a conventional current transformer, thereby providing at low costs an overload current protection device having a wide current detection range.

Overload current protection device using magnetic impedance element

In an overload current protection device for cutting off power from a power supply to a load () such as a motor by means of a contactor (switch) () at overloading, an MI element having a magnetic impedance (MI) effect as current detectors (, and) is installed at a position capable of detecting a current flowing through the secondary winding of power supply transformers (, and) that generate a control power supply to thereby reduce costs without using a constant voltage power supply and expand a current detection range by eliminating magnetic saturation due to a core, a problem with a conventional current transformer, thereby providing at low costs a high-precision overload current protection device having a wide current detection range.

A current sensor which constitutes an overload protection apparatus and senses a current supplied from a power source to a load is constituted by providing a magnetic sensor having the effect of magnetic impedance (MI), an AC supply means which impresses AC on this sensor, a bias current supply means which supplies a bias current to a bias coil, a peak sensing means which senses the peak or a change in impedance of the magnetic sensor as a change in voltage, and a switch which selects the output of the peak sensing means in accordance with each phase. A holding means which holds switch outputs one after another and an amplification means are provided in common to enable current sensing for each phase. Thus, a range of current sensing is enlarged to reduce power consumption and cost.

Overload current protection apparatus

A small, low-cost, wide-range current sensor excellent in environmental resistance and noise resistance and high in accuracy, and an application device, a DC magnetic field is applied to two magnetic elements () having a magnetic impedance effect by means of a magnet (), while a negative feedback magnetic field is applied to both elements by means of a coil (). The variation of the magnetic field depending on the external magnetic field applied to the magnetic elements () is detected by detection units (). The difference between the output is amplified by a differential amplifier unit (). Thus, detection is achieved in a wide range while eliminating the influence of the noise.

Current sensor and overload current protective device therewith

To provide a magnetism detection apparatus that is small and low in cost and power consumption, a biasing coiland a negative-feedback coil are integrated with a magnetic impedance element having a magnetic impedance effect in a resinous structure. The magnetism detection apparatus has a reduced magnetic resistance between the magnetic impedance element and the coil, thereby making it possible to apply a bias magnetic field and a negative-feedback magnetic field to the magnetic impedance element with a reduced power consumption.

Magnetic sensor

A cordless telephone set having a base unit and handset units and enabling communications using a channel selected from a plurality of channels. The cordless telephone set comprises apparatus for storing a specified number of channels selected by the telephone apparatus and storing historical channel use data. Whether or not a channel is unused is determined and channels used with high frequency with the data stored in the first storage are changed to those used with low frequency according to the historical use data. Channels that are stored are progressively specified prior to a start of call and a specified channel is selected, if it is determined that the channel is an unused one.

Adaptive channel selection method for a cordless telephone

A capacitance-based pressure detecting apparatus detects a pressure applied to a diaphragm based on a capacitance which varies depending on the change in portion of the diaphragm. The pressure detecting apparatus comprises a diaphragm which changes position depending on a differential pressure between a first pressure and a second pressure, a first electrode which is provided opposite a first plane of the diaphragm and forms, together with the diaphragm, a first capacitor, a second electrode which is provided opposite a second plane of the diaphragm and forms, together with the diaphragm, a second capacitor, a third capacitor altering a capacitance according to the first pressure, a detecting unit for detecting the capacitance of the first through third capacitors, and an operation unit for obtaining a pressure applied to the diaphragm based on the capacitance of the first and second capacitors, and amending the obtained pressure based on the capacitance of the third capacitor.

Pressure detecting apparatus for measuring pressure based on detected

A cordless telephone set having various functions, such as transplantation, secrecy, repeated display and compressed display function is disclosed. A control circuit of a main unit and a control circuit of a subunit of the cordless telephone set are preprogrammed to realize a transplantation function for transplanting functions of the digital telephone set to the cordless telephone set, a secrecy function for preventing the digital telephone set from eavesdropping on communication conducted through the cordless telephone set, a repeated display function for repeatedly displaying a display message received from digital switching equipment when the subunit Y issues no answer to a call, and a compressed display function for displaying, in a compressed manner, a display message received from the digital switching equipment.

Cordless telephone set

A time measurement device for measuring a duration of an input signal based on a clock signal comprises a first gate for outputting a gate signal based on an input signal; a first holding circuit for holding the gate signal at the time of falling of the clock signal; a second holding circuit for holding the gate signal at the time of rising of the clock signal; a second gate for passing the clock signal according to either of the widths of output signals of the first and second holding circuits; a third holding circuit for holding an output state of the second holding circuit at the timing of a leading edge of an output of the first holding circuit; a fourth holding circuit for holding an output state of the second holding circuit at the timing of a trailing edge of an output of the first holding circuit; and a counter for counting the clock signal output from the second gate. The count value is corrected based on the outputs of the third and fourth holding circuits.

Time measurement device

Communication method, communication apparatus, and cordless telephone

For use with communications equipment, a handset unit that does not require a mold solely for the preparation of a window member, does not incur increased manufacturing costs, can be manufactured without requiring a special step for mounting the window member only to a handset unit cover, and has a reinforced recess for engagement with a hook. The handset unit includes a window member (22B) and a body (22A) that are integrated to form a speaker holder (22). A recess (60) for engagement with a hook is provided at the lower end of the member (22). The window member is fixed to the handset cover near the recess (60).

Handset unit and assembly method therefore

Growing community of inventors

Tokyo, Japan

Takahiro Kudo