Patents by Inventor Kazuya Hashimoto

Kazuya Hashimoto has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6185298
    Abstract: In a telephone, a speech band switching circuit selectively provides a received speech with one of a plurality of frequency characteristics. A sensing circuit senses the level of noise around the telephone. A speech band control circuit compares the noise level sensed by the sensing circuit with a predetermined level and controls the speech band switching circuit on the basis of the result of comparison. When the noise level is higher than the predetermined level, the control circuit sends a control signal to the switching circuit. In response, the switching circuit selects a high-pass filter in place of a low-pass filter. As a result, a received speech is easy to hear despite the noise around the telephone because the low frequency range thereof is filtered out.
    Type: Grant
    Filed: September 16, 1997
    Date of Patent: February 6, 2001
    Assignee: NEC Corporation
    Inventor: Kazuya Hashimoto
  • Patent number: 5867797
    Abstract: A portable telephone set has a power supply in which a secondary cell is employed. A charging detector for detecting whether a charger for charging the secondary cell is connected to the power supply, wherein the charging detector generates a detection signal when it detects that the charger is connected to the power supply. A power controller turns on power of the portable telephone set when it receives the detection signal from the charging detector.
    Type: Grant
    Filed: December 27, 1995
    Date of Patent: February 2, 1999
    Assignee: NEC Corporation
    Inventor: Kazuya Hashimoto
  • Patent number: 5793863
    Abstract: In a telephone, a speech band switching circuit selectively provides a received speech with one of a plurality of frequency characteristics. A sensing circuit senses the level of noise around the telephone. A speech band control circuit compares the noise level sensed by the sensing circuit with a predetermined level and controls the speech band switching circuit on the basis of the result of comparison. When the noise level is higher than the predetermined level, the control circuit sends a control signal to the switching circuit. In response, the switching circuit selects a high-pass filter in place of a low-pass filter. As a result, a received speech is easy to hear despite the noise around the telephone because the low frequency range thereof is filtered out.
    Type: Grant
    Filed: March 27, 1995
    Date of Patent: August 11, 1998
    Assignee: NEC Corporation
    Inventor: Kazuya Hashimoto
  • Patent number: 5734978
    Abstract: In order to prevent illegal use of a mobile telephone, a call is repeatedly originated from a telephone or base station to the mobile telephone over a wireless path. When the call is received by the mobile telephone over the wireless path so that a communication channel is established, a destruction code including a cryptographic data is transmitted from the telephone or base station to said mobile telephone. The mobile telephone receives the destruction code and compares the cryptographic data of the received destruction code with a preset data stored in the mobile telephone to determine whether both the data are matched. When it is determined that both the data are matched, the mobile telephone destroys a telephone functioning information stored in the mobile telephone and necessary for performing communication.
    Type: Grant
    Filed: December 15, 1995
    Date of Patent: March 31, 1998
    Assignee: NEC Corporation
    Inventors: Tetsuo Hayatake, Kazuya Hashimoto
  • Patent number: 5513386
    Abstract: A receiver for being mounted on an automobile telephone or similar mobile station which is included in a cellular mobile radio communication system. The receiver has a high frequency amplifier for amplifying a received input wave, and a mixer for converting the received input wave to an intermediate frequency. The gain of the amplifier or that of the mixer is changed on the basis of the level of the field strength of the received input wave and whether or not the mobile station is communicating with a base station. The receiver enhances the reception sensitivity characteristic at locations where the reception field strength is low or the intermodulation distortion characteristic at locations where the field strength is high and intermodulation distortions occur.
    Type: Grant
    Filed: November 17, 1994
    Date of Patent: April 30, 1996
    Assignee: NEC Corporation
    Inventors: Tooru Ogino, Kazuya Hashimoto
  • Patent number: 5465407
    Abstract: A digital mobile radio receiver comprising a limiter amplifier, an orthogonal detector, a low pass filter, an A/D converter and a digital signal processing unit, additionally having a head amplifier able to vary a gain between said low pass filter and said A/D converter and a gain control unit controlling a gain of said head amplifier according to a command from said digital signal processing unit.
    Type: Grant
    Filed: February 26, 1993
    Date of Patent: November 7, 1995
    Assignee: NEC Corporation
    Inventor: Kazuya Hashimoto
  • Patent number: 5438700
    Abstract: A digital mobile radio communication apparatus having a speech signal testing function and a data transmitting and receiving function. A pair of terminals are selectively used as speech signal test terminals or data transmit and receive terminals via switches.
    Type: Grant
    Filed: November 30, 1992
    Date of Patent: August 1, 1995
    Assignee: NEC Corporation
    Inventors: Kazuya Hashimoto, Takashi Murakami
  • Patent number: 5309115
    Abstract: A burst control circuit for use in a TDMA communications system comprises a power amplifier having two separate control terminals. A level control signal which is the difference between a reference signal and the level of the output burst signal of the amplifier, feedback-controls the level of the output burst signal through a first control terminal, and a waveform control signal having a predetermined waveform, controls the waveform of the output burst signal through a second control terminal. When the level of the reference signal is decreased, the amplitude of the waveform control signal is decreased as a function of the level of the reference signal.
    Type: Grant
    Filed: October 14, 1992
    Date of Patent: May 3, 1994
    Assignee: NEC Corporation
    Inventors: Kazuya Hashimoto, Daiji Horikoshi
  • Patent number: 5261121
    Abstract: In order to enable a diversity reception in a portable radiotelephone without detrimentally increasing the size and weight thereof, an adaptor to which diversity antennas are coupled and into which the radiotelephone is inserted in an in-car mode, is provided with a diversity switch and a diversity switch controller. The portable radiotelephone is arranged to switch over from its own antenna to the diversity antennas upon insertion into the adaptor. The portable radiotelephone is further provided with an arrangement for exhibiting a correct receive signal strength irrespective of the fact it is set in the adaptor or used in a portable mode.
    Type: Grant
    Filed: August 13, 1990
    Date of Patent: November 9, 1993
    Assignee: NEC Corporation
    Inventor: Kazuya Hashimoto
  • Patent number: 5223961
    Abstract: On the inside surface of one of a pair of opposed transparent substrates forming an active liquid crystal substrate there are formed first and second insulating layers. Between the insulating layers there are provided transparent pixel electrodes arranged in a matrix form and source lines corresponding to respective columns of the pixel electrodes. A short-circuit metal layer is formed on the substrate, the opposite ends of the metal layer underlying a marginal portion of each pixel electrode and the source line adjacent thereto, respectively, but separated therefrom by the first insulating layer. In these overlapping regions welding metal pads are formed on the pixel electrode and the source line. Other welding metal pads of a ductile metal are formed on the second insulating layer right above the first-mentioned welding metal pads, respectively.
    Type: Grant
    Filed: October 21, 1992
    Date of Patent: June 29, 1993
    Assignee: Hosiden Corporation
    Inventors: Yasuhiro Ukai, Tomihisa Sunata, Kazuya Hashimoto, Minori Otsuki
  • Patent number: 5204972
    Abstract: A first control circuit is provided with a temperature detector and a memory in which temperature related control data is stored. The control circuit outputs a control signal, which varies with ambient temperature, to a local oscillator which is connected with a mixer. The mixer receives an incoming radio frequency signal and a local frequency signal from the local oscillator and outputs an IF signal. The local oscillator is controlled in a manner wherein the frequency of the IF signal parallels the temperature dependent shift in center frequency of a surface acoustic wave type IF filter. The IF signal is applied to a second mixer to which a second control circuit is coupled. The second control circuit maintains the output of the second mixer at a predetermined value to compensate for the first IF's frequency shift caused by the first control circuit.
    Type: Grant
    Filed: June 5, 1992
    Date of Patent: April 20, 1993
    Assignee: NEC Corporation
    Inventor: Kazuya Hashimoto
  • Patent number: 4829591
    Abstract: A portable transceiver has a narrow band square microstrip antenna connected to a first radio receiver, a wideband sleeve or whip antenna connected to an associated duplexer, and a second radio receiver and a transmitter both connected to the wideband antenna via the duplexer. The square microstrip antenna if formed of a conductive emission plate and a conductive ground plate joined by a conductive connector plate. A housing enclosing the transceiver has an earphone and microphone set in its front side, the microstrip antenna under its back side, and the wideband sleeve or whip antenna mounted upright on its top side.
    Type: Grant
    Filed: August 19, 1986
    Date of Patent: May 9, 1989
    Assignee: NEC Corporation
    Inventors: Kazuya Hashimoto, Hiroshi Asazawa
  • Patent number: 4823398
    Abstract: A diversity receiver includes first and second receivers, a first switch, a comparator, a second switch, and a controller. The first and second receiver have receiver antennas and generate demodulated signals and electric field detection outputs in accordance with received electric fields, respectively. The first switch performs switching between the demodulated signals from the first and second receivers in accordance with an output switching control signal and outputs a selected demodulated signal. The comparator compares the electric field detection outputs from the first and second receivers, respectively, and supplies the output switching control signal to the first switch. The second switch turns on/off a power source of the first receiver in accordance with a power source switching control signal.
    Type: Grant
    Filed: December 19, 1986
    Date of Patent: April 18, 1989
    Inventor: Kazuya Hashimoto
  • Patent number: 4749877
    Abstract: A bias circuit for an FET comprises a voltage divider having two potential points. A first of the potential points is connected to a gate of the FET. The other potential point is connected through a second FET which may be turned off or on to vary the potential at the first potential point in order to control the bias on the gate of the first FET. The switching of the second FET is controlled as a function of a threshold voltage between its gate and a voltage in the source-drain circuit of the second FET. In one embodiment, a diode feedback circuit may be used to provide the threshold current.
    Type: Grant
    Filed: August 11, 1986
    Date of Patent: June 7, 1988
    Assignee: NEC Corporation
    Inventors: Hiroshi Asazawa, Kazuya Hashimoto
  • Patent number: 4706381
    Abstract: A multi contact connector includes a ground terminal block and signal and power source terminals connected with tape wires. Bare wires of the tape wires connected to the signal and power source terminals are provided with roundabout portions respectively to form slacks in the bare wires. With this arrangement, when external tensile forces act upon the connector, the slacks prevent disconnection of bare wires for signal and power source terminals indispensable for operation of the connector, even if a few bare wires among a number of bare wires connected to the ground terminal block are disconnected.
    Type: Grant
    Filed: May 16, 1986
    Date of Patent: November 17, 1987
    Assignees: Daiichi Denshi Kogyo Kabushiki Kaisha, Hitachi, Ltd.
    Inventors: Matsuo Kato, Tomonari Ohtsuki, Kazuya Hashimoto, Masami Nakaide