Patents by Inventor Yoshiharu Tamura

Yoshiharu Tamura 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: 5404390
    Abstract: A rod antenna is contained to be slant in a housing case, such that a top of the rod antenna is positioned on the side of the housing case remote from a user head, and a bottom of the rod antenna is on the side of the housing case near the user head. The remote and near sides are opposite to each other. When the rod antenna is pulled up out of the housing case, the rod antenna top becomes more remote from the user head in accordance with the slantly contained mode.
    Type: Grant
    Filed: December 20, 1993
    Date of Patent: April 4, 1995
    Assignee: NEC Corporation
    Inventor: Yoshiharu Tamura
  • Patent number: 5335368
    Abstract: A portable radio apparatus having a casing thereof keeps a matching state of an antenna thereof in the call waiting state and in the operating state of the apparatus. The casing is foldable and expandable and accommodates therein a transmitting and receiving circuit connected via a variable matching circuit to the antenna. The matching circuit is connected to a sensor disposed in the casing for sensing a folded state thereof. Depending on a result of the sensing operation of the sensor, the matching circuit changes the matching state.
    Type: Grant
    Filed: May 29, 1992
    Date of Patent: August 2, 1994
    Assignee: NEC Corporation
    Inventor: Yoshiharu Tamura
  • Patent number: 5255001
    Abstract: An antenna for a portable radio apparatus has a first antenna construction connected to the casing of the apparatus and a second antenna construction affixed to a base plate or earth plate which is incorporated in the casing. The first antenna construction has a movable joint which allows the first antenna construction to move between a first position where it is regarded as forming a part of the contour of the casing and a second position where it is protruded from the contour and regarded as being located in free space. The second antenna construction corrects the matching state of the first antenna construction such that adequate antenna radiation characteristics are set up in the first position. Optimal antenna characteristics are, therefore, achievable when the first antenna construction is in any one of the first and second positions.
    Type: Grant
    Filed: December 14, 1990
    Date of Patent: October 19, 1993
    Assignee: NEC Corporation
    Inventors: Yoshiharu Tamura, Takao Ono
  • Patent number: 5193219
    Abstract: A mobile radio transceiver comprises a portable transceiver and a vehicular power booster. The portable transceiver generates a RF transmit signal and sets the power of the RF signal at one of multiple power levels. The power booster is coupled by a connecting cable to the transceiver to receive the RF signal, and includes a first power detector for detecting the power of the received signal. One of multiple reference voltages is identified as corresponding to the power detected by the first power detector. A gain-controlled power amplifier stage amplifies the RF signal from the transceiver for coupling to an antenna. The output power of the power amplifier is detected and a gain control driver responds to a difference between it and the identified voltage by controlling the power amplifier so that the difference reduces to a minimum. In a modification, the power amplifier stage is a class C amplifier and the booster additionally includes a preamplifier stage.
    Type: Grant
    Filed: August 17, 1990
    Date of Patent: March 9, 1993
    Assignee: NEC Corporation
    Inventor: Yoshiharu Tamura
  • Patent number: 5167514
    Abstract: In a plug and a receptacle of a microstrip line connector, the plug has a rectangular parallelpipedic insulating support block, a signal contact projecting upward from the center of the insulating support block and a pair of L-angle brackets projecting out upward from both ends of the insulating support block, the pair of brackets being connected to opposite ends of a coupling plate portion provided along the side wall surface of the insulating support block. The coupling plate portion has at the center of its lower marginal edge a recess formed astride a signal conductor of a microstrip line provided on a printed circuit board.
    Type: Grant
    Filed: November 5, 1991
    Date of Patent: December 1, 1992
    Assignees: Japan Aviation Electronics Industry Limited, NEC Corporation
    Inventors: Takao Suzuki, Hiroshi Uesugi, Yoshiharu Tamura, Naoki Hirasawa, Hirofumi Matsumoto
  • Patent number: 5043651
    Abstract: An apparatus having a rechargeable battery and a battery voltage detector which detects the output voltage of the battery to produce a detection signal when the output voltage falls below a predetermined threshold level. A controller stores a battery capacity value and accumulates the discharge of the battery to produce an accumulated capacity value. The controller also calculates a difference between the stored capacity value and the accumulated capacity value. Using the difference, a display displays the remaining charge value of the battery thereon. If the difference exceeds a predetermined value at a time the controller receives the detection signal, the controller changes the stored capacity value to a new capacity value. Alternatively, the controller may change a rate of accumulating the battery discharge.The apparatus may have a current detector for detecting a current flowing through the battery. The controller may accumulate the battery discharge based on the detected current.
    Type: Grant
    Filed: September 13, 1989
    Date of Patent: August 27, 1991
    Assignee: NEC Corporation
    Inventor: Yoshiharu Tamura
  • Patent number: 5040998
    Abstract: A plug connector used to connect a microstrip line and another microstrip line. The body of the plug connector, which is made of an insulating material of an oblong shape, has a signal contact housing hole and a ground contact housing hole. These holes are in parallel and opposed to each other. A signal female contact made of a metal plate is housed in the signal contact hole and a ground female contact made of a metal plate is contained in the ground contact housing hole. The ground female contact has a ground plate of a width wider than the width of the signal female contact. The ground female contact and the signal female contact constitute substantially a microstrip line.
    Type: Grant
    Filed: March 11, 1991
    Date of Patent: August 20, 1991
    Assignees: Japan Aviation Electronics Industry Limited, NEC Corporation
    Inventors: Takao Suzuki, Yoshiharu Tamura, Naoki Hirasawa
  • Patent number: 4914714
    Abstract: A portable radio communication apparatus includes a first antenna that can extend away from, or be retracted towards, an apparatus housing. The apparatus includes a second, usually flat antenna mounted within or around the outer periphery of the housing. When the first antenna is extended away from the housing, it is connected via a switch to a node, in turn, connected via respective filters to both a transmitter and a diversity receiver. At this time, the second antenna is connected to the diversity receiver via a respective filter. When the first antenna is sufficiently retracted towards the housing, a switch, mechanically coupled to the first antenna, disconnects the first antenna from the node, connects the second antenna to such node, and disconnects the second antenna from the diversity receiver.
    Type: Grant
    Filed: August 28, 1987
    Date of Patent: April 3, 1990
    Assignee: NEC Corporation
    Inventor: Yoshiharu Tamura
  • Patent number: 4907122
    Abstract: In a relay circuit, a stationary contact of a relay is coupled to a DC voltage source and a moving contact of the relay is coupled to a load circuit. The moving contact is switched to the stationary contact in response to a rapidly rising edge of a DC voltage applied to the relay. A voltage sensor is connected to the moving contact for detecting a voltage which appears thereat. For operating the relay, a switch is closed to apply a voltage from the DC voltage source to a pulse generator. The pulse generator generates a rectangular pulse and applies it to the relay to cause it to switch the moving contact to the stationary contact. If a voltage is not detected by the voltage sensor at the moving contact after energization of the relay, the pulse generator reapplies a rectangular pulse to the relay until a voltage appears at the moving contact, whereupon the pulse generator applies a constant voltage to the relay.
    Type: Grant
    Filed: July 6, 1988
    Date of Patent: March 6, 1990
    Assignee: NEC Corporation
    Inventor: Yoshiharu Tamura
  • Patent number: 4866396
    Abstract: A temperature stabilized RF detector has a first diode connected between an input terminal for receiving an RF signal and an output terminal for outputting the detection signal of the RF signal, and a second diode connected between the input terminal and a constant voltage source through a buffer circuit. Connecting directions of the first and second diodes are opposite to each other in a circuit for connecting the output terminal and the constant voltage source.
    Type: Grant
    Filed: June 27, 1988
    Date of Patent: September 12, 1989
    Assignee: NEC Corporation
    Inventor: Yoshiharu Tamura
  • Patent number: 4850006
    Abstract: A booster and charger unit for a hand-held portable (HHP) telephone capable of preventing a casing of the unit from being heated to an excessive temperature. The casing has thereinside a charging device for charging a battery, which is installed in the telephone, and a temperature sensor responsive to the temperature of the casing. When the temperature of the casing sensed by the sensor rises to a predetermined level, charging by the charging device is interrupted or the charging current thereof is reduced.
    Type: Grant
    Filed: November 16, 1987
    Date of Patent: July 18, 1989
    Assignee: NEC Corporation
    Inventors: Yutaka Sasaki, Yoshiharu Tamura
  • Patent number: 4820995
    Abstract: A temperature stabilized RF detector uses a series circuit including a detecting diode coupled in series with a similarly poled stabilizing diode so that a single current flows in a single direction through both diodes. The temperature related effects of the two diodes are mutually balancing so that temperature variations in the detecting diode do not adversely affect the detection of an RF signal.
    Type: Grant
    Filed: May 13, 1988
    Date of Patent: April 11, 1989
    Assignee: NEC Corporation
    Inventor: Yoshiharu Tamura
  • Patent number: 4810101
    Abstract: A noise detection circuit for a digital radio receiver comprises a sampling circuit for sampling a digital baseband signal having a noise component when an eye opening of the baseband signal is largest. A waveform generator is connected to the output of the sampling circuit for generating a waveform which is a replica of the baseband signal and free from the noise component. The waveform generator comprises a threshold comparator having decision thresholds and a waveform recovery circuit which includes a resistor, a plurality of storage capacitors of equal values and a switch responsive to the output of the threshold comparator for selectively coupling the output of the sampling circuit through the resistor to the storage capacitors. A substractor is connected to the outputs of the sampling circuit and the waveform generator for generating a signal representative of the noise component of the baseband signal.
    Type: Grant
    Filed: March 5, 1987
    Date of Patent: March 7, 1989
    Assignee: NEC Corporation
    Inventors: Kouzou Kage, Yoshiharu Tamura
  • Patent number: 4736060
    Abstract: Method for optical resolution of DL-cysteine by (1) reacting DL-cysteine with formaldehyde to prepare DL-thiazolidine-4-carboxylic acid (DL-TCA), (2) forming diastereomer salts of D-TCA and of L-TCA by reacting DL-TCA with an optically active 1-(1-naphthyl)ethylamine, (3) separating said diastereomer salts by difference of the solubilities thereof in a solvent, (4) recovering D-TCA from said diastereomer salt of D-TCA and finally obtain D-cysteine, and recovering L-TCA from said diastereomer salt of L-TCA and finally obtain L-cysteine.
    Type: Grant
    Filed: August 1, 1986
    Date of Patent: April 5, 1988
    Assignee: Nippon Rikagakuyakuhin Co., Ltd.
    Inventors: Keizo Tomuro, Yoshiharu Tamura, Yoko Morimoto, Shigeyoshi Katoh
  • Patent number: 4709404
    Abstract: A battery-powered radio communication apparatus is disclosed which comprises a power amplifier and a power detector for detecting the output power of the power amplifier. A supply voltage detector compares a standard voltage with the output voltage of a battery supplying power to the power amplifier. A gain control circuit controls the gain of the power amplifier in response to the output of the power amplifier and to the output of the supply voltage detector so as to prolong, by a certain time, the communicable state of the apparatus prior to battery depletion.
    Type: Grant
    Filed: August 13, 1985
    Date of Patent: November 24, 1987
    Assignee: NEC Corporation
    Inventors: Yoshiharu Tamura, Katsuji Kimura
  • Patent number: 4576132
    Abstract: An increase in the amount of fuel when an engine is started or being idled is controlled on the basis of a detected intake air temperature or outside air temperature in addition to detected engine speed, intake air pressure and engine coolant temperature. Therefore, it is possible to obtain a mixture with an appropriate air-to-fuel ratio corresponding to intake air temperature in starting the engine, thus improving engine starting characteristics at low outside air temperature.
    Type: Grant
    Filed: October 29, 1984
    Date of Patent: March 18, 1986
    Assignee: Nissan Motor Company, Limited
    Inventors: Masataka Nakajima, Yasushi Mase, Yoshiharu Tamura
  • Patent number: 4572135
    Abstract: In a carburetor in which air-to-fuel ratio is feedback controlled into a stoichiometric mixture ratio in response to oxygen sensor signals, air-to-fuel ratio is determined to a lower value to supply a rich mixture to an engine when intake air temperature and engine coolant temperature both exceed each reference value, so that engine overheat can be prevented at high temperatures. The lower air-to-fuel ratio is determined to a fixed value or to an appropriate value under consideration of intake air temperature and engine coolant temperature or additionally vehicle speed.
    Type: Grant
    Filed: October 29, 1984
    Date of Patent: February 25, 1986
    Assignee: Nissan Motor Company, Limited
    Inventors: Masataka Nakajima, Yasushi Mase, Yoshiharu Tamura
  • Patent number: 4510460
    Abstract: An output power control circuit provided with a power amplifier circuit of an input amplifier and an output amplifier connected in series with the input amplifier, has: a first transistor having a first electrode connected to a direct current power supply and a second electrode connected to a power supply terminal of the output amplifier; a second transistor having a first electrode connected to a third electrode of the first transistor and a second electrode connected to a power supply terminal of the input amplifier; and at least one diode connected between the direct current power supply and the power supply terminal of the input amplifier.
    Type: Grant
    Filed: November 21, 1983
    Date of Patent: April 9, 1985
    Assignee: NEC Corporation
    Inventor: Yoshiharu Tamura
  • Patent number: 4509165
    Abstract: An antenna duplexer is made compact by a use of a SAW filter, and yet it eliminates the possibility that the SAW filter might be burned, and it avoids additional circuits, e.g., an impedance compensation circuit. The antenna duplexer comprises a local oscillation filter. A reception filter is coupled to the local oscillation filter. The coupled side is partly constituted by a SAW filter. A transmission filter is coupled to the reception filter and an antenna is coupled between the reception filter and the transmission filter.
    Type: Grant
    Filed: December 22, 1982
    Date of Patent: April 2, 1985
    Assignee: Nippon Electric Co., Ltd.
    Inventor: Yoshiharu Tamura