Patents by Inventor Nobuaki Miyakawa

Nobuaki Miyakawa 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: 4797583
    Abstract: A level converter for transforming differential input voltages into an output voltage comprises a voltage-current conversion circuit for transforming the differential input voltages into differential currents, a current detection circuit for detecting the differential currents, a current amplifying circuit for amplifying the differential currents in response to the output of the current detection circuit, and a current-voltage conversion circuit for transforming the amplified differential currents into an output voltage, thereby allowing fast operation and drastic level conversion.
    Type: Grant
    Filed: December 19, 1984
    Date of Patent: January 10, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Masahiro Ueno, Kozaburo Kurita, Ikuro Masuda, Nobuaki Miyakawa
  • Patent number: 4665505
    Abstract: A write circuit for a semiconductor storage device which comprises a data output stage constructed by a composite circuit including at least one MOS transistor logic circuit and bipolar transistor. The Mos transistor circuit operates in response to an input signal to control the on-off states of at least one of the bipolar transistors. The write circuit implements less power consumption.
    Type: Grant
    Filed: December 24, 1984
    Date of Patent: May 12, 1987
    Assignees: Hitachi, Ltd., Hitachi Haramachi Semi-Conductor Ltd.
    Inventors: Nobuaki Miyakawa, Yoshiaki Yazawa, Shoichi Ozeki, Kinya Mitsumoto
  • Patent number: 4578693
    Abstract: In a semiconductive photodetector device having a semiconductor substrate and a plurality of photodiodes juxtaposed in one major surface of the semiconductor substrate, exposed edges of adjacent pn junctions of adjacent photodiodes are covered with a polysilicon film.
    Type: Grant
    Filed: June 17, 1983
    Date of Patent: March 25, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Yoshiaki Yazawa, Nobuaki Miyakawa, Toji Mukai, Takahide Ikeda, Tatsuya Kamei
  • Patent number: 4527148
    Abstract: An A/D converter used with an A/D conversion system in which each of input analog signals applied thereto is amplified at a gain selected depending or the level of said each signal and subjected to A/D conversion. The A/D converter is arranged to select a desired one of predetermined gain select modes concerned with the selection of gain of the amplifier. Further, the A/D converter produces a reference analog signal of a level corresponding to the selected gain select mode and compares the input analog signal with the reference analog signal, thereby determining whether or not the gain of the amplifier is to be changed.
    Type: Grant
    Filed: October 28, 1982
    Date of Patent: July 2, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Shigeo Kuboki, Kazuo Kato, Nobuaki Miyakawa
  • Patent number: 4454500
    Abstract: An analog data acquisition device fetches a plurality of analog data by a multiplexer in time-division, compares the analog data fetched with a reference value applied from a digital-to-analog converter by a two-input comparator, and produces the result of comparison to a data bus. The result of comparison is also applied to a successive approximation register where the analong-to-digital conversion is effected by successively changing the digital data to the digital-to-analog converter, and the digital data converted is read out onto the data bus.The digital data applied to the digital-to-analog converter is either the output from the successive approximation register or the output from the reference register loaded through the data bus, in accordance with the contents of the control register loaded through the data bus. Thus, in which mode the device operates, in the comparing mode or in the analog-to-digital conversion mode, is selected by the control register.
    Type: Grant
    Filed: February 16, 1982
    Date of Patent: June 12, 1984
    Assignee: Hitachi, Ltd.
    Inventors: Kazuo Kato, Nobuaki Miyakawa, Makoto Aihara, Kiyoshi Matsubara
  • Patent number: 4404648
    Abstract: In a system for displaying a plurality of parameters, such as on an instrument panel of a vehicle, a plurality of signals in the form of pulses each having a pulse frequency corresponding to a respective parameter are generated by respective sensors. Each pulse supplied from these signals to a status register results in generation of an interrupt request signal to a central processing unit. The central processing unit controls a mask register which in turn controls a gating arrangement which selectively masks or inhibits the application of pulses from one or more sensors to the status register so that upon receiving a first interrupt request signal, the central processing unit can mask all sensors but the one responsible for the interrupt request signal and proceed with calculation of the parameter associated therewith by measuring the interval between subsequently-generated interrupt request signals, such measurement being carried out by execution of increment instructions.
    Type: Grant
    Filed: July 10, 1979
    Date of Patent: September 13, 1983
    Assignee: Hitachi, Ltd.
    Inventors: Nobuaki Miyakawa, Masayuki Miki
  • Patent number: 4181944
    Abstract: An apparatus for the optimum control of a combustion engine, which is capable of compensating for the change in the combustion engine with time caused by mechanical wear. An optimum control value is stored in a memory. The data stored in the memory is compared in a microcomputer with an output from at least one sensor for detecting the operating conditions of the combustion engine, so that the optimum control signal for the present operating conditions is applied to the control apparatus for the combustion engine. In response to an output from a combustion pressure sensor for detecting the change with time of the combustion engine, calculations for correcting the data in the memory are conducted, followed by the updating of the data therein.
    Type: Grant
    Filed: July 14, 1978
    Date of Patent: January 1, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Teruo Yamauchi, Yoshishige Oyama, Nobuaki Miyakawa
  • Patent number: 4149149
    Abstract: In a display circuit for actuating a display having plural liquid crystal segments or luminescent diodes, an improved comparator is provided for determining the number of the display segments to be energized and activated in accordance with an analogue input voltage. The analogue input voltage is applied to one terminal of a resistance having plural resistors connected in series, the other terminal of which is grounded. The comparator is composed of an integrated circuit of MOS type which has plural logical circuits. Each of one input terminals of the logical circuits is connected to a corresponding one of junctions of the resistors connected in series. Each logical circuit of the comparator provides "1" output signal when the voltage at the corresponding junction exceeds a threshold value thereof. An actuator, which is constructed with exclusive OR gates or transistors, energizes the liquid crystal segments or the luminescent diodes in response to the "1" output signals from the comparator.
    Type: Grant
    Filed: February 14, 1977
    Date of Patent: April 10, 1979
    Assignee: Hitachi, Ltd.
    Inventors: Masayuki Miki, Nobuaki Miyakawa
  • Patent number: 4149150
    Abstract: A display device for displaying input analog quantities by lighting luminescent display elements, comprising an arithmetic circuit for dividing each of the input analog quantities into plural ranges and for amplifying each of the divided input quantities up to a predetermined level, a circuit for dividing the predetermined level into plural levels, comparison circuits each provided for the respective divided levels and for determining the lighting of the display elements by comparing the divided levels with a reference signal, a circuit for generating a clock signal for determining the timing of the lighting of the display elements, and drive circuits each connected between the respective comparison circuits and the respective display elements thereby for delivering effective voltages for lighting the display elements in response to the output signals of the comparison circuits and the clock signal, whereby resolution is improved over the whole ranges of the input analog quantities.
    Type: Grant
    Filed: April 5, 1977
    Date of Patent: April 10, 1979
    Assignee: Hitachi, Ltd.
    Inventors: Nobuaki Miyakawa, Masayuki Miki
  • Patent number: 4142407
    Abstract: An air flow metering apparatus for measuring a suction air flow fed to an internal combustion engine comprises at least two Karman' vortex type air flow meters disposed separately in at least two air suction passages, respectively. The output signals from the flow meters are switched in such manner that in a predetermined range of high air flow rates, the output signal from one of the flow meter is utilized for measuring or sensing the air flow rate, while in a predetermined low flow rate range, the output signal from the other flow meter is utilized for the same purpose. Alternatively, in a predetermined low flow rate range, only one of the air suction passages is employed, while both of the air suction passages are employed in a predetermined range of high air flow rates. The air flow metering apparatus assures the detection or measurement of the suction air flow rate over a whole operation range of the engine with a high reliability and enhanced accuracy.
    Type: Grant
    Filed: May 17, 1977
    Date of Patent: March 6, 1979
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Kuroiwa, Yoshishige Ohyama, Yutaka Nishimura, Nobuaki Miyakawa
  • Patent number: 4100432
    Abstract: A drain resistor is connected to a drain electrode of a Field Effect Transistor (FET). One of the input signals to be multiplied is applied to the drain electrode through the drain resistor. The other input signal to be multiplied is applied to a gate electrode of the FET. An output proportional to the product of two signals appears across a resistor connected between a source electrode of FET and ground. In such an arrangement the resistance value of the drain resistor is so determined that the gradient of the characteristics of the drain current to the one input signal becomes almost equal to that of the characteristics of the drain current to the other input signal.
    Type: Grant
    Filed: October 19, 1976
    Date of Patent: July 11, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Nobuaki Miyakawa, Masayuki Miki
  • Patent number: 4097857
    Abstract: A display apparatus receives analogue signals representing the detected values of the number of revolutions per minute of an automobile's engine, the residual fuel, the automobile's speed, the temperature at the various portions of the automobile and the like. An analogue signal desired for display is selected from those analogue signals by means of a switching device. The selected signal is applied to a common terminal. A plurality of light emitting diodes are connected between the common terminal and the terminals of a voltage-dividing device consisting of a plurality of resistors thereby to display the detected values.
    Type: Grant
    Filed: May 11, 1976
    Date of Patent: June 27, 1978
    Assignee: Hitachi, Ltd.
    Inventor: Nobuaki Miyakawa
  • Patent number: 4068138
    Abstract: A signal converter for converting a varying input voltage, such as an output signal from a detector, into an output voltage in absolute value, including an operational amplifier, a comparator and two groups of electronic switches. The comparator compares the varying input voltage to a predetermined reference voltage. The operational amplifier has negative and positive input terminals and generates an output voltage signal in proportion to the difference between the voltages applied to its two input terminals. When the input voltage is less than the reference voltage, one group of electronic switches turns on, so that the input voltage and the reference voltage are applied to the negative and the positive input terminals of the operational amplifier, respectively.
    Type: Grant
    Filed: May 17, 1976
    Date of Patent: January 10, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Nobuaki Miyakawa, Osamu Igarashi
  • Patent number: 4041299
    Abstract: A plurality of input signals to be multiplied are applied sequentially to a logarithmic time-width transformer in a form of electric analog signal in a predetermined order. The transformer converts each of the inputs into a signal having a time width in logarithmic relation with the analog value of corresponding input signal in response to the input signal to thereby provide a plurality of converted signals. Each of the converted signals is further converted into a train of pulses, the number thereof corresponding to the time width of the converted signal so as to convert the plurality of converted signals into a plural train of pulses. Each of the plural trains of pulses are applied to a counter so as to count up the number of pulses of the plural trains of pulses to thereby obtain the total amount of the time width of the plurality of counted signals.
    Type: Grant
    Filed: March 30, 1976
    Date of Patent: August 9, 1977
    Assignee: Hitachi, Ltd.
    Inventor: Nobuaki Miyakawa
  • Patent number: 4034722
    Abstract: A system for supplying fuel to an internal combustion engine, the fuel supply being dependent on the driving condition of the engine, comprises two types of detectors for detecting engine driving conditions and a memory for generating a signal representative of the fuel injection quantity in response to the engine driving conditions. A time-control circuit generates a pulse having a time duration determined by the output from the memory and a fuel injector injects fuel into the engine in accordance with the pulse of the time-control circuit.
    Type: Grant
    Filed: February 9, 1976
    Date of Patent: July 12, 1977
    Assignee: Hitachi, Ltd.
    Inventor: Nobuaki Miyakawa
  • Patent number: 4023159
    Abstract: A non-linear analogue-to-digital converter having analogue-to-digital conversion relation curves on the basis of which the conversion is carried out and which curves can be freely exchanged. The converter comprises a gate pulse generator circuit for producing gate pulses of a predetermined duration, an oscillator for producing a signal of a variable frequency in response to a signal representing an input analogue quantity in which an element for varying analogue-frequency relation is incorporated, a counter for counting the signal from the oscillator during the duration of the gate pulse signal, and an arrangement for controlling the converter in accordance with pre-determined patterns in dependence on the count value of the counter.
    Type: Grant
    Filed: January 28, 1975
    Date of Patent: May 10, 1977
    Assignee: Hitachi, Ltd.
    Inventors: Nobuaki Miyakawa, Masayuki Miki