Patents Assigned to Tadashi Shibata
  • Patent number: 6456532
    Abstract: The present invention is intended to provide a semiconductor memory circuit that can store analog and many-valued data at high speed and with a high degree of accuracy.
    Type: Grant
    Filed: February 7, 2001
    Date of Patent: September 24, 2002
    Assignees: Tadahiro Ohmi, Tadashi Shibata, UCT Corporation, I & F Inc.
    Inventors: Tadahiro Ohmi, Tadashi Shibata, Keng Hoong Wee, Takemi Yonezawa, Toshiyuki Nozawa, Takahisa Nitta
  • Patent number: 6115725
    Abstract: The real time compression of moving images employing vector quantization is realized using simple hardware and with an optimal compression ratio with respect to the communication line capacity employed.
    Type: Grant
    Filed: January 28, 1998
    Date of Patent: September 5, 2000
    Assignees: Tadashi Shibata, Tadahiro Ohmi
    Inventors: Tadashi Shibata, Tadahiro Ohmi, Akira Nataka, Tatsuo Morimoto, Masahiro Konda
  • Patent number: 6011714
    Abstract: A semiconductor circuit assembly is capable of accurately storing a plurality of analog or multi-valued data using circuitry having a small surface area. The circuit assembly includes a first circuit provided in the form of a target memory cell device comprising memory cells which conduct the writing and storage of analog signals. The first circuit has output terminals for outputting stored values to the exterior as voltage signals. Mechanisms supply at least two index voltages. A second circuit performs the function of halting the writing of the analog signals when the output signal at the first circuit output terminals reaches a value representing a desired voltage plus the difference between the two index voltages.
    Type: Grant
    Filed: February 5, 1998
    Date of Patent: January 4, 2000
    Assignees: Tadashi Shibata, Tadahiro Ohmi
    Inventors: Tadashi Shibata, Tadahiro Ohmi, Yuichiro Yamashita
  • Patent number: 5982462
    Abstract: A thin film transistor device with its leakage current being controlled is provided. With such a thin film transistor device incorporated, a liquid crystal display apparatus presents a high-contrast image at a reduced power consumption. The thin film transistor is formed on an insulating substrate. The gate electrode of the transistor is electrically floating gate electrode, which is capacitance coupled to one or more input electrodes. The liquid crystal display apparatus incorporates the thin film transistor in its switching element and/or driving circuit.
    Type: Grant
    Filed: March 6, 1997
    Date of Patent: November 9, 1999
    Assignees: Frontec Incorporated, Tadashi Shibata, Tadahiro Ohmi
    Inventors: Akira Nakano, Tadashi Shibata, Tadahiro Ohmi
  • Patent number: 5973535
    Abstract: A simple semiconductor circuit by which analog data or multilevel data can be fetched and stored. The circuit receives a first signal and converts the first signal into a second signal composed of multilevel. The second signal is fed back to the circuit. The circuit is constituted of a first circuit which converts the first signal into a signal group composed of multiple quantized signals and second circuit which converts the signal group into the second signal. In addition, the first or/and second circuits are constituted of one or more neuron MOS transistors.
    Type: Grant
    Filed: October 15, 1996
    Date of Patent: October 26, 1999
    Assignees: Tadahiro Ohmi, Tadashi Shibata
    Inventors: Tadashi Shibata, Tadahiro Ohmi, Takeo Yamashita
  • Patent number: 5973960
    Abstract: A nonvolatile semiconductor memory which is capable of a high degree of integration and can conduct the writing of analog data at high speed and with a high degree of accuracy.The memory device comprises two or more semiconductor devices comprising a first MOS transistor having a first floating gate which is electrically insulated, a first electrode which is capacitively coupled with the first floating gate, a second electrode provided with the first floating gate via a tunnel junction, and a third electrode connected to the second electrode via a switch; the present invention is further provided with a fourth electrode connected commonly with the third electrodes of the semiconductor devices, a fifth electrode connected commonly with the source electrodes of the first MOS transistors, a sixth electrode which is capacitively coupled with the fourth electrode, and a seventh electrode which is connected with the fourth electrode via a switch.
    Type: Grant
    Filed: February 9, 1998
    Date of Patent: October 26, 1999
    Assignee: Tadahiro OHMI and Tadashi Shibata
    Inventors: Tadashi Shibata, Tadahiro Ohmi, Yuichiro Yamashita
  • Patent number: 5959484
    Abstract: A feedback circuit is provided which is capable of realizing handshake functions, flip flop functions, and other functions using a smaller number of elements and chip surface. The threshold circuit is provided with an electrode which is electrically floating and a plurality of input electrodes which are connected with the floating electrode via capacity elements, and the circuit has a mechanism for essentially determining the potential of the floating electrode by means of the potentials applied to the input electrodes, and the output of the circuit is determined by the potential of the floating gate; the output of the threshold circuit is connected to at least one of the plurality of input electrodes, either directly, or via at least one circuit of some type.
    Type: Grant
    Filed: February 27, 1997
    Date of Patent: September 28, 1999
    Assignees: Tadashi Shibata, Tadahiro Ohmi
    Inventors: Tadahiro Ohmi, Tadashi Shibata, Hiroaki Terada, Koji Kotani
  • Patent number: 5939925
    Abstract: A semiconductor operational circuit conducts real-time analog vector operations to permit the determination of the center of gravity of an image of a moving object. The circuit employs a first processing stage utilizing CMOS source follower circuits to perform weighted linear sum operations on the analog signals. A second processing stage utilizes comparator circuitry to perform comparison operations involving data from the weighted-sum and non-weighted-sum operations. A third processing stage utilizes exclusive OR gates to provide digital data outputs based on the comparison operation results.
    Type: Grant
    Filed: November 7, 1997
    Date of Patent: August 17, 1999
    Assignee: Tadashi Shibata and Tadahiro OHMI
    Inventors: Tadashi Shibata, Tadahiro Ohmi, Ning Mei Yu, Tsutomu Nakai
  • Patent number: 5937399
    Abstract: A semiconductor integrated circuit includes one or more neuron MOS transistors on a substrate. The MOS transistor comprises a semiconductor region of one conductivity type, source and drain regions of opposite conductivity type disposed in this region, floating gate disposed on an insulating film between the source and drain regions, and a plurality of input coupling electrodes making capacitive coupling with the floating gate through the insulating film, wherein the floating gate is connected to at least one switching device.
    Type: Grant
    Filed: June 11, 1996
    Date of Patent: August 10, 1999
    Assignees: Tadahiro Ohmi, Tadashi Shibata
    Inventors: Tadahiro Ohmi, Tadashi Shibata, Koji Kotani
  • Patent number: 5923205
    Abstract: A semiconductor arithemetic circuit which performs calculation of an analog vector with a high accuracy at a high speed.
    Type: Grant
    Filed: November 7, 1997
    Date of Patent: July 13, 1999
    Assignees: Tadashi Shibata, Tadahiro Ohmi
    Inventors: Tadashi Shibata, Tadahiro Ohmi, Masahiro Konda
  • Patent number: 5917742
    Abstract: A semiconductor arithmetic circuit which realizes multiple-item addition processing at high speed and with a small surface areas The semiconductor arithmetic circuit adds a plurality of data expressed in binary format which is provided with terminals for the simultaneous input of the plurality of data, a mechanism for conducting a batch addition operation with respect to all the bits of the plurality of data, and for generating an analog or multi-valued signal having a linear relationship with the results of this addition and a mechanism for converting the analog or multi-valued signal to a digital signal. The plurality of data comprise bit data signals, and 4 or more of these are subjected to batch addition. A plurality of bit groups including a plurality of connected bits are also subjected to batch addition.
    Type: Grant
    Filed: February 27, 1997
    Date of Patent: June 29, 1999
    Assignee: Tadashi Shibata
    Inventors: Tadahiro Ohmi, Makoto Imai, Koji Kotani, Tadashi Shibata
  • Patent number: 5822497
    Abstract: A device comprising invertor circuit group including two or more invertor circuits formed by neuron MOS transistors; means for applying a first signal voltage common to the two or more invertors of the invertor circuit group to a first input gate of the invertor circuit; means for applying a given second signal to one or more second input gates other than the first input gate of the invertor circuits; a delay circuit for transmitting the variation of the output voltage of at least one of the invertor circuits of the invertor circuit group with a time delay generated by used of the variation with time of the signal voltage of either or both of the first and second signal voltages; a transistor whose ON and OFF is controlled by the signal transmitted from the delay circuit; storage circuits taking in signals by the ON and OFF of the transistor; and means for executing a given logical operation with respect to the output voltage signals generated by the invertor circuit group.
    Type: Grant
    Filed: September 29, 1995
    Date of Patent: October 13, 1998
    Assignee: Tadashi Shibata and Tadahiro Ohmi
    Inventors: Tadahiro Ohmi, Tadashi Shibata, Takeo Yamashita
  • Patent number: 5818081
    Abstract: Synapse can be formed from a smaller number of elements in a low-power semiconductor device, which realize a highly integrated neural network. Precise modifications of synapse weighting become possible and a neuron computer chip of a practical level can be accomplished.The semiconductor device includes a first electrode for charge injection, connected to a floating gate through a first insulating film; a second electrode for applying programming pulses, connected to the floating gate through a second insulating film, and a MOS transistor using the floating gate as its gate electrode, wherein the charge supplied from the source electrode of the MOS transistor sets the potential at the first electrode to a predetermined value determined by the potential of the floating gate, and charges are transferred between the floating gate and the first electrode through the first insulating film by applying a predetermined pulsating voltage to the second electrode.
    Type: Grant
    Filed: July 1, 1996
    Date of Patent: October 6, 1998
    Assignees: Tadahiro Ohmi, Tadashi Shibata
    Inventors: Tadahiro Ohmi, Tadashi Shibata, Hideo Kosaka, Takeo Yamashita
  • Patent number: 5784018
    Abstract: The invention provides a semiconductor circuit which can fetch and store analog and multilevel data by using a simple circuit. The invention also provides a multilevel memory which can freely change the number of quantizing levels by using external signals. This semiconductor circuit comprises a first circuit which converts first signals into a group of quantized signals, a second circuit which converts the signal group into second multilevel signals, and structure which feeds back the second signals to the first circuit as first signals. The semiconductor circuit further has a structure to electrically separates at least one signal included in the signal group from the input of the second circuit, and structure which feeds back the second signals to the input of the second circuit instead of the signal previously separated.
    Type: Grant
    Filed: August 12, 1996
    Date of Patent: July 21, 1998
    Assignees: Tadahiro Ohmi, Tadashi Shibata
    Inventors: Tadahiro Ohmi, Takeo Yamashita, Tadashi Shibata
  • Patent number: 5745416
    Abstract: A non-volatile semiconductor memory which is capable of high speed and highly accurate analog data writing. The memory includes a first MOS type transistor having a first floating gate which is electrically isolated. A first electrode is capacitively coupled with the first floating gate. A second electrode is connected via a tunnel junction with the first floating gate. A third electrode is capacitively coupled with the second electrode. A second MOS type transistor interconnects the first and second electrodes. A means is provided for applying a predetermined potential difference between the first and third electrodes to thereby cause a tunnel current to flow in the tunnel junction and to store an electric charge in the first floating gate to thereby cause the second MOS type transistor to conduct when the electric charge has reached a predetermined value.
    Type: Grant
    Filed: December 29, 1995
    Date of Patent: April 28, 1998
    Assignees: Tadashi Shibata, Tadahiro Ohmi
    Inventors: Tadashi Shibata, Tadahiro Ohmi, Yuichiro Yamashita
  • Patent number: 5719520
    Abstract: A semiconductor circuit which realizes a read-only memory cell having zero stand-by power consumption and capable of non-volatile storage of multiple-valued or analog data. This semiconductor device is comprises of at least a single-channel or p-channel MOS transistor in a source-follower circuit configuration. The input of this source-follower circuit is a floating gate which is capacitively coupled to multiple control gates. The voltages applied to the control gates and the coupling ratios of the control gates determine the potential of the floating gate. When a voltage supply is applied to the drain electrode of the source-follower circuit, the source-electrode potential will nearly equal the floating gate potential.
    Type: Grant
    Filed: October 13, 1995
    Date of Patent: February 17, 1998
    Assignee: Tadashi Shibata
    Inventors: Rita Wai-Chi Au, Tadashi Shibata, Tadahiro Ohmi
  • Patent number: 5684738
    Abstract: A semiconductor memory circuit which realizes a source follower having a voltage gain equal to one, a decrease in the time necessary for the source follower to reach its full output voltage. Furthermore, the multiple-valued or analog output voltage can be easily converted to a binary-digital form with this memory circuit. This semiconductor circuit comprises at least an MOS transistor. A multiple-valued or analog data line is connected to the inputs of multiple-valued comparators, the outputs of said comparators are coupled capacitively to the input gate of a source-follower circuit, and the output of said source-follower circuit is fed back to the data line.
    Type: Grant
    Filed: November 9, 1995
    Date of Patent: November 4, 1997
    Assignees: Tadashi Shibata, Tadahiro Ohmi
    Inventors: Rita Au, Tadashi Shibata, Tadahiro Ohmi
  • Patent number: 5682109
    Abstract: The present invention relates to a semiconductor integrated circuit. In greater detail, the present invention relates to a semiconductor integrated circuit which conducts calculations using a voltage adding function by means of capacity and threshold operations.
    Type: Grant
    Filed: February 13, 1996
    Date of Patent: October 28, 1997
    Assignees: Tadahiro Ohmi, Tadashi Shibata
    Inventors: Tadahiro Ohmi, Tadashi Shibata, Koji Kotani
  • Patent number: 5661421
    Abstract: A semiconductor integrated circuit for effecting data matching at high speed is provided in a simple circuit. The semiconductor integrated circuit includes a first input terminal and a second input terminal to which first and second voltage signals representing first and second values are inputted, respectively, and an output terminal. A predetermined output signal is produced at the output terminal when the difference between the first and second values is smaller than a predetermined difference value. The semiconductor integrated circuit of this invention comprises first and second inverters, each inverter comprising neuron MOS transistors having a plurality of input gates. The first and second signals or, first and second processed signals obtained by applying predetermined processing to the first and second signals, are inputted to at least one of the input gates of the inverters.
    Type: Grant
    Filed: September 29, 1995
    Date of Patent: August 26, 1997
    Assignees: Tadashi Shibata, Tadahiro Ohmi
    Inventors: Tadahiro Ohmi, Tadashi Shibata, Koji Kotani
  • Patent number: 5608340
    Abstract: A semiconductor device of this invention comprises on a substrate a first semiconductor region of one conductive type, first source and drain regions of the opposite conductive type formed in said semiconductor region, a first gate electrode formed in a region separating said source and drain regions, the first gate electrode being electrically floating through an insulating film, and at least two second gate electrodes connected to said first gate electrode by capacitive coupling, wherein an inversion layer is formed under said first gate electrode and said first source and drain regions are electrically connected together only when a predetermined threshold value is exceeded by the absolute value of a value obtained by linearly summing up the weighted voltages applied to said second gate electrodes.
    Type: Grant
    Filed: May 11, 1993
    Date of Patent: March 4, 1997
    Assignee: Tadashi Shibata
    Inventors: Tadashi Shibata, Tadahiro Ohmi