Patents by Inventor Hirohiko Mochizuki

Hirohiko Mochizuki 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: 4870617
    Abstract: A semiconductor memory device comprises a plurality of reset circuits connected to a data bus pair at different locations. Before each read operation, the reset circuits reset the data bus pair to a predetermined reset voltage. The resetting of the data bus pair is virtually unaffected by the distributed resistances and parasitic capacitances of the data bus pair, since the resetting is carried out at a plurality of locations on the data bus pair.
    Type: Grant
    Filed: September 16, 1987
    Date of Patent: September 26, 1989
    Assignees: Fujitsu Limited, Fujitsu Vlsi Limited
    Inventors: Masao Nakano, Tsuyoshi Ohira, Hirohiko Mochizuki, Yukinori Kodama, Hidenori Nomura
  • Patent number: 4821232
    Abstract: A semiconductor memory device comprises a memory cell array comprising a plurality of memory cells arranged in a matrix arrangement, a sense amplifier, operatively connected to the memory cell array, amplifying a signal read out from one of the memory cells and having a pair of output terminals for outputting a complementary signal, a pair of data buses for transferring the complementary signal, a transfer gate for connecting the pair of output terminals to the pair of data buses responsive to a read operation, a data output buffer connected to the pair of data buses for outputting an output signal, and a reset circuit for resetting the pair of data buses to a predetermined voltage before each read operation responsive to a reset clock signal.
    Type: Grant
    Filed: September 16, 1987
    Date of Patent: April 11, 1989
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Masao Nakano, Tsuyoshi Ohira, Hirohiko Mochizuki, Yukinori Kodama, Hidenori Nomura
  • Patent number: 4807192
    Abstract: A memory device employing address multiplexing comprises a counter. An external address is initially set in the counter and a counter address value is incremented responsive to toggle of a column address strobe. The counted address value in the counter is supplied as an address signal directly to a column decoder or indirectly to the column decoder through an address buffer. The memory device may be provided with a switching logic circuit which switches the address bits in the counter depending on switching information so that it is possible to arbitrarily determine which address bits in the counter are to determine a nibble address.
    Type: Grant
    Filed: August 31, 1987
    Date of Patent: February 21, 1989
    Assignees: Fujitsu Limited, Fujitsu Vlsi Limited
    Inventors: Masao Nakano, Hirohiko Mochizuki, Tsuyoshi Ohira, Yukinori Kodama, Hidenori Nomura
  • Patent number: 4799197
    Abstract: A semiconductor memory device comprises a memory cell array comprising memory cells; a plurality of pairs of bit lines which are coupled to the memory cells and a data bus, each bit line being divided into at least two pairs of bit line parts; at least one sense amplifier provided between the pairs of bit line parts in each of the pairs of bit lines, for sensing a difference in potential between bit line parts in each pair, the sense amplifier being formed with complementary metal oxide semiconductor transistors; and at least a pair of transfer gates provided between a non-data bus side and a data bus side of the sense amplifier, the pair of transfer gates being held in an off-state when the sense amplifier is activated.
    Type: Grant
    Filed: September 1, 1987
    Date of Patent: January 17, 1989
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Yukinori Kodama, Hirohiko Mochizuki, Masao Nakano, Tsuyoshi Ohira, Hidenori Nomura
  • Patent number: 4672372
    Abstract: A semiconductor device having a dynamic circuit and a static circuit, wherein a clock signal, in synchronization with the operation of the static circuit, initiates the operation of the dynamic circuit. A delay circuit of a static type is provided to delay the clock signal and generate a delayed clock signal. The delayed clock signal initiates operation of one stage of the dynamic circuit. As a result, the final-operation timing of the dynamic circuit is substantially controlled by the delayed clock signal, thereby matching the operation of the dynamic circuit with the operation of the static circuit, regardless of the power supply voltage.
    Type: Grant
    Filed: November 28, 1984
    Date of Patent: June 9, 1987
    Assignee: Fujitsu Limited
    Inventors: Hatsuo Miyahara, Fumio Baba, Hirohiko Mochizuki
  • Patent number: 4653027
    Abstract: A semiconductor memory device operated synchronously with clock signals, such as a MOS dynamic RAM device. The semiconductor memory device includes a switch circuit inserted between a prestage output amplifier circuit receiving a readout signal from a memory cell and an output buffer circuit. The switch circuit is turned on just before the output signal is supplied from the prestage output amplifier circuit to the output buffer circuit and turned off after the output condition of the output buffer circuit is settled. The potential corresponding to the output data is maintained in the circuit between the switch circuit and the output buffer circuit. The output condition of the output buffer circuit is therefore retained even during the reset period of the prestage drive circuit, and the duration period of the output signal is expanded.
    Type: Grant
    Filed: December 3, 1984
    Date of Patent: March 24, 1987
    Assignee: Fujitsu Limited
    Inventors: Fumio Baba, Hirohiko Mochizuki, Hatsuo Miyahara
  • Patent number: 4601017
    Abstract: A semiconductor memory device comprises active pull-up circuits (APU.sub.1, APU.sub.2) each provided for one bit line (BL.sub.1, BL.sub.1). Each active pull-up circuit (APU.sub.1) has connections to two bit lines. That is, an active pull-up circuit (APU.sub.1) for a first bit line (BL.sub.1) comprises a first transistor (Q.sub.1) connected between a power supply terminal (V.sub.CC) and the first bit line, a second transistor (Q.sub.2) connected between the gate of the first transistor and the first bit line, and a capacitor (C.sub.1) connected to the gate of the first transistor. The gate of the second transistor is connected to a second bit line (BL.sub.1) which is paired with the first bit line. The capacitor receives an active pull-up signal (.phi..sub.AP). A circuit (Q.sub.3, Q.sub.4, Q.sub.5) is provided for transmitting a high level potential to the gate (N.sub.1) of the first transistor to precharge the capacitor.
    Type: Grant
    Filed: December 15, 1983
    Date of Patent: July 15, 1986
    Assignee: Fujitsu Limited
    Inventors: Hirohiko Mochizuki, Yoshihiro Takemae, Tomio Nakano, Kimiaki Sato
  • Patent number: 4558434
    Abstract: A semiconductor memory device having matrix-arranged memory cells, carrying out data write or read operations to or from a selected memory cell through a pair of data buses by the selection of a word line and a pair of bit lines, includes two transfer devices which transfer data between bit lines and data buses and which are separately operated for either writing or reading. Even if a data read operation is stopped midway by a system reset or the like, the stored data in the memory cell is not destroyed.
    Type: Grant
    Filed: January 25, 1984
    Date of Patent: December 10, 1985
    Assignee: Fujitsu Limited
    Inventors: Fumio Baba, Hirohiko Mochizuki, Hatsuo Miyahara
  • Patent number: 4413272
    Abstract: A semiconductor memory device has fuses coated with a protecting layer. The protecting layer is selectively etched to open windows so as to expose narrow center portions of the fuses. After the opening of the center windows, the fusing operation of the fuses is carried out to open a gap in the center window portion of the fuse material. In a preferred embodiment, another protective layer is then added to fill the gaps in the blown fuses.
    Type: Grant
    Filed: September 3, 1980
    Date of Patent: November 1, 1983
    Assignee: Fujitsu Limited
    Inventors: Hirohiko Mochizuki, Masao Nakano, Fumio Baba, Tomio Nakano, Yoshihiro Takemae
  • Patent number: 4392211
    Abstract: A semiconductor memory device wherein a redundancy memory cell array incorporated with main memory cell matrixes is disclosed. Memory cells of the main memory cell matrixes are selected by first and third decoders while memory cells of the redundancy memory cell array are selected by second and third decoders. When the redundancy memory cell array is selected by the second decoder, the transmission of a clock signal to the first decoders is stopped by a switching circuit.
    Type: Grant
    Filed: February 20, 1981
    Date of Patent: July 5, 1983
    Assignee: Fujitsu Limited
    Inventors: Masao Nakano, Fumio Baba, Tomio Nakano, Yoshihiro Takemae, Hirohiko Mochizuki
  • Patent number: 4382194
    Abstract: A boosting circuit boosts a voltage of a load capacitor which is charged by a specific voltage. The boosting circuit comprises a boosting capacitor one end of which is connected to receive a clock signal, a charging circuit for charging the boosting capacitor, a gate circuit provided between the load capacitor and the other end of the boosting capacitor, and a gate control circuit for opening the gate circuit upon discharging of the charge of the boosting, that is controlled by the clock signal, to the load capacitor and for closing the gate circuit during discharging of the load capacitor. The charging circuit is provided separately from a circuit for supplying the specific voltage. The charges of the boosting capacitor under the control of the clock signal flow through the gate circuit to the load capacitor.
    Type: Grant
    Filed: December 5, 1980
    Date of Patent: May 3, 1983
    Assignee: Fujitsu Limited
    Inventors: Masao Nakano, Fumio Baba, Hirohiko Mochizuki