Patents by Inventor Tsutomu Mezawa

Tsutomu Mezawa 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: 6784526
    Abstract: According to the present invention, for a module in which a plurality of integrated circuit devices are mounted in parallel, the inductance generated by the unit length of a branched signal line on a motherboard is so set that it is smaller for a branched signal line a longer distance from its branching point to its distal end, and is so set that it is larger for a branched signal line having a shorter distance from its branching point to its distal end, so that the time required for transmission of a signal from the branching point to the distal end of each branched signal line is the same.
    Type: Grant
    Filed: July 22, 1998
    Date of Patent: August 31, 2004
    Assignee: Fujitsu Limited
    Inventor: Tsutomu Mezawa
  • Patent number: 4458337
    Abstract: A buffer circuit comprises a flip-flop which is receives an external input via a first input circuit and a reference voltage via a second input circuit. Internal complementary outputs are then produced via an output circuit. The flip-flop cooperates with at least one level setting device by way of a second input circuit. The level setting device functions to produce a voltage level to deactivate the second input circuit during activation of the flip-flop.
    Type: Grant
    Filed: March 3, 1982
    Date of Patent: July 3, 1984
    Assignee: Fujitsu Limited
    Inventors: Yoshihiro Takemae, Shigeki Nozaki, Tsutomu Mezawa, Katsuhiko Kabashima, Seiji Enomoto
  • Patent number: 4451908
    Abstract: An address buffer for a dynamic memory includes a flip-flop. The flip-flop is coupled at its one input/output terminal with both a first input circuit and a third input circuit connected in parallel with each other and at its other input/output terminal with a second input circuit. The second input circuit receives a reference voltage and is activated by an external address timing clock during a normal operation mode. The first input circuit is also activated by the external address timing clock, but receives an external address. The third input circuit receives an internal refresh address and is activated by an internal refresh address. The address buffer cooperates with a switcher which produces the internal refresh address timing clock and the external address timing clock, alternatively, by switching a basic timing clock generated by an address drive clock generator.
    Type: Grant
    Filed: March 3, 1982
    Date of Patent: May 29, 1984
    Assignee: Fujitsu Limited
    Inventors: Yoshihiro Takemae, Shigeki Nozaki, Katsuhiko Kabashima, Seiji Enomoto, Tsutomu Mezawa
  • Patent number: 4447745
    Abstract: A semiconductor circuit used as a buffer circuit having an input stage circuit for receiving an input clock signal and an inverted input clock signal, a bootstrap circuit including a transistor for receiving the output of the input stage circuit and for maintaining the gate voltage of the transistor at a high level during the standby period, and an output circuit, including a transistor which is switched on and off by the output of the bootstrap circuit, for generating an output clock signal; the semiconductor circuit further comprising a current leak circuit for maintaining, during the standby period, the voltage of a point in the semiconductor circuit which is charged during the standby period at the value corresponding to the voltage of the power source, whereby the delay of the output clock signal, caused of the fluctuation by the voltage of the power supply during the standby period, is improved and then the high speed access time in the dynamic memory is carried out.
    Type: Grant
    Filed: November 18, 1981
    Date of Patent: May 8, 1984
    Assignee: Fujitsu Limited
    Inventors: Yoshihiro Takemae, Seiji Enomoto, Shigeki Nozaki, Tsutomu Mezawa, Katsuhiko Kabashima
  • Patent number: 4417329
    Abstract: An active pull-up circuit for use in a sense amplifier or the like, comprises an enhancement type MIS transistor, a MIS capacitor controlled by a clock signal, and a depletion type MIS transistor controlled by another clock signal (.phi..sub.2 '). In this circuit, the two clock signals are bilevel signals having potentials which are the same as potentials of two power supplies.
    Type: Grant
    Filed: July 27, 1981
    Date of Patent: November 22, 1983
    Assignee: Fujitsu Limited
    Inventors: Tsutomu Mezawa, Katsuhiko Kabashima, Shigeki Nozaki, Yoshihiro Takemae
  • Patent number: 4387448
    Abstract: Disclosed is a dynamic semiconductor memory device with decreased clocks having a pull up circuit associated with a pair of bit lines. The pull up circuit comprises a pair of first switching transistors connected between a power supply line and the associated bit line, and, a pair of second switching transistors. Each gate of the second switching transistors is connected to the bit line of opposite side. The turning on or off of the second switching transistor controls the gate potential of the first switching transistor.
    Type: Grant
    Filed: April 15, 1981
    Date of Patent: June 7, 1983
    Assignee: A. Aoki & Associates
    Inventors: Yoshihiro Takemae, Shigeki Nozaki, Tsutomu Mezawa
  • Patent number: 4262341
    Abstract: Disclosed is the addition of a capacitor circuit for augumenting the voltages at predetermined points in a sense amplifying circuit, in order to ensure a satisfactory refreshing of memory cells, since, if the potentials at the connecting points between a sense amplifying circuit and bit lines fall below a predetermined value when the sense amplifying circuit is caused to operate, it is difficult to achieve a complete refreshing of the memory cells.
    Type: Grant
    Filed: October 18, 1978
    Date of Patent: April 14, 1981
    Assignee: Fujitsu Limited
    Inventors: Jun-ichi Mogi, Kiyoshi Miyasaka, Fumio Baba, Tsutomu Mezawa