Patents by Inventor Masaharu Atsumi

Masaharu Atsumi 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).

  • Thyristor with "on" protective circuit and darlington output stage
    Patent number: 4654543
    Abstract: A thyristor is preferably fabricated as a single thyristor device in an integrated circuit. The thyristor is made conductive by applying an ordinary gating voltage to the gate thereof. However, the thyristor can be kept in a conductive state, even though a current flowing through the anode and cathode thereof is stopped, if the current is restored to flow through it again within a predetermined short time after has stopped. The thyristor is composed of a first transistor and a second transistor (both of which are also used in a typical thyristor component) a third transistor which forms a Darlington connection with the second transistor, a resistor which is connected between the base and the emitter of the third transistor, and a capacitor which is connected between the base of the second transistor and the emitter of the third transistor.
    Type: Grant
    Filed: December 13, 1984
    Date of Patent: March 31, 1987
    Assignee: Fujitsu Limited
    Inventor: Masaharu Atsumi
  • One-terminal type level control circuit
    Patent number: 4476426
    Abstract: A constant-current source transistor, which exhibits a constant-current characteristic corresponding to the power source voltage of a sensor and is connected to an input signal terminal of an input circuit, such as a microprocessor. A first transistor is connected so that it may supply a current from the power source of the input circuit to the constant-current source transistor, and a second transistor is connected in parallel to the constant-current source transistor. When the signal level at the input signal terminal exceeds a predetermined value, the second transistor is turned ON to effect level control so the input signal level may not become excessively high and damage the input circuit.
    Type: Grant
    Filed: June 3, 1982
    Date of Patent: October 9, 1984
    Assignees: Fujitsu Ten Limited, Fijitsu Limited
    Inventors: Satoru Kishimoto, Masaharu Atsumi, Yoshiaki Sano
  • Input protection circuit
    Patent number: 4446499
    Abstract: A clamping transistor is connected to a signal input terminal of a signal processing circuit, such as a microprocessor, which operates on the output voltage from a stabilized power source circuit. When the output voltage from the stabilized power source circuit is below a predetermined value at the time of turning ON or OFF a power source switch, the clamping transistor is held in the ON state, thereby preventing the application of an input signal of a level higher than the power source voltage of the signal processing circuit, to the signal input terminal of the signal processing circuit.
    Type: Grant
    Filed: June 3, 1982
    Date of Patent: May 1, 1984
    Assignees: Fujitsu Ten Limited, Fujitsu Limited
    Inventors: Satoru Kishimoto, Masaharu Atsumi, Yoshiaki Sano