Patents by Inventor Ken Takeya

Ken Takeya 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: 6526511
    Abstract: The present invention discloses a method for randomizing a microprocessor system, such as an IC card, in order to prevent the microprocessor system from being tampered with. The method ensures that the randomized microprocessor system realizes a functionality equivalent to that of an original microprocessor system and enables easy modification of a configuration of the microprocessor system. In the context of this disclosure, to randomize a microprocessor system means to randomize a microprocessor and a program included in the microprocessor system while maintaining an equivalence of functionality realized by the microprocessor system regardless of this randomization.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: February 25, 2003
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Masami Urano, Tomoo Fukazawa, Ken Takeya
  • Patent number: 6242951
    Abstract: An adiabatic charging logic circuit includes a logic circuit and a power supply section. The logic circuit is constituted by a plurality of logic elements. The power supply section supplies power to the logic circuit to cause the logic circuit to perform logic processing after an input signal is supplied to the gate of each of the logic elements, and stops supply of the power before a new input signal is supplied to the gate of each of the logic elements after completion of the logic processing.
    Type: Grant
    Filed: September 2, 1998
    Date of Patent: June 5, 2001
    Inventors: Shunji Nakata, Takakuni Douseki, Mitsuru Harada, Ken Takeya
  • Patent number: 5808473
    Abstract: An electric signal measurement apparatus using the electro-optic sampling which is capable of measuring electric signals propagating on a signal line with only a lower disturbance, in a high precision over a wide bandwidth, and economically by a relatively compact apparatus size. The apparatus has a conductor body to be set in one point contact with the signal line, and an electro-optic material which changes a birefringence according to a strength of an electric field coupled by the conductor body, and which has a sufficient thickness between the lower surface and an upper surface such that a potential at the upper surface due to the electric field coupled by the conductor body is effectively zero. A polarization detector for detecting the laser beam with a polarization changed due to a change of the birefringence of the electro-optic material can be provided within a handy type probe body to which a probe head is attached.
    Type: Grant
    Filed: August 3, 1995
    Date of Patent: September 15, 1998
    Assignee: Nippon Telegraph & Telephone Corp.
    Inventors: Mitsuru Shinagawa, Tadao Nagatsuma, Makoto Yaita, Ken Takeya