Patents by Inventor Yasuhiro Kita

Yasuhiro Kita 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: 4122417
    Abstract: To form a simple and economical variable equalizer, the equalizer is constructed of a differential amplifier having two input terminals to which an input signal to be equalized and an equalized output signal derived from the output terminal are applied, a first impedance circuit connected between the differential amplifier and the output terminal, and a series circuit having a second impedance circuit and a variable resistor connected in series between the output terminal and a ground terminal.
    Type: Grant
    Filed: May 13, 1977
    Date of Patent: October 24, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitaka Takasaki, Kohei Ishizuka, Yasuhiro Kita, Yoshinori Nagoya, Takeo Kusama
  • Patent number: 4101851
    Abstract: A variable equalizer wherein a series circuit which consists of a voltage source and an impedance circuit having an impedance Z.sub.x is connected in parallel with a circuit for changing an input voltage into a current, and an impedance circuit having an impedance Z.sub.y is also connected in parallel with this current source. The voltage value of the voltage source is made one which is obtained by multiplying the current by a value proportional to 1/Z.sub.y, and the impedance circuit having the impedance Z.sub.y is endowed with a frequency characteristic.
    Type: Grant
    Filed: November 26, 1976
    Date of Patent: July 18, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Kohei Ishizuka, Yasuhiro Kita
  • Patent number: 4097824
    Abstract: A variable equalizer adapted to be fabricated in an integrated circuit structure and having improved compensation characteristics comprises a parallel connection of two circuits, one including a series connection of a first impedance circuit (impedance: Zy) and an input A.C. signal source circuit having a voltage v.sub.i, the other comprising a series connection of a second impedance circuit (impedance: Z.sub.x) and an A.C. signal source circuit having a voltage amplitude v.sub.z which is equal to v.sub.i (K/Z.sub.y).sup.2, where K is a constant, and the second impedance circuit, consists of a variable resistor.
    Type: Grant
    Filed: February 28, 1977
    Date of Patent: June 27, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Kohei Ishizuka, Yasuhiro Kita, Yoshitaka Takasaki, Junichi Nakagawa
  • Patent number: 4080580
    Abstract: In order to realize a precision variable equalizer of little errors by a simple circuit arrangement, a plurality of variable transmission circuits having variable transfer coefficients are connected in series between input and output terminals, and feed-back and feed-forward are applied from input and output sides of the respective variable transmission circuits to input and output portions of the variable equalizer through transmission networks having specified transfer characteristics.
    Type: Grant
    Filed: November 4, 1976
    Date of Patent: March 21, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitaka Takasaki, Yasuhiro Kita, Jun'ichi Nakagawa, Kohei Ishizuka, Osamu Yumoto, Yoshinori Nagoya
  • Patent number: 4004253
    Abstract: An inductorless variable equalizer comprises input and output terminals. A first transmission network is situated in the forward path between the input and output terminals and has a variable transfer coefficient; second and third transmission networks are situated in the feedback and feedforward paths, respectively, between the input and output terminals. Each of these networks has a fixed transfer coefficient and the transfer coefficients of the feedback and feedforward networks having polarities opposite each other.
    Type: Grant
    Filed: June 18, 1975
    Date of Patent: January 18, 1977
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitaka Takasaki, Narimichi Maeda, Jun'ichi Nakagawa, Kohei Ishizuka, Yasuhiro Kita