Patents by Inventor Kohei Ishizuka

Kohei Ishizuka 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).

  • Publication number: 20200122374
    Abstract: A work holding mechanism includes a body part having a three-dimensional shape including at least a recess or a protrusion, and an adsorption part for holding a work by adsorbing the work onto the body part in conformity to the three-dimensional shape of the recess or the protrusion provided in the body part. The work is held by being adsorbed in conformity to the three-dimensional shape of the body part, and, therefore, the amount of usage of the work in a work molding system can be reduced as compared with when the work is held so as to have a flat shape.
    Type: Application
    Filed: April 3, 2018
    Publication date: April 23, 2020
    Inventors: Kohei Ishizuka, Taisuke Uematsu, Takashi Konno, Hiroyuki Atake, Yoshiyuki Meiki, Minoru Ariyama, Masato Idegami
  • Patent number: 5479288
    Abstract: A light transmission module is disclosed, having a light receiving element module, in which a photodiode and a coupling portion between the photodiode and a first optical fiber are hermetically sealed, and a light emitting element module, in which a laser diode driven by an electric signal and a coupling portion between said laser diode and a second optical fiber are also hermetically sealed. A two-sided print board is provided, on the two sides of which electric circuits for a transmitting system and a receiving system are mounted. The electric circuits for the transmitting and receiving circuits are; isolated electrically from each other, and are sealed in one body by molds, and accommodated in cases, together with the light receiving element module and the light emitting element module.
    Type: Grant
    Filed: March 8, 1993
    Date of Patent: December 26, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Kohei Ishizuka, Masaya Nakata, Teruhisa Azumaguchi, Junji Takeda, Hiroki Irie, Atushi Miura, Tamio Takeuchi, Tsutomu Kohno, Akisada Moriguchi
  • Patent number: 4531089
    Abstract: In a gain control circuit, an electric power calculating circuit is connected to a variable gain amplifier and a gain setting circuit for generating a gain control signal applied to the variable gain amplifier to control the gain thereof.
    Type: Grant
    Filed: February 11, 1982
    Date of Patent: July 23, 1985
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki Kaisha
    Inventors: Kohei Ishizuka, Yasuhiro Kita, Narimichi Maeda, Masahiro Koya, Kazuhiko Takaoka, Yoshiro Kokuryo
  • Patent number: 4477913
    Abstract: An equalizer apparatus suitable for use in a MODEM for receiving a signal having passed through a number of carrier-band lines is disclosed in which the number of carrier-band lines is detected from a training signal, and electrical connection of a fixed equalizer to a variable equalizer is controlled on the basis of the number of carrier-band lines, in order to form a precise, simple automatic equalizer apparatus.
    Type: Grant
    Filed: April 15, 1982
    Date of Patent: October 16, 1984
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki Kaisha
    Inventors: Masahiro Koya, Narimichi Maeda, Kohei Ishizuka, Kazuhiko Takaoka, Yoshiro Kokuryo, Yasuhiro Kita
  • Patent number: 4292596
    Abstract: A circuit for varying the gain of an amplifier circuit linearly in decibel by the use of a digital code signal varying linearly, wherein a resistance network to be connected between an amplifier having a fixed gain and an input or output portion for the amplification is connected and the gain of the amplifier as well as the values of resistance elements constituting the resistance network is set so that the transfer function of the amplifier circuit may become: ##EQU1## .
    Type: Grant
    Filed: August 13, 1979
    Date of Patent: September 29, 1981
    Assignee: Hitachi, Ltd.
    Inventors: Kohei Ishizuka, Yasuhiro Kita, Narimichi Maeda
  • Patent number: 4204176
    Abstract: A variable equalizer whose frequency characteristic varies in a range of 1-1/Y(f).sup.2when the gain x of a variable amplifier varies from 0 (zero) to .infin. (infinity), and which reduces the number of shaping networks for the variable frequency characteristic.It is constructed of a forward pass circuit which consists of a variable amplifier and a frequency-dependent first circuit connected in the order mentioned between input and output terminals, a feedback pass circuit which is dependent upon the frequency and which feeds-back an output of the variable amplifier to an input thereof, and a feed forward pass circuit which is independent of the frequency and which feeds forward part of the input of the variable amplifier to an output of the first circuit.
    Type: Grant
    Filed: April 3, 1978
    Date of Patent: May 20, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Yoshitaka Takasaki, Yasuhiro Kita, Junichi Nakagawa, Kohei Ishizuka
  • Patent number: 4187479
    Abstract: A variable equalizer is provided which, using a single variable resistor, can make compensations in both the directions of the gain side, and the loss side and can set a reference gain as desired.An input signal to be equalized is received as an antiphase input signal of a differential amplifier, an output signal which has been equalized is fed back to the antiphase input signal, and a difference signal between an in-phase input signal and the antiphase input signal is delivered as an output. A resistor is connected between an input terminal and ground, first and second impedance circuits and a variable resistor are connected between an intermediate point of the first-mentioned resistor and ground in the order mentioned, and a voltage at the junction point between the first and second impedance circuits is used as the in-phase input signal.
    Type: Grant
    Filed: December 13, 1977
    Date of Patent: February 5, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Kohei Ishizuka, Yoshitaka Takasaki, Yasuhiro Kita, Yoshinori Nagoya, Takeo Kusama
  • 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