Patents by Inventor Yasuji Kamata

Yasuji Kamata 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: 4888561
    Abstract: Herein disclosed are an amplifier and a display which uses the former. The amplifier includes a current amplifying circuit for sending out an amplified output current varying according to an input signal, and a current-voltage converting circuit for converting the output current of the current amplifying circuit into a voltage thereby to generate a high output voltage in response to the input signal. The supply voltage V.sub.cc1 of the current amplifying means and the supply voltage V.sub.cc2 of the current-voltage converting means are set separately of each other to have a relationship of V.sub.cc1 <V.sub.cc2. Thus, a high output voltage can be obtained from the current-voltage converting circuit without the need for the current amplifying means to have high breakdown voltage elements.
    Type: Grant
    Filed: May 4, 1988
    Date of Patent: December 19, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Ryushi Shimokawa, Seiichi Ueda, Yasuji Kamata, Kenkichi Yamashita, Kazuo Kato, Hideo Sato
  • Patent number: 4755768
    Abstract: Herein disclosed are an amplifier and a display which uses the former. The amplifier includes a current amplifying circuit for sending out an amplified output current varying according to an input signal, and a current-voltage converting circuit for converting the output current of the current amplifying circuit into a voltage thereby to generate a high output voltage in response to the input signal. The supply voltage V.sub.cc1 of the current amplifying means and the supply voltage V.sub.cc2 of the current-voltage converting means are set separately of each other to have a relationship of V.sub.cc1 <V.sub.cc2. Thus, a high output voltage can be obtained from the current-voltage converting circuit without the need for the current amplifying means to have high breakdown voltage elements.
    Type: Grant
    Filed: April 3, 1986
    Date of Patent: July 5, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Ryushi Shimokawa, Seiichi Ueda, Yasuji Kamata, Kenkichi Yamashita, Kazuo Kato, Hideo Sato
  • Patent number: 4646029
    Abstract: Herein disclosed is a variable gain amplifying circuit which comprises a heating element, a heat-sensitive resistance coupled thermally to the heating element, an amplifier including the heat-sensitive resistance, and means for controlling the heat of the heat element. This heat of the heating element is controlled so as to control the value of the heat-sensitive resistance. As a result that the value of the heat-sensitive resistance is controlled, the gain of that amplifier is controlled.
    Type: Grant
    Filed: July 2, 1985
    Date of Patent: February 24, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Yasuji Kamata, Kazuo Kato
  • Patent number: 4638308
    Abstract: A CRT picture display apparatus of the raster scan type comprises a cathode ray tube for raster scanning, a horizontal deflection circuit for supplying a horizontal deflection current to a horizontal deflection coil of the CRT, a vertical deflection circuit for supplying a vertical deflection current to a vertical deflection coil of the CRT, and a display data generator for supplying data to be displayed to the CRT.
    Type: Grant
    Filed: September 26, 1984
    Date of Patent: January 20, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Kuwabara, Jushi Ide, Yasuji Kamata, Kenkichi Yamashita
  • Patent number: 4603008
    Abstract: Disclosed herein is a critical temperature sensitive resistor material which comprises 60 to 90% by weight of VO.sub.2 and 40 to 10% by weight of RuO.sub.2. This material exhibits hysteresis of resistance that decreases remarkably over a temperature range in which the resistance varies greatly, and is hence used for measuring the temperature maintaining a high precision.
    Type: Grant
    Filed: June 27, 1985
    Date of Patent: July 29, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Hiromi Tosaki, Hideo Arima, Akira Ikegami, Yasuji Kamata
  • Patent number: 4438366
    Abstract: An improved apparatus for driving a cathode-ray tube (CRT) with minimized power consumption is disclosed. In the apparatus, a voltage regulator element (a Zener diode) supplying a regulated voltage substantially equal to that voltage of the associated cathode providing a maximum image luminance is connected in series with the cathode between the driving circuit and the cathode, thereby reducing the driving voltage of the driving power source and reducing the power consumption of the CRT driving apparatus.
    Type: Grant
    Filed: July 22, 1981
    Date of Patent: March 20, 1984
    Assignee: Hitachi, Ltd.
    Inventor: Yasuji Kamata
  • Patent number: 4401922
    Abstract: In a convergence distortion correction method and apparatus for raster-scanned color CRT having a dynamic convergence magnet assembly, the CRT display screen is divided into a plurality of zones. A digital memory is provided with a data storage field and a flag bit field at each address. Addresses of the zones are generated by means of a sync signal regenerated from an input video signal. First, the addresses of zones to be subjected to the adjustment of convergence distortion are selected to set flags in the flag bit fields of the digital memory at its addresses specified by the selected zone addresses. Then, by referring to the flags, guide patterns are displayed on the selected zones and are used to adjust the convergence distortions in those zones. Preferably, one of the displayed guide patterns is flickered. Correction data based on the results of the adjustment are stored in the data storage fields of the digital memory at the corresponding addresses.
    Type: Grant
    Filed: June 24, 1982
    Date of Patent: August 30, 1983
    Assignee: Hitachi, Ltd.
    Inventors: Yasuji Kamata, Hiroshi Kuwahara, Jushi Ide, Kenkichi Yamashita, Koji Takahashi
  • Patent number: 4009460
    Abstract: An inductor having a coil member commonly wound on a couple of closed magnetic circuits made of a soft magnetic material. A magnetic gap is provided at a part of the soft magnetic material of at least one of the two closed magnetic circuits, and a permanent magnet providing a magnetic bias is inserted in the magnetic gap. This inductor is used in series between a DC power source providing a superimposed current of a DC current and an AC current and a load. The inductance of the inductor is very large with respect to a small DC current, while it reduces sharply when the applied DC current increases to be a certain value to show a substantially constant low value with respect to a DC current value beyond the certain value.
    Type: Grant
    Filed: September 19, 1975
    Date of Patent: February 22, 1977
    Assignees: Hitachi Metals, Ltd., Hitachi, Ltd.
    Inventors: Masahiko Fukui, Yasuji Kamata
  • Patent number: 3935526
    Abstract: A DC-to-DC converter for providing a DC output voltage proportional to a DC voltage applied to the primary winding of a transformer by turning on and off the applied DC voltage by means of a switching element connected in series with the primary winding. The voltage developed across the secondary winding of the transformer upon the turning on and off of the applied DC voltage is rectified and smoothed by means of a circuit including a rectifying diode, a choke coil and a capacitor. The transformer has a core which exhibits a rectangular hysteresis characteristic. When the switching element is turned off, the current flowing through the choke coil when the switching element is conductive is caused to flow as a reset current through a part of the secondary winding of the transformer so that the level of the magnetic flux of the core of the transformer may be restored to its initial value.
    Type: Grant
    Filed: August 14, 1973
    Date of Patent: January 27, 1976
    Assignee: Hitachi, Ltd.
    Inventors: Yasuji Kamata, Kazuo Katou
  • Patent number: 3931582
    Abstract: A DC amplifier circuit with transformer coupled isolation comprises a DC amplifier, an electronic switching element connected to the output terminal of the DC amplifier, a pulse generator for driving the electronic switching element, a small pulse transformer having a primary winding and secondary winding. To the primary winding of the small transformer pulsating signals from the electronic switching element are applied, and two substantially identical circuits each having a diode and a condenser in series are connected respectively across the primary winding and the secondary winding of the small pulse transformer. Means for feeding back the smoothed signals from the circuit across the primary winding of the small pulse transformer is connected to a negative input terminal of the DC amplifier.
    Type: Grant
    Filed: August 22, 1974
    Date of Patent: January 6, 1976
    Assignee: Hitachi, Ltd.
    Inventors: Kazuo Kato, Yasuji Kamata