Patents Assigned to Hitachi Device Eng. Co., Ltd.
  • Patent number: 4857795
    Abstract: A novel internal magnetic shield support apparatus for a color picture tube is disclosed, in which a mask frame is fixed on the interior of the periphery of a panel of the color picture tube, an internal magnetic shield is arranged along the inner wall surface of a funnel of the color picture tube, and the internal magnetic shield is secured to the mask frame with a buffer member interposed therebetween.
    Type: Grant
    Filed: July 1, 1987
    Date of Patent: August 15, 1989
    Assignees: Hitachi, Ltd., Hitachi Device Eng. Co. Ltd.
    Inventors: Shoichi Wakita, Shigemi Hirasawa
  • Patent number: 4825120
    Abstract: In an electron gun apparatus for color cathode-ray tube, first and second focusing electrodes respectively for focusing electron beams emitted from three electron guns are disposed. Between the first and second focusing electrodes, a pair of third focusing electrodes for forming an axial-nonsymmetrical electron lens are also disposed. Mutually different dynamic voltages are supplied to the third focusing electrodes in accordance with the change in deflection angle of the electron beam. Owing to the above described structure, uniform resolution is obtained at both the central part and the peripheral part of the screen.
    Type: Grant
    Filed: October 22, 1987
    Date of Patent: April 25, 1989
    Assignees: Hitachi, Ltd., Hitachi Device Eng. Co. Ltd.
    Inventor: Yoshiaki Takahashi
  • Patent number: 4777575
    Abstract: A switching power supply, in which a series circuit consisting of a primary winding of a transformer and a controllable switch is connected with a DC power source and a secondary winding of the transformer is connected with a first voltage source outputting the voltage developed across the secondary winding during the on-period of the controllable switch and a second voltage source storing the exciting energy of the transformer during the off-period of the controllable switch by using the exciting inductance of the transformer as a current source, a series circuit consisting of the first and the second voltage sources being connected with a load. Owing to this construction, even if voltage-current characteristic of a load having constant voltage characteristic, such as a magnetron, vary due to variations in the temperature, etc., the output voltage is automatically compensated and a stable electric power can be supplied to the load.
    Type: Grant
    Filed: March 23, 1987
    Date of Patent: October 11, 1988
    Assignees: Hitachi Ltd., Hitachi Nisshin Electronics, Co., Hitachi Device Eng. Co., Ltd.
    Inventors: Ikuo Yamato, Norikazu Tokunaga, Hisao Amano, Shoichi Noguchi, Teruaki Odaka
  • Patent number: 4742272
    Abstract: A magnetron includes inner and outer strap rings for providing a linkage among vanes which are disposed inside of an anode cylinder. The inner and outer strap rings have their diameters determined such that their algebraic mean is 1.75-1.95 times the diameter of an interaction space defined by the inner tips of the vanes. The magnetron structure achieves a significant leakage supression effect against spurious microwaves, particularly the fifth harmonic.
    Type: Grant
    Filed: February 10, 1987
    Date of Patent: May 3, 1988
    Assignees: Hitachi, Ltd., Hitachi Device Eng. Co., Ltd.
    Inventors: Jiro Kusano, Akikazu Harada, Seiji Kitakaze