Patents by Inventor Machio Kawashima

Machio Kawashima 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: 4642527
    Abstract: There is provided an in-line color picture tube apparatus with a dynamic convergence correction device. Dynamic convergence correction means is disposed between a self-convergence deflection yoke and a static convergence correction magnet assembly which are mounted on the neck portion of the tube. The dynamic convergence correction means comprises a support member made of a non-magnetic substance, eight coil assemblies having cores fixedly disposed on the support member concentrically of the tube axis with mutual equal circumferential spacings, and coils wound on the cores. The coils are connected in such a manner as to generate a four-pole magnetic field having a horizontal axis, a six-pole magnetic field having the horizontal axis, four-pole magnetic field having an axis making an angle of 45.degree. with respect to the horizontal axis, and a six-pole magnetic field having a vertical axis.
    Type: Grant
    Filed: January 16, 1986
    Date of Patent: February 10, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Koji Takahashi, Machio Kawashima
  • Patent number: 4514664
    Abstract: A color television receiver includes a color picture tube having three electron guns including cathodes and heaters therefor, respectively, and an automatic cutoff adjusting circuit for adding a reference voltage signal substantially at a black level to a luminance signal during an interval beginning substantially at the end of a vertical blanking period, and for detecting cathode currents flowing toward the cathodes during the above-described interval to control cathode voltages for the cathodes for keeping the cathode currents at a predetermined level by way of feedback of voltages proportional to the cathode currents. There is provided a circuit for applying a positive voltage to each of the heaters during the above-described interval to reduce a potential difference between the heater and corresponding one of the cathodes to thereby lower a leakage current flowing between the cathode and the heater.
    Type: Grant
    Filed: May 10, 1982
    Date of Patent: April 30, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Kunisuke Kasagi, Machio Kawashima
  • Patent number: 4326147
    Abstract: A color picture tube having a shadow mask is disclosed in which, with a view to making occurrence of moire imperceptible, electron beam transmissive apertures of the shadow mask are formed in such an array that a plurality of trains of the electron beam transmissive apertures each arrayed in the vertical direction with a pitch P.sub.y are juxtaposed to one another, wherein, assuming that the order of the harmonics is represented by n and m is an odd number smaller than 2n, there exist the relations (n-0.5)P.sub.l .ltoreq.P.sub.y .ltoreq.(n+0.05)P.sub.l and (m-0.35)P.sub.y /2n.ltoreq..DELTA.y.ltoreq.(m+0.35)P.sub.y /2n among the pitch P.sub.y, pitch P.sub.l of scanning lines and vertical deviation .DELTA.y between two adjacent apertures in the horizontal direction.
    Type: Grant
    Filed: November 9, 1979
    Date of Patent: April 20, 1982
    Assignee: Hitachi, Ltd.
    Inventors: Takeshi Nakayama, Takehiko Nishimoto, Machio Kawashima, Kozi Takahashi, Kuniharu Osakabe
  • Patent number: 4210842
    Abstract: A color picture tube having a shadow mask provided with a plurality of vertical aperture rows arranged as horizontally juxtaposed to one another, each vertical row comprising the electron beam transmissive apertures vertically arranged in line with a predetermined pitch P.sub.y. With a view to making possibly occurring moires imperceptible, the arrangement of the apertures are made such that, when spatial deviation in the vertical positions between any two apertures in the horizontally adjacent aperture rows is represented by .DELTA.y, there may be included combinations of at least two different type aperture rows of different deviations .DELTA.y which satisfy the following condition ##EQU1## at least when n is equal to 1, 2, 3 or 4 and k is an odd number smaller than 2n.
    Type: Grant
    Filed: August 31, 1976
    Date of Patent: July 1, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Takeshi Nakayama, Takehiko Nishimoto, Machio Kawashima, Kozi Takahashi, Kuniharu Osakabe