Patents by Inventor Mutsumi Maehara

Mutsumi Maehara 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: 20020195920
    Abstract: A color cathode ray tube comprises a panel which outside surface is flat and inside surface has curvature, and a pressed shadow mask having a curved surface opposed to the panel inside surface. The curved surface of the shadow mask is such that the radius of curvature decreases approximately linearly as the position moves from the center to the periphery. Radii of curvature on the major axis, minor axis, and diagonal axis at positions having the same distance from the shadow mask center do not have large differences. This configuration can increase the mechanical strength of the shadow mask.
    Type: Application
    Filed: May 1, 2001
    Publication date: December 26, 2002
    Inventors: Takeharu Furusawa, Nobuhiko Hosotani, Mutsumi Maehara
  • Patent number: 6407494
    Abstract: A color cathode ray tube includes a panel having an outer surface which is flat and an inner surface which is a curved surface, and the inner surface has an approximately rectangular effective screen on which an image is to be displayed. Letting Tc, Td and D be, respectively, the glass thickness of the panel at the center thereof, the glass thickness of an end of a diagonal effective diameter, and half of the diagonal effective diameter, (Td−Tc)/D≦7.5% and the maximum deflection angle is between 96° and 99°.
    Type: Grant
    Filed: September 6, 2000
    Date of Patent: June 18, 2002
    Assignees: Hitachi LTD, Hitachi Device Engineering Co.
    Inventors: Mutsumi Maehara, Syunichi Matsumoto
  • Patent number: 6339282
    Abstract: A color cathode-ray tube includes a panel portion, a neck portion, a funnel portion connecting the panel and neck portions, a fluorescent layer formed on an inner surface of a face plate of the panel portion, a shadow mask disposed opposite to the fluorescent layer, an electron gun housed in the neck portion, and an internal magnetic shield disposed in the funnel portion. The internal magnetic shield is formed in a substantially quadrangular pyramid-shape having a substantially rectangular first opening with a smaller diagonal dimension at one end adjacent to the electron gun and a substantially rectangular second opening with a larger diagonal dimension than the smaller diagonal dimension at the other end adjacent to the shadow mask.
    Type: Grant
    Filed: December 11, 2000
    Date of Patent: January 15, 2002
    Assignee: Hitachi, Ltd.
    Inventor: Mutsumi Maehara
  • Patent number: 6307310
    Abstract: A color cathode ray tube comprising a perforated molded mask curved inward in the middle between its two opposite sides and having round corners, and a support frame curved outward in the middle between its two opposite sides and having round corners, wherein the corners of mask are respectively brought into contact with the corners of the mask and the frame. Therefore, the alignment accuracy between a shadow mask assembly and phosphor film and the magnetic shielding of the color cathode ray tube can be improved.
    Type: Grant
    Filed: March 17, 1999
    Date of Patent: October 23, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Mutsumi Maehara, Tsuyoshi Iwata, Hiroshi Yoshioka
  • Patent number: 6278232
    Abstract: A color cathode ray tube comprises a vacuum envelope in which there is mounted a shadow mask having a curved surface having a plurality of electron beam passing holes and a skirt extending downward from the margin of the curved surface. The shadow mask is supported by a mask frame having a substantially rectangular side wall. A shadow mask assembly constituted by fitting and securing the skirt into the side wall is set in the panel of the envelope, and the skirt is fitted and secured into the side wall by curving the middles of two or four facing sides of the skirt inward. Thereby, it is possible to provide a color cathode ray tube having the shadow mask assembly capable of obtaining a superior magnetic shielding characteristic by enlarging the effective region of the curved surface of the shadow mask.
    Type: Grant
    Filed: January 27, 2000
    Date of Patent: August 21, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Hisashi Nose, Mutsumi Maehara, Tsuyoshi Iwata
  • Publication number: 20010011864
    Abstract: A color cathode ray tube including a shadow mask assembly and an inner shield provided for the shadow mask assembly which are disposed within the tube. The shadow mask assembly includes a substantially rectangular shadow mask, a substantially rectangular mask frame, and a spring for mounting the shadow mask assembly in the panel of the cathode ray tube. The shadow mask has a curved surface having electron beam passing holes and a skirt folded from the margin of the curved surface and extending in a tube axis direction. At least one of the major and minor sides of the substantially rectangular shadow mask has a curvature convex to the tube axis with corners thereof being round and at least one of the major and minor sides of the substantially rectangular mask frame is linear or has a curvature concave to the tube axis with corners thereof being round.
    Type: Application
    Filed: April 19, 2001
    Publication date: August 9, 2001
    Inventors: Hisashi Nose, Mutsumi Maehara, Tsuyoshi Iwata
  • Patent number: 6262526
    Abstract: An in-line type color Braun tube having a fluorescent screen and a shield cup at an end of an electron gun, the shield cup including a cylindrical side wall and a bottom having a center electron beam passing hole and two side electron beam passing holes aligned in a horizontal direction. A convergence correcting member including a base and a pair of horizontal plates, the base and horizontal plates being a one piece member, and a bottom member of the base being cross-shaped and including two side electron beam passing holes and a center electron beam passing hole. A pair of horizontal plates sandwiches an electron beam passing through each of the side electron beam passing holes, in a direction vertical to the electron beam.
    Type: Grant
    Filed: January 27, 2000
    Date of Patent: July 17, 2001
    Assignee: Hitachi, LTD
    Inventors: Hiroshi Miyazawa, Makoto Koizumi, Mutsumi Maehara, Hidetoshi Kida
  • Publication number: 20010000645
    Abstract: A color cathode-ray tube includes a panel portion, a neck portion, a funnel portion connecting the panel and neck portions, a fluorescent layer formed on an inner surface of a face plate of the panel portion, a shadow mask disposed opposite to the fluorescent layer, an electron gun housed in the neck portion, and an internal magnetic shield disposed in the funnel portion. The internal magnetic shield is formed in a substantially quadrangular pyramid-shape having a substantially rectangular first opening with a smaller diagonal dimension at one end adjacent to the electron gun and a substantially rectangular second opening with a larger diagonal dimension than the smaller diagonal dimension at the other end adjacent to the shadow mask.
    Type: Application
    Filed: December 11, 2000
    Publication date: May 3, 2001
    Inventor: Mutsumi Maehara
  • Patent number: 6177758
    Abstract: A color cathode-ray tube includes a panel portion, a neck portion, a funnel portion connecting the panel and neck portions, a fluorescent layer formed on an inner surface of a face plate of the panel portion, a shadow mask disposed opposite to the fluorescent layer, an electron gun housed in the neck portion, and an internal magnetic shield disposed in the funnel portion. The internal magnetic shield is formed in a substantially quadrangular pyramid-shape having a substantially rectangular first opening with a smaller diagonal at one end adjacent to the electron gun and a substantially rectangular second opening with a larger diagonal dimension than the smaller diagonal dimension at the other end adjacent to the shadow mask.
    Type: Grant
    Filed: December 20, 1999
    Date of Patent: January 23, 2001
    Assignee: Hitachi, Ltd.
    Inventor: Mutsumi Maehara
  • Patent number: 6104132
    Abstract: A color cathode ray tube comprises a vacuum envelope in which there is mounted a shadow mask having a curved surface having a plurality of electron beam passing holes and a skirt extending downward from the margin of the curved surface. The shadow mask is supported by a mask frame having a substantially rectangular side wall. A shadow mask assembly constituted by fitting and securing the skirt into the side wall is set in the panel of the envelope, and the skirt is fitted and secured into the side wall by curving the middles of two or four facing sides of the skirt inward. Thereby, it is possible to provide a color cathode ray tube having the shadow mask assembly capable of obtaining a superior magnetic shielding characteristic by enlarging the effective region of the curved surface of the shadow mask.
    Type: Grant
    Filed: March 10, 1997
    Date of Patent: August 15, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Hisashi Nose, Mutsumi Maehara, Tsuyoshi Iwata
  • Patent number: 6028392
    Abstract: An in-line type color Braun tube includes a shield cup electrode which opens at the side facing a fluorescent surface of the tube, provided at the end of an electron gun, wherein the shield cup electrode comprises a cylindrical side wall for shielding three electron beams generated by the electron gun from influences of electrostatic charge accumulated at a wall surface of a glass bulb of the tube, a base plate having three beam passing holes aligned in the horizontal direction, and two cylinders made of non-magnetic and conductive material, for suppressing eddy current induced at the shield cup electrode, each of the two cylinders surrounding one of two paths of electron beams passing through both side holes of the three beam passing holes, projecting from a surface facing the fluorescent surface, of the base, in the direction facing the fluorescent surface.
    Type: Grant
    Filed: September 16, 1996
    Date of Patent: February 22, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Hiroshi Miyazawa, Makoto Koizumi, Mutsumi Maehara, Hidetoshi Kida
  • Patent number: 6020678
    Abstract: A color cathode-ray tube including a panel portion, a neck portion and a funnel portion connecting these two portions and having an internal magnetic shield, wherein the internal magnetic shield is disposed in the funnel portion and made of a substantially quadrangular pyramid-shaped frame structure which has a substantially rectangular first opening of small diameter at one end adjacent to an electron gun and a substantially rectangular second opening of large diameter at the other end adjacent to a shadow mask and creased lines formed between corresponding corners of the first and second openings, side faces of the internal magnetic shield opposite to each other being formed with substantially V-shaped notches respectively in the portions thereof adjacent to the first opening, and each of the creased lines of the internal magnetic shield is formed in such a manner that an end of an imaginary line extension of the creased line adjacent to the second opening is located on a projected plane parallel to the sec
    Type: Grant
    Filed: October 15, 1997
    Date of Patent: February 1, 2000
    Assignee: Hitachi, Ltd.
    Inventor: Mutsumi Maehara
  • Patent number: 5910702
    Abstract: A shadow mask type color cathode ray tube includes a generally rectangular shadow mask having a curved apertured portion having a multiplicity of electron-transmissive apertures, a curved imperforate portion surrounding and integral with the apertured portion and a skirt portion bent back from a periphery of the curved imperforate portion to form a rearwardly extending wall, and a generally rectangular support frame for suspending the shadow mask by spot welding the skirt portion thereto, within a panel portion of the color cathode ray tube, and at least one of short and long sides of the skirt portion contains only a pair of embossments extending in a direction parallel to a longitudinal axis of the color cathode ray tube on opposite sides of the spot welding point of the support frame and the skirt portion at a center of the at least one of short and long sides of the skirt portion within a distance of one fourth or less of a length of the at least one of short and long sides of the generally rectangular sh
    Type: Grant
    Filed: November 13, 1997
    Date of Patent: June 8, 1999
    Assignee: Hitachi, Ltd.
    Inventor: Mutsumi Maehara
  • Patent number: 5814933
    Abstract: A color cathode ray tube includes a front panel having a phosphor screen deposited on its interior surface. A contour of the interior surface is configured such that a radius Rx of a surface curvature of sections parallel to a horizontal axis and a radius Ry of a surface curvature of sections parallel to a vertical axis of the front panel are substantially constant, respectively, within a screen area of the phosphor screen.
    Type: Grant
    Filed: March 4, 1997
    Date of Patent: September 29, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Tsuyoshi Iwata, Mutsumi Maehara, Hiroshi Yoshioka