Patents Examined by Do Popovici
  • Patent number: 5138461
    Abstract: An implosion-protected cathode-ray tube has a bulb and a metallic band tightly binding the front outer peripheral portion of the bulb to suppress the occurrence of accidental implosion of the bulb during the manufacturing processes including a heating and evacuation process and a rapid cooling process after the heating and evacuation process as well as after the manufacture of the cathode-ray tube. The material forming the metallic band and the size of the metallic band meet the following conditions: i) the thermal expansion coefficient .alpha..sub.s of the material is not less than the thermal expansion coefficient .alpha..sub.g of the glass forming the bulb; ii) a value expressed by: L(1+.alpha..sub.s..delta.t), where L is the inner perimeter of the metallic band at the ambient temperature when the tightened metal band is removed from the bulb and where .alpha.
    Type: Grant
    Filed: December 18, 1989
    Date of Patent: August 11, 1992
    Assignees: Hitachi Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Takao Kawamura, Masaharu Kumada, Hiroshi Kawasaki