Nec Corporation

Shinji Arai

Nobumitsu Aibara

Hiroshi Hasegawa

Yoshiaki Yanai

Masahiro Ueda

Tadachika Hidaka

A color cathode-ray tube is provided with constitution between a shadow mask electrode and a frame body such that difference of expansion and contraction between the shadow mask electrode and the frame body according to heat brings no-picture quality deterioration with practical cost. The shadow mask electrode made of metal whose thermal expansion rate is low. The shadow mask electrode is supported by a shadow mask electrode supporting body made of metal whose thermal expansion rate is approximately the same as that of the shadow mask electrode. The shadow mask electrode supporting body is supported by a frame body made of metal whose thermal expansion rate is different from that of the shadow mask electrode.

Color cathode-ray tube

A shadow mask assembly is provided, which reduces the necessary tensile force to be applied to the shadow mask and the weight and fabrication cost of the assembly itself. This assembly is comprised of (a) a pair of bars arranged in substantially parallel at a specific distance; the pair of bars being made of metal having a first thermal expansion coefficient; (b) a pair of arms fixed to the pair of bars in such a way that each of the pair of arms links the pair of arms together; the pair of arms applying a force that moves the pair of bars away from each other; the pair of arms being made of metal having a second thermal expansion coefficient; the pair of arms constituting a frame having an approximately rectangular opening along with the pair of bars; and (c) a shadow mask fixed to the pair of the bars so as to cover the opening of the frame; the shadow mask being applied with a tensile force in a direction approximately perpendicular to the pair of bars due to the force of the pair of arms that moves the pair of bars away from each other, thereby keeping the mask in its specific shape; the shadow mask being made of metal having a third thermal expansion coefficient that is low enough for suppressing the doming phenomenon; the third thermal expansion coefficient of the mask being less than the second thermal expansion coefficient of the pair of arms.

Shadow mask assembly with three therman expansion coefficients

A color cathode ray tube apparatus is provided to reduce the amount of deflection power required, this apparatus having a panel part, on the inside surface of which is formed a phosphor film that emits three primary colors, a funnel part that has its expanded aperture joined to the panel part and a funnel-shaped part, a neck part in which is housed an electron gun structure, and which is joined to the reduced-diameter &phgr; a aperture of the funnel part, and a deflection yoke that is disposed between the funnel part and the neck part, the neck part being formed by a main part that houses the electron gun structure and a reduced-diameter part to which are attached the deflection yokes. The funnel part has a quadrangular pyramid shape at the end that is joined to the neck part, and this can also be used for attachment of the deflection yoke.

Color cathode ray tube having a reduced diameter part in the neck

An electron gun fixer comprising bulb spacers fixed to an electron gun to be inserted into a bulb neck. Each of the bulb spacers has a supporting portion to be put into press contact with the inner surface of the bulb neck. The expression &ldquo;R &gE;R >R &rdquo; holds for the supporting portion, where R is the radius of curvature in the cross section along the direction of insertion of the electron gun into the bulb neck, R is the curvature of a peripheral part in the cross section perpendicular to the direction of insertion, and R is the radius of curvature for the remaining parts in the cross section perpendicular to the direction of insertion. R is substantially equal to the radius of curvature R of the bulb neck.

Growing community of inventors

Shiga, Japan

Shinji Arai