Other

Hitachi, Ltd.

Hitachi Electronic Device Co., Ltd.

Koji Hagiwara

Hiroshi Ito

Nobuhiko Hosotani

Masahiro Ito

Yoichi Ito

Hideharu Sakamoto

The invention provides a color cathode ray tube using a shadow mask capable of avoiding ruptures or cracks during press-working. The shadow mask has an apertured region having color selecting apertures, and an unapertured region which surrounds the apertured region. A skirt portion is bent from the unapertured region in the direction of the tube axis. The shadow mask has at least two inclined surfaces in a boundary portion between the unapertured region and the skirt portion.

Color cathode ray tube

A color cathode ray tube can reduce a warp amount derived from a spring back after shaping a shadow mask and can suppress the deformation of a main surface of the shadow mask after fixedly securing the shadow mask and a mask frame to each other. The color cathode ray tube includes tongue portions which are protruded from distal ends of skirt portions of the shadow mask and a plurality of stress absorption holes are formed in the tongue portions.

A 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, 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. The skirt portion is provided with a plurality of embossments and is fitted inside the support frame. The embossments protrude inwardly and extend in a direction of a height of the skirt portion. A distance between a bottom of each of the plurality of embossments and a border of the curved apertured portion is at least 4.5 mm.

Color cathode ray having a shadow mask structure with curl reduced in a skirt portion thereof

A color cathode ray tube includes a rectangular shadow mask made of an Fe-Ni alloy material, and having an apertured portion, an imperforate portion surrounding the apertured portion and a skirt portion bent back from the imperforate portion, and a rectangular support frame for suspending the shadow mask by spot welding the skirt portion thereto. The skirt portion is provided with plural slits and plural embossments extending in a direction of the height of the skirt portion in one of long and short sides of the skirt portion, and the slits and embossments are juxtaposed around a circumference of the skirt portion. A majority of the slits in the one of the long and shirt sides of the skirt portion are slits delimiting continuous openings in the skirt portion which are not bridged by members other than the support frame.

Color cathode ray tube having an improved shadow mask

A color cathode ray tube including a generally rectangular shadow mask with at least a long side, a short side and a corner, and having a curved apertured portion with 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. A generally rectangular support frame is provided for suspending the shadow mask by spot welding the skirt portion thereto within a panel portion of the color cathode ray tube. The skirt portion is provided with a plurality of slits extending in a direction of a height of the skirt portion and a plurality of embossments extending in the direction of the height of the skirt portion in one of a long side and a short side of the skirt portion. The plurality of slits and the plurality of embossments are juxtaposed around a circumference of the skirt portion with a majority of the plurality of slits in the one of the long side and the short side of the skirt portion being unbridged slits or with the plurality of slits extending a distance no greater than 70% of the height of the skirt portion from a rear end of the skirt portion on an opposite side thereof from the panel portion.

Color cathode ray tube having an improved shadow mask structure

A 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, 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. The skirt portion is provided with plural embossments extending in a direction of a height of the skirt portion, and the embossments are distributed over each of central portions extending a distance PHL and a distance PVL in long and short sides of the skirt portion, respectively, PHL and PVL satisfying following inequalities: 0.5 HL&lE;PHL&lE;0.85 HL, 0.5 VL&lE;PVL&lE;0.85 VL, and HL and VL being longitudinal lengths of said long and short sides of said skirt portion, respectively, wherein a depth of the embossments decreases or increases with increasing distance from centerlines of the long and short sides.

Color cathode ray tube having a shadow mask structure with curl reduced in a skirt portion thereof

A 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, 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. The skirt portion is provided with a plurality of slits extending in a direction of a height of the skirt portion and a plurality of embossments extending in the direction of the height of the skirt portion, and the slits and the embossments are juxtaposed around a circumference of the skirt portion.

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Mobara, Japan

Koji Hagiwara