Kabushiki Kaisha Toshiba

Takeshi Nakayama

Hiroyuki Oda

Tohru Takahashi

Takuya Mashimo

Masatsugu Inoue

Takashi Murai

Shinichiro Nakagawa

A shadow mask has a main mask and an auxiliary mask overlapped on the main mask. Electron beam passage apertures formed in the main mask and the auxiliary mask are arranged at given pitches in the direction of a major axis. Each electron beam passage aperture of the auxiliary mask is a communicating hole, which is formed of a smaller hole in that surface of the auxiliary mask which is in contact with the main mask and a larger hole opening in the opposite surface of the auxiliary mask. The smaller and larger holes of each electron beam passage aperture of the auxiliary mask have their respective central axes extending coaxially with each other and substantially at right angles to the surface of the auxiliary mask in the direction of the major axis.

Color cathode ray tube

A shadow mask is formed by lapping a main mask and an auxiliary mask on each other. The auxiliary mask includes a porous portion having electron beam passage holes, nonporous portions situated individually at the opposite ends of the porous portion, a pair of skirt portions extending individually from the nonporous portions and lapped on the skirt portion of the main mask, and second beads formed individually on the skirt portions and overlapping first beads of the main mask. The height or width of the first beads and the second beads in a superposed portion in which the main mask and the auxiliary mask are lapped on each other is differentiated from that of the beads in non-superposed portions outside the superposed portion.

Color cathode ray tube and method of manufacturing the same

A shadow mask includes a substantially rectangular effective region formed having a number of electron beam passage apertures and opposed to a phosphor screen and a substantially rectangular skirt portion provided around the effective region and extending in the direction of a tube axis. The skirt portion has a pair of long sides extending substantially parallel to a major axis and a pair of short sides extending substantially parallel to a minor axis, the long and short sides being welded to the inner surface of a substantially rectangular mask frame. A distance a from an extending end of the skirt portion on each long side to the weld spot is longer than a distance b from an extending end of the skirt portion on each short side to the weld spot.

Growing community of inventors

Fukaya, Japan

Takeshi Nakayama