Cathode-ray tube
AssigneeTokyo Shibaura Denki Kabushiki Kaisha
InventorKiyoshi Tokita
Life of this patent
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Abstract
A flatter faceplate cathode-ray tube. If maximum effective dimensions perpendicular to a tube axis, which correspond to the distances between the center of the inner surface and a peripheral portion along the lateral axis, between the center of the inner surface and a peripheral portion along the longitudinal axis, and between the center of the inner surface and a corner along the diagonal axis, are represented by Ss, Sl and Sd, respectively. The ratio between these three values is selected to be 3:4:5. The distances between the center of the inner surface and those individual points along the tube axis defined as .DELTA.D, .DELTA.L and .DELTA.S, respectively, are limited as follows to obtain the dimensions of a flatter source CRT: 0.06.ltoreq..DELTA.D.ltoreq.0.12, 0.05.ltoreq..DELTA.L.ltoreq.0.10, 0.04.ltoreq..DELTA.S.ltoreq.0.80.
Claims11
A cathode-ray tube (CRT) comprising:
- a substantially funnel-shaped glass portion having a tube axis;
- and
- a substantially rectangular faceplate, joined with said funnel-shaped portion to form the envelope of said CRT, said faceplate having curved inner and outer surfaces, a pair of long sides, a pair of short sides and four curved corners at which corresponding long and short sides meet, the dimensions of the faceplate being chosen so as to satisfy the relation ##STR1## wherein Rd is the radius of curvature of the inner surface in a plane including said tube axis and a diagonal connecting a pair of diagonally opposite corners among said four corners, and
- Sd is one half of the diagonal dimension distance between a pair of diagonally opposite corners.
Dependencies are inferred from the claim text.