CATHODE-RAY TUBE Russian patent published in 1994 - IPC

FIELD: cathode-ray tubes. SUBSTANCE: cathode-ray tube has envelope with rectangular bottom with outer surface curved along its minor and major axes and cathode-luminescent screen on its inner surface. In central part of bottom of envelope curvature along minor axis is at least 10 per cent bigger than curvature along major axis. Points over outer surface close to ends of major axis X-X on edge of cathode-luminescent screen lie in first plane PI perpendicular to central longitudinal axis Z-Z of tube. Points over outer surface close to ends of minor axis Y-Y on edge of cathode-luminescent screen lie in second plane 12 parallel to first plane. Points on outer surface close to ends of diagonal of rectangular bottom of envelope on edge of cathode-luminescent screen lie in third plane P3 parallel to first plane. In this case first, second and third planes are carried away from fourth plane P parallel to them and tangent to central part of bottom of envelope in the following order: second, first and third planes. With this relationship of distances between planes P2-P and P3-P is bigger than relationship of the square of size of minor axis of cathode-luminescent screen to the square of size of its diagonal, but less than one. Relationship between planes P1-P and P3-P is bigger than relationship of the square of size of major axis of cathode-luminescent screen to the square of size of its diagonal, but less than one. EFFECT: improved stability of operational characteristics. 12 dwg