Abstract: The present invention realizes a cathode ray tube which holds the stable electron emission characteristics when the cathode ray tube is operated in a high current density state for a long time. An electron emissive material layer which constitutes a cathode is formed by dispersing a scandium compound having an average particle size of equal to or less than 1.2 &mgr;m to an oxide layer formed of alkaline earth metal (barium, strontium, calcium) oxide, wherein an atomic weight ratio of scandium with respect to strontium is set to a value within a range of 0.003 to 0.3. A base metal includes a reducing metal containing nickel as a main component and a plate thickness of a surface of a top portion of the base metal which comes into contact with the electron emissive layer is set to a value equal to or more than 0.17 mm.

Abstract: A cathode ray tube has a phosphor screen and an electron gun including an indirectly heated cathode structure and a plurality of electrodes disposed downstream of the indirectly heated cathode structure for projecting an electron beam toward the phosphor screen, and a deflection yoke for scanning the electron beam on the phosphor screen.

Abstract: A cathode ray tube has an electron gun including an indirectly heated cathode structure having a heater therein. The heater has a major heating portion formed of a spirally wound heating wire and two leg portions connected to opposite ends of the major heating portion. The two leg portions are welded to electrical conductors for applying voltages thereto at portions in the vicinity of open ends of the two leg portions, respectively, and the heater is covered with an insulating film except for the portions for welding. The two leg portions includes at least five layers of winding formed by spirally winding heating wires identical with the heating wire of the major heating portion, and the numbers of turns per unit length in each of the at least five layers of winding are smaller than a number of turns per unit length of the heating wire of the major heating portion.

Abstract: A cathode ray tube is provided with a phosphor screen and an electron gun including a cathode having an electron-emissive material layer formed on a surface of a cathode base metal. The electron-emissive material layer includes a first layer made of an alkaline earth metal oxide on the surface of the cathode base metal, a second layer on a surface of the first layer which is an alkaline earth metal oxide layer containing at least one rare earth metal oxide in a range of 0.

Abstract: A cathode ray tube includes a phosphor screen and an electron gun. The electron gun includes an indirectly heated cathode structure and plural grid electrodes in axially spaced relationship. The cathode structure includes a base metal having an electron emissive material coating and a heater for heating the base metal. The heater includes a major heating portion having a spirally wound heating wire and leg portions disposed at ends of the major heating portion, and each of the leg portions includes a first multilayer winding portion having heating wires wound spirally in plural layers and a second multilayer winding portion disposed intermediate between the major heating portion and the first multilayer winding portion and having heating wires wound in plural layers.

Abstract: A cathode ray tube has an electron gun including an indirectly heated cathode structure having a heater therein. The heater has a major heating portion formed of a spirally wound heating wire and two leg portions connected to opposite ends of the major heating portion. The two leg portions are welded to electrical conductors for applying voltages thereto at portions in the vicinity of open ends of the two leg portions, respectively, and the heater is covered with an insulating film except for the portions for welding. The two leg portions includes at least five layers of winding formed by spirally winding heating wires identical with the heating wire of the major heating portion, and the numbers of turns per unit length in each of the at least five layers of winding are smaller than a number of turns per unit length of the heating wire of the major heating portion.

Abstract: A cathode ray tube include phosphor screen and an electron gun. The electron gun includes an indirectly heated cathode structure and plural grid electrodes arranged in axially spaced relationship. The cathode structure includes a base metal having an electron emissive material coating and a heater for heating the base metal. The heater includes a major heating portion having a spirally wound heating wire and a pair of leg portions connected to opposite ends of the major heating portion. The major heating portion and an inner portion of each of the leg portions on a major-heating-portion side thereof are covered with an insulating coating, and the heater is welded to electrical conductors for applying a voltage thereto at an outer portion of each of the leg portions, the outer portion not being covered with the insulating coating.

Abstract: A cathode ray tube has a phosphor screen and an electron gun including an indirectly heated cathode structure and a plurality of electrodes disposed downstream of the indirectly heated cathode structure for projecting an electron beam toward the phosphor screen, and a deflection yoke for scanning the electron beam on the phosphor screen.

Abstract: A cathode ray tube includes a phosphor screen and an electron gun. The electron gun includes an indirectly heated cathode structure and plural grid electrodes arranged in axially spaced relationship. The cathode structure includes a base metal having an electron emissive material coating and a heater for heating the base metal. The heater includes a major heating portion having a spirally wound heating wire and a pair of leg portions connected to opposite ends of the major heating portion. The major heating portion and an inner portion of each of the leg portions on a major-heating-portion side thereof are covered with an insulating coating, and the heater is welded to electrical conductors for applying a voltage thereto at an outer portion of each of the leg portions, the outer portion not being covered with the insulating coating.

Abstract: A cathode ray tube includes a phosphor screen and an electron gun. The electron gun includes an indirectly heated cathode structure and plural grid electrodes in axially spaced relationship. The cathode structure includes a cap-shaped base metal having an electron emissive material coating and a heater for heating the cap-shaped base metal. The heater includes a major heating portion having a spirally wound heating wire and leg portions, and each of the leg portions includes a first multilayer winding portion having heating wires wound spirally in plural layers and a second multilayer winding portion intermediate between the major heating portion and the first multilayer winding portion and having heating wires wound in plural layers.