Abstract: A heat generating portion of a heater which is incorporated in an indirectly heated cathode structure of an electron gun for a cathode ray tube is formed by joining a first winding portion and a second winding portion which differ in the number of coil winding layers and by twisting and winding a joined body in a double helical structure. The present invention allows a cathode temperature to have a high temperature and hence, it is possible to enhance the electron irradiation characteristics even when a degree of in-tube vacuum is lowered.

Abstract: The indirectly heated cathode structure includes a base metal having a thermal electron emitting material layer, a cylindrical sleeve holding the base metal at one end portion thereof and housing a heating heater in the inside thereof, an support having a large-diameter portion and g a small-diameter portion, and a cathode disc having a large-diameter portion at the leg-portion-side of the heating heater and having a small-diameter portion at the heater-main-portion side of the heating heater, wherein an outer surface of another end portion of the sleeve and an inner surface of the small-diameter portion of the support are fixed to each other, and an outer surface of the large-diameter portion of the support and an inner surface of the small-diameter portion of the cathode disc are fixed to each other.

Abstract: A heat generating portion of a heater which is incorporated in an indirectly heated cathode structure of an electron gun for a cathode ray tube is formed by joining a first winding portion and a second winding portion which differ in the number of coil winding layers and by twisting and winding a joined body in a double helical structure. The present invention allows a cathode temperature to have a high temperature and hence, it is possible to enhance the electron irradiation characteristics even when a degree of in-tube vacuum is lowered.

Abstract: The present invention provides a display device which can suppress a gas emission in the inside of a vacuum envelope. A display device of the present invention includes a vacuum envelope which has a panel which forms a phosphor screen on an inner surface thereof, an electron source device, and a connecting portion which connects the panel and the electron source device. The phosphor screen includes phosphor pixels, a black matrix which surrounds the phosphor pixels and a metal thin film which covers the black matrix film and the phosphor pixels, and the connecting portion includes a conductive film on an inner surface thereof. At least one of the phosphor pixels, the black matrix and the conductive film contains boron so as to suppress the gas emission in the inside of the vacuum envelope.

Abstract: The indirectly heated cathode structure includes a base metal having a thermal electron emitting material layer, a cylindrical sleeve holding the base metal at one end portion thereof and housing a heating heater in the inside thereof, an support having a large-diameter portion and g a small-diameter portion, and a cathode disc having a large-diameter portion at the leg-portion-side of the heating heater and having a small-diameter portion at the heater-main-portion side of the heating heater, wherein an outer surface of another end portion of the sleeve and an inner surface of the small-diameter portion of the support are fixed to each other, and an outer surface of the large-diameter portion of the support and an inner surface of the small-diameter portion of the cathode disc are fixed to each other.

Abstract: A cathode ray tube has a cathode and plural grid electrodes fixed by insulating support rods. The cathode is supported within an eyelet disposed within and bonded to a cup-shaped support by a crystallized glass. The cup-shaped support is fixed by the insulating support rods. The crystallized glass is formed by firing a glass composition composed chiefly of zinc oxide, boron oxide, silicon oxide, and magnesium oxide. The crystallized glass exhibits a ratio in intensity of a diffraction peak A to a diffraction peak B in a range from 0.25 to 0.80 in an X-ray diffraction analysis using X-rays of 0.154 nm in wavelength, where the diffraction peak A is in the vicinity of 2&thgr;=25.5°, the diffraction peak B is in the vicinity of 2&thgr;=26.5°, 2&thgr;is an angle which a diffracted X-ray beam from a specimen surface makes with an incident X-ray beam.

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 color cathode ray tube has an electron gun in its neck portion. Its focus electrodes and anode are fixed by two insulating support rods. A voltage-dividing resistor is disposed in the vicinity of one of the insulating support rods for producing an intermediate voltage applied to a first one of the focus electrodes adjacent to the anode by dividing an anode voltage. The voltage-dividing resistor includes an insulating film, a resistance pattern, an insulating substrate, and a second film containing an oxide of transition metal, in the order named from the insulating film toward the inner wall of the neck portion. A metal conductor surrounding the voltage-dividing resistor and the one of the insulating support rods is fixed to a second one of the focus electrodes which is disposed upstream of the first one of the focus electrodes in a path of the electron beams.

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 color cathode ray tube having at least an evacuated envelope comprising a panel portion having a phosphor screen formed on an inner surface thereof, a neck portion, and a funnel portion connecting the panel portion and the neck portion. A shadow mask is spaced from the phosphor screen and suspended within the panel portion, an in-line type electron gun is housed in the neck portion and include three cathodes, a first grid electrode spaced from the three cathodes and a plurality of electrodes spaced between the first grid electrode and the shadow mask for generating and directing three electron beams toward the phosphor screen. A deflection yoke is mounted in the vicinity of the junction between the neck portion and the funnel portion.

Abstract: A color cathode ray tube has an electron gun in its neck portion. The electron gun includes plural focus electrodes and an anode fixed in axially spaced relationship by two support rods. The electron gun also includes a voltage-dividing resistor for producing a voltage applied to a first focus electrode by dividing a voltage applied to the anode, and a metal conductor surrounding the resistor and fixed to a second focus electrode upstream of the first focus electrode. The resistor is disposed in the vicinity of one of the support rods, is formed of an insulating film, a resistance pattern, and a substrate disposed in the order named from the insulating film toward the neck portion. The resistance pattern is such that a potential difference between the metal conductor and a portion of the resistance pattern facing the metal conductor is equal to or smaller than 4 kV.

Abstract: A cathode ray tube has an electron beam generating section including an indirectly heated cathode structure and first and second electrodes arranged in the order named. The cathode structure is composed of a cathode sleeve for housing a heater therein, a cathode base metal disposed at an end of the cathode sleeve facing toward the first electrode, and an electron emissive oxide layer disposed on the cathode base metal. The electron emissive oxide layer is formed with a depression on a surface thereof facing the electron beam transmissive aperture in the first electrode. A maximum diameter of the depression is smaller than a maximum diameter of the electron beam transmissive aperture in the first electrode, and a maximum depth of the depression is smaller than the maximum diameter of the depression.

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 a cathode and plural grid electrodes fixed by insulating support rods. The cathode is supported within an eyelet disposed within and bonded to a cup-shaped support by a crystallized glass. The cup-shaped support is fixed by the insulating support rods. The crystallized glass is formed by firing a glass composition composed chiefly of zinc oxide, boron oxide, silicon oxide, and magnesium oxide. The crystallized glass exhibits a ratio in intensity of a diffraction peak A to a diffraction peak B in a range from 0.25 to 0.80 in an X-ray diffraction analysis using X-rays of 0.154 nm in wavelength, where the diffraction peak A is in the vicinity of 2&thgr;=25.5°, the diffraction peak B is in the vicinity of 2&thgr;=26.5°, 2&thgr;is an angle which a diffracted X-ray beam from a specimen surface makes with an incident X-ray beam.

Abstract: A color cathode ray tube has an electron gun in its neck portion. Its focus electrodes and anode are fixed by two insulating support rods. A voltage-dividing resistor is disposed in the vicinity of one of the insulating support rods for producing an intermediate voltage applied to a first one of the focus electrodes adjacent to the anode by dividing an anode voltage. The voltage-dividing resistor includes an insulating film, a resistance pattern, an insulating substrate, and a second film containing an oxide of transition metal, in the order named from the insulating film toward the inner wall of the neck portion. A metal conductor surrounding the voltage-dividing resistor and the one of the insulating support rods is fixed to a second one of the focus electrodes which is disposed upstream of the first one of the focus electrodes in a path of the electron beams.

Abstract: A color cathode ray tube has an electron gun in its neck portion. The electron gun includes plural focus electrodes and an anode fixed in axially spaced relationship by two support rods. The electron gun also includes a voltage-dividing resistor for producing a voltage applied to a first focus electrode by dividing a voltage applied to the anode, and a metal conductor surrounding the resistor and fixed to a second focus electrode upstream of the first focus electrode. The resistor is disposed in the vicinity of one of the support rods, is formed of an insulating film, a resistance pattern, and a substrate disposed in the order named from the insulating film toward the neck portion. The resistance pattern is such that a potential difference between the metal conductor and a portion of the resistance pattern facing the metal conductor is equal to or smaller than 4 kV.

Abstract: An electron gun for a cathode-ray tube for image display including a cathode having a sleeve made of a refractory metal, a support provided at one end of the sleeve and made of a refractory metal containing a reducing element, a heater arranged in a space defined by the sleeve and the support, and an electron emissive material layer for emission of electrons. The electron emissive material layer is mainly made of an oxide of an alkaline earth metal and contains an oxide of a rare earth metal. The electron emissive material layer is prepared by forming a first layer on the support by spraying, and forming a second layer on the first layer by spraying. A dispersion amount of an oxide of a rare earth metal in the second layer is larger than that in the first layer and a first grid electrode is provided adjacent the cathode. The grid electrode has an electron beam passage hole for the electrons from the electron emissive material layer, and the electron beam passage hole has a diameter which is less than 0.4 mm.

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.