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. The major heating portion and at least a portion of the second multilayer winding portion are covered with an insulating coating, the heater is welded to electrical conductors for applying a voltage thereto at the first multilayer winding portion, and a number of turns per unit length in the first multilayer winding portion is smaller than that in the second multilayer winding portion.
Abstract:
A filament for an X-ray tube has a varied wire diameter but has a constant coil outside diameter to obtain a good uniformity of the longitudinal temperature distribution of the filament. The filament has a wire diameter d which is gradually reduced from the longitudinal central region to the longitudinal ends while the coil outside diameter D is fixed along the longitudinal direction. The wire is polished at only the inside of the coil to reduce the wire diameter. In order to make the longitudinal temperature distribution uniform as far as possible, the difference Δd between the wire diameter dmax at the longitudinal central region and the wire diameter dmin at the longitudinal ends should satisfy the following limitation: Δd/dmax=0.041 to 0.145.
Abstract translation:用于X射线管的灯丝具有变化的线径,但具有恒定的线圈外径以获得长丝的纵向温度分布的良好均匀性。 灯丝具有从纵向中心区域到纵向端部逐渐减小的线径d,而线圈外径D沿着纵向方向固定。 线材只在线圈内部抛光,以减少线径。 为了使纵向温度分布尽可能均匀,在纵向中心区域的线径d max max之间的差值Deltad与线径d < 纵向端应满足以下限制:<?in-line-formula description =“In-line formula”end =“lead”?> Deltad / d sub> = 0.041 to 0.145。 <?in-line-formula description =“In-line Formulas”end =“tail”?>
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. The outer portion of each of the leg portions includes a first multilayer winding portion having heating wires wound spirally in plural layers, and the inner portion of each of the leg portions includes a second multilayer winding portion having heating wires wound spirally in plural layers. The number of turns per unit length in the first multilayer winding portion is smaller than that in the second multilayer winding portion.
Abstract:
Direct and indirect electron bombardment provide a sufficiently high degree of temperature uniformity across the emitting surface of a large-area electron source for an electron beam projection system such that a broad beam having illumination uniformity within 1% can be achieved. A diode gun is used to obtain extraction field uniformity and maintain uniformity of illumination. Power requirements and power dissipation in beam periphery truncating apertures is reduced by roughening the surface of a monocrystalline cathode or depositing materials having a higher work function thereon.
Abstract:
A planar filament comprising two bonding pads and a non-linear filament connected between the two bonding pads. The filament may be wider in the center to increase filament life. The planar filament may be mounted on a substrate for easier handling and placement. Voltage can be used to create an electrical current through the filament, and can result in the emission of electrons from the filament. The planar filament can be utilized in an x-ray tube.
Abstract:
A filament assembly for use in an x-ray emitting device or other filament-containing device is disclosed. In one embodiment, an x-ray tube is disclosed, including a vacuum enclosure that houses both an anode having a target surface, and a cathode positioned with respect to the anode. The cathode includes a filament assembly for emitting a beam of electrons during tube operation. The filament assembly comprises a heat sink and a plurality of filament segments. The filament segments are configured for simultaneous emission of an electron beam for impingement on the target surface of the anode, and are electrically connected in series. Each filament segment includes first and second end portions that are thermally connected to the heat sink, and a central portion that can be configured with a modified work function for preferential electron emission.
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. The indirectly heated cathode structure includes: a base metal having an electron emissive material coating on an outer top surface thereof; a metal sleeve having the base metal attached to an end of the metal sleeve; a heater housed partly within the metal sleeve which includes a major heating portion formed of a spirally wound heating wire and leg portions formed of heating wires wound spirally in a plurality of layers; an insulating film covering the major heating portion and a portion of each of the leg portions continuous with the major heating portion; and a black coating film covering a portion of the insulating film extending from the major heating portion toward each of the leg portions, the whole of the black coating film being housed within the metal sleeve.
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. The indirectly heated cathode structure includes: a base metal having an electron emissive material coating on an outer top surface thereof; a metal sleeve having the base metal attached to an end of the metal sleeve; a heater housed partly within the metal sleeve which includes a major heating portion formed of a spirally wound heating wire and leg portions formed of heating wires wound spirally in a plurality of layers; an insulating film covering the major heating portion and a portion of each of the leg portions continuous with the major heating portion; and a black coating film covering a portion of the insulating film extending from the major heating portion toward each of the leg portions, the whole of the black coating film being housed within the metal sleeve.
Abstract:
A filament assembly for use in an x-ray emitting device or other filament-containing device is disclosed. In one embodiment, an x-ray tube is disclosed, including a vacuum enclosure that houses both an anode having a target surface, and a cathode positioned with respect to the anode. The cathode includes a filament assembly for emitting a beam of electrons during tube operation. The filament assembly comprises a heat sink and a plurality of filament segments. The filament segments are configured for simultaneous emission of an electron beam for impingement on the target surface of the anode, and are electrically connected in series. Each filament segment includes first and second end portions that are thermally connected to the heat sink, and a central portion that can be configured with a modified work function for preferential electron emission.
Abstract:
A filament for an X-ray tube has a varied wire diameter but has a constant coil outside diameter to obtain a good uniformity of the longitudinal temperature distribution of the filament. The filament has a wire diameter d which is gradually reduced from the longitudinal central region to the longitudinal ends while the coil outside diameter D is fixed along the longitudinal direction. The wire is polished at only the inside of the coil to reduce the wire diameter. In order to make the longitudinal temperature distribution uniform as far as possible, the difference Δd between the wire diameter dmax at the longitudinal central region and the wire diameter dmin at the longitudinal ends should satisfy the following limitation: Δd/dmax=0.041 to 0.145.
Abstract translation:用于X射线管的灯丝具有变化的线径,但具有恒定的线圈外径以获得长丝的纵向温度分布的良好均匀性。 灯丝具有从纵向中心区域到纵向端部逐渐减小的线径d,而线圈外径D沿着纵向方向固定。 线材只在线圈内部抛光,以减少线径。 为了使纵向温度分布尽可能均匀,在纵向中心区域的线径d max max之间的差值Deltad与线径d < 纵向端应满足以下限制:<?in-line-formula description =“In-line Formulas”end =“lead”?> Deltad / d sub> = 0.041 to 0.145 < line-formula description =“In-line Formulas”end =“tail”?>