439results about "Discharge tube electron guns" patented technology

The invention relates to an apparatus for generating a plurality of charged particle beamlets, comprising a charged particle source for generating a diverging charged particle beam, a converging means for refracting said diverging charged particle beam and a lens array comprising a plurality of lenses, wherein said lens array is located between said charged particle source and said converging means.

In this way, it is possible to reduce aberrations of the converging means.

Field emission display and method for fabricating the same, the field emission display including a cathode array having a cathode electrode formed on a substrate, insulating layers and carbon nanotube films for use as emitter electrodes formed alternately on the cathode electrode, and a gate electrode formed on the insulating layer, thereby permitting fabrication of a large sized cathode plate at a low cost because the film is formed by screen printing and exposure, which can reduce the cumbersome steps in fabrication of the related art Spindt emitter tip, and both a low voltage and a high voltage FEDs because the carbon nanotube film used as the emitter has a low work function, with an easy and stable electron emission capability.

The present invention discloses a new field emitter cell and array consisting of groups of nanofilaments forming emitter cathodes. Control gates are microprocessed to be integrally formed with groups of nanofilament emitter cathodes on a substrate. Groups of nanofilaments are grown directly on the substrate material. As a result, the control gates and groups of nanofilaments are self-aligned with one another.

An electron source include a first cathode electrode disposed over a substrate and terminated to provide electrons; an emitter layer disposed over the cathode electrode and formed from one or plurality vertically aligned and mono-dispersed nano-structures that are truncated to the same length, embedded in a solid matrix and protruding above the surface for emitting electrons; an insulator disposed over the emitter layer and having one or plurality of apertures, each is self-aligned with and exposes one nano-structure in the emitter layer; and a second gate electrode disposed over the insulator, having one or plurality of apertures self-aligned with the apertures in the insulator and terminated to extract electrons from the exposed nano-structures through the apertures. The gate aperture is substantially less than one micrometer and the gated nano-structures can have a density on the order of 10⁸/cm². Such an electron source can be modulated with an extra low voltage, emits electrons with high current density and high uniformity, and operates with high energy-efficiency and long lifetime.

An x-ray tube comprising an electron gun assembly having an electron gun container housing an electron generator for generating electrons in a first direction along a first axis. The beam of electrons impinges upon an anode which emits x-rays in response to the beam of electrons. The gun container is characterized by having a discharge end comprising a solid spherical shape.

A self-aligned gated field emission device and an associated method of fabrication are described. The device includes a substrate and a porous layer disposed adjacent to the surface of the substrate, wherein the porous layer defines a plurality of substantially cylindrical channels, each of the plurality of substantially cylindrical channels aligned substantially parallel to one another and substantially perpendicular to the surface of the substrate. The device also includes a plurality of substantially rod-shaped structures disposed within at least a portion of the plurality of substantially cylindrical channels defined by the porous layer and adjacent to the surface of the substrate, wherein a portion of each of the plurality of substantially rod-shaped structures protrudes above the surface of the porous layer. The device further includes a gate dielectric layer disposed on the surface of the porous layer, wherein the gate dielectric layer is disposed between the plurality of substantially rod-shaped structures. The device still further includes a conductive layer selectively disposed on the surface of the gate dielectric layer, wherein the conductive layer is selectively disposed between the plurality of substantially rod-shaped structures.

A field emission array adopting carbon nanotubes as an electron emitter source, wherein the array includes a rear substrate assembly including cathodes formed as stripes over a rear substrate and carbon nanotubes; a front substrate assembly including anodes formed as stripes over a front substrate with phosphors being deposited on the anodes, a plurality of openings separated by a distance corresponding to the distance between the anodes in a nonconductive plate, and gates formed as stripes perpendicular to the stripes of anodes on the nonconductive plate with a plurality of emitter openings corresponding to the plurality of openings. The nonconductive plate is supported and separated from the front substrate using spacers. The rear substrate assembly is combined with the front substrate assembly such that the carbon nanotubes on the cathodes project through the emitter openings.

An electron beam apparatus, in which an electron beam emitted from an electron gun having a cathode and an anode is focused and irradiated onto a sample, and secondary electrons emanated from the sample are directed into a detector, the apparatus further comprising means for optimizing irradiation of the electron beam emitted from the electron gun onto the sample, the optimizing means may be two-stage deflectors disposed in proximity to the electron gun which deflects and directs the electron beam emitted in a specific direction so as to be in alignment with the optical axis direction of the electron beam apparatus, the electron beam emitted in the specific direction being at a certain angle with respect to the optical axis due to the fact that, among the crystal orientations of said cathode, a specific crystal orientation allowing a higher level of electron beam emission out of alignment with the optical axis direction.

An electron emission device is provided comprising first and second substrates facing each other and separated from each other by a predetermined distance. An electron emission unit is disposed on the first substrate, and an image display unit is disposed on the second substrate. A focusing electrode comprising a plurality of beam-guide holes is disposed between the first and second substrates. The portion of the focusing electrode located near a beam-guide hole comprises a thin layer. The remainder of the focusing electrode comprises a thick layer having a thickness larger than the thickness of the thin layer.

Provided is a field emission display (FED) with a carbon nanotube emitter and a method of manufacturing the same. A gate stack that surrounds the CNT emitter has a mask layer that covers an emitter electrode adjacent to the CNT emitter, and a gate insulating film, a gate electrode, a focus gate insulating film (SiO_x, X<2), and a focus gate electrode formed on the mask layer. The focus gate insulating film has a thickness 2 μm or more, and preferably 3˜15 μm and is preferably made using PECVD. A flow rate of silane and nitric acid for forming the focus gate insulating film and/or the gate insulating film are maintained at 50˜700 sccm and 700˜4,500 sccm, respectively. By doing so and by making the oxide thick, the oxide is less apt to crack and thus less apt to generate a leakage current.

An electron beam device wherein a low temperature gaseous plasma is generated in a chamber divided by two parallel wire grids. A semiconductor wafer serves as a cathode drawing ions from the plasma to impinge on the wafer, generating secondary electrons that are accelerated toward an anode on the opposite side of the grids where a target resides. In order to have a beam with uniform cross-sectional flux characteristics, the semiconductor wafer is doped with a graded dopant concentration that promotes a uniform beam.

A field emission device comprises a glass substrate, an emitter electrode formed on the glass substrate, a carbon nanotube (CNT) emitter formed on the emitter electrode, and a gate stack formed around the CNT emitter for extracting electron beams from the CNT emitter and focusing the extracted electron beams onto a given position. The gate stack includes a mask layer covering the emitter electrode and provided around the CNT emitter, a gate insulating layer formed on the mask layer to a predetermined height, a mirror electrode formed on an inclined plane of the gate insulating layer, a gate electrode formed on the gate insulating layer and spaced apart from the mirror electrode, and a focus gate insulating layer and a focus gate electrode sequentially formed on the gate electrode. The field emission device is manufactured and employed in a display device in accordance with the present invention.

A cold cathode field emission display comprising at least (A) a display panel having a cathode panel CP provided with a plurality of electron-emitting regions EA and an anode panel AP provided with a phosphor layer 31 and an anode electrode 34, said cathode panel and said anode panel being bonded to each other in their circumferential regions, (B) a focus-electrode control circuit 41, (C) a resistance element R, and (D) a capacitor C, in which the focus electrode 15 formed in the electron-emitting region EA is connected to a first voltage-output portion 41A of the focus-electrode control circuit 41 through the resistance element R, and the focus electrode 15 is further connected to a second voltage-output portion 41B of the focus-electrode control circuit 41 through the capacitor C.

A field emission device including a cathode having an electric field emitter for emitting electrons, a field emission inducing gate for inducing electron emission, and an anode for receiving the emitted electrons. A field emission suppressing gate is interposed between the cathode and the field emission inducing gate for suppressing electron emission, so that problems such as gate leakage current, electron emission due to anode voltage, and electron beam spreading of the conventional field emission device are significantly overcome.

A light-emitting device contains getter material (58) typically distributed in a relatively uniform manner across the device's active light-emitting portion. An electron-emitting device similarly contains getter material (112, 110/112, 128, 132, and 142) typically distributed relatively uniformly across the active electron-emitting portion of the device.

Cathodoluminescent field emission display devices features a radioactive cathode emitter which is used to produce primary electron emissions to drive the FED device. Radioactive emitters eliminate the need for complex emitter structures, such as conventional Spindt cathodes. In addition, the use of a radioactive emitter allows for an "all-firm" FED, and thus represents an improvement over existing devices by reducing emitter to phosphor spacing, as well as eliminating the use of internal vacuums.

An electron gun having an electron source emitting electrons includes: an acceleration electrode which accelerates the electrons; an extraction electrode which has a spherical concave surface having the center on an optical axis and facing the electron emission surface, and which extracts an electron from the electron emission surface; and a suppressor electrode which suppresses electron emission from a side surface of the electron source. In the electron gun, an electric field is applied to the electron emission surface while the electron source is kept at a low temperature in such an extent that sublimation of a material of the electron source would not be caused, to cause the electron source to emit a thermal field emission electron.

A method for fabricating a self-aligned gated carbon nanotube field emitter structure includes providing a substrate, depositing a dielectric material on the surface of the substrate and depositing a conductor layer on the surface of the dielectric material. The method also includes selectively etching the conductor layer to form an opening and selectively etching the dielectric material to form a micro-cavity. The method further includes depositing a base layer structure in the micro-cavity adjacent to the surface of the substrate, wherein the base layer structure has a substantially conical shape, and depositing a catalyst on a portion of the surface of the base layer structure, wherein the catalyst is suitable for growing at least one carbon nanotube. The method still further includes applying an electrical potential to the substrate and the conductor layer, wherein the electrical potential generates a plurality of electrical field lines that are deflected around the surface of the base layer structure, and wherein the plurality of electrical field lines have a strength that is greatest in a direction substantially perpendicular to the surface of the substrate. Finally, the method includes growing at least one carbon nanotube from the catalyst in the presence of the plurality of electrical field lines, wherein the at least one carbon nanotube is grown in a direction substantially perpendicular to the surface of the substrate.

In a channel spark source triggered by gas discharge for generating a stable focused electron beam, a gas supply for a hollow cathode thereof is provided which generates in the hollow cathode a pressure differential so that the multiplication of charge carriers in a trigger plasma of a trigger plasma source connected to the hollow cathode provides for a reliable gas discharge and the formation of a stable electron beam which exits the arrangement and which does not damage the internal passages of the arrangement.

A triode structure of a field emission display and fabrication method thereof. A plurality of cathode layers arranged in a matrix is formed overlying a dielectric layer. A plurality of emitting layers arranged in a matrix is formed overlying the cathode layers, respectively. A plurality of lengthwise-extending gate lines is formed on the dielectric layer, in which each of the gate layers is disposed between two adjacent columns of the cathode layers.