Abstract:
A high power short arc gas discharge lamp includes an electrically insulating reflector body having a concave internal reflector surface with a focal point; an anode and a cathode spaced from the anode to create an arc gap between them proximate the focal point; the reflector body having a conical external surface for reducing the thickness of the reflector body between the concave internal surface and the conical external surface; and an external electrically isolated heat sink mounted on the external conical surface proximate the arc gap.
Abstract:
In an electron beam apparatus including an enclosure in which an electron-emitting device having an electron-emitting region between opposite electrodes is disposed, the electron-emitting device exhibits such a characteristic as that an emission current is uniquely determined with respect to a device voltage. The interior of the enclosure is maintained under an atmosphere effective to prevent structural changes of the electron-emitting device. An image-forming apparatus includes an enclosure in which an electron source and an image-forming member are disposed, the electron source having the above electron-emitting device. An emission current is stable with a very small change in the amount of electrons emitted, a sharp image is produced with high contrast, and gradation control is easily carried out.
Abstract:
Electrophoretic deposition provides an efficient process for manufacturing a field emission cathode. Particles of an electron emitting material mixed with particles of an insulating material are deposited by electrophoretic deposition on a conducting layer overlying an insulating layer to produce the cathode. By controlling the composition of the deposition bath and by mixing insulating particles with emitting particles, an electrophoretic deposition process can be used to efficiently produce field emission cathodes that provide spatially and temporally stable field emission. The deposition bath for the field emission cathode includes an alcohol, a charging salt, water, and a dispersant. The field emission cathodes can be used as an electron source in a field emission display device.
Abstract:
A method of fabricating a field emission array that employs a single mask to define the emitter tips thereof and their corresponding resistors. A layer of conductive material is disposed over a substrate of the field emission array. A plurality of substantially mutually parallel conductive lines is defined from the layer of conductive material. At least one layer of semiconductive material or conductive material is disposed over the conductive lines and over the regions of the substrate exposed between adjacent conductive lines. A mask material is disposed over the layer of semiconductive material or conductive material, substantially above each of the conductive lines. Portions of the layer of semiconductive material or conductive material exposed through the mask material may be removed to expose substantially longitudinal center portions of the conductive lines. Other portions of the layer of semiconductive material or conductive material may remain over peripheral lateral edges of the conductive lines. The mask material may be removed and the layer of semiconductive material or conductive material planarized. A mask is disposed over the field emission array and portions of the layer of semiconductive material or conductive material removed therethrough to define emitter tips and their corresponding resistors. The substantially longitudinal center portion of each of the conductive lines may be removed to electrically isolate adjacent columns of pixels of the field emission array from each other. Field emission arrays fabricated by the method of the present invention are also within the scope of the present invention.
Abstract:
A field emission device having bundles of aligned parallel carbon nanotubes on a substrate. The carbon nanotubes are oriented perpendicular to the substrate. The carbon nanotube bundles may be up to 300 microns tall, for example. The bundles of carbon nanotubes extend only from regions of the substrate patterned with a catalyst material. Preferably, the catalyst material is iron oxide. The substrate is preferably porous silicon, as this produces the highest quality, most well-aligned nanotubes. Smooth, nonporous silicon or quartz can also be used as the substrate. The method of the invention starts with forming a porous layer on a silicon substrate by electrochemical etching. Then, a thin layer of iron is deposited on the porous layer in patterned regions. The iron is then oxidized into iron oxide, and then the substrate is exposed to ethylene gas at elevated temperature. The iron oxide catalyzes the formation of bundles of aligned parallel carbon nanotubes which grow perpendicular to the substrate surface. The height of the nanotube bundles above the substrate is determined by the duration of the catalysis step. The nanotube bundles only grow from the patterned regions.
Abstract:
A mount assembly for supporting the arc tube of a lamp within an outer envelope has first and second axially aligned banding straps. Each of the straps has a closed crimp section and an open crimp section. The straps are positioned so that an open crimp section of one strap overlies a closed crimp section of the other strap, thereby equalizing tensions when the crimps are closed. The mount assembly includes also a mount frame comprised of two elongated rods which are affixed to the banding straps. The straps are mounted upon the glass stem of the lamp.
Abstract:
An improved arc lamp with a ceramic body, an anode supported by a base, and a cathode suspended by a strut system opposite to the anode, and having an inside volume filled with xenon gas. The improvements include a groove in the ceramic body such that an angled area is presented to a head area of the anode that reduces heat coupling by radiation. A neck in the anode provides for a thermal choking such that a head portion of the anode will elevate in temperature during operation. A cavity is relieved in the base and all around the anode to provide a fixed means for managing the temperature of a head portion of the anode during operation. A stem portion of the cathode has a reduced diameter for attachment to the strut system and this provides reduced optical blockage. A base for the anode has a longer length than its diameter for improved heat transfer to an anode heatsink. A braze-ring recess is machined in an inner diameter of the base to help prevent a contamination of the surface of the anode facing the cathode with any braze material during manufacturing. A chamfer is cut in each of three legs in the strut system to reduce the tendency for electricity to arc-over to a reflector that surrounds the anode. A cathode heatsink surrounds a window sleeve supporting a lens and has an angled inside face for reducing lamp-thermal gradients. A waist-area heatsink is clamped-on the ceramic body in the gap on an outside surface between an anode heatsink and a cathode heatsink with enough clearance provided so that inter-heatsink electrical arcing does not occur.
Abstract:
In accordance with the invention, an electron beam source for exposing selected portions of a surface to electrons comprises a plurality of nanoscale electron emitters and, associated with each electron emitter, a directional control element to direct the emitter toward a selected portion of the surface. In a preferred embodiment, the emitters are nanotubes or nanowires mounted on electrostatically controlled MEMS directional control elements. An alternative embodiment uses electrode directional control elements.
Abstract:
A multiplexed grid structure for electron emission displays allows each of the grid portions to be independently controllable from each other so that electrons can be emitted from their respective pixel sites as each grid portion is addressed.
Abstract:
A field emission element includes a substrate, a cathode conductor disposed on the substrate, an insulating layer structure on the cathode conductor that has a first insulating layer on the cathode conductor and a second insulating layer on the first insulating layer, a gate disposed on the second insulating layer, a gate hole provided through the gate and the insulating layer structure to expose a portion of the cathode conductor therethrough, and an emitter on the exposed portion of the cathode conductor in the gate hole. The first insulating layer is covered by the second insulating layer at a side surface of the gate hole and a dielectric constant of the first insulating layer is different from that of the second insulating layer.