Abstract:
A method for making a field emission cold cathode for use in vacuum tubes. A carbon velvet material is coated with a low work function cesiated salt and bonded to a cathode surface. Alternatively, the carbon velvet material is bonded to the cathode surface before being coated with the cesiated salt. The coating may be applied by spraying the carbon velvet material with a cesiated salt solution, or by dipping the material into a crucible of molten cesiated salt. This abstract is provided to comply with the rules requiring an abstract, and is intended to allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning the claims.
Abstract:
An apparatus for emitting electrons is provided. The apparatus includes a subsurface emitter having a sharp tip, a substrate including a base, and electrical continuity between the tip, the base, and an external circuit. This emitter structure may be used to form individual emitters or arrays of emitters. Also provided is a method of making electron emitters which is comprised of implanting energetic ions into a diamond lattice to form cones or other continuous regions of damaged diamond. These regions are more electrically conducting than the surrounding diamond lattice, and have locally sharp tips at or near the point of entry of the ion into the diamond. The tips may then also be additionally coated with a layer of a wide band-gap semiconductor. An electrically conducting material may also be placed in proximity to the tips to generate an electric field sufficient to extract electrons from the conducting tips into either the region above the surface, or into the wide band-gap semiconductor layer in contact with the tips. Electrical contact is made to the electrically conducting damage tracks and the electrical circuit may be completed with an electrically conducting material on the surface of the wide band-gap semiconductor or diamond, or in the ambient above the surface of the emitter. The surface of the wideband gap semiconductor or diamond may be chemically modified to enhance the emission of electrons from the surface.
Abstract:
A field emission display device (1) includes a cathode plate (20), a resistive buffer (30) in contact with the cathode plate, a plurality of electron emitters (40) formed on the buffer, and an anode plate (50) spaced from the electron emitters. Each electron emitter includes a rod-shaped first part (401) and a conical second part (402). The buffer and first parts are made from silicon oxide. The combined buffer and first parts has a gradient distribution of electrical resistivity such that highest electrical resistivity is nearest the cathode plate and lowest electrical resistivity is nearest the anode plate. The second parts are made from niobium. When emitting voltage is applied between the cathode and anode plates, electrons emitted from the electron emitters traverse an interspace region and are received by the anode plate. Because of the gradient distribution of electrical resistivity, only a very low emitting voltage is needed.
Abstract:
There are here disclosed an electron-emitting device, comprising a pair of conductors arranged on a substrate so as to face each other, and a pair of deposited films containing carbon as a main component which are connected to the pair of conductors respectively and which ate arranged putting a gap therebetween, wherein silver is contained in a ratio of 5 mol % to 10 mol % with respect to carbon in the deposited film, an electron source comprising the plurality of electron-emitting devices arranged on a substrate and a wire connected to the electron-emitting devices and an image-forming apparatus comprising the electron source and an image-forming member which performs image formation by the collision of electrons emitted from the electron source.
Abstract:
An electron field emission device is provided by placing a substrate in a reactor, heating the substrate and supplying a mixture of hydrogen and a carbon-containing gas at a concentration of about 8 to 13 per cent to the reactor while supplying energy to the mixture of gases near the substrate for a time to grow a first layer of carbon-based material to a thickness greater than about 0.5 micrometers, subsequently reducing the concentration of the carbon-containing gas and continuing to grow a second layer of carbon-based material, the second layer being much thicker than the first layer. The substrate is subsequently removed from the first layer and an electrode is applied to the second layer. The surface of the substrate may be patterned before growth of the first layer to produce a patterned surface on the field emission device. The device is free-standing and can be used as a cold cathode in a variety of electronic devices such as cathode ray tubes, amplifiers and traveling wave tubes.
Abstract:
This disclosure is directed toward field emission surfaces, and is more particularly directed toward improvements in cold, low field, high current, low noise field emission devices and surfaces. Such devices are used in field emission display devices such as video displays and information displays. The device utilizes a cermet with graded concentration of insulative and conductive particles deposited on the truncated point of a conical emitter. The emission surface of the cermet is insensitive to gases that oxidize or poison the emission surface. Such gases and other contaminants emanate from a phosphor when the emission device is used in phosphor display devices. The field emission device is operated at lower potentials thereby reducing power requirements and minimizing heat dissipation requirements. Further, the field emission device which operates at lower field in order to reduce mechanically and temporally unstable emission sites which result in current bursts and current deficits at these sites. Still further, the field emission device incorporates internal resistors which provide series resistance to limit noise at affected emission areas thereby eliminating the need to limit noise by incorporating high-valued resistors, typically in series with the cathode terminal of the emission device, which reduce the potential to the entire emission surface and increasing potentials required to produce current sufficient to excite display phosphor.
Abstract:
A multi type electron emission element comprises a plurality of electrodes formed on a deposition surface of an insulating material and each having a conical portion of a single crystal, an insulating layer formed on the deposition surface and having openings respectively centered on the conical portions, and a deriving electrodes, part of which is formed near at least the concial portions, the deriving electrode being formed on the insulating layer.
Abstract:
The present invention relates to afield emission cathode, comprising an at least partly electrically conductive base structure, and a plurality of electrically conductive micrometer sized sections spatially distributed at the base structure, wherein at least a portion of the plurality of micrometer sized sections each are provided with a plurality of electrically conductive nanostructures. Advantages of the invention include lower power consumption as well as an increase in light output of e.g. a field emission lighting arrangement comprising the field emission cathode.
Abstract:
A stable cold field electron emitter is produced by forming a coating on an emitter base material. The coating protects the emitter from the adsorption of residual gases and from the impact of ions, so that the cold field emitter exhibits short term and long term stability at relatively high pressures and reasonable angular electron emission.