Patent Application
20080018227
Many aspects of the present field emission device can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present field emission device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Reference will now be made to the drawings to describe in detail the preferred embodiment of the field emission device.
Referring to
The sealed container 11 is a hollow member that defines an inner space, the inner space containing a vacuum. The main portion of the sealed container 11 in cross-section can be, for example, a circle, a quadrangle, a triangle, or a polygon. In the illustrated embodiment, the main portion of the sealed container is a cylinder. The light-permeable portion 12 may be a planar surface, a spherical surface, or an aspherical surface, which can be selected according to application. The sealed container 11 should be light-permeable, and should preferably be transparent. The sealed container 11 according to the embodiment is made of a nonmetal material, for example, quartz or glass. Such materials as quartz or glass are beneficial in that they are electrically insulative.
The light-permeable anode 14 is a metal film with good electrical conductivity. In the preferred embodiment, the anode 14 is an aluminum film. In the illustrated embodiment, the shielding barrel 16 is a cylinder with a central axis oriented perpendicularly to the light-permeable portion 12. It can be understood that other shapes of the shielding barrel 16 can be selected according to the shape of the sealed container 11.
The solidified nano slurry layer 17 contains a conductive nano material. The conductive nano materials are selected from the group consisting of carbon nanotubes, carbon nano-sticks, carbon nano-yarns, Buckminster-fullerenes (C60), carbon nano-particles. The conductive nano material is also can be selected from the group consisting of nanotubes, nano-sticks, nano-yarns, and nano-particles of conductive metal and semiconductor material. In the preferred embodiment, the conductive nano material consists of carbon nanotubes. Firstly, the nano slurry is spread on the inner surface of the shielding barrel 16 and solidified. The slurry is then scrubbed with rubber to expose ends of the carbon nano tubes, thus enhancing the conductivity of the shielding barrel 16. Distance between edge (e.g., top end) of the nano slurry layer 17 and edge (e.g., top end) of the shielding barrel 16 determines shielding effect of the shielding barrel 16. The distance is bigger; the effect is more apparently.
Preferably, in order to maintain the vacuum of the inner space of the sealed container 11, a getter 20 may be arranged therein to absorb residual gas inside the sealed container 11. More preferably, the getter 20 can be arranged on an inner surface of the sealed container 11 around the cathodes 18, 19. The getter 20 may be evaporable getter introduced by high frequency heating. The getter 20 can also be non-evaporable getter. It must be ensured that the getter 20 does not form on the light-permeable anode 14, in order to avoid short-circuiting between the light-permeable anode 14 and the cathodes 18, 19.
The sealed container 11 further includes an air vent 21. The air vent 21 connects a vacuum pump to the sealed container 11 thus creating a vacuum before packaging the sealed container.
In operation, when putting a voltage over the cathodes 18, 19 and the light-permeable anode 14, electrons will emanate from two openings of the shielding barrel 16. The electrons move towards and transmit through the light-permeable anode 14. When the electrons hit the phosphor layer 13 visible lights will be emitted. One part of the light will transmit through the light-permeable portion 12, and the other part of the light will be reflected by the light-permeable anode 14, and spread out of the light-permeable portion 12. A plurality of such tubes 10 can be arranged together to use for lighting and displaying. Because of the shielding effect of the shielding barrel, the field emission device can operate with a higher level of stability at high voltages.
While the present invention has been described as having preferred or exemplary embodiments, the embodiments can be further modified within the spirit and scope of this disclosure. This application is therefore intended to include any variations, uses, or adaptations of the embodiments using the general principles of the invention as claimed. Further, this application is intended to include such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and which fall within the limits of the appended claims or equivalents thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 95126673 | Jul 2006 | TW | national |
| 200610061804.8 | Jul 2006 | CN | national |
This application is related to commonly-assigned copending application Ser. No. ______, entitled “FIELD EMISSION DEVICE” (attorney docket number US 11274). Disclosures of the above-identified application are incorporated herein by reference.
