Field emission cold-cathode device

Claim 2

A vacuum micro device comprising: a support member; an emitter formed on said support member to emit electrons, said emitter comprising a fullerene or a carbon nanotube arranged to cause said emitter to emit electrons with an improved field emission efficiency; a surrounding member configured to form, together with said support member, a vacuum discharge space surrounding said emitter; and an extracting electrode formed to be spaced apart from said emitter, said emitter emitting electrons due to a potential difference between said emitter and said extracting electrode, wherein said carbon nanotube is defined by a cylindrical wall formed by winding a graphite sheet, which essentially includes an array of 6-membered rings of carbon, in a direction in which the 6-membered rings has a period substantially of 0.426 nm or 0.738 nm.

Claim 3

A device according to claim 1, wherein said emitter comprises a plurality of fullerenes or carbon nanotubes.

Claim 4

A device according to claim 1, further comprising a cathode interconnecting layer formed on said support member, wherein said emitter is formed on said cathode interconnecting layer.

Claim 5

A device according to claim 3, wherein said cathode interconnecting layer consists essentially of a material selected from the group consisting of Mo, Ta, W, Cr, Ni, and Cu.

Claim 6

A device according to claim 1, wherein said emitter comprises a conductive projection supported by said support member, and said fullerene or carbon nanotube is supported by a tip of said conductive projection.

Claim 7

A device according to claim 5, wherein said fullerene or carbon nanotube is partially buried in said conductive projection.

Claim 8

A device according to claim 5, wherein said conductive projection consists essentially of a material selected from the group consisting of Mo, Ta, W, Cr, Ni, Si, LaB 6 , AlN, GaN, graphite, and diamond.

Claim 9

A device according to claim 1, wherein said support member consists essentially of a synthetic resin.

Claim 10

A device according to claim 1, wherein said emitter comprises a plurality of carbon nanotubes, and 70% or more of the carbon nanotubes have a diameter of not more than 30 nm.

Claim 11

A device according to claim 1, wherein an end portion of said carbon nanotube is closed with a graphite sheet containing 5-, 6-, and 7-membered rings of carbon.

Claim 12

A device according to claim 1, wherein an aspect ratio representing a ratio of a height to a bottom diameter of said carbon nanotube forming said emitter is not less than 3 and not more than 1×10 6 .

Claim 13

A device according to claim 11, wherein the aspect ratio is not less than 3 and not more than 1×10 3 .

Claim 14

A device according to claim 1, further comprising a conductive filling layer formed in said carbon nanotube and capable of emitting electrons.

Claim 15

A device according to claim 13, wherein said filling layer consists essentially of a material selected from the group consisting of Mo, Ta, W, Cr, Ni, Si, LaB 6 , AlN, GaN, graphite, and diamond.

Claim 16

A device according to claim 1, wherein said extracting electrode is a gate electrode supported by said support member.

Claim 17

A device according to claim 15, wherein an anode electrode is formed in a position on said surrounding member where said anode electrode opposes said emitter.

Claim 18

A device according to claim 1, wherein said extracting electrode is an anode electrode formed in a position on said surrounding member where said anode electrode opposes said emitter.

Claim 19

An image display device comprising: a support member; an emitter formed on said support member to emit electrons, said emitter comprising a fullerene or a carbon nanotube arranged to cause said emitter to emit electrons with an improved field emission efficiency; a surrounding member configured to form, together with said support member, a vacuum discharge space surrounding said emitter; an extracting electrode formed to be spaced apart from said emitter, said emitter emitting electrons due to a potential difference between said emitter and said extracting electrode; and a display portion configured to display an image in accordance with excitation by electrons emitted from said emitter, said display portion being turned on and off under a control of the potential difference between said emitter and said extracting electrode, on which emission of electrons from said emitter depends, wherein said carbon nanotube is defined by a cylindrical wall formed by winding a graphite sheet, which essentially includes an array of 6-membered rings of carbon in a direction in which the 6-membered rings has a period substantially of 0.426 nm or 0.738 nm.

Claim 20

An image display device comprising: a support member; an emitter formed on said support member to emit electrons, said emitter comprising a fullerene or a carbon nanotube arranged to cause said emitter to emit electrons with an improved field emission efficiency; a surrounding member configured to form, together with said support member, a vacuum discharge space surrounding said emitter; an extracting electrode formed to be spaced apart from said emitter, said emitter emitting electrons due to a potential difference between said emitter and said extracting electrode; and a display portion configured to display an image in accordance with excitation by electrons emitted from said emitter, said display portion being turned on and off under a control of the potential difference between said emitter and said extracting electrode, on which emission of electrons from said emitter depends, wherein said carbon nanotube is defined by a cylindrical wall formed by winding a graphite sheet, which essentially includes an array of 6-membered rings of carbon in a direction in which the 6-membered rings has a period substantially of 0.426 nm or 0.738 nm.

Claim 21

The device according to claim 18, wherein said vacuum discharge space contains a substance for emitting light due to excitation by electrons emitted from said emitter.

Claim 22

The device according to claim 19, wherein said substance comprises a phosphor.

Claim 23

The device according to claim 19, wherein said substance forms a layer arranged at a position facing said emitter.