TWI416571B - Field emission cathode device and field emission display - Google Patents

Abstract

The present invention relates to a field emission cathode device. The field emission cathode device includes a cathode substrate, a gate, a first dielectric layer, a cathode, and an electron emission layer. The gate is located on a surface of the cathode substrate. The first dielectric layer is located on a surface of the gate and defines a first opening. The cathode is spaced from the gate via the first dielectric layer and defines a second opening in alignment with the first opening to expose the gate. The electron emission layer is located on a surface of the cathode and near the second opening. A field emission display using the field emission cathode device is also related.

Description

Field emission cathode device and field emission display

The invention relates to a field emission cathode device and a field emission display, in particular to a field emission cathode device and a field emission display with a back gate structure.

Field emission displays are the next generation of emerging technologies with the most potential after cathode ray tube (CRT) displays and liquid crystal (LCD) displays. Compared with the previous display, the field emission display has the advantages of good display effect, large viewing angle, low power consumption and small volume, especially the field emission display based on carbon nanotubes, which has received more and more attention in recent years.

In general, the structure of a field emission display can be divided into a two-pole type and a three-pole type. The so-called two-pole type includes a field emission structure having an anode and a cathode. This structure is difficult to control due to the need to apply a high voltage, and the uniformity and electron emission are difficult to control, and the driving circuit is high in cost, and is basically unsuitable for the practical application of the high-resolution display. The triode structure is improved on the basis of the dipole type. The gate is added to control the electron emission, and electrons can be emitted under a lower voltage condition, and the electron emission is easily controlled by the gate. According to the position of the gate, the three-pole field emission display can be divided into two types: a positive gate structure and a back gate structure. Among them, the field emission display of the back gate structure has attracted much attention due to the simple process and low preparation cost.

Referring to FIG. 9 and FIG. 10, the prior art provides a field emission display 30 of a back gate structure including a lower substrate 304, a gate layer 308 disposed on the surface of the lower substrate 304, and an isolation disposed on the surface of the gate layer 308. The layer 310 is disposed on the surface of the isolation layer 310, the cathode layer 312, an electron emission layer 316 disposed on the surface of the cathode layer 312, an upper substrate 302, an anode layer 320 disposed on the surface of the upper substrate 302, and a surface disposed on the anode layer 320. Fluorescent layer 322. A vacuum space 306 is defined between the upper substrate 302 and the lower substrate 304 to accommodate other components. The electron emission layer 316 is disposed opposite to the phosphor layer 322. The electron emission layer 316 is typically a circular carbon nanotube slurry layer.

However, when the field emission display 30 of the back gate structure of the prior art operates, the electric field generated by the gate layer 308 can only penetrate from the periphery of the cathode layer 312 to the surface of the electron emission layer 316. Therefore, the electron emission layer 316 mainly emits electrons 324 by the edges, thereby causing uneven illumination of the pixel dots, resulting in a circular display effect as shown in FIG.

In view of the above, it is necessary to provide a field emission cathode device and a field emission display having a back gate structure in which pixels are uniformly illuminated.

A field emission cathode device comprising: a cathode substrate; a gate electrode disposed on a surface of the cathode substrate; a first insulating layer disposed on a surface of the gate electrode; and a cathode electrode passing through the first insulating layer The gate electrode is disposed at intervals; and a cathode emission layer is disposed on the surface of the cathode electrode, wherein: the first insulation layer is provided with a first opening, and the cathode electrode is provided with a second opening, An opening corresponding to the second opening and communicating with each other to expose the surface of the gate electrode to the opening position, the cathode emitting layer being disposed only adjacent to the cathode electrode The surface of the second opening position.

A field emission display comprising: a cathode substrate; a plurality of gate electrodes are parallel to each other and spaced apart from a surface of the cathode substrate; a plurality of cathode electrodes are parallel and spaced apart from each other, the plurality of cathode electrodes and a plurality of gates The electrodes are disposed at different intersections, the intersection area of the gate electrode and the cathode electrode defines a pixel area, and the cathode electrode defines a second opening corresponding to each pixel area; a first insulating layer is disposed at the Between the plurality of gate electrodes and the plurality of cathode electrodes, and the first insulating layer defines a first opening corresponding to each of the pixel regions and the second opening, wherein the gate electrode corresponds to the first a surface of the first opening and the second opening is exposed; a second insulating layer is disposed on the surface of the plurality of cathode electrodes, and a fifth opening is defined corresponding to each of the pixel regions, the fifth opening The inner diameter is larger than the inner diameter of the second opening, and the surface of the portion of the cathode electrode adjacent to the second opening is exposed; the plurality of annular cathode emitting layers respectively correspond to the second opening of the cathode electrode And disposed at a position where the exposed surface of the cathode electrode is close to the second opening; a focusing electrode is disposed on the surface of the second insulating layer, and a fourth opening and a portion are defined corresponding to each pixel region a five-hole connection; an anode substrate is opposite to the cathode substrate and spaced apart, a vacuum space is defined between the anode substrate and the cathode substrate; an anode electrode is disposed on a surface of the anode substrate opposite to the cathode substrate; The phosphor powder layer is disposed on the surface of the anode electrode and is disposed in one-to-one correspondence with the plurality of ring cathode emission layers.

Compared with the prior art, since the first insulating layer is provided with a first opening, the cathode electrode is provided with a second opening, and the first opening and the second opening are correspondingly disposed and communicate with each other. The gate electrode is exposed to a surface of the opening position, The cathode emitting layer is disposed only on the surface of the cathode electrode near the second opening position, so that the electric field of the gate electrode can penetrate the surface of the cathode emitting layer through the second opening of the cathode electrode to make the ring cathode emitting layer The electrons are emitted to obtain circular pixels with uniform illumination.

10,20‧‧‧ field emission display

100,200‧‧‧ field emission cathode device

102,202‧‧‧Anode substrate

104,204‧‧‧Cathode substrate

106,206‧‧‧vacuum space

108,208‧‧‧gate electrode

110,210‧‧‧first insulation

1102, 2102‧‧‧ first opening

112,212‧‧‧Cathode electrode

1122, 2122‧‧‧ second opening

114,214‧‧‧Second insulation

1142‧‧‧5th opening

116,216‧‧‧ cathode emission layer

1162‧‧‧3rd opening

118,218‧‧‧focus electrode

1182, 2182‧‧‧ fourth opening

120,220‧‧‧Anode electrode

122, 222‧‧‧Fluorescent powder layer

124‧‧‧Electron beam

126‧‧‧ secondary electron emission layer

2104‧‧‧ seventh opening

2124‧‧‧6th opening

2126‧‧‧Part II

2127‧‧‧Connecting Department

2128‧‧‧Part 1

30‧‧‧ Field emission display

302‧‧‧Upper substrate

304‧‧‧lower substrate

306‧‧‧vacuum space

308‧‧‧Gate layer

310‧‧‧Isolation

312‧‧‧ cathode layer

316‧‧‧electron emission layer

320‧‧‧anode layer

322‧‧‧Fluorescent layer

324‧‧‧Electronics

FIG. 1 is a schematic structural diagram of a pixel unit of a field emission display according to a first embodiment of the present invention.

2 is a schematic diagram showing the positional relationship between a cathode emission layer and a cathode electrode of a field emission display according to a first embodiment of the present invention.

FIG. 3 is a schematic perspective structural view of a field emission display according to a first embodiment of the present invention.

FIG. 4 is a schematic diagram showing the display effect of the field emission display according to the first embodiment of the present invention.

FIG. 5 is a schematic structural diagram of a pixel unit of a field emission display according to a second embodiment of the present invention.

6 to 8 are schematic structural views of a cathode electrode of a field emission display according to a second embodiment of the present invention.

9 is a schematic structural view of a field emission display in the prior art.

Fig. 10 is a view showing the display effect of the field emission display in the prior art.

The field emission cathode device provided by the embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Field emission display. The field emission display can include one or a plurality of pixel units. The following takes a pixel unit as an example for description, and then introduces a field emission display using a plurality of pixel units.

Referring to FIG. 1 , a first embodiment of the present invention provides a field emission display 10 including a cathode substrate 104 , a gate electrode 108 , a first insulating layer 110 , a cathode electrode 112 , and a cathode emitting layer 116 . The focusing electrode 118, an anode substrate 102, an anode electrode 120, and a phosphor layer 122. The cathode substrate 104, the gate electrode 108, the first insulating layer 110, the cathode electrode 112, the cathode emission layer 116, and the focusing electrode 118 constitute the field emission cathode device 100 of the field emission display 10.

The anode substrate 102 is opposed to the cathode substrate 104 and spaced apart from each other. A vacuum space 106 is defined between the anode substrate 102 and the cathode substrate 104 to receive the gate electrode 108, the first insulating layer 110, the cathode electrode 112, the cathode emission layer 116, the focusing electrode 118, the anode electrode 120, and the fluorescent Light powder layer 122. The gate electrode 108 is disposed on a surface of the cathode substrate 104 relative to the anode substrate 102. The first insulating layer 110 is disposed on a surface of the gate electrode 108 away from the cathode substrate 104, and the first insulating layer 110 defines a first opening 1102, so that the gate electrode 108 corresponds to the first The position of the opening 1102 is exposed and disposed facing the anode substrate 102. The cathode electrode 112 is disposed on a surface of the first insulating layer 110 away from the cathode substrate 104, and is spaced apart from the gate electrode 108 by the first insulating layer 110, and the cathode electrode 112 defines a a second opening 1122 that communicates with the first opening 1102. The cathode emission layer 116 is disposed on a surface of the cathode electrode 112 away from the cathode substrate 104 and is electrically connected to the cathode electrode 112. Preferably, the cathode emission layer 116 is disposed only at a position where the surface of the cathode electrode 112 is close to the second opening 1122.

The cathode emission layer 116 defines a third opening 1162 that communicates with the second opening 1122. The anode electrode 120 is disposed on a surface of the anode substrate 102 with respect to the cathode substrate 104. The phosphor layer 122 is disposed on the surface of the anode electrode 120. The focusing electrode 118 is disposed between the cathode electrode 112 and the anode electrode 120, and defines a fourth opening 1182 to expose a portion of the cathode electrode 112 and the cathode emission layer 116.

The material of the cathode substrate 104 may be tantalum, glass, ceramic, plastic or polymer. The shape and thickness of the cathode substrate 104 are not limited, and may be selected according to actual needs. Preferably, the shape of the cathode substrate 104 is square or rectangular. In this embodiment, the cathode substrate 104 is a square glass plate.

The gate electrode 108 is a conductive layer, and its thickness and size can be selected according to actual needs. The gate electrode 108 may be disposed only on a surface of the cathode substrate 104 exposed through the first opening 1102 or may extend between the first insulating layer 110 and the cathode substrate 104. The position of the gate electrode 108 corresponding to the first opening 1102 may also have a protruding structure (not shown) to lower the turn-on voltage. The material of the gate electrode 108 may be an elemental metal, a metal alloy, indium tin oxide or a conductive paste or the like. It can be understood that when the cathode substrate 104 is a ruthenium, the gate electrode 108 can be an erbium doped layer. In this embodiment, the gate electrode 108 is an aluminum film having a thickness of 20 micrometers. The aluminum film is deposited on the surface of the cathode substrate 104 by magnetron sputtering.

The first insulating layer 110 is disposed between the cathode electrode 112 and the gate electrode 108 for electrically insulating the cathode electrode 112 from the gate electrode 108. The material of the first insulating layer 110 may be a resin, a thick film exposure glue, glass, ceramic, an insulating oxide or a mixture of the above materials, or the like. The insulating oxide includes cerium oxide, aluminum oxide or cerium oxide, and the like, and the thickness and shape of the first insulating layer 110 may be According to actual needs. The first insulating layer 110 may be disposed directly on the surface of the cathode substrate 104 or on the surface of the gate electrode 108. The first insulating layer 110 is a layered structure having a through hole, and the through hole is defined as the first opening 1102. It can be understood that if the first insulating layer 110 has no opening and the cathode electrode 112 has an opening, a small amount of electrons emitted by the cathode emitting layer 116 in the direction of the gate electrode 108 may accumulate on the surface of the first insulating layer 110. Thereby, the electric field distribution of the gate electrode 108 is affected. The first opening 1102 can cause a small amount of electrons emitted by the cathode emission layer 116 to move toward the gate electrode 108 to reach the gate electrode 108 and be guided away by the gate electrode 108. In this embodiment, the first insulating layer 110 is a photoresist having a thickness of 100 micrometers disposed on the surface of the glass plate, and defines a circular through hole as the first opening 1102. The gate electrode 108 is disposed on the first insulating layer 110 and the cathode substrate 104 and covers the first opening 1102.

The cathode electrode 112 is disposed on a surface of the first insulating layer 110 away from the cathode substrate 104. The cathode electrode 112 is a conductive layer, and the material thereof may be an elemental metal, a metal alloy, indium tin oxide (ITO) or a conductive paste. The thickness and size of the cathode electrode 112 can be selected according to actual needs. Specifically, the cathode electrode 112 may be a layered structure having a through hole, and the through hole defines the second opening 1122. The second opening 1122 is disposed corresponding to the first opening 1102 and communicates with each other. Preferably, the second opening 1122 is coaxially disposed with the first opening 1102 and has the same aperture. Since the cathode electrode 112 has the second opening 1122, the electric field generated by the gate electrode 108 can penetrate the surface of the cathode emission layer 116 through the first opening 1102 and the second opening 1122, and the cathode emission layer 116 emits electrons. In this embodiment, the cathode electrode 112 is an aluminum conductive layer and has a circular through hole as the second opening 1122.

Referring to FIG. 2, the cathode emission layer 116 is disposed only on the surface of the cathode electrode 112 near the second opening 1122, and the cathode emission layer 116 is an annular structure defining a third opening 1162. . The cathode emission layer 116 is disposed only on a surface of the cathode electrode 112 that faces the anode electrode 120 and is exposed through the fourth opening 1182. The cathode emission layer 116 may be disposed on a portion of the surface or exposed surface of the cathode electrode 112 exposed through the fourth opening 1182. Preferably, the cathode emission layer 116 is a circular ring. The third opening 1162 and the second opening 1122 are corresponding to the first opening 1102 and communicate with each other. Preferably, the third opening 1162 and the second opening 1122 and the first opening 1102 are The hole diameter is the same, that is, the hole wall of the third opening 1162 is flush with the hole wall of the second opening 1122 and the first opening 1102. It can be understood that since the cathode emission layer 116 is disposed close to the second opening 1122, the electric field generated by the gate electrode 108 can penetrate through the second opening 1122 to the entire surface of the cathode emission layer 116, so that the entire cathode emission layer 116 is emitted. electronic.

The cathode emission layer 116 includes a plurality of electron emitters such as a carbon nanotube, a carbon fiber, or a nanowire. Further, the surface of the cathode emission layer 116 may further be provided with an anti-ion bombardment material to improve its stability and life. The anti-ion bombardment material may be selected from one or a plurality of zirconium carbide, tantalum carbide, and lanthanum hexaboride. In this embodiment, the cathode emission layer 116 is a circular carbon nanotube slurry layer. The carbon nanotube slurry includes a carbon nanotube, a low melting glass powder, and an organic vehicle. Wherein, the organic carrier evaporates during the baking process, the low-melting glass frit melts during the baking process, and the carbon nanotubes are fixed to the surface of the cathode electrode 112.

The focusing electrode 118 can be a metal grid or a conductive layer. The focusing electrode 118 is disposed between the cathode electrode 112 and the anode electrode 120, and defines a fourth opening 1182 to A portion of the surface of the cathode electrode 112 adjacent to the second opening 1122 is exposed through the fourth opening 1182. The focusing electrode 118 may be spaced apart from the cathode electrode 112 by a second insulating layer 114 and electrically insulated. The material of the second insulating layer 114 is the same as that of the first insulating layer 110, and the thickness and shape thereof can be selected according to actual needs. The second insulating layer 114 is disposed on a surface of the cathode electrode 112 away from the cathode substrate 104. The second insulating layer 114 defines a fifth opening 1142 communicating with the fourth opening 1182 to expose a portion of the surface of the portion of the cathode electrode 112 adjacent to the second opening 1122, thereby exposing the cathode emitting layer 116. And directly facing the anode substrate 102. In this embodiment, the fourth opening 1182 is coaxial with the fifth opening 1142 and has the same aperture. It can be understood that when the focusing electrode 118 is a self-supporting metal grid, the focusing electrode 118 can also be suspended between the cathode electrode 112 and the anode electrode 120. The material of the focusing electrode 118 may be a metal, an alloy, indium tin oxide (ITO) or a conductive paste or the like. The thickness and size of the focusing electrode 118 can be selected according to actual needs. The focusing electrode 118 is used to concentrate electrons emitted by the cathode emission layer 116.

The anode substrate 102 is a transparent substrate, and its shape and thickness are not limited, and may be selected according to actual needs. Preferably, the shape of the anode substrate 102 is square or rectangular. The vacuum substrate 106 may be defined by an insulating strip (not shown) between the anode substrate 102 and the cathode substrate 104. In this embodiment, the anode substrate 102 is a square glass plate.

The anode electrode 120 is a transparent conductive layer such as a carbon nanotube film, an indium tin oxide film or an aluminum film. The shape and thickness of the anode electrode 120 are not limited, and may be selected according to actual needs. In this embodiment, the anode electrode 120 is an oxygen having a thickness of 100 micrometers. Indium tin film.

The phosphor layer 122 may be disposed on a surface of the anode electrode 120 away from the anode substrate 102 or between the anode electrode 120 and the anode substrate 102. The shape and thickness of the phosphor layer 122 are not limited, and may be selected according to actual needs. Preferably, the phosphor layer 122 has a circular shape and a radius greater than or equal to an inner radius of the cathode emission layer 116 that is less than or equal to an outer radius of the cathode emission layer 116. In this embodiment, the phosphor layer 122 is circular and has a radius equal to an outer radius of the cathode emission layer 116.

When the field emission display 10 is in operation, the cathode electrode 112 is connected to a zero potential (ground), the gate electrode 108 is applied with a positive voltage V1, the anode electrode 120 is applied with a positive voltage V2, and the focusing electrode 118 is applied. A negative voltage V3. The operating voltage V1 of the gate electrode 108 is 10 volts to 100 volts, the operating voltage V2 of the anode electrode 120 is 500 volts to 5000 volts, and the operating voltage V3 of the focusing electrode 118 is negative 5 volts to minus 50 volts. . The electric field generated by the gate electrode 108 can penetrate the surface of the cathode emission layer 116 through the second opening 1122, and cause the cathode emission layer 116 to emit electrons. The electrons are directed toward the anode electrode 120 under the electric field force of the anode electrode 120 and form an electron beam 124. Since the focus electrode 118 applies a negative voltage, the negative voltage has a repulsive effect on the electrons, thereby functioning to concentrate the electron beam 124.

Further, the field emission display 10 may further include a secondary electron emission layer 126 to increase the electron emission efficiency of the field emission cathode device 100. The secondary electron emission layer 126 is disposed on the surface of the gate electrode 108 in the first opening 1102. The material of the secondary electron emission layer 126 includes magnesium oxide (MgO), beryllium oxide (BeO), magnesium fluoride (MgF ₂ ), beryllium fluoride (BeF ₂ ), antimony oxide (CsO), and barium oxide (BaO). One or several of them, the thickness and size can be selected according to actual needs. The secondary electron emission layer 126 may be formed on the surface of the gate electrode 108 by coating, electron beam evaporation, thermal evaporation, or magnetron sputtering. It is understood that the surface of the secondary electron emission layer 126 may also be formed with a concavo-convex structure to increase the area of the secondary electron emission layer 126, and the secondary electron emission efficiency may be improved. In this embodiment, the secondary electron emission layer 126 is a ruthenium oxide layer having a thickness of about 5 μm.

With further reference to FIG. 3, a first embodiment of the present invention further describes an implementation of a field emission display 10 that includes a multi-pixel unit. Specifically, the field emission display 10 includes a common cathode substrate 104, a plurality of strip gate electrodes 108, a common first insulating layer 110, a plurality of strip cathode electrodes 112, and a plurality of circular cathode emitters. Layer 116, a common focusing electrode 118, a common anode substrate 102, a common anode electrode 120, and a plurality of circular phosphor layers 122.

The plurality of strip gate electrodes 108 are disposed in parallel and equally spaced on the surface of the cathode substrate 104. The plurality of strip-shaped cathode electrodes 112 are disposed in parallel and at equal intervals, and the plurality of strip-shaped cathode electrodes 112 are disposed perpendicular to and perpendicular to the plurality of strip-shaped gate electrodes 108. The intersection area of the gate electrode 108 and the cathode electrode 112 defines a pixel area. The cathode electrode 112 defines a second opening 1122 corresponding to the pixel area. The first insulating layer 110 is disposed between the plurality of gate electrodes 108 and the plurality of cathode electrodes 112, and the first insulating layer 110 defines a plurality of first openings 1102 corresponding to the pixel regions. It can be understood that the first insulating layer 110 can also be a plurality of spaced apart insulating strips. Preferably, the insulating strips have the same shape as the strip gate electrodes 108 or the strip cathode electrodes 112. The first opening 1102 is corresponding to and in communication with the second opening 1122 to expose the gate electrode 108. The second insulating layer 114 is disposed on the surface of the plurality of strip cathode electrodes 112, and the pixel region The fields correspond one-to-one to define a plurality of fifth openings 1142 to partially expose the cathode emission layer 116. It can be understood that the second insulating layer 114 can also be a plurality of spaced apart insulating strips. Preferably, the insulating strips have the same shape as the strip-shaped cathode electrodes 112. The plurality of annular cathode emitting layers 116 are disposed in one-to-one correspondence with the pixel regions, and each of the annular cathode emitting layers 116 is disposed on a surface of the cathode electrode 112 exposed through the fifth opening 1142. The third opening 1162 of the annular cathode emitting layer 116 is corresponding to and in communication with the second opening 1122. The focusing electrode 118 is disposed on the surface of the second insulating layer 114 and defines a plurality of fourth openings 1182 corresponding to the fifth opening 1142. The focusing electrode 118 can be an integral conductive layer having a plurality of fourth openings 1182, or a plurality of conductive strips disposed at intervals and having a fourth opening 1182. The anode electrode 120 is an entire transparent conductive layer disposed on the surface of the anode substrate 102. The plurality of circular shaped phosphor layers 122 are disposed on the surface of the anode electrode 120 and are disposed in one-to-one correspondence with the pixel regions or in one-to-one correspondence with the cathode emission layer 116. Further, a black matrix may be disposed between the plurality of circular shaped phosphor layers 122 to increase the contrast of the field emission display 10.

Please refer to FIG. 4, which shows the display effect of the field emission display 10 of the second embodiment of the present invention. In the embodiment of the invention, a circular cathode emitting layer 116 is used, and circular pixels with uniform illumination can be obtained.

Referring to FIG. 5, a second embodiment of the present invention provides a field emission display 20 including a cathode substrate 204, a gate electrode 208, a first insulating layer 210, a cathode electrode 212, and a cathode emitting layer 216. The second insulating layer 214, a focusing electrode 218, an anode substrate 202, an anode electrode 220, and a phosphor layer 222. Wherein, the cathode substrate 204, the gate electrode 208, the first insulating layer 210, and the cathode electrode 212, cathode emission layer 216, focusing electrode 218 constitute field emission cathode device 200 of field emission display 20. The field emission display 20 provided by the second embodiment of the present invention is substantially the same as the first embodiment of the present invention. The difference is that the cathode electrode 212 further defines one or more surrounding second openings 2122. The sixth opening 2124.

With further reference to FIGS. 6-8, the sixth opening 2124 substantially surrounds the second opening 2122. The sixth opening 2124 divides the cathode electrode 212 into a first portion 2128 and a second portion 2126 which are disposed at intervals. The first portion 2128 is disposed between the second insulating layer 214 and the first insulating layer 210. The second portion 2126 is disposed between the cathode emission layer 216 and the first insulating layer 210. The cathode emission layer 216 is disposed only on the surface of the second portion 2126. The second opening 2122 is defined by the second portion 2126. The first portion 2128 and the second portion 2126 are connected by at least one connecting portion 2127 to achieve electrical conduction. The shape of the sixth opening 2124 is not limited and may be selected according to the shape of the second opening 2122. When the second opening 2122 is circular, the sixth opening 2124 may be an annular opening as shown in FIG. 6, two semi-annular openings as shown in FIG. 7, or a plurality of FIG. The curved opening shown. It can be understood that when the second opening 2122 is square, the sixth opening 2124 can be an elongated opening parallel to the four sides of the square second opening 2122. In this embodiment, the second opening 2122 is circular, and the sixth opening 2124 is four arc-shaped openings surrounding the second opening 2122, and between the two adjacent sixth openings 2124 The portion is the connection portion 2127. The inner diameter of the sixth opening 2124 is greater than or equal to the outer diameter of the cathode emission layer 216, and the outer diameter of the sixth opening 2124 is less than or equal to the aperture of the fourth opening 2182. Preferably, the inner diameter of the sixth opening 2124 is equal to the outer diameter of the cathode emission layer 216, the outer diameter of the sixth opening 2124, and the like. The aperture of the fourth opening 2182. It can be understood that the sixth opening 2124 can cause the electric field of the gate electrode 208 to penetrate from the sixth opening 2124 to the surface of the cathode emission layer 216, thereby improving the electron emission efficiency of the cathode emission layer 216.

Further, the first insulating layer 210 may further define one or a plurality of seventh openings 2104 corresponding to the sixth openings 2124. The seventh opening 2104 substantially surrounds the first opening 2102. The gate electrode 208 is exposed to a portion of the surface of the position of the seventh opening 2104 and the sixth opening 2124 such that a small amount of electrons emitted by the cathode emission layer 216 in the direction of the gate electrode 208 reaches the gate electrode 208. And is guided away by the gate electrode 208.

The field emission display 10 has the following advantages: first, the first insulating layer is provided with a first opening, the cathode electrode is provided with a second opening, and the first opening is corresponding to the second opening And communicating with each other to expose the surface of the gate electrode to the surface of the opening, the cathode emitting layer is disposed only on a surface of the cathode electrode adjacent to the second opening, so that the electric field of the gate electrode can be The second opening of the cathode electrode penetrates into the surface of the cathode emission layer to cause the ring cathode emission layer to emit electrons, thereby obtaining circular pixels having uniform light emission. Moreover, electrons emitted from the cathode emissive layer in the direction of the gate electrode can reach the gate electrode and be guided away by the gate electrode, thereby avoiding accumulation of charges on the surface of the first insulating layer and affecting the electric field distribution of the gate electrode. Second, by providing a secondary electron emission layer on the surface of the gate electrode in the first opening, the electron emission efficiency of the field emission cathode device can be improved. Third, the cathode electrode defines one or a plurality of sixth openings surrounding the second opening such that an electric field of the gate electrode penetrates from the sixth opening to the surface of the cathode emission layer, thereby improving the cathode emission layer. Electron emission efficiency.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10‧‧‧ field emission display

100‧‧ ‧ field emission cathode device

102‧‧‧Anode substrate

104‧‧‧Cathode substrate

106‧‧‧vacuum space

108‧‧‧Gate electrode

110‧‧‧First insulation

1102‧‧‧First opening

112‧‧‧Cathode electrode

1122‧‧‧Second opening

114‧‧‧Second insulation

1142‧‧‧5th opening

116‧‧‧ Cathode emission layer

1162‧‧‧3rd opening

118‧‧‧Focus electrode

1182‧‧‧4th opening

120‧‧‧Anode electrode

122‧‧‧Fluorescent powder layer

124‧‧‧Electron beam

126‧‧‧ secondary electron emission layer

Claims (12)

A field emission cathode device comprising: a cathode substrate; a gate electrode disposed on a surface of the cathode substrate; a first insulating layer disposed on a surface of the gate electrode; and a cathode electrode passing through the first insulating layer The gate electrode is disposed at intervals; and a cathode emission layer is disposed on the surface of the cathode electrode, wherein the first insulating layer is provided with a first opening, and the cathode electrode is provided with a second opening. The first opening is disposed corresponding to the second opening and communicates with each other to expose the surface of the gate electrode to the opening position, and the cathode emission layer is disposed only on the cathode electrode adjacent to the second opening a surface of the location, and the cathode electrode further defines one or a plurality of sixth openings surrounding the second opening. The field emission cathode device of claim 1, wherein the cathode emission layer is annular, and the cathode emission layer defines a third opening corresponding to the second opening and the first opening. Connected to each other. The field emission cathode device of claim 2, wherein the first opening, the second opening, and the third opening are coaxially disposed and have the same inner diameter. The field emission cathode device of claim 1, wherein the first insulating layer is further defined with one or a plurality of seventh openings surrounding the first opening, and the seventh opening and the sixth opening The openings are correspondingly arranged and connected to each other. The field emission cathode device of claim 4, wherein the second opening is circular, and the sixth opening is an annular opening, two semi-annular openings or a plurality of arcs Shape the hole. The field emission cathode device of claim 5, wherein the sixth opening has an inner diameter greater than or equal to an outer diameter of the cathode emission layer. The field emission cathode device of claim 4, further comprising a focusing electrode spaced apart from the cathode electrode, the focusing electrode defining a fourth opening corresponding to the second opening, the fourth The inner diameter of the opening is larger than the outer diameter of the sixth opening to expose a portion of the surface of the gate electrode corresponding to the position of the seventh opening and the sixth opening. The field emission cathode device of claim 7, wherein the cathode electrode is exposed through the fourth opening portion, and the cathode emission layer is disposed only on a portion of the surface of the cathode electrode exposed through the fourth opening. The field emission cathode device of claim 1, further comprising a secondary electron emission layer disposed on the surface of the gate electrode in the first opening. A field emission display comprising: a cathode substrate; a plurality of gate electrodes are parallel to each other and spaced apart from a surface of the cathode substrate; a plurality of cathode electrodes are parallel and spaced apart from each other, the plurality of cathode electrodes and a plurality of gates The electrodes are disposed at opposite sides, the intersection area of the gate electrode and the cathode electrode defines a pixel area, and the cathode electrode defines a second opening corresponding to each pixel area, and the cathode electrode further defines one or a plurality of sixth openings surrounding the second opening; a first insulating layer is disposed between the plurality of gate electrodes and the plurality of cathode electrodes, and the first insulating layer corresponds to each of the pixel regions Defining a first opening in communication with the second opening, the gate electrode corresponding to the first opening and the second opening a second insulating layer is disposed on the surface of the plurality of cathode electrodes, and a fifth opening is defined corresponding to each of the pixel regions, and an inner diameter of the fifth opening is larger than the second opening The inner diameter is exposed to a portion of the surface of the cathode electrode adjacent to the second opening; the plurality of annular cathode emitting layers are respectively disposed corresponding to the second opening of the cathode electrode, and the exposed surface of the cathode electrode is adjacent to the second a position of the opening; a focusing electrode is disposed on the surface of the second insulating layer, and a fourth opening is connected to the fifth opening corresponding to each pixel region; an anode substrate is opposite to the cathode substrate a vacuum space is defined between the anode substrate and the cathode substrate; an anode electrode is disposed on a surface of the anode substrate opposite to the cathode substrate; and a plurality of phosphor layers are disposed on the surface of the anode electrode, and a plurality of The ring cathode emitting layers are arranged one by one. The field emission display of claim 10, wherein the first insulating layer is further defined with one or a plurality of seventh openings surrounding the first opening, and the seventh opening and the sixth opening The holes are correspondingly arranged and communicate with each other. The field emission display of claim 11, wherein the sixth opening is disposed only at a position where the cathode electrode is exposed through the fifth opening.