JP2003059431A - Fluorescence display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve light emitting efficiency with a simple electrode structure. SOLUTION: An electron emitting source has a mesh-like conductive electrode formed on a surface, and an anode oppositely arranged to this mesh-like conductive electrode, and forming a phosphor layer on a surface, and looks the phosphor layer straight from the mesh-like conductive electrode side. The mesh-like conductive electrode is a mesh-like metallic electrode, and the mesh-like metallic electrode is arranged in a space in a vacuum vessel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent display device, and more particularly to a direct-viewing type fluorescent display device having a diode structure.

[0002]

2. Description of the Related Art There are known fluorescent display devices and the like in which electrons emitted from an electron source arranged on the cathode side are caused to collide with a light emitting portion formed of a phosphor layer formed on a counter electrode to emit light. This fluorescent display element is a kind of vacuum microdevice using a micro electron emission source of submicron to micron size. The basic configuration is the same triode as the conventional vacuum tube, but it does not use a hot cathode, but uses an electron emission source, in which a high electric field is concentrated in the cathode (emitter) and electrons are extracted by a quantum mechanical tunnel effect, as the cathode. The extracted electrons are accelerated by the voltage between the anode and the cathode to collide with and excite the phosphor layer formed on the anode to emit light. In terms of excitation and emission of the phosphor by the cathode ray, the principle is the same as that of a cathode ray tube, but it has the features of smaller volume, weight, and power consumption than a cathode ray tube. Further, compared with the liquid crystal display device, it does not require a backlight and has a wide viewing angle.

FIG. 4 shows a conventional fluorescent display device having a cathode as an electron emission source. FIG. 4 is a sectional view of the fluorescent display element.
In a conventional fluorescent display element 8, a front glass plate 2 and a back plate 3 facing each other and a side plate 4 formed around the front glass plate 2 and the back plate 3 are vacuum-sealed with frit glass. Composed. A transparent conductive layer 11 serving as an anode is formed on the inner surface of the front glass plate 2, and a phosphor layer 11a is formed thereon to form a light emitting portion. The cathode serving as an electron emission source is the insulating substrate 3
The cathode 9 is formed on the cathode 9 and the electron emission layer 9a is formed on the cathode 9, and the gate electrode 10 is provided via a spacer (not shown). Electrons extracted from the electron emission layer collide with and are excited by the phosphor layer to emit light, which is directly viewed from the front glass plate 2 side. Therefore, the anode 1
1 was formed of a transparent electrode or the like.

[0004]

However, the conventional fluorescent display device having the electron-emitting source as the cathode shown in FIG.
There is a problem that the structure of the fluorescent display element, especially the structure of the field emission cold cathode that emits electrons becomes complicated and the number of manufacturing steps increases. In addition, there is a problem that the manufacturing price increases.
In addition, since the surface is viewed directly from the anode display surface 11 side, there is a problem in that the phosphor screen becomes transmissive, and the luminous efficiency is reduced. The present invention has been made to address such a problem, and an object thereof is to provide a fluorescent display element having a simple electrode structure and excellent emission efficiency.

[0005]

According to the present invention, there is provided a mesh conductive electrode having an electron emission source formed on the surface thereof, and an anode having a phosphor layer formed on the surface of the mesh conductive electrode so as to face the mesh conductive electrode. The fluorescent display element is characterized in that the phosphor layer is directly viewed from the mesh conductive electrode side. Further, the mesh-shaped conductive electrode is a mesh-shaped metal electrode. Further, the mesh metal electrode is arranged in a space inside the vacuum container.

A net-like conductive electrode having an electron emission source formed on its surface and an anode having a phosphor layer formed on the surface thereof, which is arranged so as to face the net-like conductive electrode, are provided from the net-like conductive electrode side. By directly looking at the phosphor layer to be the display portion, a direct-viewing type fluorescent display device having a diode structure can be obtained. For this reason,
The number of manufacturing steps and the number of parts can be reduced with a simple structure, and an inexpensive fluorescent display device can be obtained. Further, the mesh conductive electrode is a mesh metal electrode, and by disposing this mesh metal electrode in the space inside the vacuum container, the distance from the anode on which the phosphor layer is formed can be arbitrarily adjusted. , Highly efficient light emission can be obtained.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An example of the fluorescent display element of the present invention will be described with reference to FIG. FIG. 1 is a sectional view of a fluorescent display element. The fluorescent display element 1 is constructed by vacuum-sealing a front glass plate 2 and a back plate 3 facing each other and a side plate 4 formed around the front glass plate 2 and the back plate 3 with frit glass. It An electron emission source 5 is placed in a vacuum container that is vacuum-sealed.
On the inner surface of the back plate 3, there are formed a mesh-shaped metal electrode 5 having a formed on the surface thereof, and an anode 7 which is arranged so as to face the mesh-shaped metal electrode 5 and has a phosphor layer 6 formed on the surface thereof. In the fluorescent display element 1, the display viewing direction (direction of arrow A) is
It is the mesh metal electrode 5 side. The mesh metal electrode 5 is preferably arranged in the internal space of the vacuum container so as to face the phosphor layer 6. By disposing it in the internal space, the distance from the phosphor layer 6 can be set to the minimum, and the brightness is improved.

Another example of the fluorescent display device of the present invention will be described with reference to FIGS. 2 and 3 are cross-sectional views of the fluorescent display device. In the fluorescent display element 1a shown in FIG. 2, the mesh metal electrode 5 having the electron emission source 5a is formed on the inner surface of the front glass plate 2 and the rear plate having the anode 7 having the phosphor layer 6 formed thereon. 3 and vacuum sealed.
Further, as shown in FIG. 3, in the fluorescent display element 1b, instead of the mesh metal electrode 5, a conductive electrode material is formed in a mesh shape on the inner surface of the front glass plate 2 by a printing method or the like to form a mesh conductive electrode. Can be

The mesh metal electrode 5 can be used as long as it is a conductive substrate on the surface of which a carbon nanotube layer or the like serving as an electron emission source can be formed. In particular, when the carbon nanotube layer is formed by a dry method, iron, nickel, cobalt, or an alloy thin plate containing them is preferable because it easily forms an electron emission source. Further, a metal thin plate having a coefficient of thermal expansion substantially equal to that of a glass plate or the like is preferable, and specifically,
Examples include 426 alloy, stainless steel (SUS304), nickel (Ni) thin plate, and the like.

When the mesh-shaped conductive electrode is formed on the inner surface of the front glass plate, a conventionally known conductive paste can be used as the forming method. In addition, especially when the carbon nanotube layer is produced by the dry method described later,
It is preferable to use iron, nickel, cobalt, or a conductive paste containing them.

The mesh-like electrode may have a shape such that the openings of the mesh are hexagonal, quadrangular, triangular, circular or the like so that the display portion can be visually recognized through the mesh, and may be stripe-shaped. Further, the portion where the mesh is formed may be at least a portion facing the display portion of the phosphor layer.

An electron emission source is formed on the surface of the mesh electrode. As the electron emission source, any material that easily emits electrons can be used. Such materials include carbon nanotubes, diamond-like carbon (D
LC), single crystal diamond, polycrystalline diamond, amorphous diamond, amorphous carbon, and other carbon-based electron emitting materials.

As the method of forming the electron emission source, a printing method, a dip coating method, an electrodeposition coating method, an electrostatic coating method, a dry method and the like are used. Among these, the dry method is preferable as the method for forming the carbon nanotubes suitable for the present invention on the surface of the mesh electrode. Here, the dry method means a laser deposition method, a resistance heating method, a plasma method, a thermal CVD method, a microwave plasma CV.
It refers to a method of forming carbon nanotubes or the like serving as an electron emission source mainly by vapor phase growth such as D method and electron beam evaporation method. Preferably, a dry method in which a reaction gas is introduced in the presence of an inert gas or hydrogen gas is preferable, and more preferably carbon monoxide is introduced in the presence of hydrogen gas, and a thermally decomposed component is carbon nanotubes on the surface of the mesh electrode. Is preferred.

The phosphor layer is formed on the anode electrode by a known method. For example, a conductive paste containing silver as a main component is formed on the inner surface of the back plate 3 by a print coating method or a thin film method of aluminum to form a wiring layer, and then a low melting point frit glass paste is printed on almost the entire surface except through holes. An insulating layer is formed by a coating method. Next, an anode electrode electrically connected through this through hole is formed by a graphite paste printing method. The phosphor layer 6 is formed on the anode electrode 7 by a printing coating method. Also,
As another method, after the wiring layer and the anode electrode 7 are simultaneously formed on the back plate 3 by the photoetching method or the sputtering method of the aluminum thin film, the insulating layer and the phosphor layer 6 are sequentially formed by the print coating method as described above. You may. Well-known phosphors such as ZnO: Zn can be used as the phosphor.

The display portion of the fluorescent display element comprises (1) a combination of a phosphor layer coated on the patterned anode and an electron emission source formed on the entire surface of the mesh-shaped conductive electrode,
(2) A combination of a phosphor layer coated on the entire surface of the anode and an electron emission source formed on a patterned mesh-shaped conductive electrode, and (3) a phosphor layer coated on the patterned anode and patterned. And a combination with an electron emission source formed on the mesh-shaped conductive electrode. A drive circuit for performing a desired display is provided on either the anode side or the mesh electrode side depending on the combination of these.

[0016]

Example 1 Using a 426 alloy having a thickness of 0.1 mm, a mesh metal electrode having a hexagonal mesh having a pitch of 0.4 mm and a line width of 0.05 mm was produced by etching. Place this mesh metal electrode in the reaction vessel, maintain the temperature at about 650 ° C, supply a mixed gas of carbon monoxide and hydrogen gas at about 100 kPa for about 30 minutes, and apply carbon to the entire surface of the mesh metal electrode. A film of nanotubes was grown. On the other hand, an aluminum wiring layer was formed on the inner surface of the glass substrate to be the back plate, and a black insulating layer was formed over the entire surface of the glass substrate so as to cover the wiring layer. An anode electrode and a (ZnO: Zn) -based phosphor layer electrically connected through a through hole or the like provided in the black insulating layer were formed according to the display pattern. The mesh-shaped metal electrode having the carbon nanotube coating with a gap of 0.3 mm on the display pattern was fixed on a glass substrate and vacuum-sealed to manufacture the fluorescent display element shown in FIG. The fluorescent display device thus obtained was driven by using a mesh metal electrode as a cathode, the display pattern was directly viewed from the front glass plate side, and the brightness at that time was measured.
It was cd / m ² .

Example 2 An iron layer is formed on the surface of the glass substrate by vapor deposition and the pitch is
Hexagonal mesh of 0.4mm and line width 0.05mm is etched.
It was made. A glass substrate on which this reticulated iron layer is formed
The plate was placed in the reaction vessel and meshed in the same manner as in Example 1.
A carbon nanotube film is grown on the entire surface of the iron layer.
It was The inside of the carbon nanotube coating layer of this glass substrate
A front glass substrate to be the surface and the same as in Example 1 were obtained.
Both glass substrates by using the glass substrate that becomes the back plate
The gap between the carbon nanotube coating surface and the fluorescent surface of
 Fluorescent display device is manufactured by setting 0.3mm and vacuum sealing.
did. The obtained fluorescent display device using the mesh iron layer as a cathode
Drive, look directly at the display pattern from the front glass plate side,
When the brightness at that time was measured, it was 2000 cd / m at 600 V. ² 
Met.

Example 3 0.6mm pitch with conductive paste containing iron powder
 , A grid with a line width of 0.2 mm is formed on the glass substrate by printing.
It was The glass substrate with the lattice iron layer formed on the surface is
Place it in a reaction container, and in the same manner as in Example 1, complete the lattice-like iron layer.
A carbon nanotube coating was grown on the surface. this
The inner surface is the carbon nanotube coating layer of the glass substrate
Front glass substrate and back surface obtained in the same manner as in Example 1.
Using the glass substrate that will be the plate, the carbo
The gap between the nanotube coating surface and the fluorescent surface is 0.3 mm.
Then, the fluorescent display element was manufactured by vacuum sealing. Profit
The fluorescent display element is driven by using the lattice-shaped iron layer as a cathode,
Looking directly at the display pattern from the front glass plate side,
The luminance of was measured to be 1200 cd / m at 600V. ² And
It was

[0019]

The present invention comprises a mesh conductive electrode having an electron emission source formed on the surface thereof, and an anode having a phosphor layer formed on the surface of the mesh conductive electrode so as to face the mesh conductive electrode. Since it is a fluorescent display element in which the display section is directly viewed from the mesh-shaped conductive electrode side, it is not necessary to make the fluorescent screen a transmissive type. As a result, high luminance and highly efficient light emission can be obtained.
In addition, since it is a direct-view type fluorescent display device having a diode structure,
And an inexpensive product can be obtained.

Since the mesh-shaped conductive electrode on the surface of which the electron emission source is formed is the mesh-shaped metal electrode and is arranged in the space inside the vacuum container, it is connected to the anode on which the phosphor layer is formed. The distance can be adjusted arbitrarily, and highly efficient light emission can be obtained. Furthermore, since the electron emission source is black, external light reflection is reduced,
A fluorescent display device with high contrast can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a fluorescent display element.

FIG. 2 is a cross-sectional view of another fluorescent display element.

FIG. 3 is a cross-sectional view of another fluorescent display element.

FIG. 4 is a cross-sectional view of a conventional fluorescent display device.

[Explanation of symbols]

1 Fluorescent display element 2 Front glass plate 3 back plate 4 Side plate 5 Mesh metal electrodes 6 Phosphor layer 7 Anode

Continued front page    (72) Inventor Kazunori Tatsuta             700 Wada, Ueno Town, Ise City, Mie Prefecture Ise             Electronic Industry Co., Ltd. (72) Inventor Tadahiko Muroi             700 Wada, Ueno Town, Ise City, Mie Prefecture Ise             Electronic Industry Co., Ltd. F-term (reference) 5C031 DD16 DD17                 5C036 EE04 EE14 EF02 EF05 EG12                       EH01 EH04

Claims (3)

[Claims] 1. A fluorescent display device comprising: a mesh-shaped conductive electrode having an electron emission source formed on a surface thereof; and an anode having a phosphor layer formed on the surface of the mesh-shaped conductive electrode facing the mesh-shaped conductive electrode. The fluorescent display element is characterized in that the phosphor layer is directly viewed from the side of the mesh-shaped conductive electrode. 2. The fluorescent display device according to claim 1, wherein the mesh-shaped conductive electrode is a mesh-shaped metal electrode. 3. The fluorescent display element according to claim 2, wherein the mesh-shaped metal electrode is arranged in a space inside a vacuum container.