JPH09306393A - Field emission type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily form a vacuum space maintainable and avoid limiting of an emitting part and decreasing of an emitting area by a spacer. SOLUTION: A field emission type display element, provided with an anode electrode 8 and a cathode electrode 6 opposed with a prescribed space, fluorescent material 9 formed in an opposed surface to the cathode electrode 6 of the anode electrode 8 and an electron emitter 10 formed in an opposed surface to the anode electrode 8 of the cathode electrode to have negative electron affinity, is set up in a vacuum structure 1 having a display surface. In this way, since a capacity, which must be formed with a vacuum space, can be enlarged, forming of vacuum and maintaining of vacuum are facilitated. Since the atmospheric pressure can be received by the vacuum structure 1, when the vacuum structure 1 itself is formed in a structure durable against the atmospheric pressure, even in the case of forming a large area of a field emission type display device, a constitution for arranging a spacer 11 only in the periphery of the anode electrode 8 and the cathode electrode 6 can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field emission display device.

[0002]

2. Description of the Related Art In recent years, as a self-luminous display that does not require a backlight, a field emission display device (hereinafter, referred to as "FED" as appropriate. The FED is a Field E
(abbreviation of mission Display) is drawing attention. This FED is thin, consumes less power, has a wide viewing angle, a high response speed, and a wide operating temperature range, and can be expected to have higher performance than a liquid crystal display.

As shown in FIG. 5, in the FED, a face glass 80 and a back glass 81, which are display surfaces, are opposed to each other with a spacer 82 at a predetermined interval, and are formed by the face glass 80, the back glass 81 and the spacer 82. The internal space is a vacuum of about 10 ^-6 Torr. A transparent conductive film 83 as an anode electrode is formed on the surface of the face glass 80 facing the back glass 81, and a phosphor 84 is formed on the surface of the transparent conductive film 83. In addition, a conductive film 85 as a cathode electrode is formed on the surface of the back glass 81 facing the face glass 80.
Are formed on the surface of the conductive film 85, and diamond-like carbon (hereinafter, referred to as an electron emitter having a negative electron affinity)
It is called “DLC”. In addition, DLC is Diamond
A film 86 (abbreviation of Like Carbon) is formed.

In the FED having the above structure, the DLC film 8
An electric field equal to or higher than the threshold value of 6 is applied between the transparent conductive film 83 and the conductive film 85 serving as the anode electrode and the cathode electrode to cause electrons to be emitted from the DLC film 86 serving as an electron emitter, and the emitted electrons emit fluorescence. The phosphor 84 is caused to emit light by utilizing the collision with the body 84.

[0005]

In the above FED, in order to emit electrons from the DLC film 86, the same DL is used.
It is necessary to apply an electric field above the threshold of the C film 86. Here, the drive voltage of the drive IC that applies a voltage to the FED is usually about 5 to 100 V, and the upper limit thereof is 200.
It is about V. The threshold value of the DLC film 86 is usually about 20 V / μm. Therefore, the transparent conductive film 83 and the conductive film 85 serving as the anode electrode and the cathode electrode, respectively.
In order to give an electric field necessary for electrons to be emitted from the DLC film 86, the gap between the transparent conductive film 83 and the conductive film 85 needs to be about 10 μm.

However, the transparent conductive film 8 is formed by the face glass 80, the back glass 81 and the spacer 82.
It is not easy to make a very high internal vacuum of about 10 ^-6 Torr and maintain it in a very narrow internal space where the gap between 3 and the conductive film 85 is about 10 μm. That is,
When a vacuum is applied between the face glass 80 and the back glass 81, the adsorbed gas is desorbed from the surfaces of the face glass 80 and the back glass 81, but the gap is small, and the face glass 80, the back glass 81 and the spacer 82.
When the volume of the vacuum space formed by is small, the influence of the degree of vacuum reduction due to desorption of the adsorbed gas becomes large,
The gap between the transparent conductive film 83 and the conductive film 85 is 10 μm
It is difficult to make a very high internal vacuum of about 10 ⁻⁶ Torr and maintain it.

Further, since atmospheric pressure is applied to the spacer 82 for forming a vacuum space between the face glass 80 and the back glass 81, especially when the area of the face glass 80 and the back glass 81 is enlarged, the face glass 80 is formed.
Also, with the configuration in which the spacer 82 is provided only around the back glass 81, it is difficult to maintain the gap between the transparent conductive film 83 and the conductive film 85 with an extremely narrow gap of about 10 μm. Therefore, the face glass 80 and the back glass 8
It is necessary to dispose a spacer other than the periphery of 1, and in this case, there are disadvantages that the spacer limits the light emitting portion or reduces the light emitting area.

The present invention has been made in view of the above circumstances, and it is possible to easily form and maintain a vacuum space, and when the area is increased, the light emitting portion is limited by the spacer and the light emitting area is reduced. It is a technical problem to be solved to provide a field emission display device capable of avoiding the inconvenience.

[0009]

In the field emission display device of the present invention for solving the above-mentioned problems, an anode electrode and a cathode electrode, which are opposed to each other at a predetermined interval, and a surface of the anode electrode facing the cathode electrode. In a vacuum structure having a display surface, there is provided a field emission display element including a phosphor formed on the cathode and an electron emitter having a negative electron affinity formed on a surface of the cathode electrode facing the anode electrode. It is characterized by being installed.

In the field emission display device of the present invention, the field emission display element is installed in the vacuum structure, so that the volume for forming the vacuum space can be increased. Therefore, it is easy to form and maintain the vacuum. Further, the vacuum structure can receive the atmospheric pressure, and the spacer for maintaining the predetermined distance between the anode electrode and the cathode electrode is not subjected to the atmospheric pressure. Therefore, if the vacuum structure itself has a structure capable of withstanding the atmospheric pressure, a spacer for maintaining a predetermined distance between the anode electrode and the cathode electrode is used as the anode electrode and the cathode electrode even when the field emission display device has a large area. It may be arranged only around the cathode electrode. Therefore, it is possible to avoid the disadvantage that the light emitting portion is limited by the spacer and the light emitting area is reduced.

[0011]

Embodiments of the present invention will be specifically described below. In the FED of this embodiment, a field emission display element is installed in a vacuum structure having a display surface. The vacuum structure has a display surface capable of displaying the light emission of a field emission display element, and can withstand atmospheric pressure when the vacuum structure is evacuated to about 10 ⁻⁶ to 10 ⁻⁷ Torr. There is no particular limitation as long as it has a structure. For example, it is possible to adopt a structure in which a transparent face substrate that serves as a display surface and a back substrate are disposed so as to face each other, and the periphery of both substrates is sealed by a side substrate. For example, a transparent glass substrate such as soda lime glass or low alkali glass is adopted as the transparent face substrate, a soda lime glass substrate or an acrylic resin substrate is adopted as the back substrate, and a soda lime glass substrate or a soda lime glass substrate is adopted as the side substrate. An acrylic resin substrate can be adopted. The thickness of the transparent face substrate back substrate and the side substrate may be about 1 to 3 mm. Further, the gap between the transparent face substrate and the back substrate can be about 2 to 5 mm.

As a method for evacuating the inside of the vacuum structure, a method of pulling out a glass tube for vacuuming from the side substrate, vacuuming the glass tube, and then melting the glass tube is adopted. You can If necessary, a ring-shaped metal (magnesium, barium, etc.) called a getter is placed inside the vacuum structure, and the metal is evaporated by high-frequency heating during vacuuming or after vacuuming and sealing. It is also possible to increase the degree of vacuum in the vacuum structure. The degree of vacuum in the vacuum structure is 1
It can be about 0 ⁻⁶ to 10 ⁻⁷ Torr.

In the field emission display device, the anode electrode and the cathode electrode are arranged to face each other at a predetermined interval, the phosphor formed on the surface of the anode electrode facing the cathode electrode, and the phosphor of the cathode electrode. And an electron emitter having a negative electron affinity formed on the surface facing the anode electrode. The anode electrode and the cathode electrode may be transparent electrodes on the side of the display surface of the vacuum structure, and may be ordinary metal electrodes or transparent electrodes on the side opposite to the display surface. As a transparent electrode, an ITO thin film, SnO ₂
Thin film, the In ₂ O ₃ thin film or In ₂ O ₃ -SnO ₂ thin film and the like, as the metal electrode may be employed Al thin film or Cu, Ti, and Cr thin film or the like. The thickness of the anode electrode and the cathode electrode can be about 0.1 to 2.0 μm.

The phosphor formed on the surface of the anode electrode facing the cathode electrode is Zn which emits green light.
O: Zn, ZnS: M that emits amber (amber) color
n or the like can be adopted. The phosphor can be uniformly applied at a rate of about 1 to 10 mg / cm ² by a sedimentation method or the like. As the electron emitter having a negative electron affinity formed on the surface of the cathode electrode facing the anode electrode, a DLC thin film, a crystalline diamond thin film, or the like can be adopted. However, it is preferable to use the DLC thin film from the viewpoint that the electron emission ability is high and the driving voltage can be lowered. The DLC thin film and the diamond thin film can be formed by a plasma CVD method, a laser vapor deposition method, or the like. The production conditions by the plasma CVD method are, for example, replacement gas: N ₂ , feed material: hydrocarbon gas, pressure:
30-80 mTorr, bias voltage: 0.4-1.4
kV, temperature: It can be set to -10 to 200 ° C. In the laser vapor deposition method, for example, Nd: YAG laser (pulse oscillation) light is irradiated onto a graphite target plate to melt the graphite target plate, and carbon atoms can be deposited on the glass substrate. The thickness of the electron emitter is 1
It can be about 30 μm.

The gap between the anode electrode and the cathode electrode can be appropriately set according to the threshold value of the electron emitter and the magnitude of the drive voltage of the drive IC for applying a voltage to the FED of the present invention, and usually. It can be about 5 to 50 μm. For example, one of the anode electrode and the cathode electrode is formed on one of the back substrate and the transparent face substrate that will be the display surface constituting the vacuum structure, and one of the anode electrode and the cathode electrode is formed. By arranging the substrate opposite to the back substrate or the transparent face substrate with a spacer made of silica or resin beads at a predetermined interval, and forming the other of the anode electrode and the cathode electrode on this substrate. It is possible to maintain a constant gap between the anode electrode and the cathode electrode.

As the substrate on which the anode electrode or the cathode electrode is formed, the anode electrode or the cathode electrode is formed on the back substrate, and the back substrate is arranged to face the back substrate at a constant interval. In this case, it is necessary to use a transparent substrate in order to transmit the light emission of the phosphor to the transparent face substrate side which is the display surface. on the other hand,
When one of the anode electrode and the cathode electrode is formed on the transparent face substrate and the above-mentioned substrate is arranged to face the transparent face substrate at a constant interval via a spacer, an Al substrate or the like is used as the substrate. In this case, since the other of the anode electrode and the cathode electrode can be formed on the Al substrate or the like by vapor deposition or sputtering, there is an advantage that the formation of the Al film on the glass substrate can be omitted. is there.

Further, an anode electrode is formed on the transparent face substrate or the back substrate, and a cathode electrode and electron emission are formed on the surface of the substrate which is arranged to face the transparent face substrate or the back substrate on which the anode electrode is formed. When forming the body, the substrate may be thin because it does not undergo atmospheric pressure. In the FED of the present embodiment having the above-mentioned configuration, the field emission display element is installed in the vacuum structure, so that the volume for forming the vacuum space can be increased. Therefore, it is easy to form and maintain the vacuum. That is, when the vacuum structure is evacuated, the adsorbed gas is desorbed from the glass substrate or the like that constitutes the vacuum structure.
When the volume of the vacuum structure is large, the influence of the vacuum degree reduction due to the desorption of the adsorbed gas becomes small. Therefore, it is easy to make the vacuum structure a high vacuum of about 10 ^-6 Torr and to maintain it. Becomes

Further, since the vacuum structure can receive the atmospheric pressure, no atmospheric pressure is applied to the spacer for maintaining the predetermined distance between the anode electrode and the cathode electrode.
Therefore, if the vacuum structure itself has a structure capable of withstanding the atmospheric pressure, a spacer for maintaining a predetermined distance between the anode electrode and the cathode electrode is used as the anode electrode and the cathode electrode even when the field emission display device has a large area. It may be arranged only around the cathode electrode. Therefore, it is possible to avoid the disadvantage that the light emitting portion is limited by the spacer and the light emitting area is reduced.

[0019]

Embodiments of the FED of the present invention will be specifically described below with reference to the drawings. (Embodiment 1) The FED of this embodiment shown in the schematic sectional view of FIG.
The field emission display element 2 is installed in the vacuum structure 1. Note that this FED has the upper side of FIG. 1 as the display side, and the phosphor is disposed on the upper side of FIG. 1 and the electron emitter is disposed on the lower side of FIG.

The vacuum structure 1 includes a transparent face glass substrate 3 serving as a display surface, a back glass substrate 4 facing the transparent face glass substrate 3 at a constant interval (3 mm), and a transparent face glass. It is composed of a substrate 3 and a side glass substrate 5 that seals the periphery of the back glass substrate 4. The transparent face glass substrate 3,
Both the back glass substrate and the side glass substrate 5 are made of soda lime glass having a thickness of 1.1 mm. Further, the vacuum structure 1 has a field emission display element 2 inside.
Is installed, a glass tube for vacuuming is pulled out from the side glass substrate 5, the glass tube is evacuated, and then the glass tube is melt-cut to obtain 10 ⁻⁶ Torr.
It is said to be the degree of vacuum.

The field emission display element 2 is composed of a cathode electrode 6 formed on the inner surface of the back glass substrate 4 and a soda having a thickness of 0.5 mm, which is arranged to face the back glass substrate 4 at a predetermined interval. A transparent glass substrate 7 made of lime glass, a transparent anode electrode 8 formed on the surface of the transparent glass substrate 7 facing the back glass substrate 4, and a transparent anode electrode 8 formed on the surface of the transparent anode electrode 8 facing the cathode electrode 6. And a fluorescent substance 9, an electron emitter 10 having a negative electron affinity formed on the surface of the cathode electrode 6 facing the transparent anode electrode 8, and the back glass disposed around the transparent glass substrate 7. It is composed of a plate-like spacer 11 made of a resin mixed with silica, in which a transparent glass substrate 7 is opposed to the substrate 4 at a predetermined interval. In addition,
The gap between the cathode electrode 6 and the transparent anode electrode 8 is 10 μm.

The cathode electrode 6 is made of an Al metal thin film having a thickness of 0.2 μm formed by vapor deposition, and the transparent anode electrode 8 is made of an ITO thin film having a thickness of 0.2 μm formed by sputtering. In addition, the phosphor 9
Is a green light-emitting ZnO formed by a sedimentation method or the like:
It is made of Zn and has a thickness of 10 μm. The electron emitter 10 is made of a DLC thin film having a film thickness of 5 μm formed by the plasma CVD method.

Therefore, in the FED of this embodiment, the cathode electrode 6 is formed on the surface of the back glass substrate 4, and the electron emitter 10 is formed on the surface of the cathode electrode 4.
Further, a transparent glass substrate 7 is arranged to face the back glass substrate 4 via a spacer 11 at a predetermined interval, and a transparent anode electrode 8 is formed on a surface of the transparent glass substrate 7 facing the back glass substrate 4. A phosphor 9 is formed on the surface of the transparent anode electrode 8 facing the cathode electrode 6. Then, when a predetermined electric field is applied between the cathode electrode 6 and the transparent anode electrode 8 from a driving power source (not shown), the electrons emitted from the electron emitter 10 collide with the phosphor 9, whereby the phosphor 9 has a predetermined color. The emitted light is transmitted through the transparent anode electrode 8, the transparent glass substrate 7 and the transparent face substrate 3 to be displayed.

(Embodiment 2) In the FED of the present embodiment shown in the schematic sectional view of FIG. 2, the lower side of FIG. 2 is the display side, and the phosphor is arranged on the upper side of FIG. The electron emitter is arranged on the lower side. That is, the transparent face glass substrate 3 is arranged on the lower side of FIG. 2, and the back glass substrate 4 is arranged on the upper side of FIG. Then, a transparent cathode electrode 6'made of an ITO thin film is formed on the inner surface of the transparent face glass substrate 3, and an electron emitter 10 is formed on the surface of this transparent cathode electrode 6 '. Also,
An Al substrate 7'is arranged at a predetermined interval to the transparent face glass substrate 3 via a spacer 11, and an anode electrode 8'made of an Al thin film is provided on a surface of the Al substrate 7'which faces the transparent face glass substrate 3. Are formed on the surface of the anode electrode 8'facing the transparent cathode electrode 6 '.
Are formed. The other configurations are similar to those of the above-described first embodiment, and thus the description thereof will be omitted.

In the FED of the second embodiment, electrons emitted from the electron emitter 10 collide with the phosphor 9 when a predetermined electric field is applied between the transparent cathode electrode 6'and the anode electrode 8'from a driving power source (not shown). As a result, the phosphor 9 emits light of a predetermined color, and this emitted light is transmitted through the transparent cathode electrode 6'and the transparent face substrate 3 to be displayed. (Embodiment 3) The FED of this embodiment shown in the schematic sectional view of FIG.
In FIG. 3, the upper side of FIG. 3 is the display side, the electron emitter is disposed on the upper side of FIG. 3, and the phosphor is disposed on the lower side of FIG.

That is, the transparent face glass substrate 3 is disposed on the upper side of FIG. 3, and the back glass substrate 4 is disposed on the lower side of FIG.
Are arranged. Then, an anode electrode 8'made of an Al thin film is formed on the inner surface of the back glass substrate 4, and a phosphor 9 is formed on the surface of this anode electrode 8 '. Further, a transparent glass substrate 7 is arranged at a predetermined interval to the back glass substrate 4 via a spacer 11, and a transparent cathode electrode 6 made of an ITO thin film is formed on a surface of the transparent glass substrate 7 facing the back glass substrate 4. 'Is formed,
An electron emitter 10 is formed on the surface of the transparent cathode electrode 6'facing the anode electrode 8 '. The other configurations are similar to those of the above-described first embodiment, and thus the description thereof will be omitted.

In the FED of the third embodiment, electrons emitted from the electron emitter 10 collide with the phosphor 9 when a predetermined electric field is applied between the transparent cathode electrode 6'and the anode electrode 8'from a driving power source (not shown). As a result, the phosphor 9 emits light of a predetermined color, and this emitted light is transmitted through the transparent cathode electrode 6 ', the transparent glass substrate 7 and the transparent face substrate 3 for display.

(Embodiment 4) In the FED of this embodiment shown in the schematic sectional view of FIG. 4, the lower side of FIG. 4 is the display side, and the electron emitter is disposed on the upper side of FIG. 4 is provided with a phosphor on the lower side. That is, the transparent face glass substrate 3 is arranged on the lower side of FIG. 4, and the back glass substrate 4 is arranged on the upper side of FIG. Then, a transparent anode electrode 8 made of an ITO thin film is formed on the inner surface of the transparent face glass substrate 3, and the transparent anode electrode 8 is formed.
Has a phosphor 9 formed on its surface. Further, an Al substrate 7'is arranged at a predetermined interval to the transparent face glass substrate 3 via a spacer 11, and a cathode electrode made of an Al thin film is provided on a surface of the Al substrate 7'which faces the transparent face glass substrate 3. 6 is formed, and the electron emitter 10 is formed on the surface of the cathode electrode 6 facing the transparent anode electrode 8. The other configurations are similar to those of the above-described first embodiment, and thus the description thereof will be omitted.

In the FED of the fourth embodiment, when a predetermined electric field is applied between the cathode electrode 6 and the transparent anode electrode 8 from a driving power source (not shown), the electrons emitted from the electron emitter 10 collide with the phosphor 9, As a result, the phosphor 9 emits light of a predetermined color, and this emitted light is transmitted through the transparent anode electrode 8 and the transparent face substrate 3 to be displayed.

[0030]

As described above in detail, in the field emission display device of the present invention, since the field emission display element is installed in the vacuum structure, the volume for forming the vacuum space can be increased. This makes it easy to create and maintain a vacuum. Therefore, the manufacturing cost and the manufacturing process can be simplified.

Further, since the vacuum structure can receive the atmospheric pressure, if the vacuum structure itself can withstand the atmospheric pressure, the anode electrode and the cathode electrode can be formed even when the area of the field emission display device is increased. A spacer for maintaining a predetermined interval can be provided only around the anode electrode and the cathode electrode, and therefore the spacer limits the light emitting portion and reduces the light emitting area. It is possible to avoid it.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an FED according to a first embodiment.

FIG. 2 is a schematic sectional view of an FED of the second embodiment.

FIG. 3 is a schematic sectional view of an FED of the third embodiment.

FIG. 4 is a schematic sectional view of an FED of the fourth embodiment.

FIG. 5 is a schematic sectional view of a conventional FED.

[Explanation of symbols]

1 is a vacuum structure, 2 is a field emission display element, 3 is a transparent face glass substrate, 4 is a back glass substrate, 6 is a cathode electrode, 6'is a transparent cathode electrode, 7 is a transparent glass substrate, and 7'is an Al substrate. , 8 is a transparent anode electrode, 8'is an anode electrode, 9 is a phosphor, 10 is an electron emitter, and 11 is a spacer.

Claims (1)

[Claims] 1. An anode electrode and a cathode electrode, which are arranged to face each other at a predetermined interval, a phosphor formed on a surface of the anode electrode facing the cathode electrode, and a surface of the cathode electrode facing the anode electrode. A field emission display device, comprising: a field emission display device having an electron emitter having a negative electron affinity formed on the substrate, the field emission display device being installed in a vacuum structure having a display surface.