JPH09306396A - Field emission type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve emitting efficiency and fineness of a fluorescent unit. SOLUTION: In an FEC(field emission type cathode) array comprising a gate cathode 5, insulating layer 6, cathode electrode 8 and a group of emitter 9, a focusing electrode 4 is provided with a space L1, an electron beam emitted from the FEC is converged, and high fineness is obtained. By setting a space L2 between the focusing electrode 4 and an anode substrate 1 to 500μm, anode voltage Va can be generated 2kV to 5kV, so that emitting efficiency of a fluorescent material layer 3 can be improved.

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 using a field emission cathode, and more particularly to a device having a high anode voltage.

[0002]

2. Description of the Related Art The applied electric field on the surface of a metal or semiconductor is reduced to 10
^At about ⁹ [V / m], electrons pass through the barrier and emit electrons in a vacuum even at room temperature due to the tunnel effect.
This is called field emission, and a cathode that emits electrons based on such a principle is called a field emission cathode. In recent years, it has become possible to make a planar surface emission type FEC made of a field emission type cathode (hereinafter referred to as FEC) array of micron size by making full use of semiconductor processing technology.

FIG. 10 shows an example of the Spindt (Spin).
1 shows a schematic structure of a field emission cathode called dt) type.
This figure is a perspective view of an FEC formed by using a semiconductor fine processing technique. In these figures, the substrate S
A cathode K is provided on the cathode K by vapor deposition or the like, and a cone-shaped emitter E is formed on the cathode K.
Silicon dioxide (SiO ₂ ) is further formed on the cathode K.
A gate GT is provided via an insulating layer I composed of the above, and the cone-shaped emitter E is located in a round hole formed in the gate GT. That is, the tip of the cone-shaped emitter E faces through a hole formed in the gate GT.

[0004] The pitch between the emitters E of the cone-shaped emitters can be manufactured with a pitch of 10 μm or less using a fine processing technique, and tens of thousands to hundreds of thousands of FECs are provided on one substrate S. I can do it. Further, since the distance between the gate GT and the tip of the cone of the emitter E can be made submicron, by applying a voltage Vgk of only several tens of volts between the gate GT and the cathode K, electrons are emitted from the emitter E. Field emission is possible. further,
An anode A is arranged at a predetermined distance from the gate GT, and by applying an anode voltage Va to the anode A, electrons emitted from the emitter E are collected. Although not shown, a fluorescent substance is adhered to the anode A. When electrons are collected by the anode A, the collected electrons excite the fluorescent substance to emit light. This light emission mode is observed through the transparent anode A.

[0005]

By the way, in the conventional field emission display device shown in FIG. 10, the distance between the gate GT and the anode A is about 200 μm. Therefore, the anode voltage Va is several hundreds in terms of withstand voltage. It was said to be about V. However, when the anode voltage Va is about several hundred V, the luminous efficiency of the phosphor is too low, and there is a problem that it is difficult to improve the luminance. Furthermore, the definition is limited when the anode voltage Va is about several hundreds of volts. In general,
The luminous efficiency of currently known phosphors tends to improve as the anode voltage increases. Therefore, it is an object of the present invention to provide a field emission type display device capable of increasing the anode voltage and focusing the electron beam emitted from the field emission cathode to have high definition.

[0006]

In order to achieve the above object, a field emission display device of the present invention comprises a field emission cathode array formed on a cathode substrate and a space L1 spaced apart from the field emission cathode array. And a focusing electrode having a focusing hole for focusing electrons emitted from the field emission cathode array, and a focusing electrode disposed at a distance L2 from the focusing electrode and excited by the electrons focused by the focusing electrode. An anode electrode to which a fluorescent substance for emitting light is applied is provided, and the distance L2 is set to be 10 to 20 times the distance L1.

In the field emission display device,
The diameter d2 of the focusing hole of the focusing electrode is set to be 1 to 10 times the size d1 of the field emission cathode array so that the electron beam emitted from the field emission cathode array is focused to improve the definition. ing. Further, the anode voltage applied to the anode electrode is 2 kV to 5 kV.
As V, the luminous efficiency of the phosphor is improved. Furthermore, the focusing electrode and the anode substrate on which the anode electrode is formed are supported by a cantilever-shaped support member at a distance L2 from each other, and the support region prevents the display area from being reduced.

Furthermore, the focusing electrode is composed of two or more sets of focusing electrodes independent of the field emission cathode array, and by applying a deflection voltage to each of the two or more sets of focusing electrodes, By deflecting the electron beam emitted from the field emission cathode, full color display is possible. Furthermore, at least one set of the focusing electrodes is formed in a recess formed in a deflection substrate mounted on the field emission cathode array, and a spacer is provided to separate the field emission cathode array from the focusing electrode. It can be omitted.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of a field emission type display device according to a first embodiment of the present invention will be described with reference to the sectional view shown in FIG. In FIG. 1, 1 is an anode substrate made of glass or the like, 2 is an anode electrode formed in a thin film on the anode substrate 1, 3 is a phosphor layer deposited on the anode electrode 2, and 4 is field emission. Focusing hole 4 for focusing electron beam
-3 is a focusing electrode, 5 is a gate electrode formed on the insulating layer 6, 6 is an insulating layer formed on the cathode electrode 7, and 7 is a thin film formed on the cathode substrate 8. Cathode electrode, 8 is a cathode substrate made of glass or the like,
Reference numeral 9 denotes a cone-shaped emitter formed in the gate hole formed in the gate electrode 5 and the insulating layer 6.

Further, FIG. 1 shows the structure of one display pixel, and a plurality of emitters 9 are formed in each pixel. That is, a Spindt-type field emission cathode array including the gate electrode 5, the insulating layer 6, the cathode electrode 7, and the plurality of emitters 9 is formed in each pixel. The perspective view of the field emission cathode array of each pixel is as shown in FIG. The size of the field emission cathode array is d1. For example, the shape of the field emission cathode array is a square having a number of emitters of 5 × 5 and a side of about 24 μm. In this case, for example, the gate hole diameter is about 1.2 μm and the pitch of the emitters 9 is about 4 μm.
It has been. The focusing hole 4-3 formed in the focusing electrode 4 is, for example, circular and has a diameter of d2. For example, the diameter d2 is about 100 μm. In addition,
The field emission cathode array may have a circular shape.
Further, the distance between the gate electrode 5 and the focusing electrode 4 is L1, and the distance between the focusing electrode 4 and the anode electrode 2 is L2. For example, the distance L1 is 50 μm, and the distance L2 is about 5.
00 μm.

Further, a gate-cathode voltage Vg1 of, for example, about 50 V is applied between the cathode electrode 7 and the gate electrode 5, and a focusing electrode of 50 to 150 V is applied between the cathode electrode 7 and the focusing electrode 4. -Cathode voltage Vg
2 is applied. The anode electrode 2 has 2 to 5
A kV anode voltage Va is applied. Next, FIG.
The operation of the field emission display device shown in FIG. 1 will be described. The space between the cathode substrate 8 and the anode substrate 1 is evacuated (not shown). By applying the gate-cathode voltage Vg1, electrons are field-emitted from the plurality of emitters 9 of the field emission cathode array. This electron is about 60
Although the electron beam is emitted with a certain degree of spread, the electron beam is focused by the focusing electrode 4 located on the gate electrode 5. Then, the focused electron beam comes to be collected by the anode electrode 2. At this time, the electron beam collides with the phosphor layer 3 and the excited phosphor layer 3 emits light.

Such a field emission cathode array is provided for each of a large number of m × n pixels arranged in a matrix of, for example, m rows and n columns. By controlling the voltage Vg1 between the cathodes according to the image signal, it becomes possible to display an image on the anode substrate 1.
FIG. 3 shows how the field emission type electron beam is focused in the field emission display device shown in FIG. The condition in FIG. 3 is that the diameter d2 of the focusing hole 4-3 of the focusing electrode 4 = 10.
0 μm, interval L1 = 50 μm, interval L2 = 500 μm,
The anode voltage Va = 2 kV, the focusing electrode-cathode electrode voltage Vg2 = 50 V, and the focusing voltage 4 has a thickness t = 50 μm. FEC indicates the above-mentioned field emission cathode array.

As shown in FIG. 3, the electrons emitted from the field emission cathode array (FEC) spread at about 60 degrees, which is illustrated by the action of the focusing electrode 4 to which a positive voltage is applied. Is focused so that the anode electrode 2
It will progress toward. Thus, since the electron beam can be narrowed down, a high-definition display device can be obtained. Although it seems that the distance L1 should be closer to the FEC, if the distance L1 is too close, the electron beam crosses over and the convergence is impaired. That is, the interval L1 is preferably set to about 50 μm. Table 1 shows simulation results of the emission width and the distribution rate of the phosphor 3 deposited on the anode electrode 2 at this time.

[Table 1]

In Table 1, as shown as analysis conditions, the diameter d2 of the focusing hole 4-3 of the focusing electrode 4 is 100 μm,
The interval L1 = 50 μm and the interval L2 = 500 μm are shown, which shows when the anode voltage Va is 2 kV and when it is 5 kV. The emission width is, as shown in Table 1,
When the anode voltage Va = 2 kV, the focusing electrode-cathode electrode voltage Vg2 applied to the focusing electrode 4 is about 50 V.
When it is set to 60 to 60 V, it becomes narrower and the definition is improved.
Further, it is understood that when the anode voltage Va = 5 kV, the definition is improved when the focusing electrode-cathode electrode voltage Vg2 applied to the focusing electrode 4 is set to about 90V to 150V. For example, in the case of full color, R
The (red), G (green), and B (blue) phosphors are formed into a stripe-shaped or dot-shaped phosphor layer 3 having a width of about 80 μm to 100 μm. Even in this case, since the emission width can be set to about 50 μm,
It becomes possible to make full color.

The distribution ratio represents the distribution ratio of electrons emitted from the field emission cathode array, and the best state is when all the emitted electrons are distributed to the anode. As shown in Table 1, when the anode voltage Va is set to 2 kV or 5 kV, even if the voltage Vg2 between the focusing electrode and the cathode electrode is changed from -20 V to 200 V, it is almost 1
Electrons are distributed to the 00% anode. From these facts, when the anode voltage Va is set to 2 kV to 5 kV and the focusing electrode-cathode voltage Vg2 is set to about 50 V to about 150 V, the emission width can be made fine and a good distribution rate can be obtained. You can see that

Next, FIG. 4 shows how the electron beam emitted from the FEC is focused when the thickness t of the focusing electrode 4 is changed. In FIG. 4A, the thickness t of the focusing electrode 4 is 60 μm.
and the thickness t of the focusing electrode 4 is shown in FIG.
Is 70 μm, and FIG.
The thickness t is 80 μm, the figure (d) is the thickness t of the focusing electrode 4 is 90 μm, and the figure (e) is the thickness t of the focusing electrode 4 is 100 μm. The case is shown. Referring to each figure of FIG. 4, the thicker the thickness t of the focusing electrode 4 is, the more the degree of focusing is improved. However, the degree is gentle and the electron beam can be sufficiently focused if the thickness t is about 50 μm or more. .

Further, when the size d1 of the FEC is about 24 μm square, if the diameter of the focusing hole 4-3 formed in the focusing electrode 4 is, for example, 50 μm, the electron beam can be narrowed down more. Since some of the emitted electrons are blocked, the distribution rate is reduced. Therefore, under the above conditions, the hole diameter of the focusing hole 4-3 is set to 100 μm so that the electrons emitted from the FEC are not blocked. That is, the hole diameter d2 of the focusing hole 4-3 is the size d.
It is preferably 1 to 10 times 1. further,
The distance L2 between the anode electrode 2 and the focusing electrode 4 is about 5 because the anode voltage Va is 2 kV to 5 kV.
It is set to be not less than 00 μm. Thus, the distance L2 is equal to the distance L
It is preferably 10 to 20 times that of 1.

In the field emission display device shown in FIG. 1, the anode substrate 1 and the cathode substrate 8 are opposed to each other and the peripheral edges thereof are sealed with a sealing material to form a vacuum container. At this time, the distance between the anode electrode 2 and the focusing electrode 4 is L
It is necessary to build a support plate or a strut between them so that they are spaced apart and face each other. A cross-sectional view of a field emission display device having such a structure is shown in FIG. In FIG. 2, a pillar material 10 is provided between the focusing electrode 4 and the anode electrode 2 on which the phosphor layer 3 is adhered. Further, glass beads 11 are provided between the focusing electrode 4 and the gate electrode 5 in order to separate the focusing electrode 4 from the gate electrode 5 by the distance L1. In this case, the pillar member 10 has a bullet-like shape to prevent the display area of the phosphor layer 3 from decreasing.

The pillar 10 is made of glass, and can be formed into a bullet shape by immersing the tip in a hydrofluoric acid solution, for example. In this case, for example, the diameter of the lower end of the pillar 10 is about 150 μm and the diameter of the upper end is about 50 μm.
The focusing electrode 4 is made of metal, and the FE for each pixel is
It is possible to use one having a large number of focusing holes 4-3 facing C, or one having a focusing hole 4-3 facing FEC formed in ceramic or glass and coating the surface thereof with a metal. Further, instead of the glass beads 11, a supporting plate formed of a thick film can be used, but in this case, when the pressure film wall is close to the emitter 9, electrons collide with the thick film and the thick film is negatively charged. Sometimes. Then, the trajectory of the emitted electron beam may be bent and the focusing action may be impaired. Therefore, the glass beads 11 or the columnar pillar shape should not be provided with an insulating portion on the trajectory of the electron emitted from the emitter 9. Is desirable.

Next, the second embodiment of the field emission display device of the present invention.
The configuration of the embodiment will be described with reference to FIG. In FIG. 5, 1 is an anode substrate made of glass or the like, 2 is an anode electrode formed in a thin film on the anode substrate 1, 3 is a phosphor layer deposited on the anode electrode 2, and 4-1 is field emission. A first focusing electrode having a focusing hole 4-3 for focusing the focused electron beam, and 4-2 is a first focusing electrode.
A second focusing electrode having a focusing hole 4-3 for focusing the electron beam arranged on the focusing electrode 4-1 is formed, 5 is a gate electrode formed on the insulating layer 6, and 6 is on the cathode electrode 7. The formed insulating layer, 7 is a cathode electrode formed in a thin film shape on the cathode substrate 8, 8 is a cathode substrate made of glass or the like, and 9 is formed in the gate hole formed in the gate electrode 5 and the insulating layer 6. It is a cone-shaped emitter.

As described above, the field emission type display device of the second embodiment is different from the field emission type display device of the first embodiment shown in FIG. Electrode 4
-1 is arranged such that the second focusing electrode 4-2 is arranged on the -1 with a distance L3 between them, and other configurations are similar to those of the field emission display device of the first embodiment. The description is omitted. Note that FIG. 5 shows the configuration of one display pixel, and a plurality of emitters 9 are formed in each pixel. That is, a field emission cathode array including a gate electrode 5, an insulating layer 6, a cathode electrode 7 and a plurality of emitters 9 is formed in each pixel.

In the field emission display device of the second embodiment, the anode electrode 2 is used with the cathode electrode 7 as the reference potential.
Is applied to the first focusing electrode 4-1, the second gate voltage Vg2, the second focusing electrode 4-2 to the third gate voltage Vg3, and the gate electrode 5 to the first gate voltage Vg1. There is. When the electric field between the emitter 9 and the gate electrode 5 becomes about 10 ⁹ [V / m] or more by applying the first gate voltage Vg1 to the gate electrode 5, electrons are field-emitted from the emitter 9. . That is,
An electron beam is radiated from the field emission cathode array, the electron beam is focused by the first focusing electrode 4-1 and further focused by the second focusing electrode 4-2 and then collected by the anode electrode 2. . Then, when collected by the anode electrode 2, the phosphor layer 3 adhered to the anode electrode 2 is excited and emits light.

In this case, an image can be displayed on the anode electrode 2 by applying the first gate voltage Vg1 corresponding to the image signal to each gate electrode 5 of the field emission cathode array forming each pixel. become.

Here, a field emission cathode array (FE
FIG. 6 shows how the electron beam emitted from C) is focused. FIG. 6 shows the distance L1 between the FEC and the first focusing electrode 4-1.
Is 50 μm, the thickness t of the first focusing electrode 4-1 is 50 μm,
Distance L3 between the first focusing electrode 4-1 and the second focusing electrode 4-2
Is 150 μm, and the thickness t of the second focusing electrode 4-2 is 50 μm.
m, the distance L2 between the second focusing electrode 4-2 and the anode electrode 2
Is 500 μm, the anode voltage Va is 2 kV, the first gate voltage Vg1 is 90 V, and the second gate voltage Vg2 is 50
It shows the state of electron beam focusing when V and the third gate voltage Vg3 are set to 250V. Observing FIG. 6,
It can be seen that by providing the second focusing electrode 4-2, the electron beam is more focused and the definition is improved. The emission width in the case shown in FIG. 6 is about 26.9 μm
By providing the focusing electrode 4-2, the definition can be improved more than twice.

By the way, the electron beam can be deflected by dividing the second focusing electrode 4-2 and applying different third gate voltages Vg3 to the divided second focusing electrodes 4-2. For example, if the second focusing electrode 4-2 is 2
FIG. 7 shows how the electron beam is deflected when divided. In FIG. 7A, the anode voltage Va = 2 kV, the second gate voltage Vg2 = 100 V, and the third gate voltage Vg3 are −5.
In the case of 0 V and 50 V, it can be seen that the position of the electron beam that is deflected and reaches the anode electrode 2 is displaced.

In the same figure (b), the third gate voltage Vg3 is set to 0V.
And when the voltage is changed to 100 V, the electron beam is more deflected. FIG. 3C shows the third gate voltage Vg3.
Is changed to 0 V and 500 V, and the electron beam is further deflected. Further, FIG. 7D shows that the anode voltage Va = 5 kV, the second gate voltage Vg2 = 100 V,
This is a case where the third gate voltage Vg3 is set to −50 V and 50 V, and the electron beam is not deflected so much because the anode voltage Va is high. In the same figure (e), the third gate voltage Vg3 is set to 0.
The electron beam was slightly deflected when the voltage was changed to V and 100V. The figure (f) shows the third gate voltage Vg.
This is when 3 is changed to 0 V and 500 V, and the electron beam is deflected.

As described above, since the electron beam can be deflected by the focusing electrode, the R, G, and B phosphors are deposited on the anode electrode 2 in a dot shape or a stripe shape so that the color signal can be obtained. By deflecting the electron beam accordingly, a full-color display device can be obtained.
In addition, in the case shown in FIG. 7, the second focusing electrode 4-2 is divided into two to deflect the electron beam, but it may be divided into four or more to perform two-dimensional deflection. Also,
The first focusing electrode 4-1 may also be divided to allow deflection.

FIG. 8 shows the structure of a third embodiment of the display device of the present invention in which the first focusing electrode and the second focusing electrode are divided into deflection electrodes. FIG.
In the figure, 1 is an anode substrate made of glass or the like, 2 is an anode electrode formed in a thin film on the anode substrate 1,
3 is a phosphor layer deposited on the anode electrode 2, 5 is a gate electrode formed on the insulating layer 6, 6 is an insulating layer formed on the cathode electrode 7, and 7 is a thin film on the cathode substrate 8. 2 is a cathode electrode formed on the substrate, 8 is a cathode substrate made of glass or the like, and 9 is a cone-shaped emitter formed in the gate hole formed in the gate electrode 5 and the insulating layer 6.

Numeral 12 is an aluminum thin film deposited on the surface of the phosphor layer 3 and has a function as a metal back. Reference numeral 13 is a support plate composed of a column of glass or the like having a height L2, and the anode substrate 1 and the deflection substrate 15 are separated from each other by a distance L2. 14 is the height L1
The support plate is made of glass beads or seal glass, and the cathode substrate 8 and the deflection substrate 15 are separated by a distance L1. Denoted at 15 is a deflection substrate in which a deflection hole 15-1 made of glass or ceramic is formed. The first deflection electrode 16 is provided on each of the upper surface and the lower surface thereof.
And the second deflection electrode 17 is formed. Reference numeral 16 denotes a first deflection electrode formed on the lower surface of the deflection substrate, which is divided into, for example, two. Reference numeral 17 denotes a second deflection electrode formed on the upper surface of the deflection substrate 15, and the first deflection electrode 16
For example, it is divided into two so as to be orthogonal to. Reference numeral 18 denotes a resistance layer formed between the cathode electrode 7 and the group of emitters 9, which uniformizes the electron emission from each emitter 9 and minimizes the influence when the emitter 9 and the gate electrode 5 are short-circuited. I try to keep it to the limit. In addition, for example, the interval L1 is about 50 μm, and the interval L2 is 500 μm.

In the third embodiment shown in FIG. 8, the structure relating to the anode electrode 1 to the emitter 9 is the same as that of the first embodiment, and therefore its explanation is omitted. Further, since the phosphor layer 3 is metal-backed with the aluminum thin film 12, the anode voltage Va is preferably set to 2 kV or more. In this case, when the phosphor layer 3 emits light, the light radiated to the cathode substrate 8 side receives the aluminum thin film 12
Since it is reflected by and is transmitted through the anode substrate 1, the brightness of the display device can be improved. Also,
Since the aluminum thin film 12 is electrically connected to the anode electrode, it is possible to prevent the phosphor layer 3 from being negatively charged by the electron beam, and it is possible to prevent a decrease in brightness.

Furthermore, the divided first deflection electrode 1
6 and the second deflection electrode 17 independently have a deflection voltage Vg.
2 or the deflection voltage Vg3 can be applied. In this case, since the electron beam can be deflected in a two-dimensional plane by changing the deflection voltages Vg2 and Vg3, the anode, electrode 2 is coated with R, G, and B phosphors in a dot shape or a stripe shape. If the electron beam is deflected according to the color signal, a full-color display device can be obtained. The first deflecting electrode 16 and the second deflecting electrode 17 may be divided into four or more to perform the deflection. Further, the focusing hole 15-1 can be formed in the deflection substrate 15 by etching.

Next, FIG. 9 shows the configuration of a modification of the third embodiment of the display device of the present invention. In this modification, the deflection substrate 15 is laminated on the cathode substrate 8 on which the field emission cathode array is formed. In this case, in order to separate the gate electrode 5 and the first deflection electrode 16 at the interval L1, the deflection substrate 15 is etched in a concave shape so that the first deflection electrode 16 is formed on the upper surface in the concave portion having the depth L1. I have to. As a result, in the modification shown in FIG. 9, the support plate 14 can be omitted, and the display device can be easily manufactured. Further, a second deflection electrode 16 is formed on the upper surface of the deflection substrate 15.
FIG. 9 shows a configuration for two pixels, and a supporting member 10 is provided between the pixels to set the deflection substrate 15 to the cathode substrate 8.
Contact. Further, the deflection substrate 15 and the cathode substrate 8 may be adhered to each other with sealing glass or the like. The support member 10 may be in the shape of a bullet as shown in FIG.

Further, the divided first deflecting electrode 16 and the second deflecting electrode 17 have their electrode dividing directions orthogonal to each other, and the first deflecting electrode 16 and the second deflecting electrode 17 are separated.
The deflection voltage Vg2 or the deflection voltage Vg3 can be independently applied to each of the divided electrodes. Therefore, since the electron beam can be deflected in a two-dimensional plane by changing the deflection voltages Vg2, Vg3, the R, G, B phosphors are deposited on the anode electrode 2 in a dot shape or a stripe shape. If the electron beam is deflected according to the color signal, a full-color display device can be obtained.

The first deflecting electrode 16 and the second deflecting electrode 17 may be divided into four or more to perform the deflection. Further, the deflection holes 15-1 formed corresponding to the field emission cathode array provided for each pixel on the deflection substrate 15 are formed on the deflection substrate 15 by etching. Anode substrate 1 and cathode substrate 8
Since it is generally made of glass, it is preferable that the deflection substrate 15 is also made of glass. Also, the first deflection electrode 1
It is preferable that the surfaces of the sixth deflection electrode 17 and the second deflection electrode 17 are covered with an insulating coating in order to prevent a short circuit. Further, the cathode substrate 8 is etched to form a concave portion,
By forming a field emission cathode array in this concave portion, a short circuit with the deflection substrate 15 may be prevented and the distance L1 may be maintained. Furthermore, in the modification shown in FIG. 9, the first deflection electrode 16 may be omitted.

[0035]

As described above, according to the present invention, in the field emission display device, the diameter d2 of the focusing hole of the focusing electrode is set to be 1 to 10 times larger than the size d1 of the field emission cathode array. Since the electron beam emitted from the cathode array is focused, the definition of the display device can be improved. Further, since the anode voltage applied to the anode electrode is set to 2 kV to 5 kV, the luminous efficiency of the phosphor can be improved. Furthermore, since the focusing electrode and the anode substrate on which the anode electrode is formed are supported by the cantilever-shaped support member at a distance L2 from each other, it is possible to prevent the display region from being reduced by the support pillar. it can.

Furthermore, the focusing electrode is composed of two or more sets of focusing electrodes independent of the field emission cathode array, and by applying a deflection voltage to each of the two or more sets of focusing electrodes, the field emission cathode is formed. By deflecting the electron beam emitted from, it is possible to achieve full color. Furthermore, by forming at least one set of focusing electrodes in a recess formed in a deflection substrate placed on the field emission cathode array, a spacer for separating the field emission cathode array from the focusing electrode is omitted. can do.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a first embodiment of a display device of the present invention.

FIG. 2 is a cross-sectional view showing a configuration in which each substrate is supported at predetermined intervals in the first embodiment of the display device of the present invention.

FIG. 3 is a diagram showing how electron beams are focused in the first embodiment of the display device of the present invention.

FIG. 4 is a diagram showing how the electron beam is focused when the thickness of the focusing electrode is changed in the first embodiment of the display device of the present invention.

FIG. 5 is a sectional view showing a configuration of a second embodiment of a display device of the present invention.

FIG. 6 is a diagram showing how an electron beam is focused in the second embodiment of the display device of the present invention.

FIG. 7 is a diagram showing how an electron beam is deflected in the second embodiment of the display device of the present invention.

FIG. 8 is a sectional view showing a configuration of a third embodiment of a display device of the present invention.

FIG. 9 is a cross-sectional view showing the configuration of a modified example of the third embodiment of the display device of the present invention.

FIG. 10 is a diagram showing a schematic structure of a conventional field emission cathode called a Spindt type.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anode substrate 2 Anode electrode 3 Phosphor layer 4,4-1,4-2 Focusing electrode 4-3 Focusing hole 5 Gate electrode 6 Insulating layer 7 Cathode electrode 8 Cathode substrate 9 Emitter 10 Support material 11 Glass beads 12 Aluminum thin film 13 , 14 Support plate 15 Deflection substrate 15-1 Deflection hole 16, 17 Deflection electrode

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masaharu Tomita 629 Oshiba, Mobara-shi, Chiba Futaba Electronics Co., Ltd. (72) Inventor Satoshi Yamaguchi 629 Oshiba, Mobara-shi, Chiba Futaba Electronics Co., Ltd.

Claims (6)

[Claims] 1. A field emission cathode array formed on a cathode substrate, and a focusing hole for focusing electrons emitted from the field emission cathode array, which is arranged on the field emission cathode array with a distance L1 therebetween. A focusing electrode and an anode electrode, which is disposed on the focusing electrode with a distance L2 therebetween and is coated with a phosphor excited and emitted by electrons focused by the focusing electrode, the distance L2 being a distance L1. The field emission display device is characterized by being 10 to 20 times larger than 2. The diameter d2 of the focusing hole of the focusing electrode is 1 to 10 times the size d1 of the field emission cathode array.
The field emission display device according to claim 1, wherein the field emission display device is doubled. 3. The field emission display device according to claim 1, wherein the anode voltage applied to the anode electrode is set to 2 kV to 5 kV. 4. The method according to claim 1, wherein the focusing electrode and the anode substrate on which the anode electrode is formed are supported by a cantilever-shaped support member at a distance L2 from each other. The field emission display device described. 5. The focusing electrode is composed of two or more sets of focusing electrodes independent of the field emission cathode array, and by applying a deflection voltage to each of the two or more sets of focusing electrodes, the electric field is generated. 5. The field emission display device according to claim 1, wherein the electron beam emitted from the emission cathode is deflected. 6. The field emission according to claim 5, wherein at least one set of the focusing electrodes is formed in a concave portion provided in a deflection substrate mounted on the field emission cathode array. Type display device.