JP2001100693A - Method for driving image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a drop of contrast in a field emission display combining a low electric field electron emission element with phosphor. SOLUTION: Reverse bias is applied between the gate and the cathode of the electron emission element connected to a scanning line of a non-selection state or the scanning line of the non-selection state is brought into a high impedance state. Unwanted electron emission from the electron emission element on the scanning line of the non-selection state is eliminated or reduced, so that the drop of the contrast is prevented, and an excellent image is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for driving an image display device for displaying an image using electron-emitting devices and phosphors arranged in a matrix.

[0002]

2. Description of the Related Art A field emission display (hereinafter referred to as "FED") is a device in which the intersections of electrode groups orthogonal to each other are pixels, each pixel is provided with an electron-emitting device, and the voltage applied to each electron-emitting device is adjusted. This adjusts the amount of emitted electrons, accelerates the emitted electrons in a vacuum, irradiates the phosphor, and causes the phosphor in the irradiated portion to emit light. Examples of the electron-emitting device include a device using a field emission type cathode, a device using a MIM (Metal-Insulator-Metal) type electron source, a device using a carbon nanotube cathode, and a device using a diamond cathode.

A carbon nanotube cathode emits electrons by applying an electric field to a linear material having a diameter of several to several tens of nm made of carbon.
Research Society Symposium Proceedings, Vol. 509
(1998) pp. 107-112. Electron emission occurs even when the externally applied electric field is as low as about 0.7 V / μm.Therefore, it has excellent features as an electron-emitting device for an image display device, such as the possibility of lowering the driving voltage and realizing a bright display device. are doing.

[0004] A diamond cathode emits electrons by applying an external electric field to diamond. For example, a diamond cathode is described in IEEE Transaction Electron Devices, Vol.
No. 4 (1999), pp. 787 to 791. Like a carbon nanotube cathode, electron emission occurs even at an external electric field as low as about 3 V / μm, so that it has excellent characteristics as an electron-emitting device for an image display device.

[0005]

The carbon nanotube cathode and the diamond cathode have an excellent feature of emitting electrons even at a low external electric field. And the contrast is reduced.
The present invention provides a driving method that solves this problem.

[0006] As a result of a detailed study of the prior art, the inventors have clarified that the causes of the above-mentioned decrease in contrast are as follows.

FIG. 2 shows the structure of a carbon nanotube cathode. Form a cathode conductor 10 on a substrate 14,
A cathode 13 is formed thereon, and a gate 11 is formed therearound via an insulating layer 12 having a thickness h. The diameter of the gate hole, that is, the portion where the cathode is formed is D. An anode 100 is located at a distance L from the cathode surface. Substrate 10-Anode 100
There is a vacuum between them. The material of the cathode 13 is a carbon nanotube. The diamond cathode is the cathode in FIG.
13 using a diamond thin film as the material,
Other configurations are almost the same.

[0008] Typical values are as follows: Insulating layer thickness h = 1 to 1
00 μm, gate hole diameter D = 1 to 100 μm (gate hole radius R =
0.5 to 50 μm), and the distance L between the cathode and the anode is about 1 to 3 mm.

Now, assume that the potential of the cathode conductor 10 is 0V. When a voltage Vg (> 0 V) is applied to the gate 11, an electric field is applied to the surface of the cathode, and electrons are emitted from the cathode 13. The emitted electrons are accelerated by the acceleration voltage Va applied to the anode 100 and reach the anode 100. As will be described later in detail in an embodiment, by forming a phosphor on the anode 100, the phosphor emits light.

In a broad field emission display composed of an electron-emitting device and a phosphor, it is important to select the phosphor and the acceleration voltage Va. This selection can be roughly classified into two types. Va = 400 using a slow electron beam excitation type phosphor.
About 800 V ("low acceleration voltage type"), or Va = 4-8 K using a phosphor for CRT or a phosphor similar thereto.
V ("high acceleration voltage type"). Recent research has revealed that the high acceleration voltage type is more preferable because the life deterioration of the phosphor is mainly controlled by the injected charge amount (Coulomb deterioration). Typical parameters for the high acceleration voltage type are Va = about 4 to 8 KV,
L = 1 to 3 mm.

However, in the case of a cathode that emits electric field in a low electric field, such as a carbon nanotube cathode or a diamond cathode, the use of a high-voltage acceleration type configuration causes the above-described problem of a decrease in contrast. Hereinafter, the mechanism of this contrast reduction will be described.

How the electric field intensity Ek applied to the surface of the cathode 13 changes with the gate voltage Vg was determined by simulation. The parameters used in the simulation were L = 1 mm, Va = 6 KV, D = 20 μm (R = 10 μm).
m), h = 5 μm.

FIG. 3 shows the electric field intensity Ek (V / μm) on the cathode surface.
The position dependency of the cathode surface was determined. The horizontal axis is a value r / R obtained by normalizing the position r (see FIG. 2) with the gate hole center being 0 as the gate hole radius R. When Vg = 50V,
Ek = 7 to 9 V / μm, and an electric field sufficient to cause electron emission is applied to the entire cathode surface. On the other hand, when Vg = 0, Ek is close to 0 in the peripheral portion of the gate hole (r / R〜1) to suppress electron emission.
/ R = 0), electron emission occurs because Ek reaches 2.5 V / μm.

Consider the case where there is no gate electrode. In this case, the average electric field E0 between the cathode and the anode is Va / L = 6V / μm. This exceeds the electron emission threshold of low field electron emission materials such as carbon nanotubes. That is, when a low-field electron emission material is used, the electric field E0 must be "shielded" by the gate electrode so as not to reach the cathode surface. When the Spindt type cathode is used, such a problem does not occur because the electron emission threshold is higher than E0. FIG.
The result is that the shielding effect by the gate electrode is not sufficient at the center of the gate hole.

FIG. 4 shows a conventional driving method of a field emission display in which low field emission cathodes are arranged in a matrix. Although not shown,
An acceleration voltage Va = 6 KV is constantly applied to the anode 100.

A scanning signal 501 (voltage -Vs) is sequentially applied to the cathode 13 as a scanning signal. Depending on the image you want to display,
A data pulse 502 (voltage + V _d ) is applied to the gate electrode 11 as a data signal. In a pixel to which a scan pulse and a data pulse are applied simultaneously, the gate of the corresponding electron source element
Since a voltage of ( _Vd + Vs) is applied between 11 and the cathode 13, electrons are emitted and the phosphor emits light.

In the conventional driving method, a state in which the scanning signal is not selected (a state in which -Vs is not applied).
Gate 11 the cathode 13 between the voltage at becomes V _d If the 0V, the V _d becomes voltage to the gate electrode 11 is applied in the case where the gate electrode 11 V _d is not applied. Therefore, as is apparent from the results of FIG. 3, electron emission occurs even in a state not selected by the scanning signal, which causes a decrease in contrast.

As the number N of scanning lines increases, and the number of non-selected scanning lines (number (N-1)) increases, the contribution of unnecessary electron emission therefrom increases, and the contrast is significantly reduced.

[0019]

According to the present invention, an electron-emitting device on a scanning electrode in a non-selected state is set so that its gate applied voltage is lower than the cathode applied voltage. Solve the above problem.

In the second aspect of the present invention, the above-mentioned structure is provided in which the scanning electrode is supplied with power to the cathode, and the scanning electrode in the non-selected state is set to a higher impedance state than the scanning electrode in the selected state and driven. Solve a problem.

FIG. 5 shows the dependence of the cathode surface electric field Ek on the gate voltage Vg obtained by simulation. The parameters are the same as in FIG. The thin line indicates the periphery of the gate hole (r
/R~0.8), the thick line indicates the gate hole center (r / R).
00).

As can be seen from FIG. 5, when Vg = -25 V, Ek = 0 at the center of the gate hole. That is, the gate voltage of the electron-emitting device on the scanning electrode in the non-selected state may be set to a voltage lower than the voltage applied to the cathode. This is the first solution.

A second solution is to supply power from the scanning electrodes to the cathode, and to set the output state of the scanning drive circuit for supplying power to the scanning electrodes to a high impedance state in the non-selected scanning electrodes. . In this case, since the flow of electrons from the cathode is interrupted, electron emission can be reduced.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image display device according to the present invention will be described in more detail with reference to embodiments of the present invention according to some embodiments shown in the drawings.

Embodiment 1 A first embodiment will be described with reference to FIGS. 6, 7, and 1. FIG. A display panel of a display device includes a substrate on which a thin-film electron source matrix is formed and a face plate on which a phosphor and the like are formed. FIG. 6 is a cross-sectional view of the display panel. The cathode conductor 10 is formed on a substrate 14 made of an insulating material such as glass or ceramic. The cathode conductors 10 are formed by the number of scanning lines of the display device. The gate electrode 11 is formed via the insulating layer 12. The gate electrode 11 is formed orthogonal to the cathode conductor 10,
It is formed in the number of rows of the display device. A plurality of gate holes are formed in a region where the gate electrode 11 and the cathode conductor 10 intersect, and a cathode 13 is formed at the bottom of the gate hole. The cathode 13 uses a carbon nanotube.

FIG. 12 is an enlarged view of the intersection between the gate electrode and the cathode conductor (the dotted line in FIG. 6). FIG. 12B is a plan view, and FIG. 12A is a cross-sectional view taken along line AB. If necessary, a resistance layer may be formed between the cathode 13 and the cathode conductor 10. The method of forming this substrate is, for example,
Materials Research Society Symposium Proceeding
s, Vol. 509 (1998) pp. 107-112.
Parameters such as the size of each gate hole provided in the intersection region between the gate electrode 11 and the cathode conductor 10 and the thickness of the insulating layer 12 are as described above. The number of gate holes provided in the intersection region, that is, the number of gate holes per pixel is usually several tens.
~ Several thousand.

A black matrix 120 is formed on a face plate 110 made of a transparent material such as glass, and a red phosphor 114
A, green phosphor 114B and blue phosphor 114C are formed in a pattern. As the phosphor, for example, red Y ₂ O ₂ S: Eu
(P22-R), green: ZnS: Cu, Al (P22-G), blue: ZnS: Ag
(P22-B) may be used.

Next, after filming with a film such as nitrocellulose, Al is applied to the entire face plate 110 to a thickness of 50 to 300 nm.
A metal back 122 is formed by vapor deposition of about m. Then, the face plate 110 is heated to about 400 ° C.
Organic substances such as VA are thermally decomposed. Thus, the face plate 110 is completed.

The face plate 110 and the substrate 14 thus manufactured are
Are sealed in an inert gas atmosphere using frit glass with a spacer 60 (not shown) interposed therebetween. Face plate 1
The phosphors 114A, 114B, 11C formed on the substrate 10 and the substrate 14
Is as shown in FIG. Considering that the electron beam emitted from the electron-emitting device spreads somewhat spatially, the width of the area where the gate hole is formed (“W” in the figure)
Is designed to be narrower than the width of the phosphor 114.

The distance between the face plate 110 and the substrate 14 is 1 to 3 m.
m. The spacer 60 is inserted to prevent the panel from being damaged by an external force of the atmospheric pressure when the inside of the panel is evacuated. Therefore, the substrate 14, the face plate 110
Using a glass with a thickness of 3 mm, width 4 cm × length 9 cm
In the case of manufacturing a display device having a display area smaller than that, it is not necessary to insert the spacer 60 because the mechanical strength of the face plate 110 and the substrate 14 can withstand atmospheric pressure. Spacer 6
As 0, plate-shaped or column-shaped columns made of glass or ceramics are arranged side by side.

The sealed panel is 1 × 10 ^-6 to 1 × 10 ^-7 To
It is evacuated to a vacuum of about rr and sealed. Immediately before or immediately after sealing, a getter film is formed or a getter material is activated at a predetermined position (not shown) in the panel in order to maintain a high degree of vacuum in the panel. For example, in the case of a getter material containing Ba as a main component, a getter film can be formed by high-frequency induction heating. Thus, the display panel is completed.

FIG. 7 is a connection diagram of a display panel manufactured in this manner to a drive circuit. The cathode conductors 10 are arranged in the row direction and connected to the scanning drive circuit 41. The gate electrodes 11 are arranged in the column direction and are connected to the data drive circuit 42. The metal back 122 is connected to the acceleration electrode drive circuit 43. The dot at the intersection of the nth electrode 10Rn in the row direction and the mth electrode 15Cm in the column direction is represented by (n, m). In FIG. 7, 3 × 3
Although only the electron-emitting devices 301 are described, in an actual display panel, hundreds to thousands of cathode conductors 10 and hundreds to thousands of gate electrodes are formed.

FIG. 1 shows the waveform of the voltage generated by each drive circuit. Although not shown in FIG. 1, a voltage of about 6 KV is constantly applied to the metal back 122.

In FIG. 1, the state to which the scanning pulse 501 is applied is a “selected scanning line”, and the other is a “non-selected scanning line”. Voltage-is applied to the selected scanning line.
Vs is applied, and a reverse bias voltage Vr is applied to the non-selected scanning lines. In this embodiment, Vr = 25V.

When the scanning line is in the selected state, the gate electrode 11
In the application of a magnitude V _d becomes data pulses 502, an electron-emitting device in the intersection, because between the gate electrode 11 cathode 13 (V _d + Vs) becomes a voltage is applied, occurs electron emission, the phosphor Flash. The waveform of the data pulse 502 changes depending on the image to be displayed. In the case of the waveform of FIG. 1, the pixels in the hatched portions in FIG. 7 emit light. In the case of a color display, one “pixel” is formed by a combination of “sub-pixels” corresponding to red, blue, and green. In this specification, a sub-pixel is also referred to as a pixel.

Although FIG. 1 shows only the first three waveforms R1, R2 and R3, this scanning is actually continued for the number of scanning lines. After scanning the entire scanning line, R1
And the scanning is repeated. Scanning of one screen is performed during one field period (1 / f). In the case of an NTSC television signal, one field period is 16.7 ms.

When displaying an image with gradation, the voltage amplitude of the data pulse 502 may be changed in accordance with the video signal, or the pulse width of the data pulse 502 may be changed.

In the driving waveform of FIG. 1, the maximum value of the voltage of the data pulse 502 is 0V. Therefore, the difference (Vg−Vk) between the potential Vg of the gate electrode 11 and the potential Vk of the cathode 13 of the electron-emitting device 301 connected to the non-selected scanning line is −
The range is from ( _Vd + Vr) to -Vr. That is, the voltage between the gate electrode 11 and the cathode 13 is at most -Vr = -25V. Therefore, as can be seen from FIG. 5, no electron emission occurs from the electron-emitting devices on the non-selected scanning lines, and the contrast does not decrease.

In this embodiment, an example in which carbon nanotubes are used as the cathode 13 has been described. However, when a diamond cathode is used, a diamond film may be used as the cathode 13. In this case, the method of manufacturing the substrate is, for example, IEEE Tran.
saction Electron Devices, Vol.46, No.4 (1999) pp.
787-791.

Embodiment 2 A second embodiment using the present invention will be described with reference to FIGS. 8, 9 and 10. FIG. A display panel of a display device includes a substrate on which a thin-film electron source matrix is formed and a face plate on which a phosphor and the like are formed. FIG. 8 is a cross-sectional view of the display panel. The display panel used in this embodiment has almost the same configuration as that used in the first embodiment,
11 are arranged in the row direction, and the cathode conductors 10 are arranged in the column direction.

The structure of the gate electrode-cathode conductor intersection (dotted line in FIG. 8) is almost the same as that of FIG. In FIG. 12, the cathode conductor 10 and the insulating layer 12 are arranged in the column direction, and the gate electrode
Read 11 in the row direction. The method of manufacturing the display panel shown in FIG. 8 is the same as that of the first embodiment.

FIG. 9 is a diagram showing a method of connecting the display panel and the drive circuit. The gate electrodes 11 are arranged in the row direction,
It is connected to the scan drive circuit 41. The cathode conductors 10 are arranged in the column direction and connected to the data drive circuit 42. The metal back 122 is connected to the acceleration electrode drive circuit 43. Nth electrode 10 in row direction
The dot at the intersection of Rn and the m-th electrode 15Cm in the column direction is (n,
m). Although only 3 × 3 electron-emitting devices 301 are shown in FIG. 9, in an actual display panel, several hundred to several thousand cathode conductors 10 and several hundreds of gate electrodes are provided.
~ Thousands are formed.

FIG. 10 shows the waveform of the voltage generated by each drive circuit. Although not shown in FIG. 10, the metal back 122
, A voltage of about 6 KV is always applied.

In FIG. 10, the state to which the scanning pulse 501 is applied is a “selected scanning line”, and the other is a “non-selected scanning line”. The voltage + Vs is applied to the selected scanning line, and the reverse bias voltage -Vr is applied to the non-selected scanning line. In this embodiment, -Vr =
-25V.

When the voltage of the cathode conductor 10 is set to 0 V when the scanning line is in the selected state, a voltage of Vs is applied between the gate electrode 11 and the cathode 13 in the electron emission element at the intersection, so that the electron emission is performed. Occurs, causing the phosphor to emit light. Also, if you do not want to emit light at a pixel on a scanning line in the selected state applies a corresponding V _d becomes voltage to the cathode conductor 10.
Then, the voltage between the gate electrode 11 and the cathode 13 becomes (Vs- _Vd ), and no emitted electrons are emitted or only a sufficiently small amount of electrons are emitted. That is, the waveform of the data pulse 502 changes depending on the video to be displayed, and in the case of the waveform of FIG. In the case of a color display, one “pixel” is formed by a combination of “sub-pixels” corresponding to red, blue, and green. In this specification, a sub-pixel is also referred to as a pixel.

Although FIG. 10 shows only the first three waveforms R1, R2, and R3, this scanning is actually continued for the number of scanning lines. When scanning of the entire scanning line is completed, R
Return to 1 and repeat the scan. Scanning of one screen is performed during one field period (1 / f). In the case of an NTSC television signal, one field period is 16.7 ms.

[0047] When displaying an image with gradation, or changes the voltage amplitude V _d of the data pulses 502 in accordance with the video signal may be either by changing the pulse width of the data pulse 502.

In the driving waveform shown in FIG.
Is set to 0V. Therefore, the difference (Vg−Vk) between the potential Vg of the gate electrode 11 and the potential Vk of the cathode 13 of the electron-emitting device 301 connected to the non-selected scanning line is
The range is from-( _Vd + Vr) to -Vr. That is, the voltage between the gate electrode 11 and the cathode 13 is at most -Vr = -25V.
Therefore, as can be seen from FIG. 5, no electron emission occurs from the electron-emitting devices on the non-selected scanning lines, and the contrast does not decrease.

In this embodiment, an example in which carbon nanotubes are used as the cathode 13 is shown. However, when a diamond cathode is used, a diamond film may be used as the cathode 13. In this case, the method of manufacturing the substrate is, for example, IEEE Tran.
saction Electron Devices, Vol.46, No.4 (1999) pp.
787-791.

Embodiment 3 Next, a third embodiment using the present invention will be described with reference to FIGS.
1 will be described. The display panel used in this embodiment is the same as that of the first embodiment, and is as shown in FIG.
Also, the method of connecting to the drive circuit is the same as in the first embodiment, and is as shown in FIG.

FIG. 11 shows the waveform of the voltage generated by each drive circuit. Although not shown in FIG. 11, the metal back 122
, A voltage of about 6 KV is always applied.

In FIG. 11, the state to which the scanning pulse 501 is applied is a “selected scanning line”, and the other states are “non-selected scanning lines”. The voltage + Vs is applied to the selected scanning line, and the non-selected scanning line is kept in a high impedance state. In FIG. 11, a dotted line indicates a high impedance state. In this embodiment, the output impedance of the drive circuit is set to 10 MΩ in the high impedance state.
And

When the scanning line is in the selected state, the gate electrode 11
In the application of a magnitude V _d becomes data pulses 502, an electron-emitting device in the intersection, because between the gate electrode 11 cathode 13 (V _d + Vs) becomes a voltage is applied, occurs electron emission, the phosphor Flash. The waveform of the data pulse 502 changes depending on the image to be displayed. In the case of the waveform of FIG. 11, the pixels in the hatched portions in FIG. 7 emit light. In the case of a color display, one “pixel” is formed by a combination of “sub-pixels” corresponding to red, blue, and green. In this specification, a sub-pixel is also referred to as a pixel.

In FIG. 11, only the first three waveforms R1, R2 and R3 are shown, but this scanning is actually continued for the number of scanning lines. When scanning of the entire scanning line is completed, R
Return to 1 and repeat the scan. Scanning of one screen is performed during one field period (1 / f). In the case of an NTSC television signal, one field period is 16.7 ms.

When displaying an image with gradation, the voltage amplitude of the data pulse 502 may be changed according to the video signal, or the pulse width of the data pulse 502 may be changed.

The non-selected scanning lines are in a high impedance state. Accordingly, since the flow (current) of electrons from the scan drive circuit 41 is limited, the emission of electrons from the corresponding cathode 13 into a vacuum is limited, and unnecessary electron emission that causes a decrease in contrast can be reduced. .

In this embodiment, an example in which carbon nanotubes are used as the cathode 13 is shown. However, when a diamond cathode is used, a diamond film may be used as the cathode 13. In this case, the method of manufacturing the substrate is, for example, IEEE Tran.
saction Electron Devices, Vol.46, No.4 (1999) pp.
787-791.

[0058]

According to the present invention, it is possible to prevent a decrease in contrast and display a good image in an image display device using a carbon nanotube cathode, a diamond cathode, or the like as a low-field electron-emitting device as an electron-emitting device. it can.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a method of driving an image display device according to the present invention.

FIG. 2 is a diagram for explaining the operation principle of a low-field electron emission element.

FIG. 3 is a diagram showing the location dependence of a cathode surface electric field.

FIG. 4 is a diagram illustrating a driving method of a conventional image display device.

FIG. 5 is a diagram showing a gate voltage dependence of a cathode surface electric field.

FIG. 6 is a cross-sectional view for explaining the structure of the display panel of the first embodiment of the image display device according to the present invention.

FIG. 7 is a diagram showing connection to a drive circuit of the display device.

FIG. 8 is a cross-sectional view for explaining a structure of a display panel of a second embodiment of the image display device according to the present invention.

FIG. 9 is a diagram showing connection to a drive circuit of the display device.

FIG. 10 is a diagram illustrating a driving method of a second embodiment of the image display device according to the present invention.

FIG. 11 is a diagram showing a driving method of a third embodiment of the image display device according to the present invention.

FIG. 12 is a diagram showing a structure of an electrode intersection region of the display panel of the first and second embodiments of the image display device according to the present invention.

[Explanation of symbols]

10 space part, 11 gate electrode, 12 insulating layer, 13
... Cathode, 14 substrate, 41 scanning drive circuit, 42 data drive circuit, 43 acceleration electrode drive circuit, 100 anode
110: Face plate, 114: Phosphor, 120: Black matrix, 1
22 ... Acceleration electrode (metal back), 301 ... Emission device, 5
01: scanning pulse, 502: data pulse.

Claims (9)

[Claims] A plurality of electrons arranged in a matrix and having a gate electrode and a cathode, wherein when a positive voltage is applied to the gate electrode with respect to the cathode, electrons are emitted from the cathode. An emission element, and a plurality of first electrodes arranged in one direction of the matrix to supply power to the cathode;
A display element comprising: a first substrate having a plurality of second electrodes arranged in a direction orthogonal to the one direction to supply power to the gate electrode; and a second substrate having a phosphor and an anode. First driving means for supplying a scanning signal to the first electrode, and second driving means for supplying a data signal to the second electrode.
And a driving means for the electron-emitting device connected to the first electrode during a period in which the first electrode is in a non-selected state. Driving the image display device so that the voltage becomes negative with respect to the voltage applied to the first electrode. 2. The electric potential of the first electrode in a non-selected state among the first electrodes is a positive electric potential than the maximum value of the voltage applied to the second electrode. 2. The driving method of the image display device according to 1. 3. A plurality of electrons arranged in a matrix, comprising a gate electrode and a cathode, wherein when a positive voltage is applied to the gate electrode with respect to the cathode, electrons are emitted from the cathode. An emission element, and a plurality of first electrodes arranged in one direction of the matrix to supply power to the cathode;
A display element comprising: a first substrate having a plurality of second electrodes arranged in a direction orthogonal to the one direction to supply power to the gate electrode; and a second substrate having a phosphor and an anode. First driving means for supplying a scanning signal to the second electrode, and second driving means for supplying a data signal to the first electrode.
And a driving means for the electron emitting element connected to the second electrode during a period in which the second electrode is in a non-selected state. Driving the image display device so that the voltage becomes negative with respect to the voltage applied to the first electrode. 4. The electric potential of a second electrode in a non-selected state among the second electrodes is a negative electric potential which is lower than a minimum value of a voltage applied to the first electrode. 4. The driving method of the image display device according to 3. 5. A plurality of electrons arranged in a matrix, comprising a gate electrode and a cathode, wherein when a positive voltage is applied to the gate electrode with respect to the cathode, electrons are emitted from the cathode. An emission element, and a plurality of first electrodes arranged in one direction of the matrix to supply power to the cathode;
A display element comprising: a first substrate having a plurality of second electrodes arranged in a direction orthogonal to the one direction to supply power to the gate electrode; and a second substrate having a phosphor and an anode. First driving means for supplying a scanning signal to the first electrode, and second driving means for supplying a data signal to the second electrode.
And driving the image display device comprising: a first electrode in a non-selected state among the first electrodes in a higher impedance state than a first electrode in a selected state. For driving an image display device. 6. The method according to claim 5, wherein in the high impedance state, the output impedance of the first driving means is 10 MΩ or more. 7. The cathode according to claim 1, wherein the cathode is capable of emitting electrons at an electric field intensity defined by a voltage applied to the acceleration electrode and a distance between the acceleration electrode and the cathode. A method for driving the image display device according to claim 1. 8. The method according to claim 1, wherein the cathode is made of a material having carbon nanotubes. 9. The method according to claim 1, wherein the cathode is made of a material containing diamond.