JPH11204023A - Driving method of electron emitting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve efficiency of the electrons reaching the anode electrode by applying a voltage between a second gate electrode and a cathode electrode larger than between a first gate electrode and the cathode electrode. SOLUTION: A first gate electrode layer 8 is laminated on an insulation substrate 7 such as glass, on which a cathode electrode layer 10 is laminated via an insulation layer 9. A second gate electrode layer 12 is laminated thereon via a second insulation layer 11. Further, an open electron emission hole 13 is provided. When a voltage is applied from a power source 15 to a first gate electrode layer 8 is V1, a voltage applied to the cathode electrode layer 10 is Vc, and a voltage applied to a second gate electrode layer 12 is V2, an apparatus is driven so as to meet a relationship of V2>V1>Vc. Thereby, a given electric field is produced between the first gate electrode 8 and second gate electrode layer 12; and the cathode electrode layer 10.

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 electron-emitting device that emits field electrons from a cathode electrode by applying a predetermined electric field to the cathode electrode.

[0002]

2. Description of the Related Art In recent years, research and development on display devices has been promoted in the direction of reducing the thickness of displays. In such a situation, a display device that has received special attention is a field emission display device (hereinafter, referred to as an FED) in which a so-called electron emission device is provided.
(Field Emission Display). ).

[0003] This FED has a portion corresponding to one pixel,
The display includes a field emission device, a cathode electrode and a phosphor disposed so as to face the field emission device, and one pixel is formed in a matrix to constitute a display.

[0004] Generally, there are two types of electron emitting devices: Spindt type and planar type. This Spindt-type electron emission device has a substantially conical cathode electrode, and emits electrons by applying a predetermined electric field to the cathode electrode. When manufacturing this Spindt-type electron emission device, a hole having a diameter of about 1 μm is formed, and a substantially conical cathode electrode is formed inside the hole by a vapor deposition method or the like.

However, such a Spindt-type electron-emitting device has a problem that it is difficult to form the above-mentioned substantially conical cathode electrode in a desired shape and does not exhibit stable electron-emitting characteristics. . In particular, when manufacturing a large-screen FED, it is necessary to uniformly form a cathode electrode on a large substrate. In other words, when the cathode electrode cannot be formed uniformly, the field electron emission characteristics become non-uniform depending on the position of the screen, and an image cannot be displayed well.

On the other hand, a flat type electron emitting device is
A substantially flat cathode electrode is sandwiched between a pair of gate electrodes via an insulating layer. Then, an electron is emitted from the cathode electrode by an electric field generated between the pair of gate electrodes and the cathode electrode.

In this flat type electron emission device, the cathode electrode for emitting electrons can be formed in a substantially flat plate shape. Therefore, it can be easily manufactured as compared with the above-mentioned Spindt-type electron emission device. In particular, large screen F
When manufacturing an ED, an electron-emitting device can be manufactured in a state where there is almost no difference in shape according to the position of the screen, as compared with the above-described substantially conical cathode electrode. Therefore, the FED using the flat-type electron emission device can display an image well.

[0008]

However, in the above-mentioned flat type electron emitting device, the amount of electrons reaching the anode electrode is lower than that in the Spindt type electron emitting device. For this reason, the flat-type electron emission device has a problem that the phosphor disposed on the anode electrode cannot emit light satisfactorily.

Accordingly, the present invention solves the above-mentioned problems of the conventional electron-emitting device, and provides a method of driving the electron-emitting device that can improve the efficiency with which electrons generated from the electron-emitting device reach the anode electrode. The purpose is to provide.

[0010]

A method of driving an electron-emitting device according to the present invention, which has solved the above-mentioned problems, comprises at least a first gate electrode formed on a substrate and the first gate electrode.
Driving an electron emission device including a cathode electrode formed on the gate electrode via a first insulating layer and a second gate electrode formed on the cathode electrode via a second insulating layer. In this case, the voltage applied to the first gate electrode is V1, the voltage applied to the cathode electrode is Vc, and the voltage applied to the second gate electrode is V2.
Where V2>V1> Vc.

In the driving method of the electron-emitting device according to the present invention having the above-described structure, a positive voltage is applied to the first gate electrode and the second gate electrode with reference to the cathode electrode. . For this reason, an electric field is generated between the first gate electrode, the second gate electrode, and the cathode electrode. Then, when this electric field is applied to the cathode electrode, electrons are emitted from the cathode electrode. At this time, a voltage higher than the voltage applied between the first gate electrode and the cathode electrode is applied between the second gate electrode and the cathode electrode. For this reason, the electric field generated from the first gate electrode and the second gate electrode causes electrons generated from the cathode electrode to pass through the second gate electrode.
In the direction of the gate electrode. Therefore, according to this method, electrons generated from the cathode electrode can be extracted in the direction of the second gate electrode.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a specific embodiment of a method for driving an electron-emitting device according to the present invention will be described with reference to the drawings.

This method is applied, for example, when driving an electron-emitting device used in a so-called FED (Field Emission Display) as schematically shown in FIG.

This FED is composed of a back plate 2 on which an electron emission device 1 for emitting field electrons is formed in a matrix.
And a face plate 4 disposed opposite to the back plate 2 and having the anode electrode 3 formed in a stripe shape. In this FED, the space between the back plate 2 and the face plate 4 is in a highly vacuum state.

In this FED, the face plate 4
Has a red phosphor 5R that emits red light on a predetermined anode electrode 3, a green phosphor 5G that emits green light on an adjacent anode electrode 3, and a blue phosphor 5G on an adjacent anode electrode 3. Is formed. That is, the face plate 4 is formed by alternately forming a red phosphor 5R, a green phosphor 5G, and a blue phosphor 5B (hereinafter, simply referred to as “phosphor 5”) in a stripe shape. I have.

In the back plate 2, the electron-emitting devices 1 are arranged at positions facing the phosphors 5 of these three colors. And in this FED,
One pixel is composed of the three color phosphors 5 and the electron emission device 1 disposed at a position facing each of the phosphors 5. In the FED, the one pixel is arranged in a matrix to form a screen.

Further, the FED has a back plate 2
And a plurality of pillars 6 arranged between the first and second face plates 4. The pillar 6 maintains a predetermined interval between the back plate 2 and the face plate 4 which are highly evacuated.

In this FED, the electron emission device 1
As shown in FIG. 2, an insulating substrate 7 such as glass, a first gate electrode layer 8 laminated on the insulating substrate 7, and a first insulating layer on the first gate electrode layer 8. 9 and the cathode electrode layer 10
And a second gate electrode layer 12 laminated on the first gate electrode 0 via a second insulating layer 11. The electron emission device has an open electron emission hole 13 for emitting electrons.

That is, in the electron-emitting device 1, openings are formed in the first insulating layer 9, the cathode electrode layer 10, the second insulating layer 11, and the second gate electrode layer 12, respectively. The portion constitutes the electron emission hole 13. In the electron-emitting device 1, these openings are formed in a substantially rectangular shape. However, the shape of the opening is not limited to this, and any shape such as a circle, an ellipse, or a polygon may be used as long as it does not include a sharp angle portion.

In the electron emission hole 13, the cathode electrode layer 10 and the second gate electrode 12 are formed so as to protrude from the first insulating layer 9 and the second insulating layer 11. That is, in the electron-emitting device 1, the opening 10A formed in the cathode electrode layer 10 and the opening 12A formed in the second gate electrode layer 12 correspond to the opening formed in the first insulating layer 9. The opening size is smaller than the opening 11A formed in the portion 9A and the second insulating layer 11. Therefore, in the electron-emitting device 1, the projecting portion 14 in which the cathode electrode layer 10 projects in the electron-emitting hole 13 is formed.

In this electron emission device 1, the substrate 7
It is mainly made of an insulating material such as glass, and has a thickness that can withstand the high vacuum pressure as described above.
In addition, the first gate electrode layer 8 and the second gate electrode layer 1
2, for example, is mainly made of a metal material such as W, Nb, Ta, Mo, and Cr, and has a thickness of about 50 to 300 nm. Further, the cathode electrode layer 10 includes, for example,
It is mainly composed of a metal material such as W, Nb, Ta, Mo, Cr or a semiconductor such as diamond, and has a thickness of about 50 to 300 nm.
It has a thickness of the order. Furthermore, the first insulating layer 9
The second insulating layer 11 is mainly made of, for example, an insulating material such as silicon dioxide, silicon nitride, or the like.
It has a thickness of about 0 nm.

As shown in FIG. 3, the electron emission device as described above has a first gate electrode layer 8, a cathode electrode layer 10
And a power supply 15 for applying a predetermined voltage to the second gate electrode layer 12. Although not shown, the power supply 15 is also connected to the anode electrode 3.

In the electron emission device 1, a power supply 15
Are configured to apply a voltage between the first gate electrode layer 9 and the cathode electrode and between the second gate electrode layer 12 and the cathode electrode layer 10, respectively. This power supply 1
In 5, a positive voltage is applied to the first gate electrode layer 9 and the second gate electrode layer 12 with reference to the cathode electrode layer 10. The power supply applies a voltage between the second gate electrode layer 12 and the cathode electrode layer 10 that is higher than the voltage applied between the first gate electrode layer 9 and the cathode electrode layer 10. Configuration.

In order to manufacture the electron emission device configured as described above, first, as shown in FIG. 4, a first gate electrode layer 8 is formed on an insulating substrate 7 made of an insulating material such as glass.
First insulating layer 9, cathode electrode layer 10, second insulating layer 1
The first and second gate electrode layers 12 are formed in this order. After that, a resist film 22 having a resist opening 21 in a predetermined region on the second gate electrode layer 12 is formed.

Next, as shown in FIG. 5, openings are formed in the first insulating layer 9, the cathode electrode layer 10, the second insulating layer 11, and the second gate electrode layer 12, as will be described in detail later. Form each. Specifically, an opening having substantially the same shape as the resist opening 21 is formed in the second gate electrode layer 12 by performing anisotropic etching such as dry etching on the surface on which the resist film 22 is formed. I do. Then, by performing isotropic etching such as wet etching from the same surface side, the resist opening 2 is formed in the second insulating layer 11.
An opening larger than one is formed. Next, by performing anisotropic etching such as dry etching from the same surface side, an opening having substantially the same shape as the resist opening 21 is formed in the cathode electrode. Next, an opening larger than the resist opening 21 is formed in the first insulating layer 9 by performing isotropic etching such as wet etching from the same surface side.

Thus, as described above, the protrusion 1
Emission device 1 including a cathode electrode layer 10 having
Can be manufactured. At this time, by controlling the etching conditions when the first insulating layer 9 and the second insulating layer 11 are isotropically etched, the amount of protrusion of the protrusion 14 can be adjusted.

The electron-emitting device to which the present technique is applied is not limited to the above-described structure, but has a structure in which an opening is formed in the first gate electrode 8 as shown in FIG. It may be. Also in this case, it is manufactured in the same manner as the above-described electron emission device 1.

The electron emission device configured as above is
It is driven by applying a predetermined voltage to each electrode, and emits electrons from the cathode electrode layer 10. In this method, the electron emission device 1 is driven using the power supply 15 described above.

Specifically, when driving the electron-emitting device 1, in this method, the voltage applied to the first gate electrode layer 8 is set to V1, and the voltage applied to the cathode electrode layer 10 is set to Vc.
When the voltage applied to the second gate electrode layer 12 is V2, V1, V2, and Vc are set to satisfy the relationship of the following expression.

V2>V1> Vc (Equation) In other words, according to this method, the first power source 15
A voltage is applied to the gate electrode layer 8 and the second gate electrode layer 12 so as to be positive with respect to the cathode electrode layer 10, and between the second gate electrode layer 12 and the cathode electrode layer 10. Then, a voltage higher than the voltage applied between the first gate electrode layer 9 and the cathode electrode layer 10 is applied.

The voltages V1, V2, V satisfying the above equations
By applying c, a predetermined electric field is generated between the first gate electrode layer 8 and the second gate electrode layer 12 and the cathode electrode layer 10 in the electron-emitting device 1. When this electric field is applied to the protrusion 14 of the cathode electrode layer 10,
Electrons are emitted from the protrusion 14.

In this method, the voltage V satisfying the above equation is used.
By applying 1, V2, and Vc, an electric field is generated such that electrons generated from the protrusion 14 are guided to the second gate electrode layer 12 side. Therefore, according to this method, electrons generated from the protruding portion 10 of the cathode electrode layer 10 almost proceed to the second gate electrode layer 12 side. Thus, according to the present method, electrons can be efficiently emitted from the electron emission holes 13 to the outside of the electron emission device 1.

More specifically, in the present method, by applying a voltage so as to satisfy the above expression and to satisfy V2 / V1 = about 1.3, of the electrons emitted from the cathode electrode layer 10, 90% of the electrons could be emitted to the outside of the electron-emitting device 1.

When driving the electron-emitting device by applying this method, the voltage V1 and the voltage V2 are set to satisfy 1.1 ≦ V2 /
It is preferable to have a relationship of V1 ≦ 2.5. V2 /
By setting V1 within this range, the present method can more reliably and efficiently emit electrons to the outside of the electron-emitting device.

On the other hand, when a voltage is applied in a relationship of V1 = V2> Vc when driving the electron emission device, the ratio of electrons emitted from the cathode electrode is guided to the side. Therefore, in this case, the ratio of electrons emitted to the outside of the electron emission device is about 40%. For this reason, in this method, the value of V2 / V1 may be larger than 1, but the value of V2 / V1 is 1.1.
Above is a remarkable effect.

The higher the value of V2 / V1, the more efficiently the emitted electrons can be guided to the second gate electrode layer 12, but there is no difference in the effect if the value is too large. For this reason, this method has a remarkable effect when the value of V2 / V1 is 2.5 or less.

The F provided with the electron-emitting device 1
In the ED, electrons emitted to the outside of the electron emission device 1 collide with the phosphor 5 and excite the phosphor 5 to emit light. At this time, in the FED, a predetermined voltage is applied from the power supply 15 to the anode electrode 3. At this time, the voltage applied to the anode electrode 3 is more positive than the voltage V2 applied to the second gate electrode layer 12 described above. As a result, a predetermined electric field is generated between the anode 3 and the electron-emitting device 1.

Electrons emitted to the outside of the electron emission device 1 are accelerated by this electric field and fly toward the anode electrode 3. When the flying electrons collide with the phosphor 5, the phosphor 5 emits light as described above.

At this time, if the electron-emitting device 1 using this method is used, the amount of electrons emitted from the electron-emitting device 1 can be increased. For this reason, according to this method, since the light emission intensity of the phosphor 5 can be improved, the brightness of the display image can be significantly improved.

In other words, the electron emission device 1
Is used, the driving voltage for generating a predetermined amount of electrons can be reduced as compared with the related art. That is, by using this method, it is possible to reduce power consumption for driving the electron-emitting device 1. Therefore, this method is suitably adopted for a low power consumption type FED.

[0041]

As described above in detail, in the method of manufacturing the electron-emitting device according to the present invention, the voltage defined by the predetermined relationship is applied to the first gate electrode, the second gate electrode, and the cathode electrode. To emit electrons from the cathode electrode. Thus, according to this method, electrons emitted from the cathode electrode can be efficiently emitted to the outside. Therefore, if this technique is adopted, electrons can be efficiently emitted at a low voltage.

[Brief description of the drawings]

FIG. 1 shows an FE using an electron emission device to which the present invention is applied.
It is a schematic perspective view which shows the structure of D schematically.

FIG. 2 is a cross-sectional perspective view of a main part of the electron emission device.

FIG. 3 is a schematic circuit diagram of a power supply for applying a voltage to the electron emission device.

FIG. 4 is a cross-sectional view for explaining a manufacturing process of the electron-emitting device.

FIG. 5 is a cross-sectional view for explaining a manufacturing process of the electron-emitting device.

FIG. 6 is a schematic circuit diagram of a power supply for applying a voltage to another electron emission device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 electron emission device, 2 back plate, 3 anode electrode, 4 face plate, 5 phosphor, 6 pillar, 7 insulating substrate, 8 first gate electrode layer, 9 first
Insulating layer, 10 cathode electrode layer, 11 second insulating layer, 12 second gate electrode layer

Claims (2)

[Claims] At least a first gate electrode formed on a substrate, a cathode electrode formed on the first gate electrode via a first insulating layer, and a second electrode formed on the cathode electrode. When driving an electron-emitting device including a second gate electrode formed through the insulating layer, a voltage applied to the first gate electrode is set to V1, a voltage applied to the cathode electrode is set to Vc, A driving method for an electron-emitting device, characterized in that, when the voltage applied to the second gate electrode is V2, the following relationship is satisfied: V2>V1> Vc. 2. A voltage V applied to the first gate electrode.
The method according to claim 1, wherein 1 and the voltage V2 applied to the second gate electrode have a relationship of 1.1≤V2 / V1≤2.5.