KR100570636B1 - Method for driving field emission display device - Google Patents

Abstract

The present invention relates to a method of driving a field emission display device which can prevent breakage of the emitter and the gate electrode and to facilitate the fabrication and driving of the device. The present invention relates to cathodes provided on first and second substrates disposed opposite to each other. The driving voltage is respectively applied to the electrode and the anode electrode so that a voltage difference greater than or equal to a threshold voltage at which electrons start to be emitted from the emitter provided to the cathode electrode is generated, and the gate electrode provided through the insulating layer to the cathode electrode is provided with the cathode electrode. It is characterized in that the driving voltage is applied so that a voltage difference of less than or equal to the threshold voltage is generated therebetween. As a result, the distance between the cathode electrode and the gate electrode can be arbitrarily set from several micrometers to several tens of micrometers, thereby preventing breakage of the emitter and the gate electrode, and eliminating the need for microfabrication at the time of device fabrication. can do.

FED, electric field, emitter, focus, gate, cathode, anode,

Description

Method of driving field emission display device {METHOD FOR DRIVING FIELD EMISSION DISPLAY DEVICE}

1 is a cross-sectional view showing the configuration of a field emission display device driven in accordance with a prior art drive method.

2 is a cross-sectional view showing the configuration of a field emission display device driven in accordance with the driving method of the present invention.

3 to 5 are diagrams showing simulation results of operating characteristics of the device according to the present invention.

The present invention relates to a method of driving a field emission display device, and more particularly, to a method of driving a field emission display device which can prevent damage to an emitter and a gate electrode and to facilitate the manufacture and driving of the device. .

In general, a field emission display device (FED) emits electrons from an emitter provided at the cathode electrode by using a quantum mechanical tunneling effect, and the emitted electrons collide with the phosphor provided at the anode electrode to form the phosphor. Herein, the display device realizes a predetermined image.

Among the various types of field emission display devices, a field emission display device having a spindt type emitter is a triode type field emission display device having a cathode electrode, a gate electrode, and an anode electrode. same.

As shown in FIG. 1, a line-shaped cathode electrode 104 is provided on one surface of the rear substrate 102, and an insulating layer 106 is provided over the substrate 102 over the cathode electrode 104. The gate electrode 108 intersects the cathode electrode 104 perpendicularly to the insulating layer 106.

In the pixel region where the cathode electrode 104 and the gate electrode 108 cross each other, a plurality of grooves (approximately hundreds) penetrating through the gate electrode 108 and the insulating layer 106 are formed, and the cathode is formed inside each groove. The electrode 104 is provided with a spire-shaped emitter 110 made of an electron emitting material such as molybdenum.

In addition, the front substrate 112 sealed with the substrate 102 at a position facing the rear substrate 102 is provided with a line-shaped anode electrode 114 in the same direction as the cathode electrode 104, and an anode electrode ( The surface of 114 is provided with a fluorescent layer 116 that emits light when the electrons emitted from emitter 110 collide.

In driving the field emission display device having such a configuration, a driving voltage is applied to the cathode electrode 104 and the gate electrode 108 such that a voltage difference of more than a threshold voltage at which electrons are emitted from the emitter 110 occurs. .

When a predetermined voltage is applied to the cathode electrode 104 and the gate electrode 108 as described above, a strong electric field is formed at the distal end of the emitter 110 according to the voltage difference applied to both electrodes 104 and 108 to generate electrons. The emitted electrons are moved toward the phosphor 116 by the voltage applied to the anode electrode 114 and collide with the phosphor 116 so that the phosphor emits light.

However, according to the conventional device driving method configured as described above, there are the following problems.

That is, conventionally, when driving the electroluminescent display device, a voltage difference of more than a threshold voltage is generated between the cathode electrode and the gate electrode so that electron emission occurs from the emitter, and the emission electrons are incident on the phosphor of the anode electrode. Implement.

Therefore, the distance between the electrodes must be set very small (approximately 0.5 占 퐉) in order to generate a voltage difference greater than or equal to the threshold voltage between the cathode electrode and the gate electrode, so that the manufacturing process of the device is complicated, A high field must be formed between the two electrodes, so that the emitter and the gate electrode are easily broken.

In the device driven by the conventional driving method, since all of the electrons emitted from the emitter are not incident on the phosphor and some of the electrons flow into the gate electrode, a leakage phenomenon occurs. There is a difficulty in driving the device, such as disturbing operation.

Accordingly, an object of the present invention is to provide a method of driving a field emission display device that can prevent damage to an emitter and a gate electrode, and to facilitate the fabrication and driving of the device.

The present invention to achieve the above object,

Driving voltages are respectively applied to the cathode and anode electrodes provided on the first and second substrates disposed opposite to each other so that a voltage difference greater than or equal to a threshold voltage at which electrons start to be emitted from an emitter provided on the cathode electrode is generated. Provided is a device driving method for applying a driving voltage to a gate electrode provided through an insulating layer such that a voltage difference below a threshold voltage is generated between the cathode and the cathode.

Hereinafter, a method of driving a field emission display device according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a cross-sectional view showing the configuration of a field emission display device driven in accordance with the device driving method of the present invention. One surface of the rear substrate 12 is provided with a line-shaped cathode electrode 14, and a cathode electrode ( Above the gate 14, the gate electrode 16 crosses the cathode electrode 14 perpendicularly through the insulating layer 18.

In the pixel region where the cathode electrode 14 and the gate electrode 16 intersect, a plurality of grooves penetrating through the gate electrode 16 and the insulating layer 18 are formed, and the cathode electrode 14 is formed inside each groove. The surface of is provided with a facet type emitter 20.

The emitter 20 is made of any one material selected from carbon-based materials, such as graphite, diamond-like carbon, carbon fiber, and carbon nanotubes, and the material has a voltage difference greater than or equal to a threshold voltage between two opposite electrodes. If it emits electrons.

Here, the surface type emitter may be provided by a thick film technique such as printing, slurry, or electrophoresis.

In addition, the front substrate 22 sealed with the substrate 12 at a position facing the rear substrate 12 is provided with an anode electrode 24 having a line shape in the same direction as the cathode electrode 14, and the anode electrode ( The surface of 24 is provided with a fluorescent layer 26 which emits light when electrons emitted from the emitter 20 collide.

In driving the field emission display device having such a configuration, a driving voltage is applied to the anode electrode 24 and the cathode electrode 14 so as to generate a voltage difference of more than a threshold voltage, and the cathode electrode 14 and the gate electrode 16 are respectively applied. The driving voltage is applied so that a voltage difference below the threshold voltage is generated between and.

Here, the threshold voltage refers to a voltage at which electrons start to be emitted from the emitter 20, and the threshold voltage has different values depending on the type of material constituting the emitter.

In addition, the gate electrode 16 serves as a control electrode for controlling an emission amount of electrons emitted from the emitter 20 and controlling a focusing distance of electrons collided with the phosphor 26. As the driving voltage of 16 increases, the electron emission amount increases and the electron focusing distance becomes wider.

Accordingly, when a predetermined voltage is applied to the anode electrode 24 and the cathode electrode 14, an electric field is formed at the emitter 20 according to the voltage difference applied to both electrodes 14 and 24, and electrons are emitted. The emitted electrons move toward the phosphor 26 and collide with the phosphor 26 to emit light.

When the device is driven as described above, the amount of electrons emitted from the emitter 20 and the focusing distance of electrons colliding with the phosphor are changed according to the values of five factors as shown in Table 1 below.

Table 1

variable Electron emission Speed Va increase increase Vg increase decrease Hag decrease Fine reduction Hcg decrease increase phi increase decrease

Table 1 shows changes in electron emission amount and focusing distance when only one variable value is increased while the other four variable values are fixed. In Table 1, Va represents a driving voltage of an anode electrode and Vg represents a gate electrode. The driving voltage, Hag, represents the distance between the anode electrode and the gate electrode, Hcg represents the distance between the cathode electrode and the gate electrode, and phi represents the hole size, that is, the emitter size, of the gate electrode provided with the emitter.

3 to 5 illustrate a case in which Va (drive voltage of an anode electrode) is increased among the variables of Table 1, and since only one half of the device is shown in FIGS. As shown, the X and Y axes represent distances.

3 to 5, the driving voltage of the gate electrode is 100 V, the distance between the anode electrode and the gate electrode is 40 μm, the distance between the cathode electrode and the gate electrode is 10 μm, and the emitter size is 10 μm. Each was set.

As shown, when a voltage of 500 V is applied to the anode electrode 24, the focusing distance of electrons colliding with the phosphor is approximately 13.82 μm (6.91 μm × 2), and when the voltage of 1000 V is applied to the electrode, It is 8.48 micrometers (4.24 micrometers x 2), and the focusing distance when the voltage of 1500V is applied to the said electrode is approximately 5.38 micrometers (2.69 micrometers x 2).

As such, when the other four variable values are fixed, when the driving voltage of the anode is increased, the electron emission amount and the collecting speed are increased, and when the other four variable values are increased, the results as shown in Table 1 are derived. .

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to

As described above, according to the element driving method of the present invention, since the electron emission from the emitter is configured by the voltage difference between the cathode electrode and the anode electrode, the distance between the cathode electrode and the gate electrode is several micrometers to several tens of micrometers. Can be set up to

Therefore, in the case of the field emission device employing the above driving method, breakage of the emitter and the gate electrode can be prevented, and the microfabrication is unnecessary at the time of device fabrication, so that the device can be easily manufactured.                     

In addition, in the present invention, since the gate electrode serves to focus the emitted electrons, when the voltage applied to the electrode is appropriately set, the collection speed of the electrons can be increased, so that a good image can be realized. Can be prevented so that the device can be easily driven.

Claims (9)

Driving voltages are respectively applied to the cathode and anode electrodes provided on the first and second substrates disposed opposite to each other so that a voltage difference greater than or equal to a threshold voltage at which electrons start to be emitted from an emitter provided on the cathode electrode is generated. And a driving voltage is applied to a gate electrode provided through an insulating layer so that a voltage difference below a threshold voltage is generated between the cathode and the cathode. The method of claim 1, wherein an electron emission amount and an electron collecting speed are adjusted by adjusting a driving voltage of the anode electrode. The method of claim 1, wherein an electron emission amount and an electron collecting speed are controlled by adjusting a driving voltage of the gate electrode. The method of claim 1, wherein an electron emission amount and an electron collecting speed are adjusted by adjusting a distance between the anode electrode and the gate electrode. The method of claim 1, wherein an electron emission amount and an electron collecting speed are adjusted by adjusting a distance between the cathode electrode and the gate electrode. The method of claim 1, wherein an electron emission amount and an electron collecting speed are controlled by adjusting the size of the emitter. 7. The method of driving a field emission display device according to any one of claims 1 to 6, wherein the emitter is a plane type. The method of claim 7, wherein the emitter is formed of a carbon-based electron emission material. The method of claim 8, wherein the electron emission material is any one selected from graphite, diamond, diamond-like carbon, carbon fiber, and carbon nanotubes.

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