KR0183174B1 - Field emission device - Google Patents

Abstract

The present invention relates to a field emission device in which the gate electrode is restructured to optimally control the electron beam emitted from the field emission device. To this end, the present invention provides a substrate, a plurality of field emitter tips projecting on the substrate to emit electrons, and a predetermined voltage is applied to form an electric field around the electrons to emit electrons from the field emitter tips. In a field emission device having a plurality of gate electrodes, an electron beam emitted from the tip is provided between the field emitter tips because at least two divided and insulated gate electrodes are provided so as to apply a predetermined voltage independently and independently. It can provide an advantage that can be easily controlled.

Description

Field emission devices

1 is a block diagram showing the basic unit configuration of a general field emission display.

2 is a band diagram illustrating the tunneling effect on a metal or silicon surface.

3 is a schematic view showing a conventional field emission device.

4 is a block diagram showing a field emission device according to the present invention.

* Explanation of symbols for the main parts of the drawings

22: transparent electrode (or anode electrode) 66: field emitter tip

80 gate electrode 85 substrate

87: insulator

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a field emission device for use in field emission displays, and more particularly to a field emission device in which the gate electrode is restructured to optimally control an electron beam emitted from the field emission device. It is about.

In general, field emission displays, unlike vacuum tubes, do not use thermal emission to emit electrons, but instead use a silicon or metal tip as a cathode and place a gate electrode close to the tip to emit electrons into a strong electric field formed at the tip. Use the emission.

The basic configuration of such a field emission display is shown in FIG. Referring to FIG. 1, the minimum unit constituting the field emission display is similar to that of a three-pole vacuum tube in micro units. That is, it is assumed that the transparent electrode 2, the gate 8, and the tip 6 of the substrate 12 having the phosphor 4 coated or deposited on the surface correspond to the anode, grid, and cathode of the vacuum tube, respectively. Can be. In the configuration of the field emission display, when a sufficient voltage is applied between the tip 6 (or the field emitter tip) and the gate 8 and the transparent electrode 2 (or the anode electrode), electrons are generated by a strong electric field. Are tunneled from the field emitter tip 6 and released outward. Electrons emitted from the field emitter tip 6 are accelerated while passing through the gate 8 and collide with high energy to the pixel of the phosphor 4 on the anode electrode 2 to emit the phosphor. At this time, the field emission display has a high luminous efficiency since electrons emitted from the field emitter tip 6 reach the phosphor 4 with little absorption at the gate 8. Here, the member number 10 is an insulator interposed between the substrate 12 and the gate 8 to insulate them.

As shown above, the principle in which electrons are tunneled and emitted at the field emitter tip 6 is shown in FIG. FIG. 2 is a band diagram of a metal surface or silicon surface. Referring to this, in the normal state (vacuum level without bias), electrons in the conduction band of the metal surface are not released out of the metal surface by the vacuum barrier, but the metal If a strong electric field is formed on the surface (the vacuum level in the bias state), the vacuum barrier is lowered and electrons can be tunneled out of the metal surface. Here, the electric field formed around the field emitter tip 6 is determined by the voltage applied to the gate 8 and the anode electrode 2 and the position of the electrode and the geometry of the field emitter tip 6.

The field emission device constituting the field emission display as described above is shown in FIG. 3, where one field emission display includes hundreds of thousands to millions of field emission devices. When a predetermined voltage is applied to the gate 8 of the field emission device as shown, electrons are emitted from the tip 6 and collide with the phosphor of the anode electrode 2.

Phosphor (micrometer level) formed at the point A of the anode electrode 2 by the gate electrode 8 and the field emitter tip (hereinafter abbreviated as tip) constituting the field emission device as described above. In order for the phosphor to emit light accurately defined), the following conditions are required. That is, in order for the electron beam emitted from the tip 6-C located at the center to be directed to the A point of the transparent electrode 2, the voltage applied to the right gate electrode 8-C of the tip 6-C is left. Must be greater than the voltage applied to the gate electrode (8-B), in order to direct the electron beam emitted from the tip (6-L) located on the left to the point A of the transparent electrode (2) to the right of the tip (6-L) The voltage applied to the gate electrode 8-B must be greater than the voltage applied to the left gate electrode 8-A, and the electron beam emitted from the tip 6-R located on the right is directed to the point A of the transparent electrode 2. In order to ensure that the voltage applied to the right gate electrode 8-D of the tip 6-R must be smaller than the voltage applied to the left gate electrode 8-C, the structure of the gate electrode 8 is shown. It will be easy to understand. Accordingly, in order to direct the electron beam emitted from the tip of the conventional field emission device in a predetermined direction, a predetermined control circuit (not shown) has to control the voltage applied to the gate. This problem occurs because one gate electrode must be driven in relation to the tip existing on both sides thereof. That is, the voltage applied to the gate electrode 8 -B should be applied with a low voltage with respect to the tip 6 -C and the high voltage with respect to the tip 6 -L.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and is a field emission device having a gate electrode structured to improve the directivity of an electron beam emitted from a tip and to simplify the voltage control applied to the gate electrode. The purpose is to provide.

In order to achieve the above object, the field emission device according to the present invention comprises a substrate, a plurality of field emitter tips protruding on the substrate to emit electrons, and an electric field around the field emitter to emit electrons. A field emission device having a plurality of gate electrodes for forming a plurality of gate electrodes, the gate emission device comprising at least two divided and insulated gate electrodes so that a predetermined voltage is applied between the field emitter tips independently. have.

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

Field emission device according to the present invention is to improve the directivity of the electron beam, and to be able to easily control the emission direction of the electron beam, the substrate 85 and a plurality of protruding from the substrate 85 to emit electrons Field emitter tip 66 and a plurality of gate electrodes 80 to which a predetermined voltage is applied to form an electric field around the electron emitter at the field emitter tip 66. Between the tips 66 (hereinafter abbreviated as tips), gate electrodes 80A..80F are divided and insulated so that a predetermined voltage is applied independently. Here, the gate electrodes 80A..80F are divided into two parts and isolated from each other regardless of whether the field emitter tip 66 is a cone shape or a wedge shape. The pairs of gate electrodes 80A, 80B, 80C, 80D, and 80E and 80F provided around the (66-L), 66-C, and 66-R may also be independently applied with voltage. Insulation is isolated. That is, in the gate electrode pairs 80A and 80B, 80A and 80B are gate electrodes to which separate voltages can be independently applied. An insulator 87 is insulated between the gate electrode 80 and the substrate 85 to insulate them.

Looking at the operation and operation of the field emission device according to the present invention configured as described above in detail with reference to FIG.

In order to send the electron beam emitted from the tip 66 to the point B of the phosphor coated on the anode electrode 22, it is applied to the divided and insulated gate electrodes 80A..F provided between each tip 66. The magnitudes of the voltages must be different. That is, in order to direct the electron beam emitted from the tip 66 -L located on the left side to the point B of the transparent electrode 22, the voltage applied to the gate electrode 80A located on the left side of the tip 66 -L. It may be smaller than the voltage applied to the gate electrode 80B located on the right side. In addition, in order to direct the electron beam emitted from the tip 66 -C located in the center to the point B of the transparent electrode 22, the voltage applied to the gate electrode 80C located on the left side of the tip 66 -C. What is necessary is just to make it smaller than the voltage applied to the gate electrode 80D located in the right side. In addition, in order to direct the electron beam emitted from the tip 66 -R located on the right side to the point B of the transparent electrode 22, the voltage applied to the gate electrode 80E located on the left side of the tip 66 -R. Is larger than the voltage applied to the gate electrode 80F located on the right side thereof.

Furthermore, in order to deflect the electron beam emitted from each tip to a desired position, preferably, the deviation of the voltage applied to the pair of gate electrodes surrounding the tip is adjusted to the deviation of the voltage applied to the pair of gate electrodes surrounding the other tip. This can be done by adjusting relative to the deviation. In addition, the same voltage may be applied to the gate electrode 80 to advance the electron beams emitted from the tips.

In addition, the field emission device according to the present invention can individually control the tips 66-L and CR so that the electron beams associated with each tip are directed simultaneously (not possible in the prior art) in the dotted line direction of FIG. You can. That is, in order to direct the emission electron beam from the tip 66-L to the point C of the anode electrode 22, the voltage applied to the gate electrodes 80A and 80B may be adjusted as described above, and the tip ( In order to direct the emission electron beam from 66-C to the point D of the anode electrode 22, the voltage applied to the gate electrodes 80C and 80D may be adjusted appropriately, and the emission electron beam from the tip 66-R may be adjusted. The voltage applied to the gate electrodes 80E and 80F may be appropriately adjusted in order to direct them to the point E of the anode electrode 22.

As described above, in the field emission device according to the present invention, each gate electrode associated with each tip is not associated with the other tip, thereby facilitating control of these electrodes, and finely adjusting the direction of the electron beam emitted from each tip. Allows you to provide adjustable benefits. It also provides the advantage that the electron beam associated with the angular tip can be driven independently by the divided gate electrode.

Claims (5)

A field emission device having a substrate, a plurality of field emitter tips protruding from the substrate to emit electrons, and a plurality of gate electrodes forming an electric field around the electrons to emit electrons from the field emitter tips. And at least two divided and insulated gate electrodes are provided between the field emitter tips to independently apply a predetermined voltage. The field emission device according to claim 1, wherein the same voltage is applied to the gate electrodes provided on both sides of the tip to advance electrons emitted from the field emitter tip. The field emission device of claim 1, wherein different voltages are applied to the gate electrodes provided on both sides of the tip to insulate electrons emitted from the field emitter tip at a predetermined angle. 4. The field emission device according to claim 3, wherein the voltage applied to the gate electrode located on the side where the electron is directed is greater than the voltage applied to the corresponding gate electrode. The field emission device according to any one of claims 1 to 4, wherein the electron beams emitted from the respective tips are individually controlled simultaneously by the respective gate electrodes.