KR100188706B1 - Field emission display - Google Patents

Abstract

The present invention adds a predetermined control electrode to increase the momentum and velocity of the electrons by increasing the interlacing time of the electrons emitted from the tip of the field emission display. The present invention relates to a field emission display in which a phosphor is located at a distance spaced by a predetermined distance corresponding to a deflection angle.

To this end, the present invention provides a substrate, a plurality of field emitter tips protruding from the substrate, and a plurality of gate electrodes for forming an electric field around the electron emitter at the field emitter tips and the emission. In a field emission display having an anode electrode provided with a phosphor that emits light by collision of electrons, the emission electrons are predetermined to increase the interlacing time of electrons emitted from the field emitter tip and traveling to the anode electrode. The control electrode for angular deflection is further provided on one side of the gate electrode, and the structure is improved so that phosphors located at a distance separated by a predetermined distance corresponding to the deflection angle of the phosphors formed on the anode electrode emit light. The luminous efficiency at the node electrode can be improved.

Description

Field emission display

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 cross-sectional view of a conventional field emission device.

4 is a schematic cross-sectional view of a conventional field emission display with deflection electrodes.

5 is a cross-sectional view of a field emission display according to the present invention.

* Explanation of symbols for main parts of the drawings

51 substrate 52 first insulating layer

53 gate electrode 54 second insulating layer

55: control electrode 56: anode electrode

57: emitter tip 58: the first conductive layer

59: electronic interlaced space 61: control unit

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a field emission display. More particularly, the present invention relates to a field emission display. The present invention relates to a field emission display. The present invention relates to a field emission display in which a control electrode is added and phosphors located at a distance spaced by a predetermined distance corresponding to the deflection angle among the phosphors formed on the anode electrode emit light.

In general, a field emission display uses a silicon or metal tip as a cathode and places a gate electrode close to the tip to emit electrons with a strong electric field formed at the tip end. 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, the transparent electrode 2 (or an anode electrode), the gate 8, and the tip 6 of the substrate 12 having the phosphor 4 coated or deposited on the surface thereof may be formed of an anode, a grid, and a cathode of the CRT. Each can be said to correspond. In this 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, electrons are tunneled from the field emitter tip 6 by a strong electric field. Emitted to the outside. 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 When a strong electric field is formed on the surface (a vacuum level in a biased state), the thickness of the vacuum barrier becomes thinner and electrons can be tunneled out of the metal surface. Such tunneling can be explained by the Fowler-Nordheim theory, which is expressed as a mathematical formula as follows.

In the formula, J is the field emission current density (A / cm ² ), E and φ are the intensity (V / cm) and work function (eV) of the surface electric field of the emitter tip, respectively, and y is the short of the work function barrier. Schottky lowering function. It can be seen from the above formula that the field emission current density (J) at the emitter tip is related to the electric field (I) at its surface and the work function (φ) of the material constituting the tip, where the strength of the electric field ( E) is determined by the voltage applied to the gate electrode, the position of the electrode and the geometry of the emitter tip. Thus, the variables that most influence the electrical properties of the field emission device are the geometry, such as the work function and tip shape of the tip material used and the distance between the tip and the gate. In other words, it is reported that the current density can be increased only by using a emitter tip and using a material having a small work function.

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 to impinge on the phosphor of the anode electrode 2: FIG. Here, the member No. 30 is an insulator interposed between the substrate 32 and each gate electrode to insulate them.

The electrons emitted from the emitter tips 6 and 36 shown in FIGS. 1 and 3 travel with a predetermined momentum and impinge on the anode electrode 2 (FIG. 1), that is, the phosphor 4. The impact amount is proportional to the magnitude of the voltage applied to the gate electrode 38. In addition, although the electrons emitted from the emitter tip go straight and collide with a predetermined anode electrode, some of them are spread out, which reduces the luminous efficiency of the anode electrode.

As a conventional technology created to solve the above problems, there is US Patent No. 5,191,217, which is shown in FIG.

Referring to FIG. 4, in addition to the gate electrode 43 (or the extraction electrode), it is a deflection electrode that controls the directivity of electrons emitted from the emitter tip and electrons that do not go straight among the electrons emitted from the emitter tip 47. 45) is further provided to solve the above problems. That is, the deflection electrode 45 serves to improve the straightness and parallelism of the electron beam emitted from the emitter tip 47. Here, reference numerals 41, 42, 44, 46, 48, and 49, which are not described, refer to the support substrate 41, the first insulating layer 42, the second insulating layer 44, and the anode electrode 46; Transparent electrode), first conductive layer 48, and interlaced space 49 of electrons.

However, the prior art as described above can improve the degree of linearity and parallelism of the electron beam emitted from the emitter tip by providing a deflection electrode, but does not increase the speed, momentum and momentum of electrons colliding with the anode electrode. There was this. That is, there is a problem in that it does not increase the total time passing from the field emitter tip to the anode electrode.

The present invention was created to solve the above problems, and the interlacing time of the electrons emitted from the emitter tip is increased, that is, the velocity of the electrons and the magnitude of the momentum are increased so that the electrons collide with the anode electrode. The purpose is to provide a field emission display that effectively increases the amount of impact.

Field emission display according to the present invention to achieve the above object,

Luminescence by a collision between a substrate, a plurality of field emitter tips protruding from the substrate, and a plurality of gate electrodes forming an electric field in the vicinity of the field emitter tips to emit electrons; In a field emission display having an anode electrode provided with a phosphor,

A control electrode for biasing the emission electrons by a predetermined angle is further provided on one side of the gate electrode to increase the interlacing time of the electrons emitted from the field emitter tip to the anode electrode.

Among the phosphors formed on the anode electrode, it is characterized in that the phosphor located at a distance spaced by a predetermined distance corresponding to the deflection angle emits light.

In the field emission display according to the present invention, a control unit for providing a control voltage to the control electrode may be preferably connected to the control electrode.

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

The field emission display according to the present invention increases the momentum and the final velocity of electrons by increasing the interlacing time of electrons emitted from the emitter tip, and protrudes on the substrate 51 and the substrate 51. A plurality of field emitter tips 57 for emitting electrons by field emission, a plurality of gate electrodes 53 disposed around the tips 57 and to which a predetermined voltage is applied to form an electric field around the tips 57; An anode electrode 56 provided with a phosphor that emits light by the collision of the emission electrons is provided.

In addition, in the field emission device according to the present invention, the control electrode 55 which deflects the emission electrons by a predetermined angle in order to increase the interlacing time of the electrons emitted from the tip 57 has one side of the gate electrode 53. Constant, that is, the deflection direction of the electrons. The electrons deflected by the control electrode 55 reach the phosphor at a position spaced apart by a predetermined distance corresponding to the deflection angle of the anode electrode 56. Further, a control portion 61 is provided to the control electrode 55 to provide a predetermined control voltage so as to deflect the emitted electrons.

Reference numerals 51, 52, 54, 56, 58, and 59 shown in the drawings indicate a support substrate 51, a first insulating layer 52, a second insulating layer 54, an anode electrode 56, or a transparent electrode. ), The first conductive layer 58, and the interlaced space 59 of the electrons.

Referring to the operation and operation of the field emission display according to the present invention configured as described above are as follows.

First, if the force of the electrons emitted from the emitter tip 57 by the voltage applied to the gate electrode 53 is F, and the time that the electrons intersect to the anode electrode 56 is T, the electrons Momentum of (M) can be expressed by the following formula.

Therefore, as can be seen from the above formula, when the interlacing time T of the electron is increased, it can be seen that the momentum corresponding to the electron increases as much, and the speed of the electron increases. The method for increasing the interlacing time T of the electrons may increase the interlacing time by deflecting electrons emitted from the tip 57 to the anode electrode 56 by a predetermined angle. That is, immediately after electrons are emitted from the emitter tip 57, when the control unit 61 applies a predetermined control voltage to the control electrode 55, the predetermined angle is deflected to intersect. In this case, the deflected electrons collide precisely with the phosphor at a predetermined point of the anode electrode 56 which is horizontally moved by the deflection angle.

When the discharge electrons are deflected by the control voltage provided from the controller 61 as described above, the interlacing time is increased and thus the momentum is increased, and the momentum of the electrons is increased, thereby increasing the anode electrode 56. In this case, the collision effect of electrons can be increased.

As described above, the field emission display according to the present invention increases the momentum and velocity of electrons by extending the interlacing time of electrons emitted from the emitter tip, thereby improving luminous efficiency due to collision at the anode electrode. To provide.

Claims (2)

Luminescence by a collision between a substrate, a plurality of field emitter tips protruding from the substrate, and a plurality of gate electrodes forming an electric field in the vicinity of the field emitter tips to emit electrons; A field emission display having an anode electrode provided with a phosphor, wherein the control electrode biases the emission electrons by a predetermined angle so that the interlacing time of the electrons emitted from each field emitter tip and proceeds to the anode electrode is increased. Is further installed on one side of each gate electrode, and phosphors located at a distance spaced by a predetermined distance corresponding to the deflection angle among the phosphors formed on the anode electrode emit light. . The field emission display of claim 1, further comprising a control unit for providing a predetermined control voltage to the control electrode.