KR19990060204A - Field emission display - Google Patents

Abstract

According to the present invention, the upper member coated with the fluorescent material and the lower member provided with the cathode ray emitting device are coupled to each other while maintaining a predetermined distance and a voltage of a predetermined size is applied between the upper member and the lower member. The present invention relates to a field emission display device including cells that emit light strongly by colliding with a fluorescent material applied to an upper member by emitting electrons strongly from a cathode ray emitting device, and particularly, formed on an upper surface of a lower member. And a first electrode having a tip shape in parallel with the lower member to emit electrons when the voltage of the first polarity is applied and formed on the insulating layer, and when the voltage of the second polarity is formed on the insulating layer. A second electrode having a tip shape in parallel with the lower member to attract electrons emitted from the first electrode, The first electrode tip and the tip of the second electrode is not opposed to each other with the cathode ray-emitting device to maintain the coupling shape maintaining a predetermined spacing member; And an electron emission direction converting means for alternately changing polarities of voltages applied to the first electrode and the second electrode constituting the cathode ray emitting element so as to alternately change the emission direction of electrons emitted from the specific electrode. The present invention relates to a field emission display device.

Description

Field emission display

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field emission display device, and more particularly, to a field emission display device for improving uniformity of a screen by changing a driving voltage of a negative charge generating device for electron emission from a DC voltage to an AC voltage.

In general, a display element called a field emission display device (FED) or a field emission array is a display element for display developed as an alternative to an LCD. Same as

The FED basically maintains a space formed between the upper member to which the fluorescent material is applied and the lower member to which the cathode ray emitting device is maintained at a predetermined distance to maintain a vacuum formed therebetween. When a voltage of several kilovolts (KV) or several hundred volts is applied between the lower member and the lower member, negative electrons are strongly emitted from the cathode ray emitting element provided in the lower member, thereby colliding with the fluorescent material applied to the upper member. The fluorescent material is composed of cells to emit light.

The cells described above form a matrix of M × N in a plane of a predetermined size, and the control technique for driving the cell array is generally similar to the LCD driving principle.

Therefore, as a result, the performance of the FED is determined by the kinetic energy of electrons generated in the cathode ray emitting device. For this purpose, an implementation of the cathode ray emitting device for field emission is shown in FIGS. 1 to 3. Various proposals have been made as follows.

1 through 3 illustrate aspects of a typical case among methods for implementing conventional field emission, in which FIG. 1 illustrates a Spindt type, and FIG. 2 illustrates an SCE type. 3 shows a DLC type, which is the most common way of Spindt type as shown in FIG.

Briefly referring to FIG. 1 with the above-described Spindt type, the Spindt type is a vertical structure that matches the characteristics of a typical FED in which electrons emitted from a tip collide with phosphors and emit light. Thus, the efficiency of electron emission is higher than the schemes shown in FIG. 2 or FIG. 3. However, there is a disadvantage that the manufacturing process of the cathode including the tip is difficult.

On the contrary, the Surface-Conduction Electron Emitter (SCE) type and the Diamond Like Carbon (DLC) type shown in FIGS. 2 and 3 are simplified methods of manufacturing a cathode by applying a planar electron source. In particular, the SCE type is classified into a horizontal structure according to the emission direction, that is, by emitting electrons in the horizontal direction and attracting these electrons from the anode, the electrons collide with the luminescent material and emit light.

However, the methods according to the planar electron source as described above are much lower in the efficiency of electron emission than the tip method.

Therefore, when the electron emission efficiency between the Spindt type and the planar electron source (SCE, DLC) is numerically compared, the electron emission efficiency of the Spindt type is 12 lm / W, whereas the method according to the planar electron source (SCE , DLC) has an electron emission efficiency of 2.8 lm / W.

Therefore, the development of a cathode and a simple but high electron emission efficiency in the formation of the cathode ray emitting device according to the manufacturing of the FED has been proposed as a problem.

Therefore, as a structural example of a planar electron source, as shown in FIG. 4 to which the technique proposed by the present inventors and the present inventors are attached to solve the above-described problems, when a voltage is applied to the cathode and the anode positive electrode, Has a structure in which an electric field is formed so that electrons are emitted from the cathode, and the cathode and the anode positive electrode have a common tip shape.

Referring to the configuration and operation of the conventional cathode ray emitting device with reference to the configuration of Figure 5, the configuration is a cathode (emitter) electrode (3) for emitting electrons on the substrate (1) and the insulator (2) layer The anode electrode 4 for attracting the emitted electrons is configured to have a tip shape. That is, as is well known, the cathode electrode 3 is provided with a plurality of conical tip electrodes. Similarly to the cathode electrode 3, the electrode 4 is provided with a plurality of conical tip electrodes.

In addition, the tip regions of the anode electrode 3 and the cathode electrode 4 were configured to face each other.

Looking at the operation of the conventional cathode ray emitting device configured as described above, when a voltage of a predetermined value or more applied to the cathode electrode 3 and the anode electrode 4, an electric field is formed on the cathode electrode 3 and the anode electrode 4 Therefore, the electrons emitted from the cathode electrode 3 are rapidly moved to the anode electrode 4 side.

At this time, the electrons emitted from the cathode side should collide with the fluorescent material due to the characteristics of the field emission display device, as an example of the process is shown in FIG. Therefore, the effect of the brightness increase according to the increase in emission can be obtained.

However, in the FED provided with the cathode ray emitting element as described above, the state of the emission is shown as shown in FIG. 5 attached to the tip. Since the angle of emission is about 30 °, the glorious body is usually designed larger than the size of the emitter. Therefore, in the case of the conventional unidirectional emission, in order to collide the electrons emitted from the cathode to the phosphor, the electron flow is bent much as shown.

That is, the light emitting state of the phosphor surface on the same side as the traveling direction of the electrons emitted from the cathode is bright, but collides with the phosphor site on the side opposite to the traveling direction of the electrons. Since the electrons are deflected in the opposite direction immediately after the emission, they collide with the body phosphor, which has a relatively reduced kinetic energy, so that the emission state is not bright.

Therefore, the phosphor cannot be uniformly emitted and has been proposed as a problem of increasing the nonuniformity of the screen.

An object of the present invention for solving the above problems is to provide a field emission display device to improve the uniformity of the screen by changing the drive voltage of the cathode ray generating device for electron emission from DC voltage to AC voltage have.

1 is a structural example of a Spindt type of a conventional cell structure for electric field emission

Figure 2 is a structural example of the SCE type of the conventional cell structure for electric field emission

3 is a structural example of a DLC type of a conventional cell structure for electric field emission

4 is a structural example of a planar electron source having a conventional tip structure shape

FIG. 5 is an exemplary diagram of a phosphor collision process of an electron beam during operation of the electron emission device according to the structure shown in FIG. 4; FIG.

6 is an exemplary configuration diagram for describing a technical background according to the present invention.

7 is an exemplary view for explaining an electron emission operation of an electron emission device according to the present invention.

8 is a diagram illustrating a fluorescent surface collision process of electrons emitted when the electron emission device according to the present invention is applied.

Features of the present invention for achieving the above object, the upper member is coated with a fluorescent material and the lower member is provided with a cathode ray emitting device in a state maintaining a predetermined distance between the predetermined between the upper member and the lower member When a voltage of a magnitude is applied, an electron is strongly emitted from a cathode ray emitting element provided in the lower member to collide with a fluorescent substance applied to the upper member, thereby causing the field to be composed of cells for emitting the fluorescent substance. A display element comprising: a first electrode formed on an insulating layer formed on an upper surface of the lower member and having a tip shape parallel to the lower member to emit electrons when a voltage of a first polarity is applied thereto; Is formed on the insulating layer and attracts electrons emitted from the first electrode when the voltage of the second polarity is applied. In order to have a second electrode having a tip shape parallel to the lower member for the tip, the tip of the first electrode and the tip of the second electrode does not face each other and maintain a matched shape maintaining a predetermined separation distance An emission element; And electron emission direction converting means for alternately changing polarities of voltages applied to the first electrode and the second electrode constituting the cathode ray emitting element so as to alternately change an emission direction of electrons emitted from a specific electrode. There is.

As an additional feature of the present invention for achieving the above object, the electron emission direction converting means generates two constant voltage sources of the same magnitude but different polarity and the voltage generated from the two constant voltage sources; It is composed of a switching element for alternately connecting to the first electrode and the second electrode.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, referring to FIG. 6 attached to the technical idea applied to the present invention, FIG. 6 is a structure proposed in US Pat. No. 5,382,867. The configuration is such that electrons are emitted on the substrate 1 and insulator 2 layers. The electrode 3A for the cathode (emitter) and the electrode 4A for the positive electrode for attracting the emitted electrons are configured to have a tip shape. It is a structure facing each other.

At this time, the US Patent 5,382,867 uses the same structure as the screw thread as shown in Figure 6, but used a single direction voltage, in the present invention uses a structure as shown in FIG. That is, instead of specifying a specific electrode as an anode or a cathode, instead of changing the polarity of the electrode, the specific electrode plays a specific role only at a certain time point and plays a different role at another time point, as shown in FIG. 5. Although the warpage phenomenon of the emitted electrons occurs, the focus is on the fact that the uniformity of the luminance can be restored on the average by alternating the position where the warpage phenomenon occurs.

Referring to FIG. 7 attached to the configuration of the field emission display device according to the present invention based on the technical spirit as described above, the configuration of the cathode light emitting device is configured as shown in FIG. Two constant voltage sources 10A and 10B having positive magnitudes with different polarizations and voltages generated from the two constant voltage sources 10A and 10B to the first electrode 3A and the second electrode 4A. Switching element SW is further configured to alternately connect.

Therefore, since the magnitude of the voltage generated by the constant voltage sources 10A and 10B is the same, even if any one of the first electrode 3A and the second electrode 4A becomes a negative electrode, the amount of electrons emitted is the same. Done.

As shown in FIG. 8, the light emitting operation of the field emission display device according to the configuration of the cathode light emitting device according to the present invention as shown in FIG. 7 is described with reference to FIG. 5. Similarly, the warpage phenomenon of the emitted electrons may occur, but the position where the warpage phenomenon of the electrons occurs alternately changes, and as shown in FIG. 8, the luminance uniformity can be restored on average.

According to the present invention operating as described above, the electrode for the cathode (emitter) for emitting electrons on the substrate and the insulator layer and the electrode for anode for drawing the emitted electrons both have a tip shape, thereby simplifying the process. At the same time there is an effect to increase the field emission rate.

Claims (2)

When the upper member coated with the fluorescent material and the lower member provided with the cathode ray emitting device are coupled in a state of maintaining a predetermined distance, and a voltage of a predetermined size is applied between the upper member and the lower member, the lower member is provided. In a field emission display device comprising a cell in which electrons are strongly emitted from a cathode ray emitting device and collide with a fluorescent material applied to the upper member, thereby causing the fluorescent material to emit light. It is formed on the insulating layer formed on the upper surface of the lower member and provided with a first electrode having a tip shape in parallel with the lower member for the emission of electrons when a voltage of a first polarity is applied, and is formed on the insulating layer A second electrode having a tip shape in parallel with the lower member to attract electrons emitted from the first electrode when a voltage of a second polarity is applied, the tip of the first electrode and the tip of the second electrode A cathode ray-emitting device for maintaining a matched shape in which a predetermined distance is maintained without facing each other; And electron emission direction converting means for alternately changing polarities of voltages applied to the first electrode and the second electrode constituting the cathode ray emitting element so as to alternately change an emission direction of electrons emitted from a specific electrode. A field emission display device characterized by the above-mentioned. The method of claim 1, The electron-emitting direction converting means includes two constant voltage sources for generating a constant voltage having the same magnitude but different polarity reflections; And a switching element for alternately connecting the voltages generated by the two constant voltage sources to the first electrode and the second electrode.