Field emission display in which a field emission device is applied to a flat display

Provided is a field emission display in which a gate hole having an inclined inner wall and a gate electrode around the gate hole are formed between an anode plate having a phosphor and a cathode plate having a field emitter and a control device for controlling a field emission current, whereby the voltage applied to the gate electrode of the gate plate serves to prohibit an electron emission of the field emitter by the anode voltage, and prevent a local arching by forming a totally uniform potential, so that the life time of the field emission display can be improved, and the gate hole having the inclined inner wall enables a fabrication of a filed emission display panel having a high brightness without an additional focusing grid.

BACKGROUND

1. Field of the Invention

The present invention relates to a field emission display (FED) in which a field emission device is applied to a flat display, and more particularly, to a field emission display comprising a gate hole having an inclined inner wall between an anode plate having a phosphor and a cathode plate having a field emitter and a control device for controlling field emission current, and a gate electrode around the top of the gate holes, wherein the field emitter of the cathode plate is constructed to be opposite to the phosphor of the anode plate through the gate hole.

2. Discussion of Related Art

A field emission display is a device representing an image through cathodeluminescence of a phosphor, by colliding an electron emitted from a field emitter of a cathode plate against the phosphor of an anode plate, wherein the cathode plate having the field emitter and the anode plate having the phosphor are formed to be opposite to each other and be separated by a given distance (for example, 2 mm), by means of vacuum packaging. Recently, many researches and developments have been made on the field emission display as a flat display capable of replacing a conventional cathode ray tube (CRT). Electron emission efficiency in the field emitter being a kernel constitutional element of the field emission display cathode plate is variable depending on a device structure, an emitter material and a shape of the emitter.

The structure of the field emission device can be mainly classified into a diode type having the cathode (or emitter) and the anode, and a triode type having the cathode, the gate and the anode. Metal, silicon, diamond, diamond like carbon, carbon nanotube, and the like have been used commonly as the emitter material. Generally, the metal and silicon have been fabricated to the triode structure, and the diamond, carbon nanotube, and etc. manufactured to the diode structure.

The diode field emitter is usually formed by making diamond or carbon nanotube a film-shaped. The diode field emitter has advantages in simplicity of the manufacturing process and high reliability of the electron emission, even though it has disadvantages in controllability of the electron emission and low-voltage driving, as compared with the triode field emitter.

Hereinafter, a conventional field emission display having a field emitter will be described with reference to the accompanying drawings.

FIG. 1is a perspective view for schematically illustrating a construction of a conventional field emission display having a diode field emitter.

A cathode plate has cathode electrodes11arranged in a belt shape on a lower glass substrate10B, and film-shaped field emitter materials12on a portion thereof. An anode plate has transparent anode electrodes13arranged in a belt shape on an upper glass substrate10T, and phosphors14of red (R), green (G) and blue (B) on a portion thereof. The elements of the cathode plate and the anode plate, as mentioned above, are vacuum packaged in parallel, while facing each other, by using spacers15as a supporter. The cathode electrodes11of the cathode plate and the transparent anode electrodes13of the anode plate are arranged to intersect each other. In the above, an intersecting region is defined as a one pixel.

In the field emission display shown inFIG. 1, an electric field required for an electron emission corresponds to a voltage difference between the cathode electrodes11and the anode electrodes13, divided by the cathode-anode distance. It has been commonly noted that the electron emission occurs in the field emitter when the electric field is applied to the field emitter material in the value of 0.1 V/μm or more.

FIG. 2shows the field emission display proposed for improving the disadvantages of the field emission display shown inFIG. 1, which schematically illustrates a construction of a conventional field emission display using a control device for controlling the field emitter in each pixel of the cathode plate.

The cathode plate includes belt-shaped scan signal lines21S and data signal lines21D, which are formed of a metal on a glass substrate20B and capable of an electrical row/column addressing, a film (thin or thick film) shaped field emitter22, in which each pixel defined by the scan signal line21S and the data signal line21D is formed of diamond, diamond like carbon, carbon nanotube, etc., and control devices23connected to the scan signal line21S, the data signal line21D and the field emitter22to control a field emission current depending on scan and data signals of the display. The anode plate includes transparent anode electrodes24arranged in a belt shape on a glass substrate20T, and phosphors25of red (R), green (G) and blue (B) on a portion thereof. The cathode plate and the anode plate are vacuum packaged in parallel, while facing each other, by using spacers26as a supporter.

In the field emission display shown inFIG. 2, a high voltage is applied to the anode electrodes24to induce an electron emission from the film-shaped field emitter22in the cathode plate, and to accelerate the emitted electrons with high energy at the same time. Then, if a signal of the display is inputted to the control devices23through the scan signal line21S and the data signal line21D, the control device23controls the amount of electrons emitted from the film-shaped field emitter to represent row/column images.

The diode field emitter used for the field emission displays shown inFIGS. 1 and 2, as described above, has advantages that the structure is simple and the manufacturing process is easy, since it does not need a gate and a gate insulating film unlike a conic triode field emitter.

Further, the diode field emitter has very low probability in the breakdown of the field emitter by the sputtering effect of positively ionized particles generated by a collision of electrons to remnant gases, so that it has a high reliability and there is no breakdown phenomenon of the gate and the gate insulator, which is very problematic in the triode field emitter.

In the field emission display having the diode field emitter shown inFIG. 1, however, a high electric field (generally, several V/μm) necessary for field emission is applied through the electrodes (cathode electrodes11and transparent anode electrodes13inFIG. 1) of the upper and lower plates being separated by a significant distance (usually, 200 μm to 2 mm), so that a display signal having a high voltage is required. As a result, there is a disadvantage that an expensive high voltage driving circuit is required.

Particularly, in the field emission display having the diode field emitter ofFIG. 1, a low voltage driving is nearly impossible since the anode electrode13is used as an acceleration electrode of the electron as well as a signal line of the display, even though the voltage necessary for electron emission is lowered by reducing the distance between the upper plate and the lower plate. In the field emission display, an electron having high energy of 200 eV or more is required to emit the light from the phosphor. The higher electron energy is, the better luminous efficiency is. Thus, a high-brightness field emission display can be obtained only if the high voltage is applied to the anode electrode.

In the conventional active-matrix field emission display having the diode field emitter shown inFIG. 2, the high voltage driving problem, non-uniformity of electron emission, cross talk, etc. can be solved by employing the control device23of the field emitter in each pixel and inputting the display signal through it. The high voltage applied to the anode electrode24for the field emission and electron acceleration, however, comes to induce a significant voltage to the control devices23of each pixel. Further, if the voltage is induced more than the breakdown voltage of the control devices23, the control device could be broken.

Therefore, the conventional active-matrix field emission display has disadvantages that the voltage applied to the anode electrodes24may be confined depending on the breakdown characteristics of the control devices23, whereby it is difficult to fabricate the field emission display having the high brightness.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made in view of the above problems, and the present invention is directed to a field emission display capable of significantly reducing the display row/column driving voltage by applying scan and data signals of the field emission display to the control device of each pixel.

In addition, the present invention is directed to a field emission display capable of improving the brightness in such a manner that the electric field necessary for a field emission is applied through the gate electrode of the gate plate to freely control the distance between the anode plate and the cathode plate, so that a high voltage can be applied to the anode.

A field emitter display of the present invention allows the gate plate and the cathode plate to be fabricated individually and then assembled, so that the fabricating process can be readily performed, and the productivity and yield can be improved by fundamentally removing the breakdown of the gate insulating film of the field emitter.

Further, according to the field emitter display of the present invention, the gate hole having the inclined inner wall serves to focus an electron beam, which is emitted from the field emitter, on a phosphor of the anode, and thus, the field emission display having a high resolution can be produced without an additional focusing grid.

The first aspect of the present invention is to provide a field emission display, comprising: a cathode plate having row/column signal lines of a belt shape for which row/column addressing is possible on a substrate, and pixels each defined by the row signal line and the column signal line, wherein each pixel has a film-shape field emitter and a control device for controlling the field emitter, having at least two terminals connected to the row/column signal lines and one terminal connected to the film-shape field emitter; an anode plate having a transparent electrode on the substrate and a phosphor on a portion of the transparent electrode, in each pixel; a gate plate having gate holes and a gate electrode around the top of the gate holes, said gate holes having an inclined inner wall; and spacers for supporting the gate plate between the cathode plate and the anode plate, wherein the field emitter of the cathode plate is constructed to be opposite to the phosphor of the anode plate through the gate holes, and is formed by vacuum packaging.

The second aspect of the present invention is to provide a field emission display, comprising: a cathode plate having row/column signal lines of a belt shape for which row/column addressing is possible on a substrate, and pixels each defined by the row signal line and the column signal line, wherein each pixel has a film-shape field emitter and a control device for controlling the field emitter, having at least two terminals connected to the row/column signal lines and one terminal connected to the film-shape field emitter; an anode plate having a transparent electrode on the substrate and a phosphor on a portion of the transparent electrode, in each pixel; a gate plate having gate holes and a gate electrode around the top of the gate holes, said gate holes each having an inclined inner wall; and spacers for supporting the gate plate between the cathode plate and the anode plate, wherein, the field emitter is composed of dots divided into a plurality of regions, the gate hole of the gate plate has the number corresponding to each of the dots, and at least one of the gate holes has an inclined inner wall.

Here, the spacers are formed between the anode plate and the gate plate.

Here, the anode plate, the cathode plate and the gate plate are formed of different transparent insulating substrates, respectively.

The third aspect of the present invention is to provide a field emission display, comprising: a cathode plate having row/column signal lines of a belt shape for which row/column addressing is possible on a substrate, and pixels each defined by the row signal line and the column signal line, wherein each pixel has a film-shape field emitter and a control device for controlling the field emitter, having at least two terminals connected to the row/column signal lines and one terminal connected to the film-shape field emitter; an anode plate having a transparent electrode on the substrate and a phosphor on a portion of the transparent electrode, in each pixel; and spacers for supporting the cathode plate and the anode plate, while keeping isolation therebetween by a predetermined distance, wherein an insulating layer including gate holes and a gate electrode around the top of the gate holes is further comprised on an upper portion of the cathode plate, in each pixel, said gate holes each having an inclined inner wall, and the field emitter of the cathode plate is constructed to opposite to the phosphor of the anode plate through the gate hole, and vacuum packaged.

The fourth aspect of the present invention is to provide a field emission display, comprising: a cathode plate having row/column signal lines of a belt shape for which row/column addressing is possible on a substrate, and pixels each defined by the row signal line and the column signal line, wherein each pixel has a film-shape field emitter and a control device for controlling the field emitter, having at least two terminals connected to the row/column signal lines and one terminal connected to the film-shape field emitter; an anode plate having a transparent electrode on the substrate and a phosphor on a portion of the transparent electrode, in each pixel; and spacers for supporting the cathode plate and the anode plate, while keeping isolation therebetween by a predetermined distance, wherein an insulating film including gate holes and a gate electrode around the top of the gate holes are further comprised on an upper portion of the cathode plate, in each pixel, said gate holes each having an inclined inner wall, the field emitter of the cathode plate is constructed to opposite to the phosphor of the anode plate through the gate hole, and vacuum packaged, and the field emitter is composed of dots divided into a plurality of regions, the gate hole of the gate plate has the number corresponding to each of the dots, and at least one of the gate holes has an inclined inner wall.

In a preferred embodiment of the present invention, the field emission display may further comprise an optical-shielding film at a given region between the phosphors of the anode to form a black matrix. Here, the image is represented by gray scale, by changing a pulse amplitude and/or pulse width (duration) of the data signal voltage applied to the field emitter through controlling of the control device.

In addition, the field emitter is composed of a thin film or a thick film comprising a diamond, a diamond carbon, or a carbon nanotube. The control device is a thin film transistor or a metal-oxide-semiconductor field effect transistor.

Further, a DC voltage is applied to the gate electrode to induce an electron emission from the film-shaped field emitter in the cathode plate; the emitted electrons are accelerated with high energy by applying the DC voltage to the transparent electrode of the anode plate; and scan and data signals are addressed to the control device of the field emitter in each pixel of the cathode plate, whereby the control device of the field emitter controls the electron emission of the field emitter to represent images.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments of the present invention are intended to more completely explain the present invention to those skilled in the art.

A field emission display according to a first embodiment is significantly different comparing with that of the prior art field, in a cathode plate and a gate hole and a method of driving the same. Hereinafter, the field emission display will be described in detail with reference toFIGS. 3 to 6.

FIG. 3is a perspective view schematically illustrating a construction of an active-matrix field emission display having a gate plate according to the present invention andFIG. 4is a perspective view schematically illustrating a cathode plate, a gate plate and an anode plate in a field emission display according to the present invention. The field emission display includes the cathode plate100, the gate plate200and the anode plate300.

The cathode plate100includes belt-shaped row signal lines120S and column signal lines120D on an insulating substrate110, wherein the belt shaped row signal line and column signal line are made of a metal and enable to a row/column addressing, and the insulating substrate110may be a glass, a plastic, various kinds of ceramics, various transparent insulating substrate, etc. The unit pixels are defined by the row signal lines120S and the column signal lines120D. Each pixel includes a film-shaped (thin or thick film) field emitter130made of diamond, diamond like carbon, carbon nanotube, etc., and a control device140thereof. Preferably, the control device140has at least two terminals connected to the row signal line120S and the column signal line120D, and one terminal connected to the film-shaped field emitter130. For example, the control device140may be an amorphous silicon thin film transistor, a polysilicon thin film transistor, or a metal-oxide-semiconductor field effect transistor.

The gate plate200includes gate holes220penetrating a substrate210, and a gate electrode230made of a metal around the gate holes220. The substrate210of the gate plate200can be formed by a transparent substrate such as a glass, a plastic, various ceramics, various transparent insulating substrates, or the like, and if necessary, a non-transparent substrate can be used as the substrate. The gate plate200may have a thickness in the range of 0.01 to 1.1 mm, for example, and a thickness of the gate electrode may be in the range of several hundreds of Å to several thousands of Å. The metal applicable to the gate electrode230may be chrome, aluminum, molybdenum, or the like, but not limited thereto. In addition, the gate holes220can be formed to be opened a little bit larger than each pixel so that the holes220can serve as an aperture of the unit pixel (for example, several tens of μm to several hundreds of μm) formed in the cathode plate100.

Here, each of the gate holes200has an inclined inner wall. In other words, the size of the gate hole in the anode plate300is small as compared with that in the cathode plate100. Therefore, the gate hole having the inclined inner wall serves to focus an electron beam, which is emitted from the field emitter, on a phosphor of the anode, whereby the field emission display having a high resolution can be produced.

Meanwhile, those skilled in the art will appreciate that a size and a shape of the gate hole220, a thickness of the gate plate200, a thickness of the gate electrode230, etc. are not specially limited but can be variously modified.

The anode plate300includes a transparent electrode320, and phosphors330of red (R), green (G) and blue (B) formed on a portion of the transparent electrode320, on a transparent insulating substrate310made of a glass, a plastic, various ceramics, various transparent insulating substrate, etc.

Meanwhile, in the cathode plate100, the gate plate200and the anode plate300, the field emitter130of the cathode plate100are vacuum packaged parallel to the phosphor330of the anode plate300through the gate holes220of the gate plate200, while facing each other, by using spacers400as a supporter. The spacers400can be manufactured by glass beads, ceramics, or, a polymer, and may have a thickness in the range of approximately 200 μm to 3 mm.

On the other hand, the gate electrode230may be also used as an optical-shielding film by selecting the type of a metal used as the gate electrode230or the thickness of the film.

Next, a method of fabricating the field emission display according to an embodiment of the present invention will be described in detail with reference toFIG. 5.FIG. 5is a cross-sectional view illustrating the unit pixel of the field emission display according to the present invention.

In the embodiment ofFIG. 5, the gate plate is adhered to the cathode plate, while the anode plate is separated and vacuum packaged from the gate plate by a spacer supported between the anode plate and the gate plate. The cathode plate, the gate plate, and the anode plate can be fabricated separately and then combined together.

The unit pixel of the field emission display shown inFIG. 5includes the cathode plate, the gate plate and the anode plate. The cathode plate has a substrate110, a thin film transistor element, the field emitter, etc.

The thin film transistor element include a gate141made of a metal on the substrate110, a gate insulating film142of the thin film transistor composed of an amorphous silicon nitride (a-SiNx) film or a silicon oxide film on the substrate110including the gate141, an active layer143of the thin film transistor formed of an amorphous silicon (a-Si) on a portion of the gate141and the gate insulating film142, a source144and a drain145of the thin film transistor formed of an n-type amorphous silicon at both ends of the active layer143, a source electrode146of the thin film transistor formed of a metal on a portion of the source144and the gate insulating film142, a drain electrode147of the thin film transistor formed of a metal on a portion of the drain145and the gate insulating film142, and an interlayer insulating film (passivation insulating film)148composed of the amorphous silicon nitride film or the silicon oxide film on the active layer143and certain portions of the source electrode146and the drain electrode147of the thin film transistor.

The field emitter130may be formed of diamond, diamond like carbon, carbon nanotube, and the like on a portion of the drain electrode147of the thin film transistor.

The surface of the gate plate having no gate electrode230is adhered to the cathode plate, and the gate hole220is arranged in accordance with the field emitter130of the cathode plate. At this time, the anode plate is separated from the gate plate by using the spacers400as the supporter between them. Further, the anode plate is arranged and vacuum packaged so that the phosphor330of the anode plate is constructed to be opposite to the field emitter130of the cathode plate.

Each of the gate holes200has an inclined inner wall. The tilt angle is not confined specifically and various modifications thereof may be made, if the gate hole having the inclined inner wall serves to focus an electron, which is emitted from the field emitter, on a phosphor of the anode.

The spacers400serve to keep isolation between the cathode plate/the gate plate and the anode plate. It is not necessarily to be installed in every pixel.

The gate plate includes the gate holes220formed by penetrating the glass substrate210, and the gate electrode230made of a metal around the gate holes220.

The anode plate includes the transparent electrode320formed on a portion of the substrate310, phosphors330of red, green, and blue formed on a portion of the transparent electrode320, and a black matrix340formed between said phosphors330.

Meanwhile, the manufacturing process can be readily performed since the gate plate and the cathode plate can be fabricated separately, and the gate insulating film in the field emitter fundamentally can be removed. Therefore, the gate plate, the cathode plate and the anode plate, which are fabricated individually, may be combined together. As a result, it is possible to significantly improve the manufacturing productivity and yield of the field emission display.

Hereinafter, a driving principle of the field emission display according to the first embodiment will be described with reference toFIGS. 3 to 5.

The electron emission from the film-shaped field emitter130of the cathode plate is induced by applying a DC voltage in the range of 50 to 1500 V to the gate electrode230of the gate plate. At the same time, said emitted electrons are accelerated with high energy by applying a high voltage of approximately 2 kV or more to the transparent electrode320of the anode plate. Meanwhile, an operation of the control device of the field emitter in each pixel of the cathode plate could be controlled, by adjusting the voltages applied to the row signal line120S and the column signal line120D of the display. In other words, the control device (i.e. the control device23ofFIG. 2) of the field emitter in each pixel represents an image by controlling an electron emission of the field emitter130.

At this time, the voltage applied to the gate electrode230of the gate plate serves to prohibit an electron emission of the field emitter by the anode voltage, and also prevent a local arching by forming a totally uniform potential between the anode plate and the gate plate. The voltages applied to the row signal line120S and the column signal line120D of the display may be applied to the gate and the source of the thin film transistor, respectively. The voltage applied to the gate may be in the range of 10 V to 50 V when the thin film transistor having the active layer formed of an amorphous silicon is turned on, and may have a negative voltage when the transistor is turned off. Further, the voltage applied to the source may be approximately in the range of 0 to 50 V. The control of the applied voltage, as described above, can be made by an external driver circuit (not shown).

Subsequently, gray scale representation of the field emission display will be explained.

Gray scale representation of the common diode field emission device is implemented by using a pulse width modulation (PWM) mode. This is the mode that the duration of the voltage of the data signal applied to the field emitter is controlled to represent gray scale, and gray scale is represented by the difference in the amount of the electrons emitted for a given time. In other words, a corresponding pixel emits a light having high brightness, if there are plenty of electrons for a given time. However, the mode has a critical limitation where the width (time) of the pulse assigned to the unit pixel is gradually reduced in implementing a large-scale screen. Further, there is a problem that it is difficult to exactly control the amount of emitted electrons.

The driving method according to the present embodiment can overcome the above problems. Gray scale representation of the field emission display may employ the pulse width modulation (PWM) mode or the pulse amplitude (PAM) mode, individually or a combination thereof. The PAM mode is that gray scale is represented based on the difference of the amplitude applied as the data signal. This mode employs that the amount of the electrons transported to the field emitter may be varied by the difference in the level of the voltage applied to the source in a state where the thin film transistor is turned on. Gray scale can be also represented by the difference of the voltage divided into two or more levels. This driving method can be applied to implement the large-scale screen and control the electrons emission constantly.

Hereinafter, a second embodiment or modified embodiments will be described in detail, with reference toFIG. 6.

FIG. 6shows a constitution of a field emission display according to another embodiment of the present invention. In this case, the anode plate is the same as that ofFIG. 5, except that the field emitter130of the cathode plate is composed of several dots and the gate hole of the gate plate has the number corresponding to each of the dots.

The constitution, as mentioned above, is very efficient to apply a high voltage to the anode plate. Thus, it is possible to prevent the high voltage from having a bad influence on the field emitter.

At least one of the gate holes220has an inclined inner wall, and the gate electrode230is placed around the top of the gate holes. On the other hand,FIG. 6exhibits the gate holes220each having an inclined inner wall, but not limited thereto.

For convenience of explanation, Example 3 will be described on the basis of a difference with Example 1. In Example 1, the field emission display includes the cathode plate, the gate plate, and the anode plate. On the other hand, a field emission display of Example 3 includes a cathode plate and an anode plate.

According to Example 3, an insulating layer is formed on an upper portion of the cathode plate of Example 1 in which the filed emitter, the control device, and so on are formed without using an additional gate plate. Here, the insulating layer includes gate holes each having an inclined inner wall.

The insulating layer can be formed using various materials, which are not specifically confined. For example, the insulating layer is formed with a thickness in the range of 0.01 mm to 2 mm. The inclined inner wall in the hole gate of the insulating layer can be formed in such a manner that a plurality of insulating layers each having a different etching selection ratio are formed and etched by means of a wet etching method, or a green sheet that is made by stacking insulators each having a different etching ratio is attached to the cathode plate by means of a lamination method, and then annealed and etched.

Thus, according to Example 3 as described above, additional gate plate is not required, so that a process of attaching the gate plate to the cathode plate can be omitted and a production cost can be reduced.

For convenience of explanation, Example 4 will be described on the basis of a difference with Example 2. In Example 2, the field emission display includes the cathode plate, the gate plate, and the anode plate. On the other hand, a field emission display of Example 4 includes a cathode plate and an anode plate.

According to Example 4, an insulating layer is formed on an upper portion of the cathode plate of Example 2 in which the filed emitter, the control device, and so on are formed without using an additional gate plate. Here, the insulating layer includes gate holes each having an inclined inner wall.

Meanwhile, the field emitter of the cathode plate comprises a number of dots and the gate holes has the number corresponding to each of the dots in the field emitter of the cathode plate.

Next, an experiment for a unit device of the field emission display having the practically fabricated gate plate according the first embodiment of the present invention will be explained.

FIG. 7is a graph showing an anode current depending on a gate voltage, in the field emission display including the gate plate with the gate holes, of which the inner walls are formed to be inclined.

In this experiment, the gate plate is fabricated to have a thickness of 0.4 mm, and the gate holes are formed to a circle. Here, diameters of a large portion and a small portion are 0.4 mm and 0.3 mm, respectively.

As a result, a tilt angle of an inclined inner wall is approximately tan−110. In addition, the control device is a thin film transistor (TFT).

Referring toFIG. 7, it can be noted that the anode emission current could be controlled by the voltage applied to the gate of the thin film transistor, in case where the voltage VAapplied to the transparent electrode of the anode plate is 1500 V and the gate voltage VMchanges to 450 V and 500 V, respectively. In addition, a leakage current of the gate in the gate plate was not nearly detected, and the anode voltage did not affect the anode emission current.

FIG. 8is a graph showing simulation results of a potential contour and a trajectory of an electron beam, in the case of the gate hole having an inclined inner wall.FIG. 8shows the trajectory of the electron beam, which are calculated in a central portion A and an edge portion B of the field emitter, respectively.

According to the results of the simulation, a beam divergence was very small. Practically, it was measured to 0.1 mm or less at 0.5 V/μm. This is a small value, as compared to a spindt-type emitter. In conclusion, the gate hole having an inclined inner wall enables a fabrication of a filed emission display panel having a high resolution without an additional focusing grid, since it has a focusing effect itself.

As described above, the present invention has a merit that the display row/column driving voltage could be decreased remarkably, and thus, the low voltage driving circuit with low cost can be employed instead of a high voltage driving circuit, at the time of the row/column driving of the diode field emission display in accordance with the prior art.

Meanwhile, a distance between the anode plate and the cathode plate can be adjusted freely since an electric field required for an field emission can be applied via the gate electrode of the gate plate, so that a high voltage can be applied to the anode, and thus, brightness of the field emission display can be enhanced remarkably.

The voltage applied to the gate electrode230of the gate plate serves to prohibit an electron emission of the field emitter by the anode voltage, and prevent a local arching by forming a totally uniform potential between the anode plate and the gate plate, whereby the life time of the field emission display can be improved.

Further, the fabrication process is very easy since the gate plate and the cathode plate are fabricated individually, and it is possible to significantly improve the manufacturing productivity and yield of the field emission display since the breakdown phenomenon of the gate and the gate insulator can be eliminated fundamentally.

Meanwhile, the gate hole having the inclined inner wall serves to focus an electron, which is emitted from the field emitter, on a phosphor of the anode. As a result, the field emission display having a high resolution can be produced without an additional focusing grid.

Although the present invention have been described in detail with reference to preferred embodiments thereof, it is not limited to the above embodiments, and several modifications thereof may be made by those skilled in the art without departing from the technical spirit of the present invention.

The present application contains subject matter related to korean patent application no. 2003-89372, filed in the Korean Patent Office on Dec. 10, 2003, the entire contents of which being incorporated herein by reference.