KR20050048311A - Field emission display device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a field emission display device in which electrons emitted from an emitter accurately reach a fluorescent film of a corresponding pixel to suppress other color emission and improve color reproduction characteristics. And a second substrate; Gate electrodes formed on the first substrate; Cathode electrodes formed over the gate electrodes with an insulating layer interposed therebetween; An electron emission source provided in the cathode electrode corresponding to the pixel region set on the first substrate; An anode formed on the second substrate; Fluorescent films positioned on one surface of the anode electrode; A field emission display device is provided between a first substrate and a second substrate, the grid plate including apertures for passing an electron beam, and wherein at least two electron emission sources share one aperture.

Description

Field emission display device {FIELD EMISSION DISPLAY DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field emission display, and more particularly, to a field emission display having an improved internal structure such that electrons emitted from an emitter accurately reach a fluorescent film of a corresponding pixel.

In general, a field emission display (FED) forms an electric field around an emitter made of an electron emission material by using a voltage difference between a cathode electrode and a gate electrode to emit electrons therefrom, and emits the emitted electrons as anode electrodes. It is a display device that implements a predetermined image by colliding with a fluorescent film provided in the device to emit light.

8 is a partial cross-sectional view showing an example of a field emission display device according to the prior art. Referring to the drawings, the gate electrode 3 and the cathode electrode 5 are formed in the first substrate 1 along a direction crossing each other with the insulating layer 7 interposed therebetween, and the gate electrode 3 and the cathode The emitter 9 is positioned on the cathode electrode 5 for each pixel region where the electrodes 5 intersect. An anode electrode 13 is formed on the second substrate 11, and red, green, and blue fluorescent films 15R, 15G, and 15B are disposed on one surface of the anode electrode 13 with a black layer 17 therebetween. Located.

A grid plate 19 having a plurality of apertures 19a is positioned between the first substrate 1 and the second substrate 11, and in general, one or more apertures 19a per pixel area. Is placed. The grid plate 19 focuses electrons emitted from the emitter 9 and prevents the damage from being directed to the first substrate 1 when arcing occurs in the vacuum vessel.

Thus, when a predetermined driving voltage is applied to the gate electrode 3 and the cathode electrode 5, an electric field is formed around the emitter 9 due to the voltage difference between the two electrodes, and electrons are emitted therefrom. The emitted electrons are attracted by the high voltage applied to the grid plate 19 and the anode electrode 13 to pass through the aperture 19a of the grid plate 19 and then reach the fluorescent film 15 to emit light. Indication is made.

However, as described above, in the structure in which the cathode electrode 5 and the emitter 9 are located above the gate electrode 3, there is no structure for focusing electrons adjacent to the emitter 9 so that the emitter ( The electrons emitted at the edge of 9) are partially diverged. In addition, even when the grid plate 19 blocks the emitted electrons, some of the electrons reach the other color fluorescent film of the neighboring pixel through the aperture 19a provided in the neighboring pixel and emit light.

Therefore, other colors are emitted, and color reproduction characteristics of the display device are deteriorated. This problem is caused by the aperture 19a of the grid plate 19 being simply arranged one-to-one in the pixel area, and the upper portion of the grid plate 19 area. It is estimated that the area ratio of the depressions 19a, that is, the geometric aperture ratio of the grid plate is large.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to emit electrons emitted from an emitter accurately to the fluorescent film of the corresponding pixel to suppress other color emission, and to improve color reproduction characteristics. To provide a device.

In order to achieve the above object, the present invention,

First and second substrates disposed at random intervals, gate electrodes formed on the first substrate, cathode electrodes formed on the gate electrodes with an insulating layer therebetween, and on the first substrate An electron emission source provided at the cathode electrode corresponding to the pixel region to be set, an anode formed on the second substrate, fluorescent films positioned on one surface of the anode electrode, and disposed between the first substrate and the second substrate And a grid plate having apertures for electron beam passage, wherein at least two electron emission sources share one aperture.

If two electron emitters share one aperture, the two electron emitters are arranged opposite to one aperture center. At this time, the cathode electrode forms openings in the electrode, and one opening is provided for every two gate electrodes. The opening includes first and second side surfaces corresponding to the two gate electrodes, respectively, and an electron emission source is disposed on the cathode electrode adjacent to the first and second side surfaces.

The two fluorescent films are disposed to face each other with respect to one aperture center, and the emitters and the fluorescent film that are arranged opposite to one aperture center form one pixel with the emitter.

When three electron emitters share one aperture, the three electron emitters are arranged at equal intervals on concentric circles corresponding to one aperture. At this time, the cathode electrode forms openings in the electrode, and one opening is provided for every three gate electrodes. The opening includes first and second and third sides corresponding to the three gate electrodes, respectively, and an electron emission source is disposed on the cathode electrode adjacent to the first, second and third sides.

In addition, the aperture of the grid plate consists of a triangle whose vertices correspond to the three electron emission sources. The fluorescent films are formed in a dot pattern, and three fluorescent films are disposed at equal intervals on concentric circles corresponding to one aperture. Preferably, the three fluorescent films are disposed corresponding to one of the three sides of the aperture.

The electron emission source is made of any one or combination of carbon nanotubes, graphite, diamond, diamond-like carbon, C ₆₀ (fulleren).

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

1 is a partially exploded perspective view of a field emission display device according to a first exemplary embodiment of the present invention, FIG. 2 is a plan view of the first substrate illustrated in FIG. 1, and FIG. 3 is a partial cross-sectional view illustrating an assembled state of FIG. 1. .

Referring to the drawings, the field emission display device includes first and second substrates 2 and 4 that are disposed at random intervals and constitute a vacuum container, and include a plurality of apertures 6a for passing an electron beam. A grid plate 6 provided between the substrates. The first substrate 2 is provided with an emitter 8 as an electron emission source for each pixel region to emit electrons by forming an electric field, and the second substrate 4 has red, green and blue colors which are excited by electrons to emit visible light. The fluorescent films 10R, 10G, and 10B are provided to implement a predetermined image.

The field emission display device according to the present invention has a configuration in which at least two emitters 8 share one aperture 6a. According to this configuration, the effective aperture ratio (the ratio of the amount of electrons reaching the fluorescent film through the aperture to the total amount of electrons emitted from the emitter) of the grid plate 6 is maintained in a range similar to that of the conventional grid plate. The geometric aperture ratio of (6) (area ratio of apertures to grid plate area) is reduced to effectively block electron beams diverging toward the fluorescent film of neighboring pixels among the electron beams emitted from the emitter 8.

First, the first embodiment of the present invention consists of a configuration in which two emitters 8 share one aperture. Referring to Figures 1 to 3 specifically described above the configuration as follows.

Referring to the drawings, the gate electrodes 12 are formed in a stripe pattern along one direction (Y direction in the drawing) on the first substrate 2, and the entire inner surface of the first substrate 2 is covered while covering the gate electrodes 12. The insulating layer 14 is located. On the insulating layer 14, cathode electrodes 16 are formed along a direction crossing the gate electrode 12 (the X direction in the drawing), and electrons are formed in each pixel region where the gate electrode 12 and the cathode electrode 16 cross each other. An emitter 8, which is an emission source, is provided on the cathode electrode 16.

The cathode electrode 16 forms openings 18 therein to expose the insulating layer 14 under the cathode electrode 16, one at the center of the two gate electrodes 12 for every two gate electrodes 12. Openings 18 are formed. The opening 18 preferably consists of a rectangle having first and second side surfaces 18a and 18b corresponding to the two gate electrodes 12, respectively, and the cathode electrode 16 adjacent to the first and second side surfaces 18a and 18b. The emitter 8 is located on. As a result, two emitters 8 are disposed to face each other with the opening 18 therebetween, and each emitter 8 is disposed corresponding to the pixel area.

In the present invention, the emitter 8 is any one of carbon nanotubes (CNT; carbon graphite), graphite (graphite), diamond, diamond-like carbon (DLC), C ₆₀ (fulleren) or their In combination.

The counter electrode 20 may be positioned on the insulating layer 14 in the opening 18 to draw the electric field of the gate electrode 12 over the insulating layer. The opposite electrode 20 is in contact with and electrically connected to the gate electrode 12 through a via hole 14a formed in the insulating layer 14, and is connected to the cathode electrode 16 and the emitter 8. Located at random intervals to prevent electrical shorts with them. In addition, the two opposing electrodes 20 located in one opening 18 are positioned at random intervals from each other to prevent signal interference between pixels.

Meanwhile, an anode electrode 22 is formed on one surface of the second substrate 4 facing the first substrate 2, and red, green, and blue fluorescent films 10R and 10G are formed on one surface of the anode electrode 22. , 10B) is positioned with the black layer 24 in between. In the present exemplary embodiment, the fluorescent films 10 are formed in a stripe or slit pattern along the direction of the gate electrode 12, and respective fluorescent films 10R, 10G, and 10B are disposed corresponding to the gate electrodes 12.

The grid plate 6 positioned between the first and second substrates 2 and 4 forms apertures 6a corresponding to one-to-one in the opening 18 provided in the cathode electrode 16. As a result, two emitters 8 and two fluorescent films 10 are disposed to face each other with respect to the center of one aperture 6a. At this time, the fluorescent film 10 disposed opposite to the center of the emitter 8 and the aperture 6a forms one pixel with the emitter 8. That is, referring to FIG. 3, the emitter 8 located on the left side of the aperture 6a and the fluorescent film 10G located on the right side of the aperture 6a correspond to one pixel, and the right side of the aperture 6a. The emitter 8 'positioned at and the fluorescent film 10R positioned at the left side of the aperture 6a correspond to one pixel.

The field emission display device configured as described above is driven by supplying a predetermined voltage to the gate electrode 12, the cathode electrode 16, the grid plate 6, and the anode electrode 22 from the outside. 12) a positive voltage of several to several tens of volts, a positive voltage of several to several tens of volts to the cathode electrode 16, a positive voltage of several tens to several hundreds of volts to the grid plate 6, and an anode A positive voltage of several hundred to several thousand volts is applied to the electrode 22.

As a result, an electric field is formed around the emitter 8 of the specific pixel due to the voltage difference between the gate electrode 12 and the cathode electrode 16, and electrons are emitted from the emitter 8, and the emitted electrons are transferred to the grid plate 6. Is led by the positive voltage applied to the light source, passes through the aperture 6a of the grid plate 6, and then is attracted by the high voltage applied to the anode electrode 22 to impinge on the fluorescent film 10 of the pixel to emit light. To implement a predetermined image.

In the above process, the electron beams emitted from the emitter 8 proceed with oblique trajectories at an inclination angle with the first substrate 2, and the fluorescent film 10 of the same pixel as the emitter 8 is apertured ( As it is positioned on the electron beam trajectory of the emitter 8 with 6a) interposed therebetween, the majority of the electron beams emitted from the emitter 8 pass through the aperture 6a to the fluorescent film 10 of the pixel. To reach. However, electron beams whose paths deviate from the main trajectory toward the fluorescent film 10 do not pass through the aperture 6a and are blocked by the grid plate 6, thereby suppressing other color emission.

4 is a partial plan view of a first substrate of the field emission display according to the second exemplary embodiment of the present invention, FIG. 5 is a partial plan view of the grid plate, and FIG. 6 is a partial plan view of the second substrate.

The second embodiment of the present invention has a configuration in which three emitters 26 share one aperture 28a. The above configuration will be described in detail with reference to FIGS. 4 to 6.

Referring to the drawings, the cathode electrode 30 forms an opening 34 in the center of the three gate electrodes 32 for each of the three gate electrodes 32 to form the insulating layer 14 under the cathode electrode 30. Expose The opening 34 preferably consists of a hexagon with first, second and third side surfaces 34a, 34b, 34c corresponding to the three gate electrodes 32, respectively, and the first, second and third side surfaces. Emitter 26 is located on cathode electrode 30 adjacent 34a, 34b, 34c.

That is, in this embodiment, the emitter 26 is formed adjacent to the odd side or even side among the six sides of the opening 34 so that the three emitters 26 are arranged at equal intervals on the concentric circle along the opening 34. Each emitter 26 is disposed corresponding to the pixel region where the gate electrode 32 and the cathode electrode 30 cross each other.

In addition, the counter electrode 36 may be disposed on the insulating layer 14 in the opening 34 to draw the electric field of the gate electrode 32 over the insulating layer 14. The opposite electrode 36 is in contact with and electrically connected to the gate electrode 32 through a via hole 14a formed in the insulating layer 14. The gate electrode 32 is, for example, an emitter of the corresponding pixel. A circular extension 32a may be formed around the rotor 26 so that the counter electrode 36 may be connected to the gate electrode 32 through contact with the extension 32a.

On the other hand, the grid plate 28 forms apertures 28a corresponding to one-to-one in the opening 34 provided in the cathode electrode 30, and each aperture 28a is preferably three emitters 26. Consists of triangles whose vertices correspond to them. The aperture 28a may correspond to the electron beam trajectory emitted from the emitter 26 when the field emission display device is viewed in plan view. Thus, in this embodiment, three emitters 26 are arranged at equal intervals on concentric circles corresponding to one aperture 28a to form a structure sharing one aperture 28a.

In addition, the red, green, and blue fluorescent films 38R, 38G, and 38B formed on the second substrate 4 are formed in a dot pattern unlike the first embodiment described above, and the three fluorescent films 38R, 38G, 38B) are arranged at equal intervals on concentric circles corresponding to one aperture 28a. In particular, in the present embodiment, three fluorescent films 38R, 38G, 38B are disposed corresponding to three sides of the aperture 28a so that each of the fluorescent films 38R, 38G, 38B has an aperture 28a therebetween. It is positioned on the electron beam trajectory of the emitter 26.

That is, referring to FIG. 5, the emitter 26 located at the upper left of the aperture 28a and the fluorescent film 38B located at the lower right of the aperture 28a correspond to one pixel, and the aperture is used. The emitter 26 located at the upper right of the 28a and the fluorescent film 38G located at the lower left of the aperture 28a correspond to one pixel, and the emitter located at the bottom of the aperture 28a. The fluorescent film 38R located at the upper end of the reference numeral 26 and the aperture 28a corresponds to one pixel.

FIG. 7 is a partial cross-sectional view of a field emission display device according to a second exemplary embodiment of the present invention, and is a cross-sectional view taken along line A-A of FIG. 5. Referring to the drawings, when the blue fluorescent film 38B is to emit light, a scan signal is applied to the cathode electrode 30 and a blue data signal is applied to the left gate electrode 32 shown in FIG. An electric field is formed around the emitter 26 using the voltage difference of and emits electrons therefrom.

At this time, the electrons emitted from the emitter 26 proceed with an oblique trajectory at an angle of inclination with the first substrate 2, and the fluorescent film 38B of the same pixel as the emitter 26 is apertured. As it is located on the electron beam trajectory of the emitter 26 with the 28a interposed therebetween, most of the electron beams emitted from the emitter 26 pass through the aperture 28a to the fluorescent film 38B of the pixel. Arrives and emits light. However, the electron beams whose paths deviate from the main trajectory toward the fluorescent film 38B do not pass through the aperture 28a and are blocked by the grid plate 28 to effectively suppress other color emission.

Meanwhile, in the above-described first and second embodiments, not shown between the first substrate 2 and the grid plates 6 and 28 and between the second substrate 4 and the grid plates 6 and 28 are not shown. Spacers may be arranged to allow the grid plates 6, 28 to be spaced apart from the first and second substrates 2, 4.

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 the range of.

As described above, as the at least two emitters share one aperture, the geometric aperture ratio of the grid plate is reduced, so that the electron beam emitted toward the neighboring pixel among the electron beams emitted from the emitter can be effectively captured. Thus, when the electron beam capture effect is applied in the vertical direction of the screen, the vertical resolution or text readability of the display device is improved, and when the electron beam capture effect is applied in the horizontal direction of the screen, the color purity of the display device is improved.

In addition, in this embodiment, even though the geometric aperture ratio of the grid plate is reduced, the effective aperture ratio can be maintained at a similar level as before, so that a sufficient electron beam passing rate can be ensured. There is an effect of increasing the assembly stability of the grid plate mounted on the container.

1 is a partially exploded perspective view of a field emission display device according to a first embodiment of the present invention.

FIG. 2 is a plan view of the first substrate illustrated in FIG. 1.

3 is a partial cross-sectional view showing the assembled state of FIG.

4, 5, and 6 are partial plan views of a first substrate, a partial plan view of a grid plate, and a partial plan view of a second substrate of the field emission display device according to the second embodiment of the present invention, respectively.

FIG. 7 is a partially coupled cross-sectional view of the field emission display device taken along the line A-A of FIG. 5.

8 is a partial cross-sectional view of a field emission display device according to the prior art.

Claims (17)

First and second substrates opposed to each other at arbitrary intervals; Gate electrodes formed on the first substrate; Cathode electrodes formed on the gate electrodes with an insulating layer interposed therebetween; An electron emission source provided in the cathode electrode corresponding to the pixel area set on the first substrate; An anode formed on the second substrate; Fluorescent films positioned on one surface of the anode electrode; And A grid plate disposed between the first substrate and the second substrate and having apertures for electron beam passage; A field emission display wherein at least two electron emission sources share an aperture. The method of claim 1, And the two electron emission sources face each other with respect to one aperture center. The method of claim 2, And the cathode forms openings in the electrode, and one opening is provided for every two gate electrodes. The method of claim 3, And the openings include first and second side surfaces corresponding to two gate electrodes, respectively, and the electron emission source is disposed adjacent to the first and second side surfaces. The method of claim 4, wherein And the field emission display further comprises an opposite electrode positioned at an interval from the electron emission source on the insulating layer in the opening. The method of claim 2, And the two fluorescent layers face each other with respect to one aperture center. The method of claim 6, And a fluorescent film disposed opposite to the emitter center with respect to the center of the aperture to form one pixel with the emitter. The method of claim 1, And the three electron emission sources are arranged at equal intervals on concentric circles corresponding to one aperture. The method of claim 8, And the cathode forms openings in the electrode, and one opening is provided for every three gate electrodes. The method of claim 9, And the openings include first, second, and third side surfaces corresponding to three gate electrodes, respectively, and the electron emission sources are disposed adjacent to the first, second, and third side surfaces. The method of claim 10, And wherein the opening is hexagonal, and the three electron emission sources are disposed adjacent to odd or even sides of six sides of the opening. The method of claim 10, And the field emission display further comprises an opposite electrode positioned at an interval from the electron emission source on the insulating layer in the opening. The method of claim 8, And the aperture of the grid plate comprises a triangle corresponding to a vertex corresponding to the three electron emission sources. The method of claim 8, And the fluorescent films are formed in a dot pattern, and three fluorescent films are disposed at equal intervals on concentric circles corresponding to one aperture. The method of claim 8, The aperture of the grid plate is formed of triangles corresponding to vertices of the three electron emission sources, the fluorescent layers are formed in a dot pattern, and the three fluorescent layers are disposed corresponding to three sides of the aperture. . The method of claim 5 or 12, And a counter electrode contacting and electrically connected to a gate electrode under the insulating layer through a via hole formed in the insulating layer. The method of claim 1, And the electron emission source is any one of carbon nanotubes, graphite, diamond, diamond-like carbon, C ₆₀ (fulleren), or a combination thereof.