KR20060019842A - Method for manufacturing phosphor screen of electron emission device - Google Patents

Abstract

The present invention relates to a fluorescent screen of a red (R), green (G) and blue (B), a black layer located between each fluorescent layer, and any one surface of the fluorescent layer and the black layer. In the method of manufacturing a fluorescent screen having an anode electrode disposed to receive a voltage required for electron beam acceleration from the outside, each R, G, B fluorescence as the voltage applied to the anode electrode when forming the fluorescent layer and the black layer increases Provided is a method for producing a fluorescent screen of an electron emitting device for forming the line width of a layer small.

Fluorescent screen, fluorescent layer, black layer, anode electrode, electron beam

Description

Method for manufacturing fluorescent screen of electron emitting device {METHOD FOR MANUFACTURING PHOSPHOR SCREEN OF ELECTRON EMISSION DEVICE}

1 is a partially enlarged perspective view of a fluorescent screen according to a first embodiment of the present invention.

2 is a partially enlarged perspective view of a fluorescent screen according to a second embodiment of the present invention.

3 is a partially exploded perspective view of the electron emitting device.

4 is a partial cross-sectional view of an electron emitting device.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron emitting device, and more particularly to a method of manufacturing a fluorescent screen that displays an image by emitting visible light by electrons.

In general, an electron emission device includes a method using a hot cathode and a cold cathode as an electron source. Among them, the electron-emitting devices using the cold cathode are field emitter array (FEA) type, surface conduction emitter (SCE) type, metal insulator metal (MIM) type, metal insulator semiconductor (MIS) type, and ballistic electron surface. Emitter type electron emission devices and the like are known.

Although the above-described electron emitting devices vary in detail depending on their type, basically, an electron emission array is formed on the first of the two substrates constituting the vacuum container to emit electrons therefrom, and the second substrate A fluorescent layer is provided on the substrate to emit light or display light.

In particular, the fluorescent layer is composed of three colors of red (R), green (G), and blue (B), and a black layer is positioned between each fluorescent layer to form a fluorescent screen. The fluorescent layers of R, G, and B each receive electrons from the corresponding electron emission arrays of sub-pixels, and emit light at a set luminance, and the electron emitting devices emit one pixel according to the degree of emission of each of the R, G, and B fluorescent layers. The full-color screen can be realized by determining the emission color and brightness of the.

At this time, one surface of the fluorescent layer toward the second substrate or one surface of the fluorescent layer toward the first substrate is provided with an electron accelerating electrode, that is, an anode electrode, so that the electrons emitted from the first substrate side are well accelerated toward the fluorescent layer. do. The anode electrode receives a fixed voltage of approximately several hundred to several thousand volts from the outside to maintain the fluorescent layer in a high potential state when the electron emission device is driven.

The fluorescent screen of the above-described configuration, for example, the black layer is formed by chromium (Cr) deposition, and the R, G, B fluorescent layer is formed by screen printing method, and the width of each fluorescent layer and the black layer in the manufacture of the fluorescent screen is electron The emitting device is generally set according to the resolution of the screen to be implemented.

However, the electron emitting device tends to increase the width of the electron beam bundle as the electrons emitted from the electron emission array pass through the vacuum region between the two substrates. Furthermore, the width of the electron beam bundle is applied to the driving electrodes provided in the electron emitting device. Changes with voltage

For example, the FEA type uses the principle that electrons are easily emitted by an electric field in vacuum when a material having a low work function or a large aspect ratio is used as the electron source. An electron emission portion made of a material is formed on the cathode electrode, and the gate electrode is provided insulated from the cathode electrode and the electron emission portion with the insulating layer interposed therebetween.

In the above structure, when a predetermined driving voltage is applied to the cathode electrode and the gate electrode, an electric field is formed around the electron emission part by the potential difference between the two electrodes, and electrons are emitted therefrom, and the emitted electrons are applied to the anode electrode. Attracted to the second substrate to reach the phosphor layer of the sub-pixel and emit light. In this driving process, the width of the electron beam bundle varies with the cathode voltage, the gate voltage, and the anode voltage.

In the electron emission device, the electron beam bundles must faithfully reach the corresponding fluorescent layer to accurately implement the intended luminance and color coordinates. However, as described above, the conventional technology of setting the line width of the fluorescent layer according to the resolution of the screen when manufacturing the fluorescent screen does not correspond to the width of the electron beam bundle that varies according to the driving voltage.

That is, when the width of the electron beam bundle that reaches the fluorescent layer becomes larger than the line width of the fluorescent layer, not only the fluorescent layer of the sub-pixel but also the neighboring other fluorescent layer emit light together, the color reproducibility of the screen is reduced, and unnecessary cross-talk ( Cross-talk phenomenon occurs and the contrast of the screen is reduced. In addition, if the width of the electron beam bundle that reaches the fluorescent layer is smaller than the line width of the fluorescent layer, desired luminance and color reproducibility cannot be obtained.

Accordingly, an object of the present invention is to solve the above problems, and an object of the present invention is to accurately implement the intended luminance and color coordinates by considering not only the resolution of the screen but also the width of the electron beam bundle that varies depending on the driving voltage. In addition, the present invention provides a method for manufacturing a fluorescent screen of an electron emitting device capable of suppressing light emission of another color fluorescent layer and improving screen quality.

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

Red (R), green (G), and blue (B) fluorescent layers, a black layer positioned between each fluorescent layer, and disposed on either surface of the fluorescent layer and the black layer to apply a voltage required for electron beam acceleration from the outside. In the method of manufacturing a fluorescent screen having a receiving anode electrode, when forming a fluorescent layer and a black layer of the electron emitting device to form a line width of each R, G, B fluorescent layer as the voltage applied to the anode electrode increases Provided is a method for producing a fluorescent screen.

When the set voltage of the anode electrode is 1 to 4 kV, the line width of each of the R, G, and B fluorescent layers is 150 to 250 µm, more preferably 200 to 240 µm. When the set voltage of the anode electrode is less than 1 kV, the line width of each R, G, B fluorescent layer is formed larger than 250 µm, and when the set voltage of the anode electrode exceeds 4 kV, the line width of each R, G, B fluorescent layer is 150 It is formed smaller than 탆.

The R, G, and B fluorescent layers may be formed in a rectangle having a horizontal width in a horizontal direction of the screen and a vertical width in a vertical direction of the screen. In this case, each of the R, G, and R electrodes is increased as the voltage applied to the anode electrode increases. , The width of the B fluorescent layer is made small.

In addition, when the fluorescent layer and the black layer are formed, the opening ratio is formed so as to satisfy the 40 to 60% condition.

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

1 and 2 are partially enlarged perspective views of a fluorescent screen for an electron emitting device according to a first embodiment and a second embodiment of the present invention, respectively.

First, referring to FIG. 1, the fluorescent screen 2 includes red (R), green (G), and blue (B) fluorescent layers 6R, which are formed on one surface of the front substrate 4 at random intervals from each other. 6G, 6B, the black layer 8 positioned between each of the fluorescent layers 6R, 6G, and 6B, and the anode electrode formed while covering the fluorescent layers 6R, 6G, 6B and the black layer 8 10). The anode electrode 10 is formed of a metal film (for example, an aluminum film) by vapor deposition, and each of the fluorescent layers 6R, 6G, and 6B has a horizontal width and a width of the screen along the horizontal direction of the screen (the x-axis direction of the drawing). It may have an elongate shape having a vertical width along a vertical direction (y-axis direction of the drawing).

On the other hand, as shown in FIG. 2, the fluorescent screen 2 'may include a transparent anode electrode 12 instead of an anode electrode made of a metal film. In this case, the anode electrode 12 may be formed of the front substrate 4 and the front substrate 4. It is located between the fluorescent layers 6R, 6G, 6B and the black layer 8. The anode electrode 12 is usually made of indium tin oxide (ITO), and is formed on the entire surface of the front substrate 4 as shown in the drawing, or may be provided in plurality by dividing into a predetermined pattern although not shown. have.

In both the fluorescent screens 2, 2 ＇shown in Figs. 1 and 2, each of the R, G, and B fluorescent layers 6R, 6G, 6B correspond to electrons from the electron emission array provided on the back substrate. Emits light at the specified brightness. In addition, the anode electrodes 10 and 12 are applied with a high voltage (approximately hundreds to thousands of volts) required for electron beam acceleration from the outside to keep the fluorescent layer 6 in a high potential state, in particular, the anode electrode 10 made of a metal film It also increases the brightness of the screen by the metal back effect.

In the above-described method of manufacturing the fluorescent screen, in the case of the fluorescent screen 2 shown in FIG. 1, for example, chromium (Cr) is deposited and patterned on one surface of the front substrate 4 to form a matrix-like black layer 8. Forming R, G, and B fluorescent layers 6R, 6G, and 6B by applying R, G, and B fluorescent materials to a portion where the black layer 8 is not formed; and forming a fluorescent layer 6R. Forming a surface planarization layer (not shown) over the 6G, 6B) and the black layer 8 and depositing a metal, for example, aluminum, to form the anode electrode 10; Removing the layer.

In addition, in the case of the fluorescent screen 2 'shown in FIG. 2, the manufacturing method of the fluorescent screen 2' includes forming an anode electrode 12 by coating ITO on one surface of the front substrate 4, and an anode electrode. (12) forming a black layer 8 having a matrix shape and R, G, B fluorescent layers 6R, 6G by applying R, G, and B fluorescent materials to a portion where the black layer 8 is not formed. , 6B).

In both of the above-described manufacturing methods of the fluorescent screens 2 and 2 ＇, the line widths of the respective fluorescent layers 6R, 6G and 6B, in particular, the horizontal width Wh of the respective fluorescent layers 6R, 6G and 6B are set. In this case, not only the resolution of the screen but also the voltage applied to the anode electrodes 10 and 12 when the electron emission device is driven, that is, the anode voltage is set in consideration. This is because the width of the electron beam bundle that reaches the fluorescent layers 6R, 6G, 6B, in particular, the width measured along the horizontal direction of the screen, changes depending on the voltage applied to each of the drive electrodes provided in the electron emission element, but most greatly. This is because the voltage varies with the anode voltage.

In other words, the width of the electron beam bundle is most affected by the anode voltage.As the anode voltage increases, the electron beam spreads as the electrons move toward the fluorescent layer, so that the electron beam spreads. When the acceleration effect is dropped, the electron beam spreads. Thus, in the present embodiment, when the fluorescent screens 2 and 2 GHz are formed, the widths of the respective fluorescent layers 6R, 6G and 6B are set in inverse proportion to the anode voltage.

More specifically, when the anode voltage is set to 1 to 4 kV, the width of each fluorescent layer 6R, 6G, and 6B is formed to be 150 to 250 µm, more preferably 200 to 240 µm. When the anode voltage is set to less than 1 kV, the widths of the fluorescent layers 6R, 6G, and 6B are made larger than 250 µm. When the anode voltage is set to 4 kV or more, the widths of the fluorescent layers 6R, 6G, and 6B are made smaller than 150 µm.

As such, in this embodiment, the line widths of the R, G, and B fluorescent layers 6R, 6G, and 6B are optimized in consideration of the width of the electron beam bundle that reaches the corresponding fluorescent layer, so that electrons are driven when the electron emission device is driven. It faithfully arrives to accurately implement the intended luminance and color coordinates, and has the effect of not invading other color fluorescent layers of neighboring sub-pixels.

On the other hand, when setting the line width of the black layer 8, this aperture ratio is considered in consideration of the aperture ratio indicating the area ratio of the fluorescent layers 6R, 6G, 6B to the total area of the fluorescent screens 2, 2 GHz. It forms to satisfy 40 to 60% of range. When the aperture ratio satisfies the above conditions, the luminance is increased and the contrast can be excellently secured.

Hereinafter, the electron beam width change according to the driving voltage will be described using an FEA type electron emission device as an example. 3 and 4 are partially exploded perspective and partial cross-sectional views of the electron emission device, respectively.

Referring to the drawings, the gate electrodes 16 are formed on the rear substrate 14 in a stripe pattern, and a plurality of gate electrodes 16 are formed along one direction (y-axis direction of the drawing) of the rear substrate 14. The insulating layer 18 is formed on the entire back substrate 14 while covering the gap. On the insulating layer 18, a plurality of cathode electrodes 20 are formed in a stripe pattern along a direction crossing the gate electrode 16 (the x-axis direction of the drawing).

The cathode electrode 20 is formed with an electron emission portion 22 at least partially in contact with the cathode electrode 20 so as to be electrically connected thereto. The electron emission section 22 is made of materials that emit electrons when an electric field is applied, such as carbon nanotubes, graphite or diamond-like carbon, and one is provided for each sub-pixel set on the rear substrate 14. Can be. In this embodiment, the sub-pixel is defined as the intersection area of the gate electrode 16 and the cathode electrode 20.

In addition, an opposite electrode 24 may be positioned on the rear substrate 14 and disposed on the same layer as the cathode electrode 20 and electrically connected to the gate electrode 16. The opposite electrode 24 is positioned at a predetermined distance from the electron emission part 22 between the cathode electrodes 20 on the insulating layer 18, and includes a via hole 18a formed in the insulating layer 18. It is in contact with and electrically connected to the gate electrode 16 through.

The counter electrode 24 itself is an electron emitter 22 when a driving voltage is applied to the gate electrode 16 to form an electric field for electron emission around the electron emitter 22 when driving the electron emission element. Further forms an electric field for electron emission. As a result, the counter electrode 24 serves to discharge electrons from the electron emitter 22 well while applying a small driving voltage to the gate electrodes 16.

Thus, on the rear substrate 14, the electron emission section 22 and the cathode electrode 20 and the gate electrode 16 as driving electrodes for controlling the electron emission are provided for each sub-pixel, and R of the fluorescent screen 2 is provided. , G, B fluorescent layers 6R, 6G, 6B are disposed one-to-one corresponding to each sub-pixel. As a result, three sub-pixels including the R, G, and B fluorescent layers 6R, 6G, and 6B are assembled to form one pixel.

Meanwhile, a grid electrode 26 may be provided between the front substrate 4 and the rear substrate 14 to block electron beam focus and the influence of the anode field on the electron emitter 22. The grid electrode 26 forms an opening 26a corresponding to the sub-pixel and passes the electron beam, and the front substrate 4 and the rear substrate 14 are formed by the upper spacers 28 and the lower spacers 30. And at regular intervals. The grid electrode 26 is usually applied a positive voltage of several tens of volts.

In the electron-emitting device having the above-described configuration, when a predetermined driving voltage is applied to the cathode electrode 20 and the gate electrode 16, the electron-emitting portion is caused by the voltage difference between the two electrodes in the sub-pixel where the voltage difference between the two electrodes is greater than or equal to the threshold. An electric field is formed around the 22 and electrons are emitted therefrom, and the emitted electrons are focused while passing through the openings 26a of the grid electrode 26, and then attracted by the high voltage applied to the anode electrode 10 to form the front substrate ( 4), a fluorescent layer (e.g., a red fluorescent layer, 16R) of the corresponding sub-pixel is reached and emits light.

The following table shows the electron beam widths measured by varying the cathode voltage Vc and the anode voltage Va while the gate voltage Vg is -80V and the grid voltage Vgr is 70V. The width of the electron beam bundle is shown.

Anode voltage (kV) Cathode voltage (V) Electron Beam Width (㎛) One 100 250 2 50 181 70 177 90 175 4 50 160 70 155 90 153 7 50 150 70 145 90 142 9 70 138

As described above, the width of the electron beam bundle reaching the fluorescent layer is slightly different according to the change of the cathode voltage Vc, but is largely changed as the anode voltage Va changes, and becomes smaller as the anode voltage Va becomes larger. Results are shown. In particular, the widths of the electron beam bundles described in the table correspond to the horizontal widths (Wh) of the R, G, and B fluorescent layers 6R, 6G, and 6B set in accordance with the anode voltage Va condition in the above-described manufacturing process of the fluorescent screen. It shows the result.

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

As described above, in the manufacturing method of the fluorescent screen according to the present invention, as the line width of the fluorescent layer is set in consideration of the anode voltage, electrons can faithfully reach the corresponding fluorescent layer when driving the electron emission device, thereby accurately implementing the intended luminance and color coordinates. have. In addition, since the fluorescent layer does not emit light of neighboring other fluorescent layers, it is possible to effectively prevent screen quality deterioration such as color bleeding and contrast reduction.

Claims (9)

Red (R), green (G), and blue (B) fluorescent layers, a black layer positioned between each fluorescent layer, and disposed on either surface of the fluorescent layer and the black layer to apply a voltage required for electron beam acceleration from the outside. In the manufacturing method of a fluorescent screen provided with a receiving anode electrode, When forming the fluorescent layer and the black layer, the line width of each R, G, B fluorescent layer is formed to be smaller as the voltage applied to the anode electrode increases. The method of claim 1, And a line width of each of the R, G, and B fluorescent layers is set to 150 to 250 µm when the set voltage of the anode is 1 to 4 kV. The method of claim 2, The fluorescent screen manufacturing method of the electron emitting element which forms the line | wire width of each said R, G, B fluorescent layer at 200-240 micrometers. The method of claim 1, And a line width of each of the R, G, and B fluorescent layers is larger than 250 µm when the set voltage of the anode is less than 1 kV. The method of claim 1, And a line width of each of the R, G, and B fluorescent layers is less than 150 µm when the set voltage of the anode exceeds 4 kV. The method of claim 1, The R, G, and B fluorescent layers are formed in a rectangle having a horizontal width in a horizontal direction of the screen and a vertical width in a vertical direction of the screen, and each of R, G, and B increases as the voltage applied to the anode electrode increases. The fluorescent screen manufacturing method of the electron emitting element which forms the width | variety of a fluorescent layer small. The method of claim 1, The fluorescent layer and the black layer is formed on a substrate, and a metal deposition on the fluorescent layer and the black layer to form the anode electrode of the fluorescent screen manufacturing method of the electron emitting device. The method of claim 1, A method of manufacturing a fluorescent screen of an electron emitting device, by coating a transparent conductive film on a substrate to form the anode electrode, and forming the fluorescent layer and a black layer on the anode electrode. The method of claim 1, The fluorescent screen manufacturing method of the electron emission element which forms so that opening ratio may satisfy 40 to 60% condition at the time of forming the said fluorescent layer and a black layer.

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