KR100804699B1 - Light emitting device and liquid crystal display with the light emitting device as back light unit - Google Patents

Abstract

The present invention provides a field emission light emitting device capable of suppressing the occurrence of arcing and improving the dynamic contrast ratio of a liquid crystal display screen, and a liquid crystal display device using the light emitting device as a backlight unit. The light emitting device according to the present invention includes a first substrate and a second substrate which are disposed to face each other and constitute a vacuum container, first electrodes formed on the first substrate in one direction of the first substrate, and an insulating layer therebetween. Second electrodes formed along the direction crossing the first electrode on the first electrodes, electron emission parts electrically connected to any one of the first electrodes and the second electrodes, and the second electrode; At least one third electrode formed on the insulating layer at a predetermined distance from the electrodes and absorbing the arcing current, and a light emitting unit located on one surface of the second substrate.

Cathode electrode, gate electrode, insulating layer, electron emitting part, arcing current, anode electrode, fluorescent layer

Description

Light emitting device and liquid crystal display using the light emitting device as a backlight unit {LIGHT EMITTING DEVICE AND LIQUID CRYSTAL DISPLAY WITH THE LIGHT EMITTING DEVICE AS BACK LIGHT UNIT}

1 is a partially exploded perspective view of a light emitting device according to an embodiment of the present invention.

2 is a cross-sectional view of a light emitting device according to an embodiment of the present invention.

3 and 4 are cross-sectional views of a third electrode illustrated to describe another embodiment of a third electrode of a light emitting device according to an embodiment of the present invention.

5 is a partially exploded perspective view illustrating another embodiment of a third electrode of a light emitting device according to an embodiment of the present invention.

6 is an exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention.

7 is a block diagram of a configuration for driving a liquid crystal display according to an exemplary embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a light emitting device that emits light using an electron emission characteristic by an electric field, and a liquid crystal display device using the light emitting device as a backlight unit.

Recently, a liquid crystal display, which is one type of flat panel display, has been widely used in place of the cathode ray tube. The liquid crystal display has a feature of changing the amount of light transmission for each pixel by using dielectric anisotropy of a liquid crystal whose twist angle changes according to an applied voltage.

Such a liquid crystal display basically includes a liquid crystal panel assembly and a backlight unit for providing light to the liquid crystal panel assembly, and the liquid crystal panel assembly receives light emitted from the backlight unit and transmits the light by the action of the liquid crystal layer. Or a predetermined image is implemented by blocking.

The backlight unit may be classified according to the type of light source, and one of them is known as a cold cathode fluorescent lamp (CCFL). Since the CCFL is a line light source, the light generated by the CCFL can be evenly dispersed toward the liquid crystal panel assembly through the optical members such as the diffusion sheet, the diffusion plate, and the prism sheet.

However, in the CCFL method, since the light generated by the CCFL passes through the optical member, considerable light loss occurs, and power consumption is high because the light must be emitted at a high intensity from the CCFL in consideration of the light loss. In addition, the CCFL method is difficult to apply to a large display device of 30 inches or more because it is difficult to large area structure.

As a conventional backlight unit, a light emitting diode (LED) method is known. LEDs are usually provided in plural as point light sources, and constitute a backlight unit by being combined with optical members such as a reflective sheet, a light guide plate, a diffusion sheet, a diffusion plate, and a prism sheet. This LED method has the advantages of fast response speed and excellent color reproducibility, but has a disadvantage of high price and large thickness.

Accordingly, recently, a field emission type backlight unit that emits light using electron emission characteristics by an electric field has been proposed as a backlight unit to replace the CCFL method and the LED method. The field emission type back light unit is a surface light source, has the advantage of low power consumption, large size, and does not require a complicated optical member.

However, in the conventional field emission type backlight unit, the gap between the front substrate and the rear substrate is extremely small, about 2 mm, and there are arcing occurrence factors such as impurity gas and fine cracks in the vacuum chamber, so arcing occurs easily when high voltage is applied to the anode electrode. Done. If arcing occurs, the structure inside the vacuum chamber is damaged, leading to product defects.

In addition, the anode voltage is proportional to the screen brightness, but the conventional field emission type backlight unit cannot increase the anode voltage in consideration of arcing, which makes it difficult to implement high brightness.

As such, the conventional backlight unit has its own problems depending on the type of light source. In addition, the conventional backlight unit has a problem that it is difficult to meet the image quality improvement required for the liquid crystal display because the entire screen is always turned on at a constant brightness when driving the liquid crystal display.

For example, when the liquid crystal panel assembly displays an arbitrary screen including a high brightness portion and a low brightness portion according to an image signal, the backlight unit provides light of different intensities to the high brightness portion and the low brightness portion. If so, it is possible to realize a screen having excellent dynamic contrast.

However, the above-described backlight unit cannot implement the above functions, and thus the conventional liquid crystal display has a limitation in increasing the dynamic contrast ratio of the screen.

Therefore, the present invention is to solve the above problems, an object of the present invention is to suppress the occurrence of arcing in the vacuum vessel and increase the anode voltage to increase the light emission intensity and using the light emitting device as a backlight unit It is to provide a liquid crystal display device.

Another object of the present invention is to provide a light emitting device capable of dividing a screen into a plurality of regions and independently controlling the light intensity of each divided region, and a liquid crystal display capable of increasing the dynamic contrast ratio of the screen by using the light emitting apparatus as a backlight unit. To provide a device.

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

A vacuum container composed of a first substrate, a second substrate, and a sealing member, first electrodes formed in one direction of the first substrate on the first substrate, and an insulating layer interposed therebetween; Second electrodes formed along a direction intersecting the first electrode, electron emission parts electrically connected to any one of the first electrodes and the second electrodes, and the second electrodes are insulated at a predetermined distance from each other. Provided is a light emitting device including at least one third electrode formed on a layer and absorbing arcing current, and a light emitting unit provided on one surface of the second substrate.

The third electrode may be formed in a wire shape, and may be formed of a material selected from the group consisting of aluminum, silver, copper, molybdenum, chromium, gold, and alloys thereof. On the other hand, the third electrode may be formed of the same material and the same thickness as the second electrodes as the electrode layer.

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

A liquid crystal display device including a light emitting device having the above-described configuration and a liquid crystal panel assembly positioned in front of the light emitting device to receive light emitted from the light emitting device to display an image. The liquid crystal panel assembly forms a plurality of pixels along the row direction and the column direction, and the light emitting device forms a smaller number of pixels than the liquid crystal panel assembly along the row direction and the column direction.

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 light emitting device according to an embodiment of the present invention, Figure 2 is a cross-sectional view of the light emitting device according to an embodiment of the present invention.

1 and 2, the light emitting device 10 according to the present exemplary embodiment includes a first substrate 12 and a second substrate 14 that are disposed to face each other in parallel at predetermined intervals. Sealing members 16 are disposed on the edges of the first substrate 12 and the second substrate 14 to bond the two substrates, and the internal space is evacuated to a vacuum of approximately 10 ⁻⁶ Torr to form the first substrate 12. And the second substrate 14 and the sealing member 16 constitute a vacuum container.

The first substrate 12 and the second substrate 14 may be divided into an effective region contributing to the actual visible light emission and an ineffective region surrounding the effective region. An electron emission unit 18 that emits electrons using an electric field is provided in the effective region of the first substrate 12, and the light emitting unit 20 that emits visible light by the electrons in the effective region of the second substrate 14. This is provided.

The electron emission unit 18 may be formed on the first electrodes 22 formed in a stripe pattern along one direction of the first substrate 12 and on the first electrodes 22 with the insulating layer 24 therebetween. Emission of electrons electrically connected to the second electrodes 26 formed in a stripe pattern along a direction crossing the first electrode 22 and to any one of the first electrode 22 and the second electrode 26. And parts 28.

When the electron emission portions 28 are formed on the first electrode 22, the first electrode 22 becomes a cathode electrode for supplying current to the electron emission portion, and the second electrode 26 is a voltage with the cathode electrode. It forms a electric field by the difference, and becomes a gate electrode which induces electron emission. On the contrary, when the electron emission parts 28 are formed on the second electrode 26, the second electrode 26 becomes a cathode electrode and the first electrode 22 becomes a gate electrode.

Among the first electrode 22 and the second electrode 26, an electrode mainly positioned in parallel with the row direction of the light emitting device 10 functions as a scan electrode, and is positioned in parallel with the column direction of the light emitting device 10. The electrode functions as a data electrode.

In the drawing, the electron emission unit 28 is formed on the first electrode 22, and the first electrodes 22 are positioned parallel to the column direction (y-axis direction in the drawing) of the light emitting device 10, and the second electrode A case in which the electrodes 26 are positioned in parallel with the row direction (x-axis direction in the drawing) of the light emitting device 10 is illustrated. The position of the electron emitter 28 and the arrangement directions of the first electrodes 22 and the second electrodes 26 are not limited to the above-described example and may be variously modified.

Openings 261 and 241 are formed in the second electrode 26 and the insulating layer 24 at each intersection region of the first electrode 22 and the second electrode 26 to form a part of the surface of the first electrode 22. The electron emission part 28 is positioned on the first electrode 22 to expose the insulating layer opening 241.

The electron emission unit 28 may be made of materials emitting electrons when an electric field is applied, such as a carbon-based material or a nanometer (nm) size material. The electron emitter 28 may include, for example, carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbons, C ₆₀ , silicon nanowires, or mixtures thereof. Chemical vapor deposition or sputtering may be applied.

On the other hand, the electron emission portion may be formed of a tip structure having a pointed tip mainly made of molybdenum (Mo) or silicon (Si).

In the above structure, one intersection area of the first electrode 22 and the second electrode 26 corresponds to one pixel area of the light emitting device 10, or two or more crossing areas are one pixel area of the light emitting device 10. It can correspond to. In the second case, two or more first electrodes 22 and / or two or more second electrodes 26 positioned in one pixel area are electrically connected to each other to receive the same driving voltage.

Next, the light emitting unit 20 includes a fluorescent layer 30 and an anode electrode 32 positioned on one surface of the fluorescent layer 30.

The fluorescent layer 30 may be formed of a white fluorescent layer or a combination of red, green, and blue fluorescent layers. The white fluorescent layer may be formed in the entire effective area of the second substrate 14 or may be divided and positioned in a predetermined pattern so that one white fluorescent layer is positioned in each pixel area. The red, green, and blue fluorescent layers are divided and positioned in a predetermined pattern in one pixel area. In the drawing, a case where the white fluorescent layer is positioned in the entire effective region of the second substrate 14 is illustrated.

The anode electrode 32 may be formed of a metal film such as aluminum covering the surface of the fluorescent layer 30. The anode electrode 32 is an acceleration electrode for attracting an electron beam to maintain the fluorescent layer 30 in a high potential state by applying a high voltage and radiate toward the first substrate 12 of visible light emitted from the fluorescent layer 30. Visible light is reflected toward the second substrate 14 to increase the brightness of the screen.

In addition, spacers (not shown) are disposed between the first substrate 12 and the second substrate 14 to support the compressive force applied to the vacuum container and to keep the distance between the two substrates constant.

The light emitting device 10 having the above-described configuration applies a predetermined driving voltage to the first electrodes 22 and the second electrodes 26 from the outside of the vacuum container, and the direct current amount of thousands of volts or more to the anode electrode 32. Drive by applying voltage.

Then, in the pixels where the voltage difference between the first electrode 22 and the second electrode 26 is greater than or equal to the threshold, an electric field is formed around the electron emission unit 28 to emit electrons therefrom, and the emitted electrons are attracted to the anode voltage. It emits light by colliding with a portion of the fluorescent layer 30. The emission intensity of the fluorescent layer 30 for each pixel corresponds to the electron beam emission amount of the corresponding pixel.

Here, the light emitting device 10 of the present embodiment forms a third electrode 34A that absorbs arcing current on the first substrate 12 to minimize damage of the internal structure by arcing.

Arcing of the light emitting device 10 is insulated from the impurity gas inside the vacuum vessel and the second crack 14 and not exposed to the fine cracks and second electrodes 26 present in the electron emission unit 18. The surface of the layer 24 is caused by a phenomenon such as charging by electron collision, etc., and mainly occurs between the second electrodes 26.

The third electrode 34A is located at the main arcing occurrence site to favor arcing current absorption. That is, the third electrode 34A is formed on the insulating layer 24 between the second electrodes 26 and is spaced apart from the second electrode 26 so as not to be shorted with the second electrode 26. It is located side by side with 26). One end of the third electrode 34A may be drawn out of the vacuum vessel and connected to the ground voltage.

Since the third electrode 34A has a voltage characteristic different from that of the second electrode 26 at the same height as the second electrodes 26, the third electrode 34A is preferably formed with a small line width so as to minimize the influence on the electron emission characteristic. . To this end, the third electrode 34A may have a wire shape having a predetermined diameter.

The third electrode 34A is formed of a metal having a sheet resistance of less than 100 mA / □, and may be formed of, for example, a material selected from the group consisting of aluminum, silver, copper, molybdenum, chromium, gold, and alloys thereof. In addition, the third electrode 34A may have a multilayer structure in which two or more kinds of metal materials are stacked in two or more layers.

As shown in FIG. 3, the third electrode 34B is formed of a laminated structure of the first layer 36 and the second layer 38, or as shown in FIG. 4, the third electrode 34C is formed of a first structure. The layer 40, the second layer 42, and the third layer 44 may be formed in a stacked structure. Such a laminated structure is effective in solving a problem such that a single metal material, for example, silver is diffused into the insulating layer 24 during a high temperature heat treatment, or a spike occurs in a portion where aluminum contacts the insulating layer 24.

In FIG. 3, the first layer 36 of the third electrode 34B may be formed of aluminum or silver, and the second layer 38 may be formed of gold. In FIG. 4, the first layer 40 and the third layer 44 of the third electrode 34C may be formed of molybdenum, and the second layer 42 may be formed of aluminum or silver. In the stacked structure of the third electrodes 34B and 34C, the constituent material of each layer is not limited to the above-described example and can be variously modified.

On the other hand, as shown in FIG. 5, the third electrode may be formed as an electrode layer having a predetermined thickness and width. The third electrode 34D may be formed of the same metal material as the second electrodes 26, and may be simultaneously patterned with the second electrode 26 to maintain the same thickness as the second electrodes 26. It may be located between the fields (26). One end of the third electrode 34D may also be drawn out of the vacuum vessel and connected to the ground voltage.

The light emitting device 10 of the above-described embodiment effectively suppresses the damage of the internal structure by the arcing, in particular the damage of the second electrode 26, as the third electrodes 34A, 34B, 34C, 34D absorb the arcing current. Can be. In addition, the light emitting device 10 according to the above-described embodiment can apply a higher voltage to the anode electrode 32 due to the suppression of arcing to increase the light emission intensity, and can improve the light emission efficiency by using a high-efficiency fluorescent layer for high voltage. .

Meanwhile, in the above-described embodiment, the first substrate 12 and the second substrate 14 may be positioned at a larger interval than the conventional field emission backlight unit, for example, at an interval of 5 to 20 mm, and may include an anode electrode ( 32 may be provided with a high voltage of 10 kV or more through the anode voltage applying unit 46. The light emitting device 10 according to the present exemplary embodiment may implement a maximum luminance of about 10,000 cd / m ² or more in the center of the effective region through the above-described configuration.

6 is an exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention using the light emitting device having the above-described configuration as a backlight unit.

Referring to FIG. 6, the liquid crystal display device 50 according to the present exemplary embodiment includes a liquid crystal panel assembly 52 that forms a plurality of pixels along the row direction and the column direction, and is positioned behind the liquid crystal panel assembly 52 so as to be positioned behind the liquid crystal panel assembly. And a light emitting device 10 that provides light to 52. Any known liquid crystal panel assembly may be applied to the liquid crystal panel assembly 52, and the light emitting device 10 of the above-described embodiment functions as a backlight unit.

An optical member (not shown) such as a diffusion plate or a diffusion sheet may be disposed between the liquid crystal panel assembly 52 and the light emitting device 10 as necessary.

The row direction may be defined as one direction of the liquid crystal display 50, for example, a horizontal direction (x-axis direction of the drawing) of the screen implemented by the liquid crystal panel assembly 52, and the column direction may be defined as the liquid crystal display 50. ) May be defined as a vertical direction (y-axis direction of the drawing) of the screen implemented by the liquid crystal panel assembly 52.

In the present embodiment, the light emitting device 10 forms a smaller number of pixels than the liquid crystal panel assembly 52 along the row direction and the column direction so that one pixel of the light emitting device 10 includes a plurality of pixels of the liquid crystal panel assembly 52. To respond.

If the number of pixels of the liquid crystal panel assembly 52 in the row direction and the number of pixels of the liquid crystal panel assembly 52 in the column direction are M and N, respectively, M and N may be defined as an integer of 240 or more. If the number of pixels of the light emitting device 10 in the row direction and the number of pixels of the light emitting device 10 in the column direction are M 'and N', respectively, M 'and N' are any integer of 2 to 99. Can be defined as

The light emitting device 10 is a kind of self-luminous display panel having a resolution of M '× N', and the light emission intensity is independently controlled for each pixel to provide light of appropriate intensity to the liquid crystal panel assembly pixels corresponding to each pixel.

In this case, 2, which is the minimum value of M 'and N', is the minimum basic condition that the light emitting device 10 of the present embodiment can be a display panel. When the resolution of the light emitting device exceeds 99 × 99, the driving of the light emitting device is stopped. As it is complicated and can lead to an increase in manufacturing cost for the driving circuit, the maximum value of M 'and N', 99, can be regarded as a value in consideration of both the functionality and ease of manufacture of the light emitting device.

7 is a block diagram of a configuration for driving a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 7, the driving unit of the liquid crystal display device includes a first scan driver 102 and a first data driver 104 connected to the liquid crystal panel assembly 52, and a gray voltage generator connected to the first data driver 104. 106, the second scan driver 114 and the second data driver 112 connected to the display unit 116 of the light emitting device 10, the light emitting device controller 110 controlling the light emitting device 10, And a signal controller 108 to control the liquid crystal panel assembly 62.

The liquid crystal panel assembly 52 includes a plurality of signal lines S ₁ -S _n , D ₁ -D _m , and a plurality of first pixels PX connected to the signal lines and arranged in an approximately matrix form in an equivalent circuit. It includes. The signal lines S ₁ -S _n and D ₁ -D _m are a plurality of first scan lines S ₁ -S _n which transmit a first scan signal, and a plurality of first data lines which transfer a first data signal. (D ₁ -D _m ).

Each of the pixels (PX), for instance the i-th (i = 1,2, ... n) first scan line (S _i) and the j-th (j = 1,2, ... m) the first data line the pixel 54 is connected to the (D _j) comprises a switching element (Q) and the liquid crystal capacitors (Clc) and a storage capacitor (Cst) connected thereto is connected to the signal line (S _i, D _j). Holding capacitor Cst can be omitted as needed.

A switching element (Q) is a three-terminal element such as thin film transistors included in liquid crystal panel assembly 52, a lower substrate (not shown), the control terminal is connected to the first gate line (S _i), the input terminal Is connected to the first data line D _j , and the output terminal is connected to the liquid crystal capacitor Clc and the storage capacitor Cst.

The gray voltage generator 106 generates two sets of gray voltage sets (or reference gray voltage sets) related to the transmittance of the first pixel PX. One of the two sets has a positive value for the common voltage Vcom, and the other set has a negative value.

The first scan driver 102 is connected to the first scan lines S ₁ -S _n of the liquid crystal panel assembly 52 to form a first scan signal composed of a combination of a switch on voltage Von and a switch off voltage Voff. Is applied to the first scan lines S ₁ -S _n .

The first data driver 104 is connected to the first data lines D ₁ -D _m of the liquid crystal panel assembly 52, and selects a gray voltage from the gray voltage generator 106 and uses the first data as a data signal. Apply to lines D ₁ -D _m . However, when the gray voltage generator 106 provides only a predetermined number of reference gray voltages instead of providing all of the voltages for all grays, the first data driver 104 divides the reference gray voltages to provide total gray levels. A gray voltage is generated and a data signal is selected from among them.

The signal controller 108 controls the first scan driver 102 and the first data driver 104, and the light emitting device controller 110 controls the second scan driver 114 and the second data driver of the light emitting device 10. Control 112. The signal controller 108 receives an input image signal R, G, B and an input control signal for controlling the display thereof from an external graphic controller (not shown).

The input image signals R, G, and B contain luminance information of each first pixel PX, and the luminance is a predetermined number, for example, 1024 (= 2 ¹⁰ ), 256 (= 2 ⁸ ), or It has 64 (= 2 ⁶ ) grays. Examples of the input control signal include a vertical sync signal Vsync, a horizontal sync signal Hsync, a main clock MCLK, and a data enable signal DE.

The signal controller 108 properly processes the input image signals R, G, and B according to the operating conditions of the liquid crystal panel assembly 52 based on the input image signals R, G, and B and the input control signal. After generating the scan driver control signal CONT1 and the first data driver control signal CONT2, etc., the first scan driver control signal CONT1 is sent to the first scan driver 102, and the first data driver control signal ( CONT2) and the processed video signal DAT are sent to the first data driver 104.

The display unit 116 of the light emitting device 10 includes a plurality of second pixels EPX, and each of the second pixels EPX includes one second scan line S ′ ₁ -S ′ _p and one agent. 2 is connected to the data lines C ₁ -C _q . Each second pixel EPX emits light according to a voltage difference applied to the second scan line S ′ ₁ -S ′ _p and the second data line C ₁ -C _q . The second scan line S ′ ₁ -S ′ _p is identical to the scan electrode of the light emitting device, and the second data line C ₁ -C _q is identical to the data electrode of the light emitting device.

The signal controller 108 uses the input image signals R, G, and B for the plurality of first pixels PX corresponding to one second pixel EPX of the light emitting device 10 to emit light. Generates a light emission control signal. The emission control signal includes a second data driver control signal CD, an emission signal CLS, and a second scan driver control signal CS. According to the second data driver control signal CD, the light emission signal CLS, and the second scan driver control signal CS, each second pixel EPX of the light emitting device corresponds to the plurality of first pixels PX. It emits light.

In detail, the signal controller 108 inputs a plurality of first pixels PX (hereinafter, referred to as a 'first pixel group') corresponding to one second pixel EPX of the light emitting device 10. The highest gray level among the first pixels PX of the first pixel group is detected using the image signals R, G, and B, and transmitted to the light emitting device controller 110. The light emitting device controller 110 calculates the grayscale required to emit the second pixel EPX according to the detected grayscale, converts the grayscale to digital data, and transmits the grayscale to the second data driver 112.

In the present exemplary embodiment, the light emission signal CLS includes 6-bit or more digital data for gray scale representation of the second pixel EPX. The second data driver control signal CD allows each second pixel EPX to emit light in synchronization with the first pixel group corresponding to the second pixel EPX. That is, the second pixel EPX is synchronized to emit light with a predetermined gray scale in accordance with the display of the image in the first pixel group corresponding to one second pixel EPX.

The second data driver 112 generates a second data signal according to the second data driver control signal CD and the emission signal CLS and applies the second data signal to each second data line C ₁ -C _q .

In addition, the light emitting device controller 110 generates the second scan driver control signal CS of the light emitting device 10 by using the horizontal synchronization signal Hsync. That is, the second scan driver 114 is connected to the second scan line S ′ ₁ -S ′ _p , generates a second scan signal according to the second scan driver control signal CS, and generates a second scan. Pass on lines S ' _1- S' _p . While the switch-on voltage Von is applied to the first pixel group corresponding to one second pixel EPX of the light emitting device 10, the second scan line S ′ ₁ -S ′ of the second pixel EPX. _p ) is applied with a second scan signal.

Then, the second pixel EPX emits light corresponding to the gray level of the corresponding first pixel group by the second scan voltage and the second data voltage. In the present embodiment, a voltage according to the gray level is applied to the second data lines C ₁ -C _q of the second pixel EPX, and a constant amount of voltage is applied to the second scan lines S ′ ₁ -S ′ _p . The second pixel EPX emits light due to a voltage difference between two lines.

The liquid crystal display device 50 according to the present exemplary embodiment may improve the dynamic contrast of the screen through the above-described process, and may implement a clearer picture quality.

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.

The light emitting device according to the present invention can suppress the damage to the internal structure of the vacuum container due to arcing by forming a third electrode to absorb the arcing current on the insulating layer. Therefore, the light emitting device according to the present invention can increase the reliability and lifespan characteristics of the product, and can apply a high voltage of 10 kV or more to the anode electrode, thereby increasing the light emission intensity.

In addition, the liquid crystal display device of the present invention using the above-described light emitting device as a backlight unit can improve the display quality by increasing the dynamic contrast ratio of the screen, and can reduce the total power consumption by reducing the power consumption of the backlight unit, 30 inches The above-mentioned large display device can be easily manufactured.

Claims (15)

A vacuum container composed of a first substrate, a second substrate, and a sealing member; First electrodes formed on the first substrate in one direction of the first substrate; Second electrodes formed along the direction crossing the first electrodes on the first electrodes with an insulating layer interposed therebetween; Electron emission parts electrically connected to ones of the first electrodes and the second electrodes; At least one third electrode formed on the insulating layer at a predetermined distance from the second electrodes and absorbing an arcing current; And Light emitting unit provided on one surface of the second substrate Including, The third electrode has a wire shape, and has a multilayer structure in which two or more kinds of metal materials are laminated in two or more layers. The method of claim 1, And the third electrode is positioned parallel to the second electrode between the respective second electrodes. delete The method of claim 1, The light emitting device of any one of the multilayer structure of the third electrode is formed of a material selected from the group consisting of aluminum, silver, copper, molybdenum, chromium, gold and alloys thereof. delete delete delete The method of claim 1, And the second electrodes and the insulating layer form an opening, and the electron emission part is formed inside the opening on the first electrodes. The method of claim 1, The light emitting device of claim 1, wherein the electron emission unit comprises at least one of a carbon-based material and a nanometer-sized material. The method of claim 1, The first substrate and the second substrate is a light emitting device which is positioned at intervals of 5 to 20mm. The method of claim 1, And a light emitting unit including a fluorescent layer, an anode positioned on one surface of the fluorescent layer, and an anode voltage applying unit configured to apply a DC voltage of 10 to 15 kV to the anode. The light emitting device according to any one of claims 1, 2, 4, and 8 to 11; And A liquid crystal panel assembly positioned in front of the light emitting device to receive light emitted from the light emitting device to display an image Liquid crystal display comprising a. The method of claim 12, Wherein the liquid crystal panel assembly forms a plurality of pixels in a row direction and a column direction, and the light emitting device forms a smaller number of pixels in the row direction and the column direction than the liquid crystal panel assembly. The method of claim 13, An integer of 240 or more pixels in the liquid crystal panel assembly in the row direction and the number of pixels in the liquid crystal panel assembly in the column direction. The method of claim 14, And a number of pixels of the light emitting device along the row direction and a number of pixels of the light emitting device along the column direction are any one of 2 to 99.

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