KR20070111863A - Light emission device, method for manufacutring electron emission unit for light emission device, and liquid crystal display device with the light emission device as back light unit - Google Patents

Abstract

A light emission device, a method for manufacturing an electron emission unit of the same, and a liquid crystal display apparatus using the same as a backlight unit are provided to stabilize the operation by raising a withstand voltage characteristic between scan electrodes and data electrodes. First and second substrates(12,14) are opposite to each other to form a vacuum envelope. First electrodes(26) are formed on the first substrate in a direction, and second electrodes(30) are formed in a direction crossing the first direction, with an insulating layer(28) interposed between the electrodes. Electron emission regions(32) are electrically connected to the first electrodes. A phosphor layer(34) is formed on the second substrate, and an anode electrode(36) is formed on the phosphor layer. The second electrodes are side by side spaced 100 through 400 micrometers.

Description

LIGHT EMISSION DEVICE, METHOD FOR MANUFACUTRING ELECTRON EMISSION UNIT FOR LIGHT EMISSION DEVICE, AND LIQUID CRYSTAL DISPLAY DEVICE WITH THE LIGHT EMISSION DEVICE AS BACK LIGHT UNIT}

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

FIG. 2 is a partially exploded perspective view showing an effective area of the light emitting device shown in FIG. 1.

3 is a partial cross-sectional view showing an effective area of the light emitting device shown in FIG. 1.

4A to 4F are partial cross-sectional views at each manufacturing step shown to explain a method for manufacturing an electron emission unit according to an embodiment of the present invention.

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

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

Such a liquid crystal display device basically includes a liquid crystal panel assembly and a backlight unit that provides 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. A plurality of LEDs are usually provided as a point light source, and are combined with optical members such as a reflective sheet, a light guide plate, a diffusion sheet, a diffusion plate, and a prism sheet to constitute a backlight unit. This LED method has the advantages of fast response speed and excellent color reproducibility, but has a disadvantage of high price and large thickness.

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

For example, when the liquid crystal panel assembly displays an arbitrary screen including a bright portion and a dark portion according to an image signal, the backlight unit applies light of different intensities to the region displaying the bright portion and the region displaying the dark portion. If it is provided, 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 device has a limitation in increasing the dynamic contrast ratio of the screen.

On the other hand, as a self-luminous display device, there is a field emission display device (FED, hereinafter referred to as 'FED') which displays using an electron emission characteristic by an electric field, and this FED is a backlight unit of a liquid crystal display device. It is known to apply the technique.

The FED basically includes a vacuum container composed of a first substrate, a second substrate, and a sealing member, an electron emission unit provided on one surface of the first substrate, the electron emission unit including an electron emission portion and drive electrodes, and a surface of the second substrate. And a light emitting unit including a fluorescent layer and an anode electrode.

The electron emitter emits arbitrary electrons per pixel according to the driving signal applied to the driving electrodes, and the anode electrode receives a direct current voltage of thousands of volts to accelerate these electrons toward the fluorescent layer, and these electrons The fluorescent layer of light is emitted to implement a predetermined image.

However, the conventional FED method merely applies the existing FED as a backlight unit and does not improve the disadvantages of the structure and the process that the FED itself has.

For example, the conventional FED wet-etches an insulating layer positioned between the data electrodes and the scan electrodes to form an opening for disposing an electron emitter. The wet etching has a feature that the width of the opening decreases as the etching depth increases. The insulating layer is formed to a thin thickness to suppress the opening width. In such an insulating layer structure, there is a problem in that driving stability is lowered because the withstand voltage characteristic between the data electrode and the scan electrode is low.

In addition, the conventional FED is narrowing the distance between the scan electrodes to secure the resolution, and after forming the conductive layer on the insulating layer, the conductive layer is patterned by a photolithography process to form the scan electrodes. In such a scan electrode structure, a process margin may be low, a manufacturing process may be complicated, and adjacent scan electrodes may be shorted.

Accordingly, an object of the present invention is to solve the above problems, and an object of the present invention is to provide a light emitting device capable of stabilizing driving by increasing a breakdown voltage characteristic between scan electrodes and data electrodes, and increasing a process margin of scan electrodes. The present invention provides a method for manufacturing an electron emission unit of a light emitting device and a liquid crystal display device using the light emitting device as a backlight unit.

Another object of the present invention is to provide a liquid crystal display device capable of realizing excellent display quality by increasing a dynamic contrast ratio of a screen.

Another object of the present invention is to provide a liquid crystal display device which reduces power consumption of a backlight unit, minimizes light loss caused by an optical member, and is advantageous for large size.

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

A first substrate and a second substrate disposed to face each other and forming a vacuum container, first electrodes formed along 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 electrodes, electron emission parts electrically connected to the first electrodes, a fluorescent layer formed on one surface of the second substrate, and positioned on one surface of the fluorescent layer It includes an anode electrode, the second electrode is provided with a light emitting device which is located next to each other at intervals of 100 to 400㎛.

The insulating layer and the second electrodes form openings communicating with each other, and an electron emission part is disposed on the first electrodes inside the opening.

The insulating layer may be formed to a thickness of 15 to 30㎛, the openings of the second electrode and the insulating layer may be formed to a diameter of 30 to 50㎛.

The electron emission unit may include at least one of a carbonaceous material and a nanometer size material.

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

Forming first electrodes in a stripe pattern on the substrate, forming an insulating layer having a thickness of 15 to 30 μm over the entire substrate to cover the first electrodes, and spaced apart from each other at 100 to 400 μm on the insulating layer Forming second electrodes having a stripe pattern along a direction crossing the first electrodes, forming openings in communication with the second electrodes and the insulating layer, and forming a first inside the opening of the insulating layer; It provides a method for manufacturing an electron emission unit of a light emitting device comprising the step of forming an electron emission portion on the electrodes.

The second electrodes may be formed by screen printing.

When the opening is formed in the insulating layer, the insulating layer is primarily wet-etched through the opening of the first mask layer to form the first opening, and then the second insulating layer is wet-etched secondly through the opening of the second mask layer. Openings may be formed. In this case, the opening of the second mask layer may be formed to have a smaller size than the opening of the first mask 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.

When the liquid crystal panel assembly forms a plurality of pixels along the row direction and the column direction, the light emitting device may form a smaller number of pixels than the liquid crystal panel assembly along the row direction and the column direction.

The liquid crystal panel assembly forms M pixels along a row direction and N pixels along a column direction, and M and N may each be defined as an integer of 240 or more.

The light emitting device may form M 'pixels in a row direction and N' pixels in a column direction, and M 'and N' may be defined as any one of 2 to 99, respectively.

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

1 is a cross-sectional view of a light emitting device according to an exemplary embodiment of the present invention, and FIGS. 2 and 3 are partial exploded perspective views and partial cross-sectional views showing effective regions of the light emitting device shown in FIG. 1, respectively.

First, referring to FIG. 1, the light emitting device 10 of the present exemplary embodiment includes a first substrate 12 and a second substrate 14 that are disposed to face each other in parallel at a predetermined interval. 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 inner space is evacuated with a vacuum of approximately 10 ⁻⁶ Torr so that the first substrate 12 The second substrate 14 and the sealing member 16 constitute a vacuum container.

The first substrate 12 and the second substrate 14 have an effective region 18 that contributes to the actual visible light emission inside the sealing member 16 and an ineffective region 20 surrounding the effective region 18. do. The effective region 18 of the first substrate 12 is provided with an electron emission unit 22 for emitting electrons, and the effective region 18 of the second substrate 14 has a light emitting unit 24 for emitting visible light. Is provided.

2 and 3, in the present exemplary embodiment, the electron emission unit 22 may include cathode electrodes 26, which are first electrodes formed in a stripe pattern along one direction of the first substrate 12, and an insulating layer. Gate electrodes 30, which are second electrodes formed in a stripe pattern along a direction intersecting the cathode electrode 26 with an interposed portion 28 between them, and electron emission parts 32 electrically connected to the cathode electrode 26. ).

The gate electrodes 30 may be arranged side by side in the row direction of the first substrate 12, and may function as scan electrodes by receiving a scan signal. The cathode electrodes 26 may be arranged side by side along the column direction of the first substrate 12, and may function as a data electrode by receiving a data signal.

Openings 301 and 281 are formed in the gate electrode 30 and the insulating layer 28 at each crossing region of the cathode electrode 26 and the gate electrode 30 to expose a portion of the surface of the cathode electrode 26 and the insulating layer 28. The electron emission part 32 is positioned on the cathode electrode 26 inside the opening 281 of the C.

The electron emission part 32 may be formed of materials that emit electrons when an electric field is applied in a vacuum, such as a carbon-based material or a nanometer (nm) size material. The electron emission part 32 may include, for example, carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbons, C ₆₀ , silicon nanowires, or a combination thereof. , Chemical vapor deposition or sputtering, and the like.

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-described structure, one intersection region of the cathode electrode 26 and the gate electrode 30 may correspond to one pixel region of the light emitting device 10, or two or more intersection regions may correspond to one pixel region of the light emitting device 10. Can be. In the second case, two or more cathode electrodes 26 and / or two or more gate electrodes 30 corresponding to one pixel area are electrically connected to each other to receive the same driving voltage.

Next, the light emitting unit 24 includes a fluorescent layer 34 and an anode electrode 36 positioned on one surface of the fluorescent layer 34. The fluorescent layer 34 may be formed of a white fluorescent layer or a combination of red, green, and blue fluorescent layers, and the first case is illustrated in the drawings.

The white fluorescent layer may be formed on the entirety of the second substrate 14, or may be divided and positioned in a predetermined pattern such that one white fluorescent layer is positioned in each pixel area. The red, green, and blue fluorescent layers may be divided and positioned in a predetermined pattern in one pixel area.

The anode electrode 36 may be formed of a metal film such as aluminum (Al) covering the surface of the fluorescent layer 34. The anode 36 serves as an acceleration electrode for attracting an electron beam to maintain the fluorescent layer 34 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 34. The visible light is reflected to the second substrate 14 to increase the brightness of the screen.

In addition, spacers (not shown) may be 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 is driven by supplying a predetermined voltage to the cathode electrodes 26, the gate electrodes 30, and the anode electrode 36 from outside the vacuum vessel. For reference, in FIG. 1, reference numeral 38 denotes a gate lead line extending from the gate electrodes 30, and reference numeral 40 denotes an anode lead line extending from the anode electrode 36.

When the cathode electrodes 26 and the gate electrodes 30 are applied with a predetermined driving voltage, an electric field is formed around the electron emission part 32 in the pixel region where the voltage difference between the two electrodes is greater than or equal to the threshold, and electrons are emitted therefrom. The emitted electrons are attracted by the high voltage applied to the anode electrode 36 and collide with the corresponding fluorescent layer 34 to emit light. The emission intensity of the pixel-specific fluorescent layer 34 corresponds to the electron beam emission amount of the pixel.

The light emitting device 10 of the present embodiment is positioned behind the liquid crystal panel assembly in the liquid crystal display device described below and functions as a backlight unit, and forms a lower resolution than the liquid crystal panel assembly, that is, fewer pixels than the liquid crystal panel assembly. .

According to the use of the light emitting device 10, the gate electrodes 30 functioning as scan electrodes in the present embodiment are positioned side by side with an interval G of 100 μm or more, preferably 100 to 400 μm. As a result, the process margin of the gate electrodes 30 may be increased, and a short circuit between the gate electrodes 30 may occur in a manufacturing process.

That is, when the distance between the gate electrodes 30 is less than 100 μm, the process margin is reduced and a short circuit may occur between the gate electrodes 30 in the patterning process. In addition, when the distance between the gate electrodes 30 exceeds 400 μm, the light emitting device 10 is disadvantageous to form an appropriate number of pixels.

In addition, in this embodiment, the insulating layer 28 is formed to have a thickness t of 15 µm or more, preferably 15 to 30 µm. Due to the proper thickness of the insulating layer 28, the withstand voltage characteristics of the cathode electrodes 26 and the gate electrodes 30 may be increased to stabilize driving of the light emitting device 10. In addition, when the cathode electrode 26 is formed of metal, even if a part of the metal material diffuses into the insulating layer 28, the withstand voltage characteristics may be prevented from being lowered due to the enlarged thickness of the insulating layer 28.

On the other hand, when the openings 281 are formed by the same wet etching method as in the state of increasing the thickness of the insulating layer 28, the bottom surface of the insulating layer 28 by the isotropic etching characteristic that the opening width decreases as the etching depth increases. Will form an opening with a small width. That is, the opening of the insulating layer 28 does not form a sidewall close to the vertical, and forms a concave sidewall.

However, the light emitting device 10 according to the present exemplary embodiment may form the sidewalls of the openings 281 of the insulating layer 28 to be perpendicular to each other through the second wet etching process, which will be described later. An opening 301 having a diameter of μm can be formed.

A method of manufacturing an electron emission unit according to an exemplary embodiment of the present invention will be described with reference to FIGS. 4A to 4F.

Referring to FIG. 4A, a conductive film is formed on the first substrate 12 and patterned to form stripe cathode electrodes 26. Subsequently, an insulating material is applied to the entirety of the first substrate 12 to cover the cathode electrodes 26 to form an insulating layer 28 having a thickness t of 15 μm or more, preferably 15 to 30 μm. The insulating layer 28 may be formed to the above-described thickness by repeating the screen printing, drying and baking processes two or more times.

Referring to FIG. 4B, the conductive film is screen printed in a stripe shape on the insulating layer 28 and dried to form gate electrodes 30 intersecting with the cathode electrode 26. At this time, the interval G between the gate electrodes 30 is 100 μm or more, preferably 100 to 400 μm. Forming the gate electrodes 30 by screen printing can omit a patterning process such as photolithography.

Referring to FIG. 4C, the first mask layer 42 is formed on the entire first substrate 12 over the insulating layer 28 and the gate electrodes 30, and is patterned to form the opening 421 at the electron emission region formation position. ). The portions of the gate electrodes 30 exposed by the openings 421 are etched to form openings 301 in the gate electrodes 30.

Referring to FIG. 4D, the portion of the insulating layer 28 exposed by the opening 301 of the gate electrode 30 is first wet-etched to form the first opening 282. The first opening 282 is formed in a portion of the insulating layer 28 without penetrating the entire insulating layer 28 due to the enlarged thickness of the insulating layer 28. After the first openings 282 are formed, the first mask layer 42 is peeled off and removed.

Referring to FIG. 4E, a second mask layer 44 is formed on the entire first substrate 12 over the gate electrodes 30 and the insulating layer 28, and patterned to form an opening 441 at the electron emission region formation position. ). The opening 441 of the second mask layer 44 may be formed to have a smaller width than the opening 421 of the first mask layer 42, in which case the second mask layer 44 is formed of the insulating layer 28. The first opening 282 is positioned over the sidewall edge.

Subsequently, the portion of the insulating layer 28 exposed by the opening 441 of the second mask layer 44 is wet etched second to form a second opening 283 penetrating the insulating layer 8, and a second mask Layer 44 is peeled off. Through this secondary wet etching, the openings 281 having sidewalls close to the perpendicular to the insulating layer 28 can be formed without expanding the width of the openings 281 of the gate electrode 30 and the insulating layer 28. have.

Referring to FIG. 4F, the electron emission part 32 is formed inside the opening 281 of the insulating layer 28 over the cathode electrodes 26.

The electron emitting part 32 may be manufactured by mixing a vehicle and a binder with an electron-emitting material such as carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbon, C ₆₀ and silicon nanowires to obtain a viscosity suitable for printing. The eggplant may be prepared by preparing a paste-like mixture, screen-printing the mixture inside the opening of the insulating layer, and then drying and baking the mixture. In addition, in addition to the screen printing method described above, direct growth, sputtering, or chemical vapor deposition may be applied to the method of manufacturing the electron emission unit 32.

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

Referring to FIG. 5, the liquid crystal display device 50 according to the present exemplary embodiment includes a liquid crystal panel assembly 52 having arbitrary pixels in a row direction and a column direction, and is positioned behind the liquid crystal panel assembly 52 so that the liquid crystal panel assembly ( 52, a light emitting device 10 that provides light. Any known liquid crystal panel assembly may be applied to the liquid crystal panel assembly 50, and the light emitting device 10 of the above-described embodiment functions as a backlight unit.

The row direction may be defined as one direction of the liquid crystal display 50, for example, a horizontal direction of a screen implemented by the liquid crystal display 50, and the column direction may be another direction of the liquid crystal display 50, for example. The display device may be defined as a vertical direction of a screen implemented by the liquid crystal display device 50.

In particular, 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 as described above, so that one pixel of the light emitting device 10 has two or more liquid crystal panels. Assembly 52 pixels.

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

By the above-described configuration, the light emitting device 10 may increase the dynamic contrast ratio of the screen by providing light having different intensities to pixels of the liquid crystal panel assembly 52 corresponding to each pixel.

6 is a block diagram of a configuration for driving a liquid crystal display device.

Referring to FIG. 6, the liquid crystal display according to the present exemplary embodiment includes a liquid crystal panel assembly 52, a gate driver 102 and a data driver 104 connected to the liquid crystal panel assembly 52, and a data driver 104. And a gray voltage generator 106, a light emitting device 10, and a signal controller 108 for controlling them.

The liquid crystal panel assembly 52 includes a plurality of signal lines G ₁ -G _n , D ₁ -D _m as viewed in an equivalent circuit, and a plurality of pixels PX connected to the signal lines and arranged in a substantially matrix form. ). The signal lines G ₁ -G _n and D ₁ -D _m are a plurality of gate lines G ₁ -G _n for transmitting a gate signal (also called a “scan signal”), and a plurality of data lines for transmitting a data signal. (D ₁ -D _m ).

Each pixel PX, for example, the i-th (i = 1,2, ... n) gate line G _i and the j-th (j = 1,2, ... m) data line D _j The pixel 54 connected to includes a switching element Q connected to the signal lines G _i and D _j , a liquid crystal capacitor Clc, and a storage capacitor Cst connected thereto. 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 a gate line (G _i), an input terminal is data It is connected to the 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 pixel PX. One of the two sets has a positive value for the common voltage Vcom, and the other set has a negative value.

A gate driver 102, the gate lines of the liquid crystal panel assembly _{(52) (G 1 -G n} ) and is connected to the gate turn-on voltage (Von) and the gate line Gate a gate signal which is a combination of a turn-off voltage (Voff) (G ₁ -G _n ).

The data driver 104 is connected to the 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 data line D ₁ -D as a data signal. _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 data driver 104 divides the reference gray voltages and thus the gray voltages for all grays. Generate and select the data signal from it.

The signal controller 108 controls the gate driver 102, the data driver 104, the light emitting device controller 110, and the like. 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 pixel PX, and luminance has a predetermined number, for example, 1024 (= 2 ¹⁰ ), 256 (= 2 ⁸ ), or 64 ( = 2 ⁶ ) There are 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 appropriately processes the input image signals R, G, and B based on the input image signals R, G, and B and the input control signals according to the operating conditions of the liquid crystal panel assembly 52, and controls the gate. After generating the signal CONT1 and the data control signal CONT2, the gate control signal CONT1 is sent to the gate driver 102, and the data control signal CONT2 and the processed image signal DAT are transmitted to the data driver Export to 104). In addition, the signal controller 108 transmits the gate control signal CONT1, the data control signal CONT2, and the processed image signal DAT to the light emitting device controller 110.

The light emitting device 10 includes a light emitting device controller 110, a column driver 112, a scan driver 114, and a display unit 116.

The display unit 116 includes a plurality of scan lines S ₁ -S _p for transmitting a scan signal, a plurality of column lines C ₁ -C _q for transferring a column signal, and a plurality of light emitting pixels EPX. . Each of the plurality of light emitting pixels EPX is positioned in a region defined by scan lines S ₁ -S _p and column lines C ₁ -C _q intersecting the scan lines. Scan lines S ₁ -S _p are connected to scan driver 114, and column lines C ₁ -C _q are connected to column driver 112. In addition, the scan driver 114 and the column driver 112 are connected to the light emitting device controller 110 and operate according to a control signal of the light emitting device controller 110.

The plurality of scan lines S ₁ -S _p are scan electrodes of the above-described light emitting device, and the column lines C ₁ -C _q are data electrodes.

The light emitting device controller 110 generates and transmits a scan driver control signal CS that controls the scan driver 114 using the gate control signal CONT1. A column driver control signal CC is generated using the data control signal, and a column signal CLS corresponding to the image signal DAT is generated. The generated column driver control signal CS and the column signal CLS are transmitted to the column driver 112. The light emitting device controller 110 generates luminance information for each pixel of the light emitting device 10 from the image signal DAT of one frame, and generates a column signal CLS according to the generated luminance information.

The scan driver 114 sequentially applies a scan signal having a predetermined pulse to the scan lines S ₁ -S _p based on the received scan driver control signal. The column driver 112 applies a driving voltage corresponding to the color signal to each column line C ₁ -C _q according to the input column driver control signal.

By the above-described configuration, the display unit 116 of the light emitting device 10 receives a driving signal synchronized with the image signal and emits light of an appropriate intensity according to the luminance information for each pixel, which is transmitted to the liquid crystal panel assembly 52. to provide. Each of the light emitting pixels EPX of the light emitting device display unit 116 is preferably driven to display gray scales of 2 to 8 bits.

As a result, when the liquid crystal panel assembly 52 displays a screen having a different brightness for each position, the light emitting device 10 provides strong light to the pixels of the liquid crystal panel assembly 52 displaying a bright portion, and the dark portion Weak light may be provided to a portion of the pixels of the liquid crystal panel assembly 52 that displays. In addition, the light emitting pixels of the light emitting device 10 corresponding to the pixels of the liquid crystal panel assembly 52 displaying black may be turned off.

As a result, the liquid crystal display 50 of the present exemplary embodiment may improve the dynamic contrast of the screen through the above-described process.

In addition, the liquid crystal display device 50 of the present embodiment uses the light emitting device 10 having the above-described configuration as a backlight unit, and accordingly, a conventional cold cathode fluorescent lamp (hereinafter referred to as 'CCFL') and a light emitting diode Compared to the backlight unit of the 'LED' method, the following advantages are obtained.

Since the light emitting device 10 of the present embodiment is a surface light source, it does not require a plurality of optical members used in the CCFL type backlight unit and the LED type backlight unit. Therefore, in the light emitting device 10 of the present embodiment, almost no light loss occurs while passing through the optical member, and the light emitting device 10 does not have to emit light of excessive intensity in consideration of the light loss, thereby achieving excellent efficiency with low power consumption. You can get it.

In addition, the light emitting device 10 of the present embodiment has a lower power consumption than the CCFL type backlight unit, and can reduce the cost by not using the optical member. Is low. In addition, since the light emitting device 10 of the present exemplary embodiment is easily enlarged, the light emitting device 10 may be easily applied to a large liquid crystal display device of 30 inches or more.

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 has the effect of increasing the process margin of the gate electrodes, simplifying the manufacturing process, and increasing the withstand voltage characteristics between the cathode electrodes and the gate electrodes by the above-described insulating layer and gate electrodes structure to stabilize driving. There is.

In addition, the liquid crystal display according to 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. It can be easily manufactured with a large display device of inches or more.

Claims (12)

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; Second electrodes formed along the direction intersecting the first electrodes on the first electrodes with an insulating layer interposed therebetween; Electron emission parts electrically connected to the first electrodes; A fluorescent layer formed on one surface of the second substrate; And An anode located on one surface of the fluorescent layer, The light emitting device of which the second electrodes are located next to each other at intervals of 100 to 400㎛. The method of claim 1, And an opening in which the insulating layer and the second electrodes communicate with each other, and the electron emission part is disposed above the first electrodes inside the opening. The method of claim 2, The insulating layer has a thickness of 15 to 30㎛. The method of claim 3, The light emitting device of which the opening has a diameter of 30 to 50㎛. 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. (a) forming first electrodes on the substrate in a stripe pattern; (b) forming an insulating layer having a thickness of 15 to 30 μm over the entire substrate to cover the first electrodes; (c) forming second electrodes having a spacing of 100 to 400 μm on the insulating layer in a stripe pattern along a direction crossing the first electrodes; (d) forming openings in communication with the second electrodes and the insulating layer; (e) forming electron emission parts on the first electrode inside the opening of the insulating layer; Method of manufacturing an electron emission unit of a light emitting device comprising a. The method of claim 6, A method of manufacturing an electron emission unit of a light emitting device, wherein the second electrodes are formed by screen printing. The method of claim 6, When forming openings in the insulating layer, First wet etching the insulating layer through the opening of the first mask layer to form a first opening, and then second wet etching the insulating layer through the opening of the second mask layer to form a second opening, And the opening of the second mask layer has a smaller size than the opening of the first mask layer. The light emitting device according to any one of claims 1 to 5; 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 9, The liquid crystal panel assembly forms a plurality of pixels along a row direction and a 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. The method of claim 10, The liquid crystal panel assembly forms M pixels along the row direction and N pixels along the column direction, And M and N are each an integer of 240 or more. The method of claim 11, The light emitting device forms M 'pixels along the row direction and N' pixels along the column direction, The liquid crystal display device wherein M 'and N' are each an integer of 2 to 99.

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