KR20080088871A - Display device - Google Patents

Abstract

A display device according to an embodiment of the present invention includes an electron emission type light emitting panel adapted to emit light, and a display panel positioned on the light emitting panel and receiving light to display an image. The light emitting panel is positioned between the first substrate and the second substrate disposed opposite to each other, the electron emission unit provided on the first substrate, the light emitting unit provided on the second substrate, and the first substrate and the second substrate. And a spacer assembly arranged along a first direction parallel to the plate surface of the second substrate and in a second direction crossing the first direction.

Description

Display device {DISPLAY DEVICE}

1 is a partially exploded perspective view of a display device according to an exemplary embodiment.

FIG. 2 is a partially exploded perspective view of the light emitting panel of FIG. 1.

3A and 3B are schematic views illustrating before and after bonding of the spacer assembly, respectively.

4 is a cross-sectional view taken along line IV-IV of FIG. 2.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly, to a display device capable of ensuring a uniform luminance in an entire area of a display panel by improving a structure of a light emitting panel.

Liquid crystal display devices are known as light-receiving display devices in which a light source is required. The liquid crystal display includes a display panel including a liquid crystal layer and a polarizing plate, and a light emitting panel that provides light to the display panel. The display panel receives light emitted from the light emitting panel and transmits or blocks the light by the action of the liquid crystal layer and the polarizing plate to implement a predetermined image.

Cold Cathode Fluorescent Lamp (CCFL, hereinafter referred to as CCFL) and Light Emitting Diode (LED) as point light sources are used to supply light to the liquid crystal display. ) Is used.

The field emission panel includes an electron emission unit and driving electrodes on a rear substrate, a fluorescent layer and an anode electrode on the front substrate, and emits light by exciting a fluorescent layer with electrons emitted from the electron emission unit. to be. Compared with CCFLs and LEDs, the field emission type light emitting panel has low power consumption, is advantageous for large size, and has an advantage of simplifying an optical member configuration.

An object of the present invention is to provide a display device capable of improving luminance uniformity of a light emitting surface.

A display device according to an embodiment of the present invention includes an electron emission type light emitting panel adapted to emit light, and a display panel positioned on the light emitting panel and receiving light to display an image. The light emitting panel is positioned between the first substrate and the second substrate disposed opposite to each other, the electron emission unit provided on the first substrate, the light emitting unit provided on the second substrate, and the first substrate and the second substrate. And a spacer assembly arranged along a first direction parallel to the plate surface of the second substrate and in a second direction crossing the first direction.

The assembly is located in the non-light emitting area of the plurality of light emitting and non-light emitting areas set in the light emitting panel. That is, the plurality of light emitting regions correspond to the plurality of unit light emitting pixels, and the spacer assembly is positioned between neighboring unit light emitting pixels among the plurality of unit light emitting pixels.

The spacer assembly includes a plurality of first spacers extending in a first direction and a plurality of second spacers extending in a second direction. The plurality of first spacers and the plurality of second spacers are coupled to each other. Each of the first spacer and the second spacer includes a first intersection portion and a second intersection portion which are engaged with each other, and a first groove and a second groove are formed at the first intersection portion and the second intersection portion, respectively.

Here, the first groove and the second groove are recessed in a direction perpendicular to the plate surface. The first groove is open toward the first substrate and the second groove is open toward the second substrate. Since the sum of the length of the first groove and the length of the second groove is equal to the height of the spacer assembly, each first spacer and each second spacer are mutually fastened while the first groove passes through the second groove. Such spacer assemblies form a lattice pattern.

On the other hand, the spacer assembly includes a body portion and an antistatic film formed on the side of the body portion. The antistatic film is made of a material having a secondary electron emission coefficient of substantially 1 or less. A reflective film is formed on the surface of the spacer assembly that faces the second substrate.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art can easily understand, the embodiments described below may be modified in various forms without departing from the concept and scope of the present invention. Where possible, the same or similar parts are represented using the same reference numerals in the drawings.

When a portion is referred to as being "above" another portion, it may be just above the other portion or may be accompanied by another portion in between. In contrast, when a part is mentioned as "directly above" another part, no other part is intervened in between.

It is to be understood that the terms first, second and third are used to describe various parts, components, regions, layers and / or sections, but are not limited to these. These terms are only used to distinguish one part, component, region, layer or section from another part, component, region, layer or section. Accordingly, the first portion, component, region, layer or section described below may be referred to as the second portion, component, region, layer or section without departing from the scope of the invention.

The terminology used herein is for reference only to specific embodiments and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” include plural forms as well, unless the phrases clearly indicate the opposite. As used herein, the term "comprising" embodies a particular characteristic, region, integer, step, operation, element, and / or component, and other specific characteristics, region, integer, step, operation, element, component, and / or group. It does not exclude the presence or addition of.

Terms indicating relative spaces such as "below" and "above" may be used to more easily describe the relationship between different parts of one part shown in the drawings. These terms are intended to include other meanings or operations of the device in use with the meanings intended in the figures. For example, when the device in the figure is reversed, any parts described as being "below" of other parts are described as being "above" other parts. Thus, the exemplary term "below" encompasses both up and down directions. The device can be rotated 90 degrees or at other angles, the terms representing relative space being interpreted accordingly.

Unless defined otherwise, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Commonly defined terms used are additionally interpreted as having a meaning consistent with the related technical literature and the presently disclosed contents, and are not interpreted as ideal or very formal meaning unless defined.

The light emitting panel includes a flat panel or a curved panel. Other types of panels may be included.

1 schematically illustrates an exploded view of a display device 1000 according to an exemplary embodiment.

Referring to FIG. 1, the display device 1000 includes a light emitting panel 100 and a display panel 200. The display apparatus 1000 further includes a first fixing member 302 and a second fixing member 304 to fix and support the display panel 200 and the light emitting panel 100. A diffusion plate 400 is disposed between the display panel 200 and the light emitting panel 100 to diffuse light emitted from the light emitting panel 100 to supply the light to the display panel 200.

The display panel 200 is formed of a liquid crystal display panel or another light receiving display panel. Hereinafter, the case where a display panel is a liquid crystal display panel as an example is demonstrated.

The display panel 200 includes a TFT substrate 210 including a plurality of thin film transistors (TFTs), a color filter substrate 220 positioned on the TFT substrate 210, and a liquid crystal injected between the panels. Layer (not shown). Polarizers (not shown) are attached to the upper portion of the color filter substrate 220 and the lower portion of the TFT substrate 210 to polarize light passing through the display panel 200.

The TFT substrate 210 is a transparent glass substrate on which a matrix thin film transistor is formed. A data line is connected to a source terminal and a gate line is connected to a gate terminal. In the drain terminal, a pixel electrode made of a transparent conductive film as a conductive material is formed.

When electrical signals are input from the printed circuit boards 230 and 240 to the gate line and the data line, respectively, electrical signals are input to the gate terminal and the source terminal of the TFT. According to the input of these electrical signals, the TFT is turned on or turned off, and the electrical signals necessary for pixel formation are output to the drain terminal.

The color filter substrate 220 is a panel in which RGB pixels, which are color pixels in which a predetermined color is expressed while light passes, are formed by a thin film process, and a common electrode made of a transparent conductive film is coated on the entire surface thereof.

When power is applied to the gate terminal and the source terminal of the TFT and the thin film transistor is turned on, an electric field is formed between the pixel electrode and the common electrode of the color filter substrate 220. The arrangement angle of the liquid crystal injected between the TFT substrate 210 and the color filter substrate 220 is changed by the electric field, and the light transmittance is changed for each pixel according to the changed arrangement angle.

The printed circuit boards 230 and 240 of the display panel 200 are connected to gate lines and data lines through respective driving IC packages 2301 and 2401. In order to drive the display panel 200, the gate printed circuit board 230 transmits a gate driving signal, and the data printed circuit board 240 transmits a data driving signal.

The light emitting panel 100 is a surface emitting type, and emits light by exciting a fluorescent layer coated with a predetermined area. The light emitting panel 100 includes a first substrate 10, a second substrate 12, an electron emission unit (not shown), and a light emitting unit (not shown). The light emitting panel 100 is a light source for supplying light to the display panel 200, and can be driven for each light emitting pixel as indicated by a dotted line. A plurality of gate lines (not shown) and a plurality of data lines (not shown) are formed in the light emitting panel 100, and they are connected to a printed circuit board (not shown) through the driving integrated circuit packages 102 and 104. The printed circuit board is positioned on the rear surface of the light emitting panel 100. The printed circuit board operates the light emitting panel 100 by applying driving signals to the gate lines and the data lines of the light emitting panel 100.

Such light emitting panels include various electron emission types including field emission array (FEA) type, surface-conductive emission (SCE) type, metal-insulating layer-metal (MIM) type, and metal-insulating layer-semiconductor (MIS) type. It can be applied to a display. In this embodiment, the field emission array (FEA) type light emitting panel 100 will be described in more detail.

2 is a partially exploded view of the light emitting panel 100 of FIG. 1. The light emitting panel 100 of FIG. 2 is for illustrating the present invention, but the present invention is not limited thereto.

Referring to FIG. 2, the first substrate 10 and the second substrate 12 are disposed in parallel to each other at a predetermined interval. And the 1st board | substrate 10 and the 2nd board | substrate 12 are joined by the sealing member (not shown) arrange | positioned at the edge, and comprise the container which has an internal space. The vessel is evacuated to a vacuum of approximately 10 ⁻⁶ Torr to constitute a vacuum vessel consisting of the first substrate 10, the second substrate 12, and the sealing member.

The first substrate 10 opposite to the second substrate 12 is provided with an electron emission unit 110 in which an array of electron emitting elements is arranged, and the second substrate 12 opposite to the first substrate 10 is fluorescent. A light emitting unit 120 is provided that includes a layer 22, an anode electrode 24, and the like. The first substrate 10 provided with the electron emission unit 110 and the second substrate 12 provided with the light emitting unit 120 combine to form the light emitting panel 100.

Cathode electrodes 14 are formed on the first substrate 10 in a stripe pattern along the y-axis direction on the first substrate 10. The first insulating layer 16 is formed on the first substrate 10 while covering the cathode electrodes 14. Gate electrodes 18 are formed on the first insulating layer 16 in a stripe pattern along the x-axis direction orthogonal to the formation direction of the cathode electrodes 14.

Therefore, an intersection region of the cathode electrode 14 and the gate electrode 18 is formed, and this intersection region may constitute one pixel region of the light emitting panel 100. Electron emitters 20 are formed in each unit pixel on the cathode electrodes 14 (as shown in the enlarged circle of FIG. 2).

The electron emission unit 20 arranged in the above structure is made of materials emitting electrons when a electric field is applied in a vacuum, such as a carbon-based material or a nanometer (nm) size material. That is, the electron emission unit 20 is composed of carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbon, fullerene (C ₆₀ ), silicon nanowires, and combinations thereof. 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).

As shown in the enlarged source of FIG. 2, the first insulating layer 16 and the gate electrodes 18 each have a first opening 161 and a second opening 181 corresponding to the electron emission section 20. Is formed to expose the electron emission unit 20 on the first substrate 10. That is, the electron emission part 20 is formed on the cathode electrode 14 and is exposed to the outside through the first opening 161 and the second opening 181. Although the electron emission unit 20 is illustrated in the form of a cylinder in the present embodiment, the shape thereof is not necessarily limited to the illustrated example.

Next, a fluorescent layer 22 is formed on one surface of the second substrate 12 facing the first substrate 10, and the fluorescent layer 22 may be formed of a white fluorescent layer. The fluorescent layer may be formed in the entire effective region of the second substrate 12 or may be formed in a predetermined pattern so that one white fluorescent layer is positioned in each unit pixel region.

On the other hand, the fluorescent layer may be composed of a combination of red, green and blue fluorescent layers, these fluorescent layers may be divided into a predetermined pattern in one pixel area. In FIG. 2, the white fluorescent layer 22 is positioned over the entire effective region of the second substrate 12.

An anode electrode 24 made of a metal such as aluminum (Al) is formed on the fluorescent layer 22. The anode electrode 24 receives a high voltage required for electron beam acceleration from the outside, for example, a voltage of 10 kV to 20 kV to maintain the fluorescent layer 22 in a high potential state. The anode electrode 24 reflects the visible light emitted toward the first substrate 10 of the visible light emitted from the fluorescent layer 22 toward the second substrate 12 to improve luminance. Here, the fluorescent layer 22 and the anode electrode 24 are sequentially stacked on the second substrate 12 so that the fluorescent layer 22 is adjacent to the second substrate 12. Accordingly, since the anode electrode 24 does not interfere with the light emitted from the fluorescent layer 22, the anode electrode 24 can be formed of an opaque metal having good electrical conductivity.

On the contrary, the fluorescent layer and the anode electrode may be stacked at different positions. That is, when the anode electrode is made of a transparent conductive film such as indium tin oxide (ITO), the transparent anode electrode may be positioned between the second substrate and the fluorescent layer. Moreover, the transparent conductive film mentioned above can be used as an anode electrode, and a metal film can also be further formed here.

A spacer assembly 26 is disposed between the first substrate 10 and the second substrate 12 to maintain a constant gap between the two substrates 10 and 12 against the atmospheric pressure applied to the vacuum vessel.

The spacer assembly 26 includes a plurality of spacers 261 and 262 having a partition shape, and the plurality of spacers 261 and 262 are combined to form an integrated body. The spacer assembly 26 includes a plurality of first spacers 261 and a plurality of second spacers 262. The first spacer 261 extends along the x-axis direction of FIG. 2, and a plurality of first spacers 261 are provided to be arranged side by side in the y-axis direction. The second spacer 262 is arranged in a direction crossing the first spacer 261. In this case, the first spacer 261 and the second spacer 262 are positioned between adjacent unit light emitting pixels D. Therefore, each unit light emitting pixel D is surrounded by the first spacer 261 and the second spacer 262.

3A and 3B schematically show a state before and after engagement of the spacer assembly 26 according to the present embodiment, respectively.

Referring to FIG. 3A, first crossings 261 ′ and second crossings 262 ′ are formed at portions where the first spacers 261 and the second spacers 262 are coupled to each other. The first crossing portion 261 ′ and the second crossing portion 262 ′ have grooves 2611 and 2621, respectively, and the first spacer 261 and the second spacer ( 262). The first groove 2611 and the second groove 2621 have a predetermined length. Here, if the length of the first groove 2611 or the second groove 2621 is too long or short, the lower surface of the first spacer 261 and the second spacer 262 are shifted from each other, so that the spacer assembly 26 is formed on the first substrate. The force supporting 10 (shown in FIG. 2) and the second substrate 12 (shown in FIG. 2) may be weakened. In consideration of this, first grooves 2611 and second grooves 2621 having appropriate lengths are formed. Therefore, the height (H) (Figure 3b of the first groove sum (h ₁ + h ₂₎ is a spacer assembly (26) of the length (h ₁₎ and the length (h ₂₎ of the second groove (2621) of 2611 Substantially the same).

The first groove 2611 and the second groove 2621 are formed along the z-axis direction at the first spacer 261 and the second spacer 262, respectively. Here, the first groove 2611 and the second groove 2621 are opened in opposite directions to each other. For example, the first groove 2611 is opened in the + z axis direction of FIG. 3, and the second groove 2621 is opened in the -z axis direction. Accordingly, the second groove 2621 is coupled to the first groove 2611 in the direction of the arrow (shown in FIG. 3A). Since the first grooves 2611 and the second grooves 2621 are engaged with each other, the first spacers 261 and the second spacers 262 are coupled to each other (see FIG. 3B). Each part where the first spacer 261 and the second spacer 262 cross each other is fastened in the above-described manner to form the spacer assembly 26 having a lattice pattern. Since the display panel 200 (shown in FIG. 1) is positioned on the light emitting panel 100 (shown in FIG. 1), a large load acts on the light emitting panel 100. Therefore, in order to separate the first substrate 10 (shown in FIG. 1) and the second substrate 12 (shown in FIG. 1) of the light emitting panel 100, a spacer having excellent strength is required. In the present embodiment, since the spacer assembly 26 is used, the area supporting the second substrate 12 is widened to withstand the load of the display panel 200.

As shown in the enlarged circle of FIG. 3B, the spacer assembly 26 includes a body portion 2612, an antistatic film 2613, and a reflective film 2614. The body portion 2612 has a partition shape and constitutes a body of each of the first spacer 261 and the second spacer 262. The body portion 2612 may be made of a material such as glass or ceramic. An antistatic film 2613 is formed on the side of the body portion 2612. The antistatic film 2613 discharges the charge charged in the spacer assembly 26 by secondary electron emission. Accordingly, the antistatic film 2613 has a lower resistance than that of the body portion 2612 so as to lower the overall resistance of the spacer assembly 26. The antistatic film 2612 may be made of a material having a secondary electron emission coefficient of substantially 1 or less, such as magnesium oxide (MgO). Additionally, a reflective film 2614 is formed on the top surface of the spacer assembly 26 opposite the second substrate 12 (shown in FIG. 2). The reflective film 2614 may reflect the light emitted from the fluorescent layer 22 (shown in FIG. 2) toward the first substrate 10 (shown in FIG. 2) toward the second substrate 12. . In addition, light emitted through the anode electrode 24 (shown in FIG. 2) and directed toward the first substrate 10 may be reflected toward the second substrate 12. Therefore, when the reflective film 2614 is formed on the upper surface of the spacer assembly 26, the luminance of the light emitting surface can be improved more efficiently.

4 is a schematic cross-sectional view taken along line IV-IV of FIG. 2.

Referring to FIG. 4, the above-described light emitting panel 100 forms a plurality of unit pixels by combining the cathode electrodes 14 and the gate electrodes 18, and a predetermined voltage is applied from the outside to the cathode electrodes 14. The gate electrodes 18 and the anode electrodes 24 are supplied and driven. For example, any one of the cathode electrodes 14 and the gate electrodes 18 receives a scan driving voltage to serve as scan electrodes, and the other electrodes receive a data driving voltage to serve as data electrodes.

In addition, the anode electrode 24 receives a voltage required for electron beam acceleration, for example, a positive DC voltage of 10 kV to 20 kV.

Then, an electric field is formed around the electron emission unit 20 in the unit pixels in which the voltage difference between the cathode electrode 14 and the gate electrode 18 is greater than or equal to the threshold value. As a result, the electron emission unit 20 is formed as shown in FIG. 2. Electrons (e-) are emitted from. The emitted electrons (e−) are attracted to the high voltage applied to the anode electrode 24 and collide with the corresponding fluorescent layer 22 to emit light.

The above-described spacer assembly 26 facilitates the flow of electric current, thereby well discharging the charge accumulated on the surfaces of the spacers 261 and 262 to the outside. That is, secondary electrons emitted from the surfaces of the spacers 261 and 262 increase, and the secondary electrons collide with the fluorescent layer to increase the luminance of the display device 1000 (shown in FIG. 1). In addition, the spacer assembly 26 has a lattice shape and is located between substantially all the light emitting regions. This can improve the brightness uniformity of the entire light emitting area as compared with the case where the bar-shaped spacer is provided.

Referring back to FIG. 1, the light emitting panel 100 forms fewer pixels than the display panel 200 so that one pixel of the light emitting panel 100 corresponds to two or more pixels of the display panel 200. Each pixel of the light emitting panel 100 may emit light corresponding to the highest gray level among the pixels of the display panel 200 corresponding thereto, and the light emitting panel 100 may express 2 to 8 bits of gray level for each pixel. have. For convenience, a pixel of the display panel 200 is called a first pixel, a pixel of the light emitting panel 100 is called a second pixel, and a plurality of first pixels corresponding to one second pixel is called a first pixel group. .

A driving process of the light emitting panel 100 will be described below. In the light emitting panel 100, a signal controller (not shown) controlling the display panel 200 detects the highest gray level among the first pixels of the first pixel group. The grayscale required for the emission of the second pixel is calculated according to the detected grayscale, and is converted into digital data. And generating driving signals of the light emitting panel using the digital data. The driving signal of the light emitting panel 100 includes a scan driving signal and a data driving signal. The second pixel of the light emitting panel 100 emits light with a predetermined gray level in synchronization with the first pixel group when an image is displayed in the corresponding first pixel group. As described above, the light emitting panel 100 independently controls the light emission intensity of each pixel to provide light having an appropriate intensity to the pixels of the display panel 200 corresponding to each pixel.

The light emitting panel 100 is driven at a lower power than the light emitting diode (LED) and the cold cathode fluorescent lamp (CCFL), and can independently control the light emission intensity of each pixel. Therefore, the dynamic contrast of the screen implemented in the display panel can be increased and sharper picture quality can be realized.

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 display device according to the exemplary embodiment of the present invention can efficiently support the first substrate and the second substrate by combining a plurality of spacers to form an integrated spacer assembly. In addition, convenience can be achieved in loading the spacer between the first substrate and the second substrate. In addition, since each of the spacers constituting the spacer assembly is formed with an antistatic film on its surface, it is possible to smoothly discharge the electric current by smoothly flowing the current. Such a spacer assembly may increase the probability that secondary electrons emitted from the spacer surface collide with the fluorescent layer by being located between unit light emitting pixels. This not only increases the luminance of the light emitting surface but also has the effect of making the luminance uniform, thereby improving display quality of the display device and increasing dynamic contrast ratio of the screen.

Claims (14)

An electron emitting light emitting panel adapted to emit light; And A display panel positioned on the light emitting panel and configured to display an image by receiving the light; Including, The light emitting panel, A first substrate and a second substrate disposed to face each other; An electron emission unit provided on the first substrate; A light emitting unit provided on the second substrate; And A spacer assembly disposed between the first substrate and the second substrate and arranged along a first direction parallel to the plate surface of the first substrate and the second substrate and a second direction crossing the first direction Display device comprising a. According to claim 1, The light emitting panel, A plurality of light emitting regions for emitting light; And A non-light emitting area disposed between the plurality of light emitting areas and formed in a plurality of lattice shapes Including, The spacer assembly is positioned in the non-light emitting area. The method of claim 2, The plurality of light emitting regions may correspond to a plurality of unit light emitting pixels, and the spacer assembly may be disposed between neighboring unit light emitting pixels among the plurality of unit light emitting pixels. According to claim 1, The spacer assembly, A plurality of first spacers extending along the first direction; And A plurality of second spacers extending along the second direction Display device comprising a. The method of claim 4, wherein And a plurality of first spacers and the plurality of second spacers are coupled to each other. The method of claim 5, Each of the first spacers of the plurality of first spacers and each of the second spacers of the plurality of second spacers respectively include a first intersection portion and a second intersection portion that are engaged with each other, and the first intersection portion and the second intersection portion respectively. A display device in which a first groove and a second groove are formed in each portion. The method of claim 6, The first groove and the second groove extend in a direction perpendicular to the plate surface. The method of claim 7, wherein The first groove is open toward the first substrate, and the second groove is open toward the second substrate. The method of claim 7, wherein The sum of the length of the first groove and the length of the second groove is substantially equal to the height of the spacer assembly. The method of claim 7, wherein The first and second spacers are coupled to each other while the first groove passes through the second groove. According to claim 1, The spacer assembly has a grid pattern. According to claim 1, The spacer assembly, Body portion; And Antistatic film formed on the side of the body portion Display device comprising a. The method of claim 12, And the antistatic layer is formed of a material having a secondary electron emission coefficient of substantially 1 or less. The method of claim 12, And a reflective film formed on a surface of the spacer assembly facing the second substrate.

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