KR100766937B1 - Light emission device and display - Google Patents

Abstract

A light emitting device and a display device are provided to minimize a light shielding effect and to fix firmly optical members by using a wire for connecting fixing plates to each other. A vacuum receptacle includes a first substrate and a second substrate which are disposed opposite to each other. An electron emission unit is formed on the first substrate. A light emitting unit is formed on the second substrate and emits the light by using electrons emitted from the electron emitting unit. A pair of fixing plates(15) are disposed at both sides of the vacuum receptacle. A wire(17) is formed to connect both sides of the fixing plates to each other. A plurality of optical members(13) are disposed on the wire. The wire is fixed and extended between the fixing plates. The fixing plates and the wire are formed of a metallic material.

Description

Light Emitting Device and Display {LIGHT EMISSION DEVICE AND DISPLAY}

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

2 is a plan view schematically illustrating a light emitting device according to an embodiment of the present invention.

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

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

The present invention relates to a light emitting device and a display device using the same as a light source, and more particularly, to a fixing structure of an optical member positioned in front of a light emitting device.

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

Recently, as a light emitting device to replace a cold cathode fluorescent lamp (CCFL) as a line light source and a light emitting diode (LED) as a point light source, a light emitting device as a surface light source using a cold cathode electron emission source is proposed. It is becoming.

In general, a cold cathode fluorescent lamp is provided with an optical member such as a diffusion plate and a prism sheet in front to secure uniformity of light. This optical member is fixed on the pins located between each cold cathode fluorescent lamp.

However, since the light emitting device using the cold cathode electron emission source is a surface light source, a fixing member such as the fins cannot be disposed between the light emitting devices, and must be installed directly on the light emitting device. However, it is difficult to directly fix the pins onto the substrate, and even if the pins are fixed, there is a problem that impedes the transmission of light emitted from the fluorescent layer.

In addition, since the light emitting device applied as the light source is always turned on at a constant brightness when the display device is driven, it is difficult to meet the image quality improvement required for the display device.

Accordingly, an aspect of the present invention is to provide a light emitting device including a fixing unit capable of fixing a plurality of optical members applied to a surface light source while minimizing blocking of light emitted from a fluorescent layer.

In addition, the present invention provides a light emitting device capable of dividing a light emitting surface into a plurality of regions and independently controlling the light emission intensity for each divided region, and a display device capable of increasing the dynamic contrast ratio of a screen by using the light emitting apparatus as a light source. To provide.

A light emitting device according to an embodiment of the present invention includes a vacuum container including a first substrate and a second substrate disposed opposite to each other, an electron emission unit provided on the first substrate, and provided in the second substrate and in the electron emission unit. A light emitting unit that emits light by the emitted electrons, a pair of holders disposed on both sides of the vacuum container, a wire connected between the holders, and optical members disposed on the wires.

In addition, the wire may be elongated and fixed to the holder to have a tension, and the holder and the wire may be made of a metal, in which case the wire may be welded to the upper surface of the holder.

In addition, the pair of holders may be arranged in plural along one side of the vacuum vessel, wherein the pair of holders may be disposed corresponding to each other. And, the fixing rod may be made of a rectangular bar shape.

In addition, the height of the holder may be formed larger than the height of the vacuum vessel.

In addition, the display device according to an exemplary embodiment of the present invention includes a light emitting device and a display panel positioned in front of the light emitting device to display an image by receiving light emitted from the light emitting device, wherein the display panel is a liquid crystal display. It may be a display panel.

In addition, the display panel may have first pixels, and the light emitting device may have a smaller number of second pixels than the first pixels, and may independently control light emission intensity for each of the second pixels.

Hereinafter, exemplary embodiments of the present invention will be described in detail 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 would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like elements throughout the specification.

In the embodiment of the present invention, the light emitting device includes all devices capable of recognizing that light is emitted when viewed from the outside. Therefore, all display devices that display information by displaying symbols, letters, numbers, and images, are also included in the light emitting device. The light emitting device can use not only its own light source but also an external light source, and thus includes a device for reflecting an external light source.

1 is an exploded perspective view of a light emitting device according to an embodiment of the present invention, Figure 2 is a plan view schematically showing a light emitting device according to an embodiment of the present invention.

Referring to FIG. 1, a light emitting device 10 according to an exemplary embodiment of the present invention may include a holder 15 and a holder for fixing an optical member 13 disposed on an upper surface of a surface light source assembly 11 that emits light. And a wire 17 connecting the stator 15.

The surface light source assembly 11 is mounted inside the frame 19, and the holders 15 are disposed in pairs on both sides of the surface light source assembly 11. As shown in FIG. 1, the pair of holders 15 may be formed in plural on both sides of the surface light source assembly 11, but may be integrally formed along one direction of the surface light source assembly 11. .

For example, the holder 15 may be formed in a rectangular bar shape, the shape may be variously modified, such as a circular columnar shape.

In addition, the holder 15 is an example of a material having elasticity to apply tension to the wire 17, it may be formed of a metal.

A wire 17 is connected between the pair of fixing stands 15, and the wire 17 is elongated to have a tension to prevent sagging of the optical member 13. To this end, the wire 17 is also preferably formed of a metal, like the holder 15.

In addition, the wire 17 is fixed to the upper surface of the holder 15, welding may be used as a joining method. However, the wire 17 may be fixed to the side of the holder 15, etc., the coupling position may be variously modified.

As described above, the optical member 13 is placed on the wire 17 connected to the holder 15 and then fixed, so that the wire 17 is spaced apart from the optical member 13 and the surface light source assembly 11 by a predetermined distance. The optical member 13 is supported. The optical member may include a diffusion plate, a brightness enhancement film (BEF), a dual brightness enhancement film (DBEF), and the like.

On the other hand, the diameter of the wire 17 is appropriately designed in consideration of securing the light transmittance and the supporting force for the optical member 13.

Referring to FIG. 2, a pair of holders 15 are disposed to correspond one to one with each other, and a single wire 17 is connected in a horizontal direction (x-axis direction in FIG. 2) between the holders 15. At this time, the number of the holder 15 and the number of wires 17 connected between the holder 15 may be variously modified according to the bearing force for the optical member 13, and the like. In FIG. 2, the dotted line shows the optical member 13 fixed on the wire 17.

In addition, although not shown, the fixing bars 15 may be alternately arranged so that the wires 17 may be arranged to form a predetermined angle with the horizontal direction.

That is, the holder 15 may be disposed outside the surface light source assembly 11, and the wires 17 only need to connect the holders 15 to each other, and thus the arrangement of the holders 15 and the wires 17 may vary. Can be modified.

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

Referring to FIG. 3, the surface light source assembly 11 according to the exemplary embodiment of the present invention includes a first substrate 12 and a second substrate 14 disposed to face each other in parallel at a predetermined interval. The sealing member 16 is disposed at the edges of the first substrate 12 and the second substrate 14 to bond the two substrates, and the internal space is evacuated with a vacuum of approximately 10 ⁻⁶ Torr to form 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 are partitioned into an effective region contributing to the actual visible light emission inside the sealing member 16 and an invalid region surrounding the effective region. The effective area of the first substrate 12 is provided with an electron emission unit 18 for electron emission, and the effective area of the second substrate 14 is provided with a light emission unit 20 for visible light emission.

The electron emission unit 18 is any one of a field emission array (FEA) type, a surface-conducting emission (SCE) type, a metal-insulating layer-metal (MIM) type, and a metal-insulating layer-semiconductor (MIS) type. It may consist of electron emitting elements. 3 shows an electron emission unit 18 consisting of a field emission array (FEA) type electron emission element.

The electron emission unit 18 includes first and second electrodes 22 and 26 formed in a stripe pattern in a direction crossing each other with the insulating layer 24 interposed therebetween, and the first electrode 22. And electron emission parts 28 electrically connected to any one of the second and second electrodes 26.

When the electron emission portion 28 is formed on the first electrode 22, the first electrode 22 becomes a cathode electrode for supplying current to the electron emission portion 28, and the second electrode 26 is a cathode electrode. An electric field is formed by the voltage difference between and the gate electrode is used to induce electron emission. On the contrary, when the electron emission part 28 is formed in the 2nd electrode 26, the 2nd electrode 26 will be a cathode and the 1st electrode 22 will be a gate electrode.

An electrode positioned along the row direction (x-axis direction in FIG. 1) of the surface light source assembly 11 among the first electrode 22 and the second electrode 26 functions as a scan electrode, and the surface of the surface light source assembly 11 An electrode located along the column direction (y-axis direction in FIG. 1) functions as a data electrode.

In the drawing, the electron emission part 28 is formed on the first electrode 22, the first electrodes 22 are positioned along the column direction of the surface light source assembly 11, and the second electrodes 26 are faced. The case where it is located along the row direction of the light source assembly 11 was shown. 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 of the first electrode 22 and the second electrode 26 to expose a part of the surface of the first electrode 22. The electron emission part 28 is positioned on the first electrode 22 inside the opening 241 of the insulating layer 24.

The electron emission unit 28 is a kind of electron emission layer having a predetermined thickness and diameter, and may be formed of materials emitting electrons when a electric field is applied in vacuum, such as a carbon-based material or a nanometer-sized material.

The electron emission unit 28 may include, for example, carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond-like carbons, fullerenes (C ₆₀ ), silicon nanowires, or a combination thereof, and may be screen printed by the method. Direct growth, chemical vapor deposition or sputtering.

The electron emitters 28 are gathered and positioned in the middle portion of the intersection region of the first electrode 22 and the second electrode 26 except for an edge in consideration of electron beam spreading characteristics.

In the above-described structure, one intersection region of the first electrode 22 and the second electrode 26 corresponds to one pixel region of the surface light source assembly 11, or two or more intersection regions are one of the surface regions of the surface light source assembly 11. It may correspond to a pixel area. In the second case, two or more first electrodes 22 or two or more second electrodes 26 corresponding to one pixel area may be 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. In the drawings, the former case is illustrated.

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

On the other hand, when the surface light source assembly 11 is applied to a display for displaying an image, the fluorescent layer 30 should be a combination of red, green and blue fluorescent layers. In this case, the red, green, and blue fluorescent layers may be divided into a predetermined pattern in one pixel area, and a black layer (not shown) may be disposed therebetween.

The anode electrode 32 may be formed of a metal film such as aluminum (Al) 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 34 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 surface light source assembly 11 of 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 vessel, and the anode electrode 32 has a quantity of thousands of volts or more. Drive by applying DC 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 to correspond. 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.

When the surface light source assembly of the above-described embodiment is used as a light source of the display device, 10 kV or more, preferably 10, through the anode pad portion of the anode electrode 32 so as to achieve a maximum brightness of approximately 10,000 cd / m ² or more in the center of the effective area. To a high voltage of about 15 kV. Accordingly, in the surface light source assembly of the present embodiment, the distance between the first substrate 12 and the second substrate 14 is increased to about 5 to 20 mm in order to eliminate electrical instability such as a short in the vacuum container due to the application of a high voltage. Keep it.

The optical member 13 is positioned on the surface light source assembly 11, and the optical member 13 is supported by the wire 17. On the other hand, the holder 15 is formed so that the height (H1) is higher than the height (H2) of the surface light source assembly 11 to position the optical member 13 higher than the surface light source assembly (11).

4 is an exploded perspective view of a display device having the above-described light emitting device. The display device shown in FIG. 4 is for illustrating the present invention, but the present invention is not limited thereto.

Referring to FIG. 4, the display device 100 includes a light emitting device 10 and a display panel 40 positioned in front of the light emitting device 10. An optical member 13 is disposed between the light emitting device 10 and the display panel 40 to uniformly diffuse the light emitted from the light emitting device 10 and provide the light to the display panel 40. The surface light source assemblies 11 are spaced apart by a predetermined distance. A top chassis 52 is positioned in front of the display panel 40.

The display panel 40 may be formed of a liquid crystal display panel or another light receiving display panel.

The light emitting device 10 forms fewer pixels than the display panel 40 so that one pixel of the light emitting device 10 corresponds to two or more pixels of the display panel 40. Each pixel of the light emitting device 10 may emit light corresponding to the highest gray level among the pixels of the display panel 40 corresponding thereto, and the light emitting device 10 may express a gray level of 2 to 8 bits for each pixel. have.

For convenience, a pixel of the display panel 40 is called a first pixel, a pixel of the light emitting device 10 is called a second pixel, and a plurality of first pixels corresponding to one second pixel is called a first pixel group. .

In the driving process of the light emitting device 10, a signal controller (not shown) controlling the display panel 40 detects the highest gray level among the first pixels of the first pixel group, and according to the detected gray level, the second pixel. The method may include calculating a grayscale required for light emission, converting the grayscale to digital data, and generating a driving signal of the light emitting device 10 using the digital data. The driving signal of the light emitting device 10 includes a scan driving signal and a data driving signal.

The second pixel of the light emitting device 10 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. The light emitting device 10 may form 2 to 99 pixels in a row direction and a column direction. When the number of pixels of the light emitting device 10 in the row direction and the column direction exceeds 99, driving of the light emitting device 10 may be complicated and may cause an increase in cost for manufacturing a driving circuit.

As such, the light emitting device 10 independently controls the light emission intensity of each pixel to provide light of appropriate intensity to the pixels of the display panel 40 corresponding to each pixel. Therefore, the display device 100 of the present exemplary embodiment can increase the dynamic contrast of the screen and can realize a clearer picture quality.

The light emitting device according to the embodiment of the present invention may include a wire connecting the fixing rod, thereby firmly fixing the optical members while minimizing the blocking of the light emitted from the light emitting device and preventing sagging of the optical members.

In addition, the display device using the above-described light emitting device as a light source improves the display quality by increasing the contrast of the screen and the dynamic contrast ratio of the screen.

Claims (15)

A vacuum container including 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 emitting light by electrons emitted from the electron emitting unit; A pair of holders disposed on both sides of the vacuum container; A wire connected between the holders; And Optical members disposed on the wire Light emitting device comprising a. The method of claim 1, The wire is a light emitting device that is fixed to the elongate fixed to the tension. The method of claim 2, The light emitting device of which the fixing stand and the wire are made of metal. The method of claim 3, The light emitting device is fixed to the wire is welded to the upper surface of the holder. The method of claim 1, The light emitting device in which a plurality of the fixed stand is arranged in plurality along one side of the vacuum container The method of claim 5, The light emitting device in which the pair of fixing rods are disposed corresponding to each other. The method of claim 6, A light emitting device of which the holder is formed in a square bar shape. The method of claim 1, And a height of the holder is greater than that of the vacuum container. The method of claim 1, The electron emission unit, First and second electrodes formed along an intersecting direction while maintaining an insulated state; And And an electron emission unit electrically connected to any one of the first electrodes and the second electrodes. A display panel displaying an image; And A light emitting device positioned behind the display panel to provide light to the display panel; A display device comprising: The light emitting device, A vacuum container including 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 emitting light by electrons emitted from the electron emitting unit; A pair of holders disposed on both sides of the vacuum container; A wire connected between the holders; And Optical members disposed on the wire; Display device comprising a. The method of claim 10, And the wire is extended to and fixed to the holder to have a tension. The method of claim 10, And a wire welded to the upper surface of the holder. The method of claim 10, And a height of the holder is greater than a height of the vacuum container. The method of claim 10, The display panel is a liquid crystal display panel. The method of claim 10, The display panel has first pixels, And a light emitting device having a smaller number of second pixels than the first pixels, and independently controlling light emission intensity for each of the second pixels.

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