KR20080088884A - Light emission device - Google Patents

Abstract

The present invention provides a light emitting device that can suppress the distortion of the electric field around the spacer to prevent display quality degradation of the screen. The light emitting device according to the present invention comprises a first substrate, a second substrate disposed opposite to the first substrate, an electron emission unit formed on the first substrate, an anode formed on the second substrate and formed on one surface of the fluorescent layer and the fluorescent layer. A light emitting unit including an electrode, a spacer disposed between the first substrate and the second substrate, the spacer including the electrode, and the non-light emitting region of the second substrate being insulated from the light emitting unit with an insulating layer interposed therebetween in contact with the electrode of the spacer. It includes a central electrode line formed in.

Description

Light Emitting Device {LIGHT EMISSION DEVICE}

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

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

3 is a bottom view of a second substrate of a light emitting device according to an embodiment of the present invention.

4 is a perspective view illustrating a modified example of the spacer of the light emitting device according to the embodiment of the present invention.

FIG. 5 is a diagram illustrating that electric field distortion generated around a spacer is compensated by a spacer electrode in a light emitting device according to an exemplary embodiment of the present invention.

The present invention relates to a light emitting device, and more particularly, to an electron emitting light emitting device capable of compensating for electric field distortion around a spacer.

In general, an electron emission type light emitting device includes one substrate having an electron emission unit consisting of an array of electron emission elements, and another substrate including a light emitting unit consisting of a fluorescent layer, an anode electrode, or the like. It includes. One substrate and the other substrate are disposed to face each other to form a vacuum container to excite the fluorescent layer with electrons emitted from the electron emission element to perform light emission.

In addition, a field emission array (FEA) type is well known as an electron emission element constituting an electron emission unit. The FEA type electron emission device includes an electron emission portion and a driving electrode for controlling electron emission of the electron emission portion, including a cathode electrode and a gate electrode, and the electron emission portion is made of a material having a low work function or a high aspect ratio. It utilizes the principle that electrons are easily released by an electric field in vacuum.

In the light emitting device, a spacer is provided inside the vacuum container to maintain a constant gap between one substrate and another substrate when forming the vacuum container and to prevent deformation and breakage of the substrate due to a difference in pressure inside and outside the vacuum container. Doing.

Such spacers are mainly made of a non-conductive material such as glass or ceramic, and are disposed to correspond to non-light-emitting regions between the fluorescent layers so that electrons emitted from the electron emission devices do not interfere with the path of movement toward the fluorescent layer.

However, in the above light emitting device, electron beam spreading occurs when electrons emitted from an electron emitting element of one substrate are directed to a corresponding fluorescent layer of another substrate by a high electric field caused by the anode electrode. This phenomenon is not completely suppressed even when the light emitting device includes a focusing electrode and continues to occur when the light emitting device is driven.

When electron beam spreading occurs in the light emitting device as described above, some of the electrons emitted from the electron emitting device may not reach the corresponding fluorescent layer and collide with the spacer. At this time, since the glass or ceramic constituting the spacer has a secondary electron emission coefficient other than 1, when the electron collides, more or less secondary electrons are emitted and the spacer is charged with a positive charge or a negative charge.

The charged spacer thus distorts the electric field around the spacer. This field distortion is further intensified by a change in the external temperature of the light emitting device, thereby changing the direction of the electrons emitted from the electron-emitting device toward the spacer side or vice versa, thereby reducing display quality such as visually confirming the position of the spacer on the screen. Will cause.

Accordingly, the present invention is to solve the problems of the prior art as described above, to provide a light emitting device that can suppress the display quality of the screen by suppressing the electric field distortion around the spacer.

A light emitting device according to an embodiment of the present invention includes a first substrate, a second substrate disposed opposite to the first substrate, an electron emission unit formed on the first substrate, a fluorescent layer and a fluorescent layer formed on the second substrate. A light emitting unit including an anode electrode formed on one surface of the second substrate; a spacer disposed between the first substrate and the second substrate; the spacer including the electrode; and the second light emitting unit being insulated from the light emitting unit with the insulating layer interposed therebetween. And a central electrode line formed in the non-light emitting region of the substrate.

The spacers may be separated from each other along the longitudinal direction of the center electrode line and formed in plurality.

The center electrode line may be formed in the insulating layer. A voltage lower than the voltage applied to the anode electrode, preferably about 1/2 of the voltage applied to the anode electrode, may be applied to the center electrode line.

The spacer may further include a matrix, an adhesive layer formed under the matrix, and an insulator surrounding the lower side of the matrix, wherein the electrodes are formed to surround the upper and upper sides of the matrix, and a portion protrudes from the central side of the matrix, An insulator may be formed to expose the protrusion of the electrode and surround the side of the electrode. At this time, the adhesive layer and the electrode may be made of a metal, respectively.

In addition, the spacer may further include a matrix, an adhesive layer formed under the matrix, and an insulator surrounding the lower side of the matrix, wherein the electrode is formed to surround the upper and upper sides of the matrix, and the insulator is formed on the central side of the matrix. It may be formed to surround the side of the electrode while exposing the electrode of the corresponding portion. In this case, the adhesive layer and the electrode may be made of metal, respectively.

The electron emission device may include a cathode electrode and a gate electrode formed on the first substrate with an insulating layer therebetween, and an electron emission portion formed on the cathode electrode. In this case, the center electrode line may be formed along the length direction of the cathode electrode or the gate electrode. The light emitting unit may include a fluorescent layer and an anode electrode formed on one surface of the fluorescent layer.

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 embodiment of the present invention, the light emitting device includes all devices capable of recognizing that light is emitted when viewed from the outside. Accordingly, the devices of all displays that display symbols, letters, numbers, images, and the like to transmit information are also included in the light emitting device. The light emitting device may also be used as a light source in a light receiving display device.

1 and 2 are partial exploded perspective and partial cross-sectional views of a light emitting device according to an exemplary embodiment of the present invention, and FIG. 3 is a bottom view of the second substrate of FIG. 1.

1 and 2, the light emitting device includes a first substrate 10 and a second substrate 12 that are disposed to face each other in parallel with each other at predetermined intervals. Sealing members (not shown) are disposed at edges of the first substrate 10 and the second substrate 12 to bond the two substrates, and the internal space is evacuated with a vacuum of approximately 10 ⁻⁶ Torr to allow the first substrate 10 to be connected. And the second substrate 12 and the sealing member constitute a vacuum container.

On the opposing surface of the first substrate 10 with the second substrate 12, an electron emission unit 100 made of an array of electron emission elements is provided, and opposing the first substrate 10 of the second substrate 12. The surface is provided with the light emitting unit 110 which consists of the fluorescent layer 26, the anode electrode 30, etc.

The electron emission device may include a field emission array (FEA) type, a surface conduction emission (SCE) type, a metal insulating layer-metal (MIM) type, or a metal insulating layer-semiconductor (MIS) type. In the present embodiment, a case where the FEA type is applied as the electron emission device will be described as an example.

First, referring to the configuration of the electron emission unit 100, the cathode electrodes 16 are formed in a stripe pattern along one direction (y-axis direction in the drawing) of the first substrate 10. The first insulating layer 14 is formed on the entire first substrate 10 over the cathode electrode 16, and the gate electrodes 18 are orthogonal to the cathode electrodes 16 on the first insulating layer 14. It is formed in a stripe pattern along the (x-axis direction in the drawing).

Electron emitters 20 are formed on the cathode electrode 16 at the intersection of the cathode electrode 16 and the gate electrode 18. In addition, openings 141 and 181 corresponding to the respective electron emission parts 20 are formed in the first insulating layer 14 and the gate electrode 18 to form the electron emission parts 20 on the first substrate 10. Expose

Here, one cathode electrode 16, one gate electrode 18, and the first insulating layer 14 and the electron emission parts 20 positioned at the intersection thereof constitute one electron emission element.

The electron emission unit 20 may be formed 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. For example, the electron emission unit 20 may include a material selected from the group consisting of carbon nanotubes, graphite, graphite nanofibers, diamonds, diamond phase carbons, fullerenes (C ₆₀ ), silicon nanowires, and combinations thereof. . In addition, the electron emission unit may be formed of a tip structure having a pointed tip mainly made of molybdenum (Mo) or silicon (Si).

In FIG. 1, the planar shapes of the electron emission part 20, the first insulating layer 14, and the openings 141 and 181 of the gate electrode 18 are circular, but their shapes are not limited to the illustrated example. Do not.

In addition, the second insulating layer 24 and the focusing electrode 22 may be sequentially formed on the gate electrode 18. In this case, the second insulating layer 24 and the focusing electrode 22 are also provided with openings 241 and 221 for passing electron beams. For example, the openings 241 and 221 are provided for each electron emission element, so that the focusing electrode ( 22) it is possible to comprehensively focus electrons emitted from one electron emitting device.

Next, referring to the configuration of the light emitting unit 110, red, green, and blue fluorescent layers 26R, 26G, 26B; 26 are formed on the second substrate 12. The black layer 28 is formed between the fluorescent layers 26 to improve contrast of the screen. An anode electrode 30 formed of a metal thin film such as aluminum is formed on the fluorescent layer 26 and the black layer 28.

The fluorescent layer 26 is formed corresponding to the electron emission device of the first substrate 10, and one fluorescent layer 26 and one electron emission device corresponding to each other form a pixel.

The anode electrode 30 receives a high voltage necessary for accelerating the electron beam from the outside, and reflects the visible light emitted toward the first substrate 10 out of the visible light emitted from the fluorescent layer 26 to the second substrate 12 side of the screen. Increase the brightness

In addition, the anode electrode 30 may be formed on one surface of the fluorescent layer 26 and the black layer 28 facing the second substrate 12, and in this case, may transmit visible light emitted from the fluorescent layer 26. The anode electrode is made of a transparent conductive material such as indium tin oxide (ITO).

On the other hand, the anode electrode 30 may have a structure in which both the metal thin film and the transparent conductive material are formed.

Along the anode electrode 30 along the length direction of the cathode electrode 16 corresponding to the non-emission region where the black layer 28 is located so as not to invade the fluorescent layer 26 with the third insulating layer 51 interposed therebetween. Center electrode lines 50 are formed. On the other hand, although not shown, the center electrode lines 50 may be formed along the length direction of the gate electrode 18 corresponding to the non-light emitting area where the black layer 28 is located.

In addition, the center electrode lines 50 may be formed by being embedded in the third insulating layer 51 as illustrated in FIGS. 1 and 2, and the pads disposed on one side of the second substrate 12 as illustrated in FIG. 3. 52 is applied to receive the voltage supplied through the pad (52).

In addition, a spacer between the first substrate 10 and the second substrate 12 to maintain a constant distance between the first substrate 10 and the second substrate 12 against an external pressure applied to the vacuum vessel ( 40 is disposed in contact with the center electrode line 50. In FIG. 2, only one spacer 40 is illustrated for convenience, but as illustrated in FIG. 3, the spacers 40 may be separated from each other along the length direction of the central electrode line 50.

In FIG. 2, the spacer 40 is a wall-type, but the shape of the spacer 40 is not limited thereto.

In addition, the spacer 40 is formed surrounding the base 41 made of a non-conductive material such as glass or ceramic, the adhesive layer 42 formed under the base 41, the upper surface and the upper side of the base 41. An insulator (43) which partially protrudes from the central side of the matrix (41), and a protrusion of the electrode (43) and surrounds the side of the electrode (43) and the rest of the matrix (41), i. 44).

Here, the adhesive layer 42 enhances the adhesion between the spacer 40 and the structure of the first substrate 10, that is, the focusing electrode 22, and the electrodes 43 of the spacer 40 are connected to the center electrode line 50. In contact with the voltage applied through the center electrode line 50 is applied. For example, the adhesive layer 42 and the electrode 43 may be made of metal, respectively.

On the other hand, as shown in FIG. 4, the electrode 43 'of the spacer 40' is formed without protruding from the central side of the matrix 41, and the insulator 44 'corresponds to the central side of the matrix 41. As shown in FIG. The electrode 43 ′ may be formed to surround the side of the electrode 43 ′ and the rest of the base 41, that is, the lower side.

The light emitting device configured as described above applies a scan signal voltage to one of the cathode electrode 16 and the gate electrode 18, and at the same time applies a data signal voltage to the other electrode, and to the focusing electrode 22. A negative voltage of several to several tens of volts is applied, a positive DC voltage of several hundred to several thousand volts is applied to the anode electrode 30, and the anode electrode to the central electrode line 50 through the pad 52. A voltage smaller than the voltage applied to 30 is applied, preferably about 1/2 of the voltage applied to the anode electrode 30. For example, in the present embodiment, a voltage of 1400 V is applied to the anode electrode 30 and a voltage of 700 V is applied to the center electrode line 50.

Then, an electric field is formed around the electron emission portion 20 in the electron emission elements in which the voltage difference between the cathode electrode 16 and the gate electrode 18 is greater than or equal to a threshold, thereby emitting electrons. The emitted electrons are focused to the center of the electron beam bundle while passing through the opening 221 of the focusing electrode 22 and are attracted by the high voltage applied to the anode electrode 30 to collide with the corresponding fluorescent layer 26 to emit light.

In this process, even if an electric field distortion occurs around the spacer 40 due to a high electric field of the anode electrode 30 and a temperature change outside the light emitting device as shown in FIG. 5, the electrode of the spacer 40 through the center electrode line 50. The distorted electric field may be compensated for by the voltage applied to 43 (see arrow of FIG. 5). As a result, the electrons emitted from the electron-emitting device are minimized toward the spacer 40 so that the display quality such as the position of the spacer 40 on the screen is visually confirmed can be prevented.

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 embodiment of the present invention can suppress the electric field distortion around the spacer, thereby preventing the display quality of the screen from being lowered.

Claims (11)

A first substrate; A second substrate disposed opposite the first substrate; An electron emission unit formed on the first substrate; A light emitting unit formed on the second substrate and including a fluorescent layer and an anode electrode formed on one surface of the fluorescent layer; A spacer disposed between the first substrate and the second substrate and including an electrode; And And a center electrode line insulated from the light emitting unit with an insulating layer interposed therebetween while being in contact with the electrode of the spacer, and formed in a non-light emitting region of the second substrate. The method of claim 1, And a plurality of spacers separated from each other along a longitudinal direction of the center electrode line. The method of claim 1, And a voltage lower than a voltage applied to the anode electrode is applied to the center electrode line. The method of claim 3, And a voltage of about 1/2 of the voltage applied to the anode electrode is applied to the center electrode line. The method of claim 1, And a center electrode line embedded in the insulating layer. The method of claim 1, The spacer matrix, An adhesive layer formed on the lower substrate, and Further comprising an insulator surrounding the lower side of the matrix, The electrode is formed surrounding the upper and upper side of the parent and a portion protrudes from the central side of the parent, Wherein the insulator exposes the protrusion of the electrode and also surrounds a side surface of the electrode. The method of claim 1, The spacer matrix, An adhesive layer formed on the lower substrate, and Further comprising an insulator surrounding the lower side of the matrix, The electrode is formed surrounding the upper surface and the upper side of the parent, A light emitting device in which the insulator also surrounds the side surface of the electrode while exposing the electrode of the portion corresponding to the central side surface of the mother body. The method according to claim 6 or 7, A light emitting device in which the adhesive layer and the electrode are each made of metal. The method of claim 1, A light emitting device in which the electron emitting unit comprises an electron emitting element array. The method of claim 9, The electron emitting device A cathode electrode and a gate electrode formed over the first substrate with an insulating layer interposed therebetween; A light emitting device comprising an electron emission portion formed on the cathode electrode. The method of claim 10, And the center electrode line is formed along a length direction of the cathode electrode or the gate electrode.

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