KR101040801B1 - Field electron emission device - Google Patents

Abstract

The present invention relates to a field emission device capable of reducing manufacturing process and manufacturing cost and improving luminance by using a patterned bus electrode instead of an ITO front electrode as an anode electrode, wherein the anode electrode of the anode panel is formed on the bottom surface of the upper substrate. Conductive bus electrodes are formed along the edges, and a phosphor layer is formed on the lower surface of the central portion of the upper substrate on which the bus electrodes are formed, and the reflective layer covers the bus electrode and the phosphor layer on the lower surface of the bus electrode and the phosphor layer. It is characterized by being formed.

In the field emission device having the above structure, an anode electrode is formed at the edge of the lower surface of the upper period to prevent the possibility of arc discharge that may occur with the gate electrode and the cathode electrode, and the bus electrode without using the ITO electrode as the anode electrode. By using, the manufacturing process and manufacturing cost can be reduced, and the brightness of light can be improved.

Field emitter, anode electrode, cathode electrode, ITO electrode, bus electrode

Description

Field emission device

The present invention relates to a field emission device, and more particularly, to a field emission device that can reduce manufacturing process and manufacturing cost and improve luminance by using a patterned bus electrode instead of an ITO front electrode as an anode electrode. .

In general, a flat panel display may be largely classified into a light emitting display device and a light receiving display device. The light emitting display includes a cathode ray tube (CRT), a plasma display panel (PDP) and a field emission display (FED), and the light receiving display includes a liquid crystal display. There is a device (LCD).

The liquid crystal display has the advantages of light weight and low power consumption. However, since the LCD itself does not emit light to form an image, and the light is incident on the outside, the liquid crystal display device forms an image. There is no problem. In order to solve this problem, a backlight unit is provided on the back of the liquid crystal display.

Conventionally, a cold cathode fluorescent lamp (CCFL) as a light source and a light emitting diode (LED) as a point light source have been mainly used as a backlight unit. However, such a backlight unit generally has a disadvantage in that its configuration is complicated, and thus manufacturing cost is high and power consumption is large. In particular, as the liquid crystal display becomes larger, it is difficult to secure uniformity of luminance.

Accordingly, recently, a field emission type light emitting device having a planar light emitting structure has been developed to solve the above problem. The backlight unit using the field emission device consumes less power than the conventional backlight unit using a cold cathode fluorescent lamp and has an advantage of displaying a relatively uniform luminance even in a wide range of emission areas. In addition, the field emission device may be variously applied not only for the light source of the backlight unit but also for general illumination.

Looking at the general structure of the field emission device with reference to Figure 1, the anode panel 10 and the cathode panel 20 are spaced apart from each other disposed. The inside of the anode panel 10 and the cathode panel 20 is sealed by a sealing member 50, and a gate for stimulating electron emission between the anode panel 10 and the cathode panel 20. The electrode 30 is seated on the gate insulator 41 on the cathode panel 20, and supports the anode panel 10 on the gate electrode 30 while maintaining a space therebetween. 42).

In the anode panel 10, an anode electrode 12 is formed on a lower surface of the upper substrate 11, a phosphor layer 13 is coated on a lower surface of the anode electrode 12, and the phosphor layer ( On the lower surface of 13, a reflective layer 14 of a metal film is formed.

In addition, the cathode panel 20 has a cathode electrode 22 formed on an upper surface of the lower substrate 21, and a plurality of emitters 23 emitting electrons by generating an electric field on an upper surface of the cathode electrode 22. ) Is formed.

In addition, a plurality of openings 31 are formed in the gate electrode 30 through which electrons emitted from the emitter 23 pass.

In the electroluminescent device according to the related art having the above structure, the anode electrode 12 of the anode panel 10 has an ITO electrode formed on the entire lower surface of the substrate 11 to apply an electric field. In this case, since the ITO exposed to the edge of the substrate may generate an arc with the gate electrode 30 and the cathode electrode 22, a process of removing only the power connection part is required. In addition, the ITO electrode generally uses a transparent electrode, but since it is not completely transparent, the transmittance is lower than that of ordinary glass, thereby reducing the luminance.

In addition, since the field emission device requires a high degree of vacuum inside when packaging, the center insulator Y of the gate insulator 41 and the spacer 42 must be aligned as shown in FIG. 2. The gate insulator 41 and the spacer There is a point that 42 is formed separately from the gate electrode 30 so that it is difficult to coincide with the central axis Y. That is, the central axis Y may be easily twisted according to the arrangement position of the gate insulator 41 and the spacer 42. In this case, the anode panel 10, the cathode panel 20, and the gate electrode ( Severe problems may occur, such as bending or contacting 30).

The present invention has been proposed to solve the above problems, by reducing the process of removing the ITO exposed to the edge of the upper substrate, to simplify the manufacturing process, to provide a field emission device that can reduce the manufacturing cost For the purpose of

In another aspect, the present invention is to provide a field emission device that can improve the brightness by preventing the ITO electrode is formed on the entire surface of the upper substrate as the anode electrode, the light transmittance is reduced by the ITO electrode to reduce the brightness. The purpose.

The field emission device of the present invention for achieving the above object is an anode panel, the anode panel and the phosphor layer, the reflective layer is formed on the lower surface of the upper substrate, the cathode panel and the cathode panel is formed on the upper surface of the lower substrate sealing member Wherein the space between the anode panel and the cathode panel includes a gate electrode supported by a gate insulator and a spacer, the anode electrode of the anode panel being formed along the bottom edge of the upper substrate. A conductive layer is formed of a conductive bus electrode, and a phosphor layer is formed on a lower surface of a central portion of the upper substrate on which the bus electrode is formed. do.

In the above-described configuration, the conductive bus electrode is made of any one of gold, platinum, silver, aluminum, chromium and copper.

In the field emission device of the above structure, an anode electrode is formed at the bottom edge of the upper substrate to prevent a possible arc discharge with the gate electrode and the cathode electrode, and the bus electrode without using the ITO electrode as the anode electrode. By using, the manufacturing process and manufacturing cost can be reduced, and the brightness of light can be improved.

The technical problem achieved by the present invention and the practice of the present invention will be apparent from the preferred embodiments described below. The following examples are merely illustrative of the present invention and are not intended to limit the scope of the present invention. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view showing a schematic structure of a field emission device according to an embodiment of the present invention, Figure 4 is a bottom view showing a schematic structure of an anode panel according to an embodiment of the present invention, Figure 5 is a A perspective view showing a fastening state between the gate electrode and the spacer according to the embodiment.

3 and 4, the field emission device according to the embodiment of the present invention is the field emission device according to the embodiment of the present invention so as to face the anode panel 10 and the anode panel 10 at the bottom A predetermined space between the disposed cathode panel 20, the gate electrode 30 for stimulating electron emission between the anode panel 10 and the cathode panel 20, and between the anode panel 10 and the cathode panel 20 And an insulating spacer 40 for electrically insulating the gate electrode 30 from the cathode panel 20.

In detail, the anode panel 10 includes the anode electrode 12, the phosphor layer 13, and the reflective layer 14 formed on the upper substrate 11 and the lower surface of the upper substrate 11. It is configured.

The upper substrate 11 is generally a glass substrate made of a transparent material, the anode electrode 12 is made of a conductive bus electrode, in particular the bus electrode 12 according to an embodiment of the present invention is an upper substrate The lower surface of the (11) is formed along the edge and on one side a power connection portion 12 'for power supply is formed. Here, the bus electrode 12 is preferably secured a predetermined distance between the edge portion of the upper substrate 11, gold (Au), platinum (Pt), silver (Ag), aluminum (Al), chromium It is made of a conductive metal material such as (Cr), copper (Cu) and the like.

The phosphor layer 13 is excited by electrons emitted from the emitter 23 to be described later to emit visible light, and is formed on the lower surface of the upper substrate 11. That is, the bus electrode 12 is formed at the edge of the lower surface of the upper substrate 11, and the phosphor layer 13 is formed at the center of the lower surface of the upper substrate 11, which is an inner space of the bus electrode 12.

The visible light emitted from the phosphor layer by the configuration of the anode electrode 12 and the phosphor layer 13 as described above is emitted directly through the upper substrate 11 without being disturbed by the electrode to improve the brightness of light. It is possible to remove the electrode exposed to the outside of the upper substrate, which simplifies the manufacturing process.

In addition, the reflective layer 14 is configured to reflect visible light emitted from the phosphor layer 13 upward, and is made of a material such as aluminum (Al).
As described above, even if the bus electrode 12 is formed along the edge of the phosphor layer 13, and the aluminum reflective layer 14 is formed on the phosphor layer 13, the bus electrode 12 can sufficiently function as an anode electrode. Can be. In this case, the aluminum reflective layer 14 is formed to a thickness of approximately 80 to 100 nm, and an acceleration voltage of approximately 10 to 15 kV is applied to the bus electrode 12. At the acceleration voltage of the bus electrode 12, the emitted electrons can penetrate the reflective layer 14 to sufficiently emit the phosphor layer 13.

The cathode panel 20 is formed by forming a cathode electrode 22 and an emitter 23 on the lower substrate 21 and the upper surface of the lower substrate 21.

Like the upper substrate 11, the lower substrate 21 may be a glass substrate made of a transparent material, and the cathode electrode 22 using a conductive material such as a metal material or indium tin oxide (ITO) may be striped on the upper surface of the lower substrate 21. It may be formed in a pattern shape such as) or with respect to the entire surface.

 In addition, a plurality of emitters 23 which are electron emission sources are formed on the upper surface of the cathode electrode 22. The emitter 23 is a component for emitting electrons by an electric field generated between the anode electrode 13 and the cathode electrode 22, and a metal such as molybdenum or carbon nano nanoparticles having excellent electron emission characteristics. Carbon nanotubes (CNT).

The gate electrode 30 is configured to stimulate and control the electron emission of the emitter 23 and to protect the emitter 23, so that the electrons emitted from the emitter 23 pass through. A plurality of openings 31 are formed, and a plurality of insertion holes 32 for inserting the insulating spacer 40 described later are formed. The gate electrode 30 is coated with a conductive metal material on the flat panel of the inorganic material or is composed of a flat panel of metal.

Meanwhile, the anode panel 10 and the cathode panel 20 having the above-described configuration are disposed to face each other at predetermined intervals, and the emitter is disposed in an internal space between the anode panel 10 and the cathode panel 20. A gate electrode 30 for stimulating electron emission of the 23 is provided with an insulating spacer 40 while maintaining a constant distance from each of the panels 10 and 20, and the gate electrode 30 The emitter 23 is disposed below the opening 31 and is laminated by a sealing member 50 for sealing the inner space at the edges of the anode panel 10 and the cathode panel 20.

Referring to FIG. 5, the insulating spacer 40 maintains the anode panel 10, the gate electrode 30, and the cathode panel 20 at regular intervals under a strong pressure according to a high vacuum environment, and the gate electrode 3. ) Is insulated from the cathode electrode 20. Specifically, the upper spacer 42 and the gate electrode 30 for supporting and maintaining the predetermined space between the anode electrode 10 and the gate electrode 20 are supported to simultaneously insulate from the cathode panel 20. The lower insulator 41 is formed integrally. That is, the upper spacer 41 supports the anode panel 10 and maintains a constant gap between the anode panel 10 and the gate electrode 30, and the lower insulator 42 is the gate electrode 30. By supporting the same, the gate electrode 30 and the cathode panel 20 are insulated at the same time while maintaining a constant gap between the gate electrode 30 and the cathode panel 20. In this case, the lower insulator 42 is preferably formed to have a larger diameter than the upper spacers 41 to support the gate electrode 30 from below.

By the integrated spacer as described above, the difficult process of matching the central axis in the packaging process while the structure is simple can be eliminated, and the defective rate of the product can be improved.

The present invention has been described above with reference to one embodiment shown in the drawings, but those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom.

1 is a cross-sectional view showing a schematic structure of a field emission device according to the prior art,

2 is a perspective view illustrating a coupling state between a gate electrode and a spacer according to the related art;

3 is a cross-sectional view showing a schematic structure of a field emission device according to an embodiment of the present invention;

Figure 4 is a bottom view showing a schematic structure of an anode panel according to an embodiment of the present invention,

5 is a perspective view showing a fastening state of the gate electrode and the spacer according to an embodiment of the present invention.

** Description of symbols for the main parts of the drawing **

10: anode panel 11: upper substrate

12 anode electrode (bus electrode) 13 phosphor layer

14: reflective layer

20: cathode panel 21: lower substrate

22 cathode electrode 23 emitter

30 gate electrode 32 insertion hole

40: insulation spacer

41: gate insulator 42: spacer

Claims (2)

A field emission device in which an anode panel having an anode electrode, a phosphor layer, and a reflective layer formed on a lower surface of an upper substrate, and a cathode panel having a cathode electrode and an emitter formed on an upper surface of a lower substrate are sealed and sealed by a sealing member. The phosphor layer is formed in the center of the lower surface of the upper substrate, The anode electrode is a field emission device, characterized in that the conductive bus electrode is formed along the edge of the phosphor layer on the lower surface of the upper substrate. The method of claim 1, The bus electrode is a field emission device, characterized in that consisting of any one of gold, platinum, silver, aluminum, chromium, copper.

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