JP4466496B2 - Spacer and flat display device - Google Patents

Description

  The present invention relates to a spacer used in, for example, a flat display device that displays information such as characters and images, and a flat display device incorporating such a spacer.

  As an image display device that can replace the mainstream cathode ray tube (CRT), various types of flat display devices have been studied. Examples of such a flat display device include a liquid crystal display device (LCD), an electroluminescence display device (ELD), and a plasma display device (PDP). Development of a flat display device incorporating an electron-emitting device is also underway. Here, as the electron-emitting device, a cold cathode field electron-emitting device, a metal / insulating film / metal-type device (also called MIM device), and a surface conduction electron-emitting device are known. The flat display device incorporating the electron-emitting device is attracting attention from the viewpoint of high resolution, high luminance color display, and low power consumption.

  A cold cathode field emission display device (hereinafter sometimes abbreviated as a display device), which is a flat display device incorporating a cold cathode field emission device, generally corresponds to each pixel arranged in a two-dimensional matrix. The cathode panel having the electron emission region and the anode panel having a phosphor layer that emits light when excited by collision with electrons emitted from the electron emission region are arranged to face each other through a vacuum layer. The electron emission region is usually provided with one or a plurality of cold cathode field emission devices (hereinafter sometimes abbreviated as field emission devices). Examples of field emission devices include Spindt type, flat type, edge type, and planar type.

  As an example, a conceptual partial end view of a display device having a Spindt-type field emission device is shown in FIG. 4, and a schematic view of a part of the cathode panel CP and the anode panel AP when the cathode panel CP and the anode panel AP are disassembled. A simple exploded perspective view is shown in FIG. The Spindt-type field emission device constituting this display device is formed on a cathode electrode 11 formed on a support 10, an insulating layer 12 formed on the support 10 and the cathode electrode 11, and an insulating layer 12. The gate electrode 13 and the opening 14 provided in the gate electrode 13 and the insulating layer 12 (the first opening 14A provided in the gate electrode 13 and the second opening 14B provided in the insulating layer 12). And a conical electron emission portion 15 formed on the cathode electrode 11 located at the bottom of the opening 14.

  Alternatively, FIG. 6 shows a conceptual partial end view of a display device having a so-called flat type field emission device having a substantially planar electron emission portion 15A. This flat field emission device includes a cathode electrode 11 formed on a support 10, an insulating layer 12 formed on the support 10 and the cathode electrode 11, and a gate electrode 13 formed on the insulating layer 12. The opening 14 provided in the gate electrode 13 and the insulating layer 12 (the first opening 14A provided in the gate electrode 13 and the second opening 14B provided in the insulating layer 12), and the opening 14 It comprises an electron emission portion 15A formed on the cathode electrode 11 located at the bottom. The electron emission portion 15A is composed of, for example, a large number of carbon nanotubes partially embedded in a matrix.

  In these display devices, the cathode electrode 11 has a strip shape extending in the first direction (Y-axis direction in FIGS. 4 to 6), and the gate electrode 13 has a second direction (FIGS. 4 to 4) different from the first direction. 6 in the X-axis direction). In general, the cathode electrode 11 and the gate electrode 13 are each formed in a strip shape in a direction in which the projected images of both the electrodes 11 and 13 are orthogonal to each other. An overlapping region where the strip-shaped cathode electrode 11 and the strip-shaped gate electrode 13 overlap is an electron emission region EA, which corresponds to a region of one subpixel. The electron emission areas EA are usually arranged in a two-dimensional matrix within the effective area of the cathode panel CP (area corresponding to the display area of the display device).

  On the other hand, the anode panel AP has a phosphor layer 22 (specifically, a red light-emitting phosphor layer 22R, a green light-emitting phosphor layer 22G, and a blue light-emitting phosphor layer 22B) having a predetermined pattern on the substrate 20. The phosphor layer 22 is formed and covered with the anode electrode 24. Between these phosphor layers 22, a light absorbing layer (black matrix) 23 made of a light absorbing material such as carbon is embedded to prevent display image color turbidity and optical crosstalk. ing. In the figure, reference numeral 21 represents a partition, reference numeral 40 represents a plate-like spacer, reference numeral 25 represents a spacer holding part, reference numeral 26 represents a frame, reference numeral 16 represents a converging electrode, and so on. Reference numeral 17 represents an interlayer insulating layer. In FIGS. 5 and 6, illustration of the partition walls, the spacers, the spacer holding portion, and the focusing electrode is omitted.

  The anode electrode 24 functions as a reflection film that reflects the light emitted from the phosphor layer 22, and rebounds from the phosphor layer 22 or secondary electrons emitted from the phosphor layer 22 (hereinafter referred to as these The electrons are collectively referred to as backscattered electrons) and have a function of preventing the phosphor layer 22 from being charged. The barrier rib 21 has a function of preventing so-called optical crosstalk (color turbidity) from occurring due to backscattered electrons colliding with another phosphor layer 22.

  One subpixel is composed of an electron emission area EA on the cathode panel side and a phosphor layer 22 on the anode panel side facing a group of these field emission elements. In the case of a color display device, one pixel (one pixel) is composed of a set of one red-emitting phosphor layer, one green-emitting phosphor layer, and one blue-emitting phosphor layer. . In the effective area, such pixels are arranged on the order of hundreds of thousands to millions, for example.

Then, the anode panel AP and the cathode panel CP are arranged so that the electron emission area EA and the phosphor layer 22 face each other, joined at the peripheral portion via the frame body 26, and then exhausted and sealed. Thus, a display device can be manufactured. A space surrounded by the anode panel AP, the cathode panel CP, and the frame body 26 is in a high vacuum (for example, 1 × 10 ⁻³ Pa or less).

  Therefore, if the spacer 40 is not disposed between the anode panel AP and the cathode panel CP, the display device is damaged by the atmospheric pressure. The spacer 40 includes a spacer base 40A and an antistatic film 40B provided on the side surface of the spacer base 40A. These will be described later.

  A relatively negative voltage is applied to the cathode electrode 11 from the cathode electrode control circuit 31, a relatively positive voltage is applied to the gate electrode 13 from the gate electrode control circuit 32, and a focusing electrode control circuit ( A relatively negative voltage (for example, 0 volts) is applied from an anode electrode control circuit 33, and a higher positive voltage than that of the gate electrode 13 is applied to the anode electrode 24. When performing display in such a display device, for example, a scanning signal is input to the cathode electrode 11 from the cathode electrode control circuit 31, and a video signal is input to the gate electrode 13 from the gate electrode control circuit 32. Alternatively, a video signal is input from the cathode electrode control circuit 31 to the cathode electrode 11, and a scanning signal is input from the gate electrode control circuit 32 to the gate electrode 13. Electrons are emitted from the electron emission portions 15 and 15A based on the quantum tunnel effect due to an electric field generated when a voltage is applied between the cathode electrode 11 and the gate electrode 13, and the electrons are attracted to the anode electrode 24. It passes through 24 and collides with the phosphor layer 22. As a result, the phosphor layer 22 is excited to emit light, and a desired image can be obtained. That is, the operation of the cold cathode field emission display is basically controlled by the voltage applied to the gate electrode 13 and the voltage applied to the cathode electrode 11.

  7A and 7B schematically show the trajectory of the electron beam in the pixel located in the vicinity of the spacer 40. FIG. In FIGS. 7A to 7B, the anode electrode and the light absorption layer (black matrix) are not shown.

As shown in FIG. 7A, the electrons emitted from the electron emission part 15 go to the phosphor layer 22. However, when electrons are emitted from the electron emitting portion 15 near the spacer 40, some electrons may collide with the surface of the side surface portion of the spacer 40. Further, a part of the electrons that have passed through an anode electrode (not shown) in the anode panel AP and collided with the phosphor layer 22 are backscattered by the phosphor layer 22, and a part of the backscattered electrons collide with the spacer 40. To do. When electrons collide with the spacer 40, secondary electrons are emitted from the surface. When there is a difference between the amount of electrons colliding with the spacer 40 and the amount of secondary electrons emitted from the spacer, the spacer 40 is charged and affects the trajectory of the electrons. Therefore, an antistatic film made of a material having a secondary electron emission coefficient close to 1, for example, an antistatic film 40B made of Cr ₂ O ₃ or the like is provided on the side surface of the spacer base 40A.

  The spacer base 40A is made of, for example, ceramic or glass. As the ceramic, mullite, alumina, barium titanate, and the like are known, and various materials are disclosed in, for example, JP-T-2003-524280. In addition, as materials constituting the antistatic film (materials whose secondary electron emission coefficient is close to 1), semimetals such as graphite, oxides, borides, carbides, sulfides, and nitrides are known. For example, various materials are disclosed in Japanese Patent Publication No. 2004-500688.

Special table 2003-524280 gazette JP-T-2004-500688

By the way, when electrons collide with the spacer 40 for a long time, the spacer 40 may be altered and its electric resistance characteristic may be changed. As described above, when a metal oxide film made of, for example, Cr ₂ O ₃ is provided on the side surface of the spacer base material 40A as the antistatic film 40B, the metal oxide film is reduced by electron collision, The electrical resistance may fluctuate. When the electric resistance characteristic of the spacer 40 changes, the electric field in the vicinity of the spacer 40 changes and the electron beam trajectory is curved (see FIG. 7B). Thereby, the luminance characteristics of the pixels in the vicinity of the spacer 40 of the display device also change.

  The variation in the electrical resistance characteristics of the spacer 40 usually increases according to the operation time of the display device. Therefore, the degree of the above-described curvature of the electron beam trajectory increases depending on the operation time of the display device. Accordingly, the luminance characteristics of the pixels in the vicinity of the spacer 40 of the display device change with time. On the other hand, the above phenomenon does not occur with respect to the pixels away from the spacer 40. For this reason, in the display screen of the display device, a relative luminance change occurs in the pixels along the spacers 40, and the uniformity of the display screen is deteriorated.

  Accordingly, an object of the present invention is to provide a spacer used in a flat display device capable of reducing a relative luminance change of pixels along the spacer, and a flat display device incorporating such a spacer. There is to do.

  In order to achieve the above object, the spacer of the present invention comprises a first panel in which a plurality of electron emission sources for emitting electrons are formed on a support, and a phosphor layer on which electrons emitted from the electron emission source collide. And a second panel in which an anode electrode is formed on a substrate, are joined at their peripheral portions, and is used in a flat display device in which a space sandwiched between the first panel and the second panel is maintained in a vacuum. The spacer is disposed between the first panel and the second panel side end.

  In order to achieve the above object, the flat display device of the present invention includes a first panel in which a plurality of electron emission sources that emit electrons are formed on a support, and electrons emitted from the electron emission sources. The colliding phosphor layer and the second panel in which the anode electrode is formed on the substrate are joined at the peripheral portion thereof, and the spacer is disposed between the first panel and the second panel side end. And the second panel are flat display devices in which a space is maintained in a vacuum.

  The spacer of the present invention or the spacer incorporated in the flat display device of the present invention comprises a spacer base material and an antistatic film provided on the side surface of the spacer base material. (A) at least one metal oxide selected from the group consisting of chromium oxide, manganese oxide, and zinc oxide (hereinafter sometimes referred to as the first metal oxide for convenience), and (B) It is characterized by comprising at least one metal oxide selected from the group consisting of titanium oxide and indium oxide (hereinafter sometimes referred to as second metal oxide for convenience). . The antistatic film may be provided directly on the side surface of the spacer base material. For example, a base film for improving adhesion is formed on the spacer base material, and the antistatic film is formed on the base film. A film may be formed.

  In the spacer of the present invention or the flat display device of the present invention (hereinafter, these may be collectively referred to simply as the present invention), an antistatic film is formed (first metal oxide, (Chromium oxide, titanium oxide), (chromium oxide, indium oxide), (manganese oxide, titanium oxide), (manganese oxide, indium oxide), (Zinc oxide, Titanium oxide) or (Zinc oxide, Indium oxide) can be mentioned. Among them, as a combination of (first metal oxide, second metal oxide), (chromium oxide) Or a combination of (chromium oxide, indium oxide).

  In the present invention, as an antistatic film forming method, for example, various PVD methods such as an evaporation method such as an electron beam evaporation method and a hot filament evaporation method, a sputtering method, an ion plating method, and a laser ablation method; a plasma CVD method and a laser CVD method. Various CVD methods such as a method, a thermal CVD method, a vapor phase synthesis method, and a vapor phase growth method; a screen printing method; a sol-gel method, and the like.

  In this invention, a spacer base material can be made into the aspect which consists of ceramics or glass, for example. As ceramics, aluminum silicate compounds such as mullite, aluminum oxide such as alumina, barium titanate, lead zirconate titanate, zirconia (zirconium oxide), cordiolite, barium borosilicate, iron silicate, glass ceramic materials, etc. Examples include titanium oxide, chromium oxide, magnesium oxide, iron oxide, vanadium oxide, nickel oxide added, and the like, for example, using materials described in JP-T-2003-524280, etc. You can also. Examples of the glass include soda lime glass, low alkali glass, non-alkali glass, and high strain point glass. The shape of the spacer base material may be a plate shape or a column shape. The cross-sectional shape when the columnar spacer base material is cut along a virtual plane orthogonal to the longitudinal direction thereof may be, for example, a substantially circular shape or a cross shape.

Here, when the flat display device is a cold cathode field emission display device, a cold cathode field emission device (hereinafter abbreviated as a field emission device) is:
(A) a strip-shaped cathode electrode formed on the support and extending in the first direction;
(B) an insulating layer formed on the cathode electrode and the support;
(C) a strip-shaped gate electrode formed on the insulating layer and extending in a second direction different from the first direction;
(D) an opening provided in a portion of the gate electrode and the insulating layer located in an overlapping region where the cathode electrode and the gate electrode overlap, and an exposed portion of the cathode electrode at the bottom; and
(E) an electron emission portion provided on the cathode electrode exposed at the bottom of the opening,
Consists of.

  The type of the field emission device is not particularly limited, and a Spindt-type field emission device (a field emission device in which a conical electron emission portion is provided on the cathode electrode positioned at the bottom of the opening) or a flat type field emission device (A field emission device in which a substantially planar electron emission portion is provided on a cathode electrode positioned at the bottom of the opening).

  From the viewpoint of simplifying the structure of the cold cathode field emission display, the projected image of the cathode electrode and the projected image of the gate electrode are orthogonal, that is, the first direction and the second direction are orthogonal. To preferred. The first direction may be the X-axis direction, the second direction may be the Y-axis direction, the first direction may be the Y-axis direction, and the second direction may be the X-axis direction. In the first panel, the electron emission regions are arranged in a two-dimensional matrix, and each electron emission region is provided with one or a plurality of field emission elements.

A field emission device can be generally manufactured by the following method.
(1) forming a cathode electrode on a support;
(2) forming an insulating layer on the entire surface (on the support and the cathode electrode);
(3) forming a gate electrode on the insulating layer;
(4) forming an opening in a portion of the gate electrode and the insulating layer in a region where the cathode electrode and the gate electrode overlap, and exposing the cathode electrode at the bottom of the opening;
(5) A step of forming an electron emission portion on the cathode electrode located at the bottom of the opening.

Alternatively, the field emission device can be manufactured by the following method.
(1) forming a cathode electrode on a support;
(2) forming an electron emission portion on the cathode electrode;
(3) forming an insulating layer on the entire surface (on the support and the electron emission portion or on the support, the cathode electrode and the electron emission portion);
(4) forming a gate electrode on the insulating layer;
(5) A step of forming an opening in a portion of the gate electrode and the insulating layer in the overlapping region of the cathode electrode and the gate electrode, and exposing the electron emission portion at the bottom of the opening.

  The field emission device may be provided with a focusing electrode. That is, for example, a field emission element in which an interlayer insulating layer is further provided on the gate electrode and the insulating layer, and a focusing electrode is provided on the interlayer insulating layer, or a focusing electrode is provided above the gate electrode. It can also be a field emission device. Here, the focusing electrode is an electrode for converging the trajectory of emitted electrons that are emitted from the opening and directed toward the anode electrode, thereby improving the luminance and preventing optical crosstalk between adjacent pixels. It is. In a so-called high-voltage type cold cathode field emission display device in which the potential difference between the anode electrode and the cathode electrode is on the order of several kilovolts and the distance between the anode electrode and the cathode electrode is relatively long, the focusing electrode Is particularly effective. A negative voltage (for example, 0 volt) relative to the anode voltage is applied to the focusing electrode from the focusing electrode control circuit. The focusing electrode is not necessarily provided for each field emission element. For example, by extending the field emission elements along a predetermined arrangement direction of the field emission elements, a convergence effect common to a plurality of field emission elements is exerted. You can also

  In the Spindt-type field emission device, as the material constituting the electron emission portion, molybdenum, molybdenum alloy, tungsten, tungsten alloy, titanium, titanium alloy, niobium, niobium alloy, tantalum, tantalum alloy, chromium, chromium alloy, and And at least one material selected from the group consisting of silicon (polysilicon and amorphous silicon) containing impurities. The electron emission portion of the Spindt-type field emission device can be formed by, for example, a sputtering method or a CVD method in addition to the vacuum evaporation method.

In the flat field emission device, it is preferable that the material constituting the electron emission portion is composed of a material having a work function Φ smaller than that of the material constituting the cathode electrode. What is necessary is just to determine based on the work function of the material which comprises a cathode electrode, the electric potential difference between a gate electrode and a cathode electrode, the magnitude | size of the emission electron current density requested | required, etc. As typical materials constituting the cathode electrode in the field emission device, tungsten (Φ = 4.55 eV), niobium (Φ = 4.02 to 4.87 eV), molybdenum (Φ = 4.53 to 4.95 eV), Examples include aluminum (Φ = 4.28 eV), copper (Φ = 4.6 eV), tantalum (Φ = 4.3 eV), and chromium (Φ = 4.5 eV). The electron emission portion preferably has a work function Φ smaller than these materials, and the value is preferably approximately 3 eV or less. As such materials, carbon (Φ <1 eV), cesium (Φ = 2.14 eV), LaB ₆ (Φ = 2.66-2.76 eV), BaO (Φ = 1.6-2.7 eV), SrO (Φ = 1.25 to 1.6 eV), Y ₂ O ₃ (Φ = 2.0 eV), CaO (Φ = 1.6 to 1.86 eV), BaS (Φ = 2.05 eV), TiN (Φ = 2. 92 eV) and ZrN (Φ = 2.92 eV). More preferably, the electron emission portion is made of a material having a work function Φ of 2 eV or less. In addition, the material which comprises an electron emission part does not necessarily need to be provided with electroconductivity.

Alternatively, in the flat type field emission device, as a material constituting the electron emission portion, a material in which the secondary electron gain δ of the material is larger than the secondary electron gain δ of the conductive material constituting the cathode electrode is used. You may select suitably. That is, silver (Ag), aluminum (Al), gold (Au), cobalt (Co), copper (Cu), molybdenum (Mo), niobium (Nb), nickel (Ni), platinum (Pt), tantalum (Ta) ), Metals such as tungsten (W), zirconium (Zr); semiconductors such as germanium (Ge); inorganic simple substances such as carbon and diamond; and aluminum oxide (Al ₂ O ₃ ), barium oxide (BaO), beryllium oxide ( BeO), calcium oxide (CaO), magnesium oxide (MgO), tin oxide (SnO ₂ ), barium fluoride (BaF ₂ ), calcium fluoride (CaF ₂ ) and other compounds can be selected as appropriate. . In addition, the material which comprises an electron emission part does not necessarily need to be provided with electroconductivity.

Alternatively, in the flat type field emission device, carbon, more specifically, amorphous diamond, graphite, carbon nanotube structure, ZnO whisker, MgO whisker, SnO ₂ whisker is particularly preferable as a constituent material of the electron emission part. , MnO whiskers, Y ₂ O ₃ whiskers, NiO whiskers, ITO whiskers, In ₂ O ₃ whiskers, and Al ₂ O ₃ whiskers. When the electron emission portion is composed of these, the emission electron current density required for the cold cathode field emission display device can be obtained with an electric field intensity of 5 × 10 ⁶ V / m or less. Further, if the material constituting the electron emission portion is an electric resistor, the emission electron current obtained from each electron emission portion can be made uniform, and accordingly, when incorporated in a cold cathode field emission display device. Luminance variation can be suppressed. Furthermore, since these materials have extremely high resistance to the sputtering effect by ions of residual gas in the cold cathode field emission display, the lifetime of the field emission device can be extended.

  Specific examples of the carbon nanotube structure include carbon nanotubes and / or graphite nanofibers. More specifically, the electron emission part may be composed of carbon nanotubes, the electron emission part may be composed of graphite nanofibers, or the electron emission is performed from a mixture of carbon nanotubes and graphite nanofibers. You may comprise a part. Macroscopically, carbon nanotubes and graphite nanofibers may be in the form of powder or thin film. In some cases, the carbon nanotube structure has a conical shape. It may be. Carbon nanotubes and graphite nanofibers are produced by various CVD methods such as the well-known arc discharge method and laser ablation method, such as PVD method, plasma CVD method, laser CVD method, thermal CVD method, vapor phase synthesis method, and vapor phase growth method. Can be manufactured and formed.

The constituent materials of the cathode electrode, gate electrode, and focusing electrode are aluminum (Al), tungsten (W), niobium (Nb), tantalum (Ta), molybdenum (Mo), chromium (Cr), copper (Cu), gold ( Metals such as Au), silver (Ag), titanium (Ti), nickel (Ni), cobalt (Co), zirconium (Zr), iron (Fe), platinum (Pt), zinc (Zn); these metal elements Alloys (eg, MoW) or compounds (eg, nitrides such as TiN, silicides such as WSi ₂ , MoSi ₂ , TiSi ₂ , TaSi ₂ ); semiconductors such as silicon (Si); carbon thin films such as diamond; ITO ( Examples thereof include conductive metal oxides such as indium oxide-tin oxide, indium oxide, and zinc oxide. In addition, as a method for forming these electrodes, for example, a vapor deposition method such as an electron beam vapor deposition method or a hot filament vapor deposition method, a sputtering method, a combination of a CVD method, an ion plating method and an etching method; a screen printing method; Plating method or electroless plating method); lift-off method; laser ablation method; sol-gel method. According to the screen printing method or the plating method, for example, a strip-like cathode electrode or gate electrode can be formed directly.

As a material for constituting the insulating layer and the interlayer insulating _{layer, SiO 2, BPSG, PSG,} BSG, AsSG, PbSG, SiON, SiN, SOG ( spin on glass), low-melting glass, SiO ₂ based materials such glass paste; SiN-based materials; Insulating resins such as polyimide can be used alone or in appropriate combination. For forming the insulating layer or the interlayer insulating layer, a known process such as a CVD method, a coating method, a sputtering method, or a screen printing method can be used.

  Planar shape of the first opening (opening formed in the gate electrode) or the second opening (opening formed in the insulating layer) (shape when the opening is cut in a virtual plane parallel to the support surface) ) Can be any shape such as a circle, an ellipse, a rectangle, a polygon, a rounded rectangle, a rounded polygon. The formation of the first opening can be performed by, for example, anisotropic etching, isotropic etching, a combination of anisotropic etching and isotropic etching, or, depending on the method of forming the gate electrode, The first opening can also be formed directly. The second opening can also be formed by, for example, anisotropic etching, isotropic etching, or a combination of anisotropic etching and isotropic etching.

  In the field emission device, depending on the structure of the field emission device, one electron emission portion may exist in one opening, or a plurality of electron emission portions may exist in one opening. In addition, a plurality of first openings are provided in the gate electrode, one second opening communicating with the first opening is provided in the insulating layer, and one or more are provided in one second opening provided in the insulating layer. There may be an electron emission portion.

In the field emission device, a resistor layer may be provided between the cathode electrode and the electron emission portion. By providing the resistor layer, it is possible to stabilize the operation of the field emission device and make the electron emission characteristics uniform. As a material constituting the resistor layer, a carbon-based material such as silicon carbide (SiC) or SiCN, a semiconductor material such as SiN or amorphous silicon, or a refractory metal oxide such as ruthenium oxide (RuO ₂ ), tantalum oxide, or tantalum nitride. It can be illustrated. Examples of the method for forming the resistor layer include a sputtering method, a CVD method, and a screen printing method. The electrical resistance value per pixel is approximately 1 × 10 ⁴ to 1 × 10 ⁹ Ω, preferably several tens of megaΩ.

As a support constituting the first panel or as a substrate constituting the second panel, a glass substrate, a glass substrate with an insulating film formed on the surface, a quartz substrate, a quartz substrate with an insulating film formed on the surface, A semiconductor substrate having an insulating film formed on the surface can be given, but from the viewpoint of reducing manufacturing costs, it is preferable to use a glass substrate or a glass substrate having an insulating film formed on the surface. As glass substrates, high strain point glass, low alkali glass, non-alkali glass, soda glass (Na ₂ O · CaO · SiO ₂ ), borosilicate glass (Na ₂ O · B ₂ O ₃ · SiO ₂ ), forsterite ( 2MgO · SiO ₂ ) and lead glass (Na ₂ O · PbO · SiO ₂ ) can be exemplified.

  Examples of configurations of the anode electrode and the phosphor layer constituting the second panel include (1) a configuration in which an anode electrode is formed on a substrate and a phosphor layer is formed on the anode electrode, and (2) on the substrate. The structure which forms a fluorescent substance layer and forms an anode electrode on a fluorescent substance layer can be mentioned. In the configuration (1), a so-called metal back film that is electrically connected to the anode electrode may be formed on the phosphor layer. In the configuration (2), a metal back film may be formed on the anode electrode.

The anode electrode may be composed of one anode electrode as a whole, or may be composed of a plurality of anode electrode units. In the latter case, it is preferable that the anode electrode unit and the anode electrode unit are electrically connected by a resistor film. Resistor films are made of carbon-based materials such as silicon carbide (SiC) and SiCN; SiN-based materials; refractory metal oxides such as ruthenium oxide (RuO ₂ ), tantalum oxide, tantalum nitride, chromium oxide, and titanium oxide. A semiconductor material such as amorphous silicon. Examples of the sheet resistance value of the resistor film include 1 × 10 ⁻¹ Ω / □ to 1 × 10 ¹⁰ Ω / □, preferably 1 × 10 ³ Ω / □ to 1 × 10 ⁸ Ω / □. The number of anode electrode units (An) may be two or more. For example, when the total number of rows of phosphor layers arranged in a straight line is α column, An = α or α = β · An (Β is an integer of 2 or more, preferably 10 ≦ β ≦ 100, more preferably 20 ≦ β ≦ 50), or a number obtained by adding 1 to the number of spacers arranged at a certain interval. It can also be a number that matches the number of pixels or sub-pixels, or an integer fraction of the number of pixels or sub-pixels. The size of each anode electrode unit may be the same regardless of the position of the anode electrode unit, or may be different depending on the position of the anode electrode unit.

The anode electrode (including the anode electrode unit) may be formed using a conductive material layer. As a method for forming the conductive material layer, for example, various PVD methods such as an evaporation method such as an electron beam evaporation method and a hot filament evaporation method, a sputtering method, an ion plating method, and a laser ablation method; various CVD methods; a screen printing method; Sol-gel method and the like. That is, it is possible to form an anode electrode by forming a conductive material layer made of a conductive material and patterning the conductive material layer based on a lithography technique and an etching technique. Alternatively, the anode electrode can be obtained by forming a conductive material based on a PVD method or a screen printing method through a mask or screen having an anode electrode pattern. The resistor film can also be formed by the same method. That is, a resistor film may be formed from a resistor material, and the resistor film may be patterned based on lithography technology and etching technology, or the resistor material may be provided via a mask or screen having a resistor film pattern. A resistor film can be obtained by formation based on the PVD method or the screen printing method. The average thickness of the anode electrode on the substrate (or above the substrate) is 3 × 10 ⁻⁸ m (30 nm) to 1 × 10 ⁻⁶ m (1 μm), preferably 5 × 10 ⁻⁸ m (50 nm) to 4 ×. 10 ^-7 m (400 nm) can be exemplified.

The constituent material of the anode electrode may be appropriately selected according to the configuration of the flat display device. That is, when the flat display device is a transmissive type (the second panel corresponds to the display surface) and the anode electrode and the phosphor layer are laminated in this order on the substrate, the substrate is originally The anode electrode itself needs to be transparent, and a transparent conductive material such as ITO (indium tin oxide) is used. On the other hand, when the flat display device is of a reflective type (the first panel corresponds to the display surface) and when the phosphor layer and the anode electrode are laminated in this order on the substrate even if it is of a transmissive type Include molybdenum (Mo), aluminum (Al), chromium (Cr), tungsten (W), niobium (Nb), tantalum (Ta), gold (Au), silver (Ag), titanium (Ti), cobalt ( Co), zirconium (Zr), iron (Fe), platinum (Pt), zinc (Zn), etc .; alloys or compounds containing these metal elements (for example, nitrides such as TiN, WSi ₂ , MoSi ₂ , TiSi _2, silicides such as TaSi _2); thin carbon film such as diamond; silicon (Si) semiconductor such as ITO (indium - tin), to illustrate indium oxide, a conductive metal oxide such as zinc oxide It is possible. When the resistor film is formed, the anode electrode is preferably made of a conductive material that does not change the resistance value of the resistor film. For example, when the resistor film is made of silicon carbide (SiC), the anode electrode is It is preferable to comprise from molybdenum (Mo).

  The phosphor layer may be composed of single-color phosphor particles or may be composed of phosphor particles of a plurality of colors (for example, three primary colors of red, green, and blue). Moreover, the arrangement | sequence form of a fluorescent substance layer may be dot shape, or may be strip | belt shape.

  When the flat display device is in color display, one row of the phosphor layers arranged in a straight line is a row that is entirely occupied by the red light emitting phosphor layer, a row that is occupied by the green light emitting phosphor layer, and It may be composed of a row occupied by the blue light emitting phosphor layer, or may be composed of a row in which the red light emitting phosphor layer, the green light emitting phosphor layer, and the blue light emitting phosphor layer are sequentially arranged. Good. Here, the phosphor layer is defined as a phosphor layer that generates one bright spot on the second panel. Further, one pixel (one pixel) is composed of a set of one red light emitting phosphor layer, one green light emitting phosphor layer, and one blue light emitting phosphor layer, and one subpixel is one phosphor. It is composed of layers (one red-emitting phosphor layer, one green-emitting phosphor layer, or one blue-emitting phosphor layer). Furthermore, the size corresponding to one subpixel in the anode electrode unit means the size of the anode electrode unit surrounding one phosphor layer.

  The phosphor layer uses a luminescent crystal particle composition prepared from luminescent crystal particles (for example, phosphor particles having a particle size of about 2 to 10 nm), for example, a red photosensitive luminescent crystal particle composition. (Red phosphor slurry) is applied to the entire surface, exposed and developed to form a red light emitting phosphor layer, and then a green photosensitive luminescent crystal particle composition (green phosphor slurry) is applied to the entire surface. Then, it is exposed to light and developed to form a green light emitting phosphor layer. Further, a blue photosensitive luminescent crystal particle composition (blue phosphor slurry) is applied to the entire surface, exposed to light and developed to emit blue light. It can be formed by a method of forming a phosphor layer. Alternatively, it can be formed by a printing method for each color of red, green, and blue. A color filter may be formed between the panel and the phosphor layer. The average thickness of the phosphor layer on the substrate is not limited, but is preferably 3 μm to 20 μm, preferably 5 μm to 10 μm.

The phosphor material constituting the luminescent crystal particles can be appropriately selected from conventionally known phosphor materials. In the case of color display, a phosphor material whose color purity is close to the three primary colors specified by NTSC, white balance is achieved when the three primary colors are mixed, the afterglow time is short, and the afterglow time of the three primary colors is almost equal. It is preferable to combine them. As phosphor materials constituting the red light emitting phosphor layer, (Y ₂ O ₃ : Eu), (Y ₂ O ₂ S: Eu), (Y ₃ Al ₅ O ₁₂ : Eu), (Y ₂ SiO ₅ : Eu) ) And (Zn ₃ (PO ₄ ) ₂ : Mn) can be exemplified, among which (Y ₂ O ₃ : Eu) and (Y ₂ O ₂ S: Eu) are preferably used. Further, as the phosphor material constituting the green light emitting phosphor layer, (ZnSiO ₂ : Mn), (Sr ₄ Si ₃ O ₈ Cl ₄ : Eu), (ZnS: Cu, Al), (ZnS: Cu, Au, Al), [(Zn, Cd) S: Cu, Al], (Y ₃ Al ₅ O ₁₂ : Tb), (Y ₂ SiO ₅ : Tb), [Y ₃ (Al, Ga) ₅ O ₁₂ : Tb] , (ZnBaO ₄ : Mn), (GbBO ₃ : Tb), (Sr ₆ SiO ₃ Cl ₃ : Eu), (BaMgAl ₁₄ O ₂₃ : Mn), (ScBO ₃ : Tb), (Zn ₂ SiO ₄ : Mn) , (ZnO: Zn), (Gd ₂ O ₂ S: Tb), and (ZnGa ₂ O ₄ : Mn), (ZnS: Cu, Al), (ZnS: Cu, Au, Al), [(Zn, Cd ) S: Cu, Al], (Y 3 Al 5 O 12: Tb), [Y 3 (A _{, Ga) 5 O 12: Tb} ], (Y 2 SiO 5: Tb) is preferably used. Further, as phosphor materials constituting the blue light emitting phosphor layer, (Y ₂ SiO ₅ : Ce), (CaWO ₄ : Pb), CaWO ₄ , YP _0.85 V _0.15 O ₄ , (BaMgAl ₁₄ O ₂₃ : Eu) , (Sr ₂ P ₂ O ₇ : Eu), (Sr ₂ P ₂ O ₇ : Sn), (ZnS: Ag, Al), (ZnS: Ag), ZnMgO, and ZnGaO _4. , (ZnS: Ag), (ZnS: Ag, Al) are preferably used.

  In the second panel, electrons recoiled from the phosphor layer or secondary electrons emitted from the phosphor layer enter another phosphor layer, and so-called optical crosstalk (color turbidity) is generated. When the electrons recoiled from the phosphor layer or the secondary electrons emitted from the phosphor layer enter the other phosphor layers through the barrier ribs, It is preferable that a plurality of barrier ribs are provided for preventing the electrons of this from colliding with other phosphor layers.

  Examples of the planar shape of the barrier ribs include a lattice shape (cross-beam shape), that is, a shape corresponding to one subpixel, for example, a shape surrounding the four sides of the phosphor layer having a substantially rectangular shape (dot shape), or A belt-like shape extending in parallel with two opposing sides of the substantially rectangular or belt-like phosphor layer can be exemplified. In the case where the partition walls are formed in a lattice shape, the shape may be a shape that continuously surrounds one side of the region of one phosphor layer, or a shape that discontinuously surrounds. When the partition wall has a strip shape, it may have a continuous shape or a discontinuous shape. After the partition wall is formed, the partition wall may be polished to flatten the top surface of the partition wall.

  Examples of the partition wall forming method include a screen printing method, a dry film method, a photosensitive method, and a sandblast forming method. Here, in the screen printing method, an opening is formed in a portion of the screen corresponding to a portion where a partition is to be formed, and the partition forming material on the screen is passed through the opening using a squeegee, and the partition is formed on the substrate. In this method, after the formation material layer is formed, the partition wall formation material layer is fired. The dry film method is a method of laminating a photosensitive film on a substrate, removing the photosensitive film at the part where the partition wall is to be formed by exposure and development, embedding a material for forming the partition wall in the opening formed by the removal, and baking. is there. The photosensitive film is burned and removed by baking, and the partition wall-forming material embedded in the openings remains to form partition walls. The photosensitive method is a method in which a barrier rib-forming material layer having photosensitivity is formed on a substrate, the barrier rib-forming material layer is patterned by exposure and development, and then fired. The sand blast forming method is, for example, for forming partition walls on which a partition wall forming material layer is formed on a substrate by using screen printing, a roll coater, a doctor blade, a nozzle discharge type coater or the like and dried. In this method, the material layer portion is covered with a mask layer, and then the exposed partition wall forming material layer portion is removed by sandblasting.

  A light absorption layer that absorbs light from the phosphor layer is preferably formed between the partition wall and the substrate from the viewpoint of improving the contrast of the display image. Here, the light absorption layer functions as a so-called black matrix. As the material constituting the light absorption layer, it is preferable to select a material that absorbs 90% or more of light from the phosphor layer. Such materials include carbon, metal thin films (eg, chromium, nickel, aluminum, molybdenum, etc., or alloys thereof), metal oxides (eg, chromium oxide), metal nitrides (eg, chromium nitride), heat resistance Materials such as photosensitive organic resins, glass pastes, glass pastes containing conductive particles such as black pigments and silver, and specifically, photosensitive polyimide resins, chromium oxides, and chromium oxide / chromium laminated films Can be illustrated. In the chromium oxide / chromium laminated film, the chromium film is in contact with the substrate. For example, the light absorption layer is a combination of a vacuum vapor deposition method, a sputtering method and an etching method, a vacuum vapor deposition method, a sputtering method, a combination of a spin coating method and a lift-off method, a screen printing method, a lithography technique, etc. It can be formed by a method appropriately selected depending on the method.

  In the cold cathode field emission display, a strong electric field generated by a voltage applied to the cathode electrode and the gate electrode is applied to the electron emission portion, and as a result, electrons are emitted from the electron emission portion by the quantum tunnel effect. The electrons are attracted to the second panel by the anode electrode provided on the second panel, and collide with the phosphor layer. As a result of the collision of electrons with the phosphor layer, the phosphor layer emits light and can be recognized as an image.

In the cold cathode field emission display, the cathode electrode is connected to the cathode electrode control circuit, the gate electrode is connected to the gate electrode control circuit, and the anode electrode is connected to the anode electrode control circuit. Note that these control circuits can be constituted by known circuits. During actual operation, the output voltage v _A of the anode electrode control circuit is normally constant, and can be, for example, 5 kilovolts to 12 kilovolts. Alternatively, when the distance between the second panel and the first panel is d (where 0.5 mm ≦ d ≦ 10 mm), the value of v _A / d (unit: kilovolt / mm) is 0.5 It is desirable to satisfy 20 or more, preferably 1 or more and 10 or less, more preferably 4 or more and 9 or less.

In the actual operation of the cold cathode field emission display device, regarding the voltage v _C applied to the cathode electrode and the voltage v _G applied to the gate electrode, when the voltage modulation method is adopted as the gradation control method,
(1) A method of changing the voltage v _G applied to the gate electrode while keeping the voltage v _C applied to the cathode electrode constant (2) A voltage v _G applied to the gate electrode by changing the voltage v _C applied to the cathode electrode (3) There is a method in which the voltage v _C applied to the cathode electrode is changed and the voltage v _G applied to the gate electrode is also changed.

The first panel and the second panel are joined at the periphery, but the joining may be performed using an adhesive layer, or a frame body made of an insulating rigid material such as glass or ceramic and an adhesive layer are used in combination. You may go. When the frame and the adhesive layer are used in combination, the distance between the first panel and the second panel can be further increased by appropriately selecting the height of the frame as compared with the case where only the adhesive layer is used. It can be set longer. As a constituent material of the adhesive layer, frit glass is generally used, but a so-called low melting point metal material having a melting point of about 120 to 400 ° C. may be used. Such low melting point metal materials include In (indium: melting point 157 ° C.); indium-gold based low melting point alloy; Sn ₈₀ Ag ₂₀ (melting point 220 to 370 ° C.), Sn ₉₅ Cu ₅ (melting point 227 to 370 ° C.) C) tin (Sn) type high temperature solder such as Pb _97.5 Ag _2.5 (melting point 304 ° C.), Pb _94.5 Ag _5.5 (melting point 304 to 365 ° C.), Pb _97.5 Ag _1.5 Sn _1.0 (melting point 309 ° C.), etc. Lead (Pb) high temperature solder; zinc (Zn) high temperature solder such as Zn ₉₅ Al ₅ (melting point 380 ° C.); Sn ₅ Pb ₉₅ (melting point 300 to 314 ° C.), Sn ₂ Pb ₉₈ (melting point 316 to 322) Tin-lead standard solder such as ° C); brazing material such as Au ₈₈ Ga ₁₂ (melting point 381 ° C) (the above subscripts all represent atomic%).

  When joining the first panel, the second panel, and the frame, the three parties may be joined at the same time, or in the first stage, either the first panel or the second panel and the frame. And the other of the first panel or the second panel and the frame may be joined in the second stage. If the three-party simultaneous bonding or the second stage bonding is performed in a high vacuum atmosphere, the space surrounded by the first panel, the second panel, the frame body, and the adhesive layer becomes a vacuum simultaneously with the bonding. Alternatively, after the three members are joined, the space surrounded by the first panel, the second panel, the frame, and the adhesive layer can be evacuated to create a vacuum. When exhausting after joining, the pressure of the atmosphere at the time of joining may be normal pressure / depressurized, and the gas constituting the atmosphere may be air, or nitrogen gas or group 0 of the periodic table An inert gas containing a gas belonging to (for example, Ar gas) may be used.

  When exhaust is performed, exhaust can be performed through a tip tube connected in advance to the first panel and / or the second panel. The tip tube is typically configured by using a glass tube, and an invalid area of the first panel and / or the second panel (an effective area that is a display area in the center portion that performs a practical function as a flat display device) Is bonded to the periphery of the through-hole provided in the frame-like area) using frit glass or the above-mentioned low-melting-point metal material, and after the space reaches a predetermined degree of vacuum, it is sealed by thermal fusion. It is done. If the entire flat display device is once heated and then cooled down before sealing, the residual gas can be released into the space, and the residual gas can be removed out of the space by exhaust. Is preferred. The tip tube may be made of metal. In this case, sealing can be performed by crimping the tip tube.

  In the spacer of the present invention or the flat display device of the present invention, the temporal change in the electric field distribution in the vicinity of the spacer can be reduced. Accordingly, it is possible to reduce a relative luminance change that occurs in the pixels along the spacer. Thereby, the deterioration of the uniformity of the display screen due to a change with time can be suppressed.

  Hereinafter, the present invention will be described based on examples with reference to the drawings.

  FIG. 1 shows a conceptual partial end view of the spacer and the flat display device of the example. The flat display device in the embodiment is a cold cathode field emission display device (hereinafter abbreviated as a display device), and a first panel (cathode panel CP) and a second panel (anode panel AP) constituting the display device. Has the same configuration and structure as the cathode panel CP and the anode panel AP in the display device described with reference to FIG. 4 and FIG. 5 or FIG. That is, in the display device of the embodiment, a first panel (cathode panel) formed by forming a plurality of Spindt type field emission elements and flat type field emission elements corresponding to an electron emission source for emitting electrons on the support 10. CP) and a second panel (anode panel) in which a phosphor layer 22 and an anode electrode 24 on which electrons emitted from an electron emission source (Spindt type field emission device or flat type field emission device) collide are formed on the substrate 20. AP) are joined at their peripheral portions, and a spacer 140 is disposed between the first panel (cathode panel CP) and the second panel (anode panel AP), and the first panel (cathode panel CP) and the first panel (cathode panel CP). A space sandwiched between two panels (anode panel AP) is maintained in a vacuum. Since these configurations, operations, and actions are the same as those described in the background art, description thereof is omitted here. In the following description, the first panel is called a cathode panel CP, and the second panel is called an anode panel AP.

  The spacer 140 according to the embodiment is a spacer disposed between the cathode panel CP and the anode panel AP, and includes a spacer base material 140A and an antistatic film 140B provided on the side surface of the spacer base material 140A. . The antistatic film 140B includes (A) at least one metal oxide (first metal oxide) selected from the group consisting of chromium oxide, manganese oxide, and zinc oxide, and (B) It consists of at least one metal oxide (second metal oxide) selected from the group consisting of titanium oxide and indium oxide.

  Hereinafter, with reference to FIGS. 1-3, the manufacturing method of the spacer of an Example and the manufacturing method of the display apparatus of an Example are demonstrated. FIG. 2 is a manufacturing process diagram of the spacer and the flat display device of the embodiment.

[Step-100]
First, a slurry containing a mixture of a binder made of an organic material such as acrylic emulsion, polyvinyl alcohol (PVA), polyethylene glycol, and the like and a powdered ceramic material is prepared (see [Step-100] in FIG. 2). If necessary, a powdered metal oxide material may be further added. Table 1 lists the ceramic materials and metal oxide materials that make up the slurry in the examples. These materials are mixed with, for example, a dispersion medium made of toluene or methyl ethyl ketone containing a surfactant to prepare a slurry.

[Step-110]
Next, the mixture contained in the slurry is shaped into a green sheet by a known method (see [Step-110] in FIG. 2). In the examples, the green sheet can be obtained by applying the slurry onto the support film by the doctor blade method and drying the slurry.

[Step-120]
Thereafter, the green sheet is fired to obtain a ceramic plate (see [Step-120] in FIG. 2). By the baking treatment, the binder in the green sheet is removed and the green sheet is sintered. In addition, the metal oxide material contained in the green sheet is reduced by the baking treatment, so that the conductive metal oxide (more specifically, in the embodiment, TiO _x (1 <x <2)) or metal ( More specifically, in the embodiment, molybdenum (Mo)). Thereby, a ceramic plate containing a conductive metal oxide or metal can be obtained.

[Step-130]
Next, the ceramic base plate containing metal is cut to obtain a spacer base material 140A (see [Step-130] in FIG. 2). In the embodiment, the dimension of the spacer base material 140A is
About 150 mm in the longitudinal direction (X direction in FIG. 1),
About 100 μm in the thickness direction (Y direction in FIG. 1)
About 2 mm in the height direction (Z direction in FIG. 1),
However, it is not limited to these. The specific resistance of the spacer base material 140A is shown in Table 1.

[Step-140]
Thereafter, an antistatic film 140B made of the first metal oxide and the second metal oxide is formed on the side surface of the spacer base material 140A (see [Step-140] in FIG. 2). Table 1 shows the composition of the antistatic film 140B on the surface of the spacer substrate. In the embodiment, the antistatic film 140B is formed by sputtering, but the present invention is not limited to this. The structure or composition of the target used for the sputtering method will be described. The target is a mixture of a first metal oxide and a second metal oxide. A method for manufacturing this target will be described. A target used for the sputtering method can be manufactured by mixing the particulate first metal oxide and the particulate second metal oxide and sintering the mixture by a general vacuum hot press method. Using this target, an antistatic film 140B is formed under the conditions exemplified in Table 2 below. In the embodiment, the antistatic film 140B having a film thickness of about 4 nm is formed. The ratio of the first metal oxide and the second metal oxide in the antistatic film 140B formed by the sputtering method depends on the structure of the target and the sputtering conditions. The value is substantially equal to the ratio between the product and the second metal oxide.

  Through the above [Step-100] to [Step-140], the spacer 140 of the embodiment including the spacer base material 140A and the antistatic film 140B can be manufactured.

[Step-150]
Next, the display device shown in FIG. 1 is assembled. Specifically, the anode panel AP and the cathode panel CP are arranged so that the phosphor layer 22 and the electron emission region EA face each other with the spacer 140 interposed therebetween. The anode panel AP and the cathode panel CP (more specifically, the support body 10 and the substrate 20) are joined together at the peripheral edge via, for example, the frame body 26. At the time of joining, frit glass is applied to the joining part between the frame body 26 and the anode panel AP, and the joining part between the frame body 26 and the cathode panel CP, and after the frit glass is dried by pre-baking, the anode panel AP and The cathode panel CP and the frame are bonded, and the main baking is performed at about 450 ° C. for 10 to 30 minutes. Thereafter, the space surrounded by the anode panel AP, the cathode panel CP, the frame body 26 and the adhesive layer is exhausted through a through hole (not shown) and a tip tube (not shown), and the pressure in the space is 10 ^−4. When the pressure reaches about Pa, the tip tube is sealed by heat melting or pressure welding. In this way, the space surrounded by the anode panel AP, the cathode panel CP, and the frame 26 can be evacuated. Thereafter, wiring with necessary external circuits is performed, and the display device of the embodiment can be completed.

Using the display device of the example, the change over time in the luminance characteristics of the pixels near the spacer 140 was measured. Specifically, using a display device for color display, white is displayed on the entire display area, and the pixel in the vicinity of the spacer 140 (one sub-pixel in the embodiment) is subjected to the luminance centroid by the method described below. Measurements were made. The driving condition of the display device is such that the voltage between the anode panel AP and the cathode panel CP is about 10 kV, and the power calculated from this voltage and the effective value of the current flowing through the anode panel is about 20 W. Set. For comparison, a spacer substrate made of a slurry having the composition listed in Table 1 and a spacer made of an antistatic film having the composition listed in Table 1 (hereinafter referred to as a comparative spacer) The luminance gravity center was measured in the same manner using a display device with a color display (hereinafter sometimes referred to as a display device of a comparative example). In addition, the spacer of this comparative example was manufactured according to said [process-100]-[process-140]. Specifically, the antistatic film of the spacer of the example does not contain the second metal oxide in [Step-140] (that is, composed of only Cr ₂ O ₃ which is the first metal oxide). It was formed using a target.

First, with reference to FIGS. 3A to 3B, a method of obtaining the luminance gravity center will be described. FIG. 3A is a diagram schematically showing an electron beam trajectory in a pixel (one subpixel in the embodiment) located in the vicinity of the spacer 140. FIG. 3B is a diagram schematically showing the luminance distribution of the phosphor layer 22 in the state shown in FIG. Usually, the brightness of the peripheral part of the phosphor layer 22 tends to be relatively lower than the brightness of the central part of the phosphor layer 22. A broken line in FIG. 3B schematically shows a luminance contour line in the phosphor layer 22. As shown in FIG. 3B, the upper right end of the phosphor layer 22 is the origin (0, 0), and the luminance at the point (x _i , y _j ) on the phosphor layer 22 is L (x _i , y _j ), the coordinates (X _C , Y _C ) of the barycenter of luminance can be obtained by the following equations (1) and (2).

For the pixel to be measured, the luminance centroid immediately after the operation of the display device (hereinafter sometimes referred to as the initial luminance centroid) and the luminance centroid after the predetermined time has elapsed in the operational state (hereinafter referred to as the time-dependent change). (Sometimes called luminance center of gravity). Specifically, the luminance distribution inside the pixel to be measured by the display device immediately after lighting was measured with a CCD camera or the like. Using the measurement result, the luminance L (x _i , y _j ) can be obtained. Next, the coordinates (X _CS , Y _CS ) of the luminance center of gravity in the initial state were calculated using the obtained luminance L (x _i , y _j ). Next, after a predetermined time has passed in the operating state of the display device, the coordinates (X _CT , Y _CT ) of the luminance center of gravity after the change with time are calculated by the same procedure as above.

By using the coordinates (X _CS , Y _CS ) of the luminance centroid in the initial state and the coordinates (X _CT , Y _CT ) of the luminance centroid after the change with time, the position change amount of the luminance centroid is obtained. Specifically, the distance between the luminance centroids may be calculated. With respect to the display device of the example and the display device of the comparative example, the above operation was performed, and the operation time until the luminance gravity center of the pixel located near the spacer moved by 5 μm was calculated. The results are shown in Table 1.

  As shown in Table 1, in the display device of the example, the change in position of the luminance centroid is slower than the change in position of the luminance centroid in the display device of the comparative example. Therefore, by using the spacer of the embodiment in the display device, it is possible to reduce the relative luminance change of the pixels along the spacer.

  Thus, the use of the spacer of the embodiment slows down the change in the position of the luminance center of gravity. This is because titanium oxide and indium oxide are effective in promoting the removal of charge accumulated in the antistatic film. it can. According to experiments conducted by the inventors, it has been found that the movement of the luminance center of gravity of the pixels in the vicinity of the spacer is due to a change in the surface resistance of the spacer with the lapse of time. It has also been found that the greater the amount of charge on the spacer surface, the faster the change in resistance of the spacer surface with time. On the other hand, titanium oxide and indium oxide have the effect of lowering the resistance value of the antistatic film. Therefore, it is considered that the temporal change of the surface resistance is suppressed by promoting the removal of the charge accumulated in the antistatic film.

[Table 1]

[Table 2]
[Conditions for forming antistatic film by sputtering method]
Spacer base material temperature: 25 ° C
Deposition rate: 0.2 nm / second Pressure: 0.5 Pa
Process gas: Ar
Sputtering method: RF sputtering

  As mentioned above, although this invention was demonstrated based on the preferable Example, this invention is not limited to these Examples. The configurations and structures of the flat display device, the first panel and the second panel, the cold cathode field emission display device and the cold cathode field emission device described in the embodiments are examples, and can be changed as appropriate. The manufacturing method of the first panel, the second panel, the cold cathode field emission display device, or the cold cathode field emission device is also an example, and can be changed as appropriate. Furthermore, the various materials used in manufacture of the 1st panel and the 2nd panel are illustrations, and can be changed suitably. The display device has been described by taking color display as an example, but it may also be a single color display.

  In the field emission device, a mode in which one electron emission portion corresponds to one opening has been described. However, depending on the structure of the field emission device, a mode in which a plurality of electron emission portions correspond to one opening. Alternatively, one electron emission portion may correspond to a plurality of openings. Alternatively, a plurality of first openings are provided in the gate electrode, a plurality of second openings connected to the plurality of first openings related to the insulating layer are provided, and one or a plurality of electron emission portions are provided. You can also.

An electron emission source can be constituted by an element commonly called a surface conduction electron-emitting element. This surface conduction electron-emitting device is formed on a support made of glass, for example, tin oxide (SnO ₂ ), gold (Au), indium oxide (In ₂ O ₃ ) / tin oxide (SnO ₂ ), carbon, palladium oxide ( A pair of electrodes made of a conductive material such as (PdO), having a small area and arranged with a predetermined gap (gap) are formed in a matrix. A carbon thin film is formed on each electrode. The row direction wiring is connected to one electrode of the pair of electrodes, and the column direction wiring is connected to the other electrode of the pair of electrodes. By applying a voltage to the pair of electrodes, an electric field is applied to the carbon thin films facing each other across the gap, and electrons are emitted from the carbon thin film. By causing the electrons to collide with the phosphor layer on the second panel, the phosphor layer is excited to emit light, and a desired image can be obtained. Alternatively, the electron emission source can be constituted by a metal / insulating film / metal type element.

FIG. 1 is a conceptual partial end view of a flat panel display (cold cathode field emission display) according to an embodiment. FIG. 2 is a manufacturing process diagram of the spacer and the flat display device (cold cathode field emission display) of the embodiment. FIG. 3A is a diagram schematically showing the trajectory of the electron beam in a pixel (in the embodiment, one subpixel) located in the vicinity of the spacer, and FIG. 3B is a diagram of FIG. In the state shown to (A), it is the figure which showed typically the luminance distribution of the fluorescent substance layer. FIG. 4 is a conceptual partial end view of a conventional cold cathode field emission display having a Spindt-type field emission device. FIG. 5 is a schematic exploded perspective view of a part of the cathode panel and the anode panel when the cathode panel and the anode panel are disassembled. FIG. 6 is a conceptual partial end view of a cold cathode field emission display having a so-called flat-type cold cathode field emission device. 7A to 7B are diagrams schematically showing the trajectory of the electron beam in the pixel located in the vicinity of the spacer.

Explanation of symbols

CP ... cathode panel, AP ... anode panel, 10 ... support, 11 ... cathode electrode, 12 ... insulating layer, 13 ... gate electrode, 14, 14A, 14B ... Opening part, 15, 15A ... Electron emission part, 16 ... Converging electrode, 17 ... Interlayer insulating layer, 18 ... Release layer, 19 ... Conductive material layer, 20 ... Substrate, 21 ..., partition walls, 22, 22R, 22G, 22B ... phosphor layer, 23 ... black matrix, 24 ... anode electrode, 25 ... spacer holding part, 26 ... frame, 31 ..Cathode electrode control circuit, 32 ... Gate electrode control circuit, 33 ... Anode electrode control circuit, 40 ... Spacer, 40A ... Spacer base material, 40B ... Antistatic film, 140・ Spacer, 140A ... Spacer base material 140B ··· antistatic film

Claims (2)

A first panel in which a plurality of electron emission sources for emitting electrons are formed on a support; a second panel in which a phosphor layer and an anode electrode with which electrons emitted from the electron emission source collide are formed on a substrate; Are used in a flat panel display device in which a space sandwiched between the first panel and the second panel is held in a vacuum, and is disposed between the first panel and the second panel. A spacer,
The spacer comprises a spacer base material and an antistatic film provided on the side surface of the spacer base material,
Antistatic film is
Consisting of chromium oxide and indium oxide, or
Consisting of manganese oxide and titanium oxide, or
Consisting of manganese oxide and indium oxide, or
Consisting of zinc oxide and titanium oxide, or
A spacer comprising zinc oxide and indium oxide . A first panel in which a plurality of electron emission sources for emitting electrons are formed on a support; a second panel in which a phosphor layer and an anode electrode with which electrons emitted from the electron emission source collide are formed on a substrate; Are flat panel display devices that are joined at their peripheral portions, a spacer is disposed between the first panel and the second panel, and a space sandwiched between the first panel and the second panel is maintained in a vacuum. There,
The spacer comprises a spacer base material and an antistatic film provided on the side surface of the spacer base material,
Antistatic film is
Consisting of chromium oxide and indium oxide, or
Consisting of manganese oxide and titanium oxide, or
Consisting of manganese oxide and indium oxide, or
Consisting of zinc oxide and titanium oxide, or
A flat display device comprising zinc oxide and indium oxide .

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