JP4857645B2 - Flat panel display - Google Patents

Description

  The present invention relates to a flat panel display device, and more specifically to a flat panel display device characterized by a getter box.

  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). In addition, development of a flat display device incorporating a cathode panel equipped with an electron-emitting device is also in progress. 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. A flat display device incorporating a cathode panel provided with 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 electron emission device as an electron emission device, generally has a plurality of cold cathode field electron emission. A cathode panel CP provided with an element (hereinafter sometimes abbreviated as a field emission element), and an anode panel AP having a phosphor layer that emits light when excited by collision with electrons emitted from the field emission element, The cathode panel CP and the anode panel AP are arranged so as to face each other through a space maintained in a high vacuum, and the peripheral edge portion is joined via a frame body 26. Here, the cathode panel CP has an electron emission region corresponding to each pixel arranged in a two-dimensional matrix, and each electron emission region is provided with one or a plurality of field emission elements. Examples of field emission devices include Spindt type, flat type, edge type, and planar type.

  As an example, FIG. 1 shows a conceptual diagram of a disassembled display device, FIG. 7 shows a conceptual partial end view of a conventional display device having a Spindt field emission device, and disassembles a cathode panel CP and an anode panel AP. FIG. 9 shows a schematic exploded perspective view of a part of the cathode panel CP and the anode panel AP when it is made. In FIG. 1, the joining portion is hatched.

In this display device, each of the cathode panel CP and the anode panel AP includes an effective area EF _C , EF _A (hatched) and an effective area EF _C , EF _{A in} which pixels are arranged and function as an actual display screen. Functionally, it is roughly divided into invalid areas NE _C and NE _A in which peripheral circuits for surrounding and selecting pixels are formed. Such a display device is provided with a getter 42 made of a material capable of trapping residual gas in the space in order to maintain the degree of vacuum in the space. The getter 42 is usually disposed in at least one of the invalid regions NE _C and NE _A of the cathode panel CP and the anode panel AP. In the illustrated example, one or a plurality of through holes 41 are provided in the invalid region NE _C of the cathode panel CP (one in the illustrated example), and the through holes 41 are disposed so as to be closed from the outside of the cathode panel CP. A getter 42 is accommodated in the getter box 40. For example, the getter box 40 made of glass is bonded to the support 10 using frit glass. Another through hole 50 for evacuation is provided elsewhere in the ineffective region NE _C , and an exhaust pipe 51, which is also called a tip pipe that is sealed after evacuation, is attached to the through hole 50.

  A Spindt-type field emission device constituting a display 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 formed on the insulating layer 12. An electrode 13, an opening 14 provided in the gate electrode 13 and the insulating layer 12 (a first opening 14 </ b> A provided in the gate electrode 13 and a second opening 14 </ b> B provided in the insulating layer 12), and an opening It is composed of a conical electron emission portion 15 formed on the cathode electrode 11 located at the bottom of the portion 14.

  Alternatively, FIG. 8 shows a conceptual partial end view of a display device having a so-called flat type field emission device provided with a substantially planar electron emission portion 15A. The 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, a gate electrode 13 formed on the insulating layer 12, a gate An opening 14 provided in the electrode 13 and the insulating layer 12 (a first opening 14A provided in the gate electrode 13 and a second opening 14B provided in the insulating layer 12) and a bottom of the opening 14 The electron emission portion 15A is formed on the cathode electrode 11 positioned. 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 x direction (refer to the x direction in FIG. 7, FIG. 8 or FIG. 9), and the gate electrode 13 is in the y direction (FIG. 7, FIG. 7) different from the x direction. 8 or the y-direction in FIG. 9). 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 one subpixel. The electron emission areas EA are usually arranged in a two-dimensional matrix within the effective area EF _C (area that functions as an actual display portion) of the cathode panel CP.

  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. A space between these phosphor layers 22 is embedded with a light absorbing layer (black matrix) 23 made of a light absorbing material such as carbon, thereby preventing display image color turbidity and optical crosstalk. . In the figure, reference numeral 21 represents a partition wall and reference numeral 26 represents a frame. In FIGS. 8 and 9, the illustration of the partition walls is omitted.

One sub-pixel is configured by an electron emission area EA on the cathode panel side and a phosphor layer 22 on the anode panel side facing the electron emission area EA. In the effective areas EF _C and EF _A , such pixels are arranged on the order of hundreds of thousands to millions, for example. In a display device for color display, one pixel (one pixel) is composed of a set of a red light emitting subpixel, a green light emitting subpixel, and a blue light emitting subpixel.

In assembling the display device, 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, and frit glass (not shown) is applied to the peripheral portion. After joining using the frame body 26, the anode panel AP and the cathode panel CP are heated, and the support corresponding to the invalid area NE _C of the cathode panel CP (that is, the area surrounding the effective area EF _C functioning as a display screen). A space (more specifically, a space between the cathode panel CP and the anode panel AP through a through hole 50 provided in the body 10 and an exhaust pipe 51 made of a glass tube attached to the support 10. The space surrounded by the cathode panel CP, the anode panel AP, and the frame body 26) is exhausted, and then the exhaust pipe 51 is sealed. Next, the getter 42 is heated to activate the getter 42. One getter box 40 may be disposed on the display device (for example, see Japanese Patent Application Laid-Open No. 2001-110301), or a plurality of getter boxes 40 (for example, refer to Japanese Patent Application Laid-Open No. 5-205669). Thus, a display device can be manufactured, but the space is in a high vacuum (eg, 1 × 10 ⁻³ Pa or less).

JP 2001-110301 A JP-A-5-205669

By the way, as described above, the getter box 40 is bonded (sealed) to the portion of the support 10 corresponding to the ineffective region NE _C of the cathode panel CP using frit glass. It is desirable to reduce the temperature of the thermal process in assembling the display device as much as possible in order to prevent damage to the components constituting the display device. Therefore, it is desirable that the frit glass used for bonding the getter box 40 to the support 10 has a baking temperature of 400 ° C. or lower. However, such a low-temperature firing type frit glass has very poor wettability after adhesion (sealing).

  For example, in a nominal 42-inch panel, the dimensions of the support 10 made of a glass substrate are, for example, width × length × thickness of 1 m × 0.5 m × 2.8 mm, and its weight is about 4 kg. For example, when the both long sides of the support 10 are held, the amount of deflection of the support 10 due to its own weight is 0.4 mm at the center of the support 10.

  Therefore, when the display device (or the support 10) is deformed by, for example, bending due to its own weight during transportation of the display device (or the support 10) or the like during manufacturing of the display device, and a peeling force is applied to the getter box 40, the frit is applied. There arises a problem that the glass peels off and the airtightness of the display device cannot be maintained.

  The method for preventing peeling of the getter box from the support by improving the adhesive strength and wettability of the frit glass for bonding the getter box to the support is still in practical use. Not realized. In addition, a method of sticking a rigid reinforcing member such as a metal plate to a supporting member or a getter box so that the supporting member or the like is not deformed by its own weight may be considered. However, during the manufacturing process of the display device, the reinforcing member It is difficult to apply it to the actual display device manufacturing process because of the presence of the support, and due to the difference in thermal expansion coefficient between the reinforcing member and the material constituting the support or getter box, the support Damage to the body and getter box may occur.

  Accordingly, an object of the present invention is to deform the flat display device (or support body, etc.) due to, for example, bending due to its own weight in transporting the flat display device (or support body, etc.), and to apply a peeling force to the getter box. However, an object of the present invention is to provide a flat display device having a structure in which the getter box is not peeled off from the display device (or support or the like).

In order to achieve the above object, a flat panel display according to a first aspect of the present invention includes a first panel in which a plurality of electron emission regions for emitting electrons are formed on a support, and emission from the electron emission region. The phosphor layer on which the electrons collide and the second panel formed by forming the anode electrode on the substrate are joined at the periphery thereof, and the space sandwiched between the first panel and the second panel is maintained in a vacuum. A flat-panel display device,
A getter box communicating with the space is bonded to the first panel and / or the second panel,
When the flat display device is freely supported by the support portion along two opposing sides of the flat display device,
The direction in which the two opposing sides of the flat display device extend is the Y-axis direction,
The axis perpendicular to the Y-axis direction and passing through the center point of the getter box is the X-axis,
The coordinates of the portion where the flat display device is in contact with one support portion when the flat display device is cut on the virtual XZ plane including the X axis are (0, 0, 0),
And then
The length of the getter box in the X-axis direction is c,
When it is assumed that there is no getter box, the radius of curvature in the portion of the flat display device corresponding to the center point of the getter box is r,
When
The getter box X length in the X-axis direction and the position of the getter box are determined so that the virtual floating amount t calculated by the following equation (1) is 3 × 10 ⁻² mm or less. To do.

In the flat display device according to the first aspect of the present invention, one getter box may be bonded to the first panel and / or the second panel on the X axis. On the X axis, a plurality of getter boxes are bonded to the first panel and / or the second panel, and in each getter box, the virtual floating amount t obtained by the above equation (1) is 3 × 10. It is also possible to adopt a configuration in which the length c of each getter box in the X-axis direction and the position of the getter box are determined so as to be ⁻² mm or less. If a plurality of getter boxes are bonded, there may be a plurality of X-axis, Y-axis directions, coordinates (0, 0, 0), and the like.

In order to achieve the above object, a flat panel display according to a second aspect of the present invention includes a first panel in which a plurality of electron emission regions for emitting electrons are formed on a support, and emission from the electron emission region. The phosphor layer on which the electrons collide and the second panel formed by forming the anode electrode on the substrate are joined at the periphery thereof, and the space sandwiched between the first panel and the second panel is maintained in a vacuum. A flat-panel display device,
N (where N ≧ 3) getter boxes are bonded to the first panel and / or the second panel, which are arranged on an axis parallel to two opposite sides of the flat display device and communicate with the space. And
When the axial length of the n-th getter box was c _n,
If N is even, a n ≦ (N / 2-1) in _{c n> c (n + 1} ), the (N / 2 + 1) ≦ n ≦ (N-1), c n <c (n + ₁₎
If N is odd, a n ≦ In (N-1) / 2 c n> c (n + 1), the (N + 1) / 2 ≦ n ≦ (N-1), c n <c (n + It is characterized by ₁₎ .

Even in the flat display device according to the second aspect of the present invention, in each getter box, each getter is set so that the virtual floating amount t calculated by the above formula (1) is 3 × 10 ⁻² mm or less. It is preferable that the length c in the axial direction of the box and the position of the getter box are determined.

  The flat display device according to the first aspect or the second aspect of the present invention including the above-described preferred configurations and forms (hereinafter, these may be collectively referred to simply as the flat display device of the present invention). In this case, a getter is placed in the getter box. Here, as a material constituting the getter, titanium (Ti), zirconium (Zr), nickel (Ni), vanadium (V), aluminum (Al), iron (Fe), cobalt (Co), Zr—Ni alloy, At least one so-called non-evaporable getter material selected from the group consisting of Ti-Zr-V-Fe alloy, Ti-Zr-Al alloy, Ti-Mn-V alloy, carbon fiber and graphite; barium (Ba And so-called evaporation type getter materials such as Ba-Al. A non-evaporable getter material and an evaporable getter material may be used in combination. In the case of the evaporation type getter material, the getter material is heated and evaporated to adhere to the inner wall of the getter box. On the other hand, even in the non-evaporable getter material, the getter material is activated by heating the getter material. Examples of the heating method include heating using laser light, heating using a high frequency, heating using a heating furnace, heating using a lamp, and heating using a heating wire.

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 a glass substrate, high strain point glass, soda glass (Na ₂ O · CaO · SiO ₂ ), borosilicate glass (Na ₂ O · B ₂ O ₃ · SiO ₂ ), forsterite (2MgO · SiO ₂ ), lead glass (Na ₂ O · PbO · SiO ₂ ) and alkali-free glass can be exemplified. The getter box may be made from any of these materials. Alternatively, the getter box can be made from any of ceramics described with reference to the material constituting the spacer described later.

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 made of an insulating rigid material such as glass or ceramics 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. Or after completion | finish of joining of three parties, the space enclosed by the 1st panel, the 2nd panel, the frame, and the contact bonding layer can be exhausted, and it can also be set as 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, the exhaust can be performed through an exhaust pipe called a tip pipe connected in advance to the first panel and / or the second panel. The exhaust pipe is typically a glass pipe, or a metal or alloy having a low coefficient of thermal expansion [for example, an iron (Fe) alloy containing 42 wt% nickel (Ni), 42 wt% nickel (Ni), A hollow tube made of an iron (Fe) alloy containing 6% by weight of chromium (Cr)] and serving as an ineffective area of the first panel and / or the second panel (practical function as a flat display device) Around the through-hole provided in the frame (the area surrounding the effective area, which is the display area in the center), it is joined using frit glass or the above-mentioned low melting point metal material, and the space reaches a predetermined degree of vacuum. After that, it is sealed by thermal fusion or sealed by pressure bonding. In addition, if the whole flat display device is once heated and then cooled before sealing, it is preferable because residual gas can be released into the space, and this residual gas can be removed out of the space by exhaust. .

  The getter box is bonded to the first panel and / or the second panel, but at what point the getter box is bonded to the first panel and / or the second panel is essentially arbitrary. For example, before joining the first panel, the second panel, and the frame body, a getter box may be bonded to the first panel or the second panel, or the first panel, the second panel, and the frame body. After joining the three, the getter box may be bonded to the first panel or the second panel, or when joining the three of the first panel, the second panel and the frame, the first panel Alternatively, a getter box may be bonded to the second panel. More specifically, the getter box may be bonded to the first panel, may be bonded to the second panel, or may be bonded to the first panel and the second panel. For adhesion of the getter box to the first panel and / or the second panel, frit glass or the above-described low melting point metal material may be used.

When the flat display device is a cold cathode field emission display device, the cold cathode field emission device (hereinafter referred to as field emission device) constituting the electron emission region is sometimes referred to as a first panel (hereinafter referred to as a cathode panel). Provided),
(A) a strip-shaped cathode electrode formed on the support and extending in the x 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 the y direction different from the x 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 An element (a field emission element in which a substantially planar electron emission portion is provided on a cathode electrode positioned at the bottom of an opening) can be given.

  In the cathode panel, the projection image of the cathode electrode and the projection image of the gate electrode are orthogonal to each other, that is, that the x direction and the y direction are orthogonal to each other, from the viewpoint of simplifying the structure of the cold cathode field emission display device. To preferred. An overlapping region where the cathode electrode and the gate electrode overlap corresponds to an electron emission region, and the electron emission regions are arranged in a two-dimensional matrix, and each electron emission region includes one or a plurality of field emission elements. Is provided.

  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 anode panel by the anode electrode provided on the second panel (sometimes referred to as an anode 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 15 kilovolts. Alternatively, when the distance between the anode panel and the cathode panel is d ₀ (where 0.5 mm ≦ d ₀ ≦ 10 mm), the value of V _A / d ₀ (unit: kilovolt / mm) is 0. It is desirable to satisfy 5 or more and 20 or less, preferably 1 or more and 10 or less, and more preferably 4 or more and 8 or less. In actual operation of the cold cathode field emission display, the voltage modulation method can be adopted as the gradation control method for the voltage V _C applied to the cathode electrode and the voltage V _G applied to the gate electrode.

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, the potential difference between the anode electrode and the cathode electrode is on the order of several kilovolts or more and the distance between the anode electrode and the cathode electrode is relatively long. The electrode is particularly effective. A relative negative voltage (for example, 0 volts) is applied to the focusing electrode from the focusing electrode control circuit. The focusing electrode does not necessarily have to be individually formed so as to surround each of the electron emission portion or the electron emission region provided in the overlapping region where the cathode electrode and the gate electrode overlap, for example, the electron emission portion or The electron emission region may be extended along a predetermined arrangement direction, or the electron emission portion or the electron emission region may be surrounded by one focusing electrode (that is, the focusing electrode may be a cold cathode field electron). It may be a thin sheet-like structure covering the entire effective area, which is the central display area that performs a practical function as an emission display device), thereby providing a plurality of electron emission areas or electron emission areas. A common convergence effect can be exerted.

  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 chemical vapor deposition method (CVD method) in addition to the vacuum deposition 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. Alternatively, the material constituting the electron emission portion may be appropriately selected from materials 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. In the flat type field emission device, carbon, more specifically, amorphous diamond or graphite, a carbon nanotube structure (carbon nanotube and / or graphite nanofiber), as a particularly preferable constituent material of the electron emission portion, Examples thereof include ZnO whiskers, MgO whiskers, SnO ₂ whiskers, MnO whiskers, Y ₂ O ₃ whiskers, NiO whiskers, ITO whiskers, In ₂ O ₃ whiskers, and Al ₂ O ₃ whiskers. In addition, the material which comprises an electron emission part does not necessarily need to be provided with electroconductivity.

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 and electroless plating method); lift-off method; laser ablation method; sol-gel method and the like. 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, SOG ( spin on glass), low-melting glass, SiO ₂ based materials such glass paste; SiN-based materials; polyimide These insulating resins 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 film may be provided between the cathode electrode and the electron emission portion. By providing the resistor film, the operation of the field emission device can be stabilized and the electron emission characteristics can be made uniform. As a material constituting the resistor film, 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 film include a sputtering method, a CVD method, and a screen printing method. The electrical resistance value per one electron emitting portion may be approximately 1 × 10 ⁶ to 1 × 10 ¹¹ Ω, preferably several tens of gigaΩ.

  In the flat display device, examples of the configuration of the anode electrode and the phosphor layer include (1) a configuration in which the anode electrode is formed on the substrate and the 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 layer. As the material constituting the resistor layer, carbon, carbon carbide (SiC), SiCN, and other carbon materials; SiN materials; ruthenium oxide (RuO ₂ ), tantalum oxide, tantalum nitride, chromium oxide, titanium oxide, and other high melting point metals Examples thereof include oxides; semiconductor materials such as amorphous silicon; ITO. It is also possible to realize a stable desired sheet resistance value by combining a plurality of films such as laminating a carbon thin film having a low resistance value on the SiC resistance film. Examples of the sheet resistance value of the resistor layer include 1 × 10 ⁻¹ Ω / □ to 1 × 10 ¹⁰ Ω / □, preferably 1 × 10 ³ Ω / □ to 1 × 10 ⁸ Ω / □. The number (Q) of anode electrode units may be two or more. For example, when the total number of rows of phosphor layers arranged in a straight line is q, Q = q or q = k · Q (K is an integer of 2 or more, preferably 10 ≦ k ≦ 100, more preferably 20 ≦ k ≦ 50), or a number obtained by adding 1 to the number of spacers arranged at a constant 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 vary depending on the position of the anode electrode unit. A resistor layer may be formed on one anode electrode as a whole.

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 physical vapor deposition methods (PVD method) 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; Examples include various CVD methods; screen printing methods; metal mask printing methods; lift-off methods; sol-gel methods. 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 layer can also be formed by a similar method. That is, a resistor layer may be formed from a resistor material, and the resistor layer may be patterned based on a lithography technique and an etching technique, or the resistor material may be provided via a mask or screen having a resistor layer pattern. The resistor layer can be obtained by formation based on the PVD method or the screen printing method. 3 × 10 ⁻⁸ m (30 nm) to 5 as the average thickness of the anode electrode on the substrate (or above the substrate) (when the partition is provided as described later, the average thickness of the anode electrode on the top surface of the partition) Examples include x10 ⁻⁷ m (0.5 μm), preferably 5 × 10 ⁻⁸ m (50 nm) to 3 × 10 ⁻⁷ m (0.3 μm).

As the constituent material of the anode electrode, 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 Silicide such as MoSi ₂ , TiSi ₂ , TaSi ₂ ); Semiconductor such as silicon (Si); Carbon thin film such as diamond; Conductive metal oxide such as ITO (indium oxide-tin oxide), indium oxide, zinc oxide can do. When the resistor layer is formed, the anode electrode is preferably made of a conductive material that does not change the resistance value of the resistor layer. For example, when the resistor layer 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 three primary color phosphor particles. The arrangement pattern of the phosphor layers is, for example, a dot shape. Specifically, when the flat display device is a color display, examples of the arrangement and arrangement of the phosphor layers include a delta arrangement, a stripe arrangement, a diagonal arrangement, and a rectangle arrangement. That is, one line of the phosphor layers arranged in a straight line is occupied by a line occupied by the red light emitting phosphor layer, a line occupied by the green light emitting phosphor layer, and a blue light emitting phosphor layer. It may be comprised from the row | line | column, and it may be comprised from the row | line | column in which the red light emission fluorescent substance layer, the green light emission fluorescent substance layer, and the blue light emission fluorescent substance layer were arrange | positioned in order. Here, the phosphor layer is defined as a phosphor region 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). A gap between adjacent phosphor layers may be filled with a light absorption layer (black matrix) for the purpose of improving contrast.

  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, after sequentially applying the red light emitting phosphor slurry, the green light emitting phosphor slurry, and the blue light emitting phosphor slurry, each phosphor slurry may be sequentially exposed and developed to form each phosphor layer. Each phosphor layer may be formed by a screen printing method, an inkjet method, a float coating method, a sedimentation coating method, a phosphor film transfer method, or the like. 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.

  The light absorption layer that absorbs light from the phosphor layer is preferably formed between adjacent phosphor layers or 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 order to prevent the electrons recoiled from the phosphor layer or the secondary electrons emitted from the phosphor layer from entering other phosphor layers, so-called optical crosstalk (color turbidity) is generated. Alternatively, when electrons recoiled from the phosphor layer or secondary electrons emitted from the phosphor layer enter the other phosphor layer through the barrier ribs, these electrons enter the other phosphor layer. In order to prevent collision, it is preferable to provide a partition wall.

  Examples of the partition wall forming method include a screen printing method, a dry film method, a photosensitive method, a casting 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 the partition wall forming material in the opening generated by the removal, and baking. . 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 (cured). The casting method (embossing molding method) refers to a method for forming a partition wall forming material layer by extruding a partition wall forming material layer made of a paste-like organic material or inorganic material onto a substrate from a mold (cast). In this method, the partition wall forming material layer is fired. The sand blast forming method is, for example, forming a partition wall forming material layer on a substrate using a screen printing or metal mask printing method, a roll coater, a doctor blade, a nozzle discharge type coater, etc. In this method, the part of the partition wall forming material layer to be covered is covered with a mask layer, and then the exposed part of the partition wall forming material layer is removed by sandblasting. After the partition wall is formed, the partition wall may be polished to flatten the top surface of the partition wall.

  As the planar shape of the part surrounding the phosphor layer in the partition wall (corresponding to the inner contour line of the projected image of the partition wall side surface, which is a kind of opening region), rectangular shape, circular shape, elliptical shape, oval shape, triangular shape, Examples include pentagonal or more polygonal shapes, rounded triangular shapes, rounded rectangular shapes, rounded polygons, and the like. By arranging these planar shapes (planar shapes of the opening regions) in a two-dimensional matrix, a lattice-like partition is formed. This two-dimensional matrix-like arrangement may be arranged, for example, like a cross or like a zigzag.

Examples of the partition wall forming material include photosensitive polyimide resin, lead glass colored with a metal oxide such as cobalt oxide, SiO ₂ , and a low melting point glass paste. A protective layer (for example, made of SiO ₂ , SiON, or AlN) is provided on the surface (top surface and side surface) of the partition wall to prevent an electron beam from colliding with the partition wall and releasing gas from the partition wall. It may be formed.

  The space between the first panel and the second panel is in a high vacuum. Therefore, if a spacer made of a high resistance material such as ceramic material or glass is not disposed between the first panel and the second panel, the flat display device is damaged by atmospheric pressure. End up. The spacer can be made of ceramics or glass, for example. When the spacer is made of ceramics, the ceramics include mullite, alumina, barium titanate, lead zirconate titanate, zirconia, cordiolite, borosilicate barium, iron silicate, glass ceramic materials, titanium oxide and chromium oxide. Examples thereof include iron oxide, vanadium oxide, and nickel oxide added. In this case, the spacer can be manufactured by forming a so-called green sheet, firing the green sheet, and cutting the green sheet fired product. Moreover, soda-lime glass can be mentioned as glass which comprises a spacer. The spacer may be fixed by being sandwiched between the partition walls, for example. Alternatively, for example, a spacer holding part may be formed on the second panel and fixed by the spacer holding part.

An antistatic film may be provided on the surface of the spacer. The material constituting the antistatic film preferably has a secondary electron emission coefficient close to 1, and as the material constituting the antistatic film, a semimetal such as graphite, an oxide, a boride, a carbide, a sulfide, and A nitride or the like can be used. For example, compounds containing a metalloid element ₂ such as a semi-metal and MoSe such as _{graphite, CrO x, CrAl x O y} , Nd 2 O 3, La x Ba 2-x CuO 4, La x Ba 2-x CuO 4, Oxides such as La _x Y _1-x CrO ₃ , borides such as AlB ₂ and TiB ₂ , carbides such as SiC, sulfides such as MoS ₂ and WS ₂ , and nitrides such as BN, TiN and AlN In addition, for example, materials described in, for example, JP-T-2004-500688 can be used. The antistatic film may be composed of a single type of material, may be composed of a plurality of types of materials, may be a single layer structure, or may be a multilayer structure. May be. The antistatic film can be formed based on a known method such as a sputtering method, a vacuum deposition method, a CVD method, or the like.

  In the present invention, examples of the electron-emitting device constituting the electron-emitting region include a cold cathode field electron-emitting device, a metal / insulating film / metal-type device (MIM device), and a surface conduction electron-emitting device. Further, as a flat display device, a flat display device (cold cathode field electron emission display device) provided with a cold cathode field emission device, a flat display device incorporating an MIM element, and a surface conduction electron emission device are incorporated. And a flat display device.

In the flat display device according to the first aspect of the present invention, the length of the getter box in the X-axis direction so that the virtual floating amount t obtained by the equation (1) is 3 × 10 ⁻² mm or less. c, and the position of the getter box is determined. Accordingly, even when the flat display device (or support or the like) is deformed by, for example, bending due to its own weight during transportation of the flat display device (or support or the like) and a peeling force is applied to the getter box, the getter box Can be prevented from peeling off from the flat display device (or the support or the like). In general, the closer to the center line of the flat display device, the greater the amount of deflection of the flat display device (or the support). In the flat display device according to the second aspect of the present invention, the size of the getter box located near the center line of the flat display device is smaller, so that the flat display device (or a support or the like) Even when the flat display device (or support or the like) is deformed by, for example, bending due to its own weight, and the peeling force is applied to the getter box, the getter box is removed from the flat display device (or support or the like). Peeling can be prevented.

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

  Example 1 relates to a flat display device according to the first aspect of the present invention. Here, more specifically, the flat display device of Example 1 includes a cold cathode field emission display device (hereinafter, abbreviated as a display device). The conceptual diagram when disassembling the first panel (hereinafter referred to as the cathode panel CP) and the second panel (hereinafter referred to as the anode panel AP) constituting the display device of Example 1 is the same as that shown in FIG. is there. In FIG. 1, the joining portion is hatched. Further, a front view and a left side view when the display device according to the first embodiment is supported by the support portion are shown in FIGS. 2A and 2B, respectively. 3A and 3B are conceptual diagrams of the support and the like for explaining the above. Here, a schematic partial sectional view of the display device of Example 1 having a Spindt type cold cathode field emission device (hereinafter referred to as field emission device) or Example 2 described later is the same as that shown in FIG. A schematic partial cross-sectional view of the display device of Example 1 having a flat type field emission device or Example 2 described later is the same as that shown in FIG. Also, a schematic exploded perspective view of a part of the first panel (cathode panel CP) and the second panel (anode panel AP) when the first panel (cathode panel CP) and the second panel (anode panel AP) are disassembled. Is the same as shown in FIG.

  That is, the display device of Example 1 or Example 2 described later includes a first panel (cathode panel CP) in which a plurality of electron emission areas EA for emitting electrons are formed on the support 10, and an electron emission area EA. A second panel (anode panel AP) in which the phosphor layer 22 and the anode electrode 24 on which the emitted electrons collide are formed on the substrate 20 is joined at the peripheral edge thereof, and the first panel (cathode panel CP). And the second panel (anode panel AP) are display devices in which a space is held in a vacuum.

Here, in Example 1 or Example 2 to be described later, the field emission element constituting the electron emission region is composed of, for example, a Spindt type field emission element. As shown in FIG. 7, the Spindt-type field emission device has
(A) a cathode electrode 11 formed on the support 10;
(B) an insulating layer 12 formed on the support 10 and the cathode electrode 11;
(C) a gate electrode 13 formed on the insulating layer 12;
(D) 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
(E) a conical electron emission portion 15 formed on the cathode electrode 11 located at the bottom of the opening 14;
It is composed of

Alternatively, in Example 1 or Example 2 to be described later, the field emission device is constituted by, for example, a flat type field emission device. As shown in FIG.
(A) a cathode electrode 11 formed on the support 10;
(B) an insulating layer 12 formed on the support 10 and the cathode electrode 11;
(C) a gate electrode 13 formed on the insulating layer 12;
(D) 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
(E) an electron emission portion 15A formed on the cathode electrode 11 located at the bottom of the opening 14;
It is composed of The electron emission portion 15A is composed of, for example, a large number of carbon nanotubes partially embedded in a matrix.

In the cathode panel CP, the cathode electrode 11 has a strip shape extending in the x direction, and the gate electrode 13 has a strip shape extending in the y direction different from the x direction. 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. A plurality of field emission elements are provided in the electron emission area EA corresponding to one subpixel. Further, an interlayer insulating layer (not shown) is provided on the insulating layer 12 and the gate electrode 13, and further, a focusing electrode (not shown) is provided between the layers along a predetermined arrangement direction of the field emission elements. It is provided on the insulating layer and can exert a common convergence effect on a plurality of field emission devices. The ineffective area NE _C of the cathode panel CP is provided with a through-hole 50 for evacuation, and an exhaust pipe 51, also called a chip pipe, which is sealed after evacuation is attached to the through-hole 50.

In Example 1 or Example 2 described later, the anode panel AP includes a substrate 20 and a phosphor layer 22 formed on the substrate 20 (in the case of color display, a red light-emitting phosphor layer 22R, a green light-emitting phosphor). A layer 22G, a blue light emitting phosphor layer 22B), and an anode electrode 24 covering the phosphor layer 22. That is, the anode panel AP is more specifically formed on the substrate 20 and the substrate 20 between the partition walls 21 formed on the substrate 20 and the phosphor layer 22 made of a large number of phosphor particles. (A red light emitting phosphor layer 22R, a green light emitting phosphor layer 22G, a blue light emitting phosphor layer 22B), and an anode electrode 24 formed on the phosphor layer 22. The anode electrode 24 is made of about 70nm of aluminum thickness (Al), a thin one sheet covering the effective region EF _A, are provided so as to cover the partition wall 21 and the phosphor layer 22. Between the phosphor layer 22 and the phosphor layer 22, and between the partition wall 21 and the substrate 20, a light absorption layer (black) is used to prevent the occurrence of color turbidity and optical crosstalk in the display image. Matrix) 23 is formed.

  An example of the arrangement | positioning state of the partition 21, the spacer 25, and the fluorescent substance layer 22 is typically shown in FIGS. The arrangement of the phosphor layers and the like in the display device shown in FIG. 7 or FIG. 8 is configured as shown in FIG. 11 or FIG. Also, the anode electrode is not shown in FIGS. The planar shape of the partition wall 21 is 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 22 having a substantially rectangular planar shape (FIGS. 10, 11, 12, and 12). 13), or a belt-like shape extending in parallel with two opposing sides of the substantially rectangular (or belt-like) phosphor layer 22 (see FIGS. 14 and 15). In the phosphor layer 22 shown in FIG. 14, the phosphor layers 22R, 22G, and 22B can be formed in a strip shape extending in the vertical direction of FIG. A part of the partition wall 21 also functions as a spacer holding portion for holding the spacer 25.

In Example 1 or Example 2 described later, the cathode electrode 11 is connected to the cathode electrode control circuit 31, the gate electrode 13 is connected to the gate electrode control circuit 32, and the focusing electrode is connected to the focusing electrode control circuit (not shown). The anode electrode 24 is connected to the anode electrode control circuit 33. These control circuits can be constituted by known circuits. During actual operation of the display device, the anode voltage V _A applied from the anode electrode control circuit 33 to the anode electrode 24 is normally constant, and can be set to, for example, 5 kilovolts to 15 kilovolts. On the other hand, regarding the voltage V _C applied to the cathode electrode 11 and the voltage V _G applied to the gate electrode 13 during actual operation of the display device,
(1) A method in which the voltage V _C applied to the cathode electrode 11 is constant and the voltage V _G applied to the gate electrode 13 is changed. (2) The voltage V _C applied to the cathode electrode 11 is changed and applied to the gate electrode 13. the voltage V _G for changing the voltage V _C applied to the method (3) a cathode electrode 11, constant, and may employ any method to change the voltage V _G applied to the gate electrode 13.

During actual operation of the display device, a relatively negative voltage (V _C ) is applied to the cathode electrode 11 from the cathode electrode control circuit 31, and a relatively positive voltage (V _G ) is applied to the gate electrode 13 in the gate electrode control circuit. For example, 0 V is applied to the focusing electrode from the focusing electrode control circuit, and a positive voltage (anode voltage V _A ) higher than that of the gate electrode 13 is applied to the anode electrode 24 from the anode electrode control circuit 33. The 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. Note that a video signal may be input to the cathode electrode 11 from the cathode electrode control circuit 31, and a scanning signal may be input to the gate electrode 13 from the gate electrode control circuit 32. 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 this display device is basically controlled by the voltage V _G applied to the gate electrode 13 and the voltage V _C applied to the cathode electrode 11.

A space sandwiched between the first panel (cathode panel CP) and the second panel (anode panel AP) is in a vacuum state (pressure: for example, 10 ⁻³ Pa or less). In order to maintain such a vacuum state, it is necessary to provide the display device with a getter.

Therefore, specifically, in the first embodiment, one getter box 40 made of glass corresponds to the invalid region NE _C of the cathode panel CP corresponding to the first panel. For example, it is bonded using frit glass. The getter box 40 is connected to the first panel via one or a plurality of through holes 41 (one in the illustrated example) provided in the portion of the support 10 corresponding to the invalid region NE _C of the cathode panel CP. It is sandwiched between the (cathode panel CP) and the second panel (anode panel AP), communicates with a vacuumed space, and is disposed so as to close the through hole 41 from the outside of the cathode panel CP. A getter 42 made of the non-evaporable getter material or the evaporative getter material described above is accommodated in the getter box 40.

Here, as shown in FIGS. 2A and 2B and FIGS. 3A and 3B, the display device is supported by the support portions 60A and 60B along the two opposite sides of the display device. When freely supported,
(1) The direction in which these two opposing sides of the display device extend is the Y-axis direction,
(2) The direction perpendicular to the Y-axis direction and passing through the center point CG of the getter box 40 is the X-axis (particularly, see FIG. 2B)),
(3) The coordinates of the portion where the display device is in contact with the one support portion 60A when the display device is cut on the virtual XZ plane including the X axis are (0, 0, 0),
And

  The length of the X-axis direction of the getter box 40 is c, and the radius of curvature at the portion of the display device corresponding to the center point CG of the getter box 40 when the getter box 40 is not present is r (particularly, FIG. 3B). In FIG. 3B, a circle having a radius of curvature r (a center point is indicated by “O”) in a portion of the display device corresponding to the center point CG of the getter box 40 is illustrated by a dotted line. In FIG. 3B, the support 10 in the bent display device is illustrated by a solid curve. The support 10 in the bent display device is hereinafter referred to as a “curved curve of the support” for the sake of convenience. 3B, the point “EG” corresponds to one end of the getter box 40 in the X-axis direction. Furthermore, the point “R” is an intersection of the line segment O-EG and the center point “O” with a circle having a radius of curvature r. In FIG. 3A, the “flexure curve of the support” is shown by a solid line, and the getter box 40 to be bonded is shown by a dotted line.

Here, a straight line (indicated by a one-dot chain line) passing through the intersection “R” and parallel to the line segment CG-EG (corresponding to the contact surface with the support of the getter box) is assumed. The distance from the EG is defined as the virtual floating amount (t). The actual floating amount (t ₀ ) is the distance from the intersection of the normal passing through the point “EG” and the “support deflection curve” to the point “EG”, but the “support deflection curve” is Since it is a complex curve represented by a fourth-order polynomial and the difference between the actual floating amount (t ₀ ) and the virtual floating amount (t) is small, the actual floating amount (t ₀ ) is changed to the virtual floating amount ( Substitute with t).

From (B) of FIG.
(Distance from point O to point CG) / (Distance from point O to point EG) = (rt) / r
It is. here,
(Distance from point O to point EG) = [r ² + (c / 2) ² ] ^1/2
(Distance from point O to point CG) = r
It is. Therefore, the virtual floating amount t is as shown in the following formula (1).

  By the way, when it is assumed that the display device is freely supported by the support portions 60A and 60B along the two opposing sides of the display device, this state is “the support beam at both ends when the uniform distribution weight q is applied. It comes down to “bending”. However, since the configuration and structure of an actual display device are complicated, for the sake of simplicity, the support 10 is used instead of the display device, and discussions, tests, and the like are performed below. For example, the value of the virtual floating amount t when the getter box 40 peels from the support 10 is equivalent to the value of the virtual floating amount t when the getter box 40 peels from the display device.

  Table 1 below shows symbols and units of various parameters of the support 10.

[Table 1]

The value of the X coordinate at the point CG is “X”. By the way, the radius of curvature r is
1 / r = M / (E · I) (2)
Can be expressed as Here, “E” and “I” are as shown in Table 1. “M” is a bending moment,
M = q · L (L−X) / 2 (3)
Can be expressed as Here, “q” and “L” are as shown in Table 1. Therefore, from the expressions (1), (2), and (3), the value of the virtual floating amount t using the value of “X” as a parameter can be obtained.

Table 2 below shows the values of various parameters when the Young's modulus (E) of the glass substrate constituting the support 10 is 73 × 10 ⁹ N / m ² and the thickness (h) of the support is 1.1 mm. Show. The values of various parameters when the Young's modulus (E) of the glass substrate constituting the support 10 is 78 × 10 ⁹ N / m ² and the thickness (h) of the support are 2.8 mm are shown in the following table. 3 shows.

[Table 2]

[Table 3]

Then, an assembly of the support 10 and the getter box 40 having the specifications shown in Table 4 is manufactured, and when the support 10 is freely supported by a support portion extending parallel to the Y-axis direction of the support, the getter box 40 Was peeled off from the support 10. The center point CG of the getter box 40 is located on a bisector of the length of the support 10 in the X-axis direction. That is, in the specification-1 and the specification-2, the value of “X” is 250 mm, and in the specification-3 and the specification-4, the value of “X” is 150 mm. The results of the peel test are shown in Table 4, where “◯” indicates that no peeling occurs, and “X” indicates that peeling occurs. Table 4 shows the value of the virtual floating amount t using the value of “X” as a parameter from the formulas (1), (2), and (3). From the test results, it was found that the getter box 40 does not peel from the support 10 if the virtual floating amount t obtained by the equation (1) is 3 × 10 ⁻² mm or less.

[Table 4]

Next, assuming that the support 10 made of two types of glass substrates having various parameter values shown in Tables 2 and 3 was used, the length (L) of the support 10 in the X-axis direction was 300 mm to 1000 mm. Until the value of the virtual floating amount t becomes 3 × 10 ⁻² mm or less when the X coordinate value of the center point CG of the getter box 40 is changed in increments of 50 mm. Tables 5 and 6 show the results of determining the length c of the box in the X-axis direction, respectively.

[Table 5]

[Table 6]

As described above, when it is assumed that the support 10 made of two types of glass substrates having the values of various parameters shown in Tables 2 and 3 is used, the virtual floating amount t obtained by Expression (1) is 3 × 10. ^{If the} length c of the X-axis direction of the getter box 40 and the position of the getter box 40 are determined so as to be ⁻² mm or less, the display device (or the support body) can be used for transporting the display device (or the support body). Etc.) can be prevented from being peeled off from the display device (or the support or the like) even if the getter box 40 is deformed by bending due to its own weight and a peeling force is applied to the getter box 40, for example.

Example 2 is a modification of Example 1, and further relates to a flat display device according to the second aspect of the present invention. In Example 1, one getter box was used. On the other hand, in Example 2, as shown in FIG. 4A, a schematic view of the support 10 viewed from below is shown on the X axis on the invalid region NE _C of the cathode panel CP which is the first panel. A plurality (specifically, three) of getter boxes 40A and 40B are bonded to each other, and in each of the getter boxes 40A and 40B, the virtual floating amount t obtained by the equation (1) is 3 × 10 ^−2. The length c in the X-axis direction of each getter box 40A, 40B and the position of the getter box 40A, 40B are determined so as to be equal to or less than mm. In this example, there is one X-axis, Y-axis direction, and coordinates (0, 0, 0).

Alternatively, the first panel (cathode panel CP) is arranged on an axis parallel to the two opposing sides of the display device and communicates with the space N (however, N ≧ 3, in the illustrated example, N = 3) getter boxes 40A and 40B are bonded,
When the axial length of the n-th getter box was c _n,
If N is even, a n ≦ (N / 2-1) in _{c n> c (n + 1} ), the (N / 2 + 1) ≦ n ≦ (N-1), c n <c (n + ₁₎
If N is odd, a n ≦ In (N-1) / 2 c n> c (n + 1), the (N + 1) / 2 ≦ n ≦ (N-1), c n <c (n + ₁₎ .

  For example, as shown in Table 5, when L = 500 mm, the X coordinate value of the center point CG of the getter box 40A is 100 mm, and the X coordinate value of the center point CG of the getter box 40B is 250 mm. If the length c of the box 40A in the X-axis direction is 56 mm or less and the length c of the getter box 40B in the X-axis direction is 44 mm or less, the getter boxes 40A and 40B can be used even if a peeling force is applied to the getter boxes 40A and 40B. Peeling from the display device (or support etc.) can be reliably prevented.

  4 (B) to (C), (A) to (C) in FIG. 5 and (A) to (B) in FIG. 6, which are schematic views of the support 10 as viewed from below. The modification of the arrangement position of a getter box is shown.

In the example shown in FIG. 4B, there are a plurality of invalid areas NE _C of the cathode panel CP which is the first panel, which are located in the vicinity of two opposing sides of the display device. (Specifically, six) getter boxes 40A and 40B are bonded, and there are two X-axis, Y-axis directions, and coordinates (0, 0, 0) in this example. .

In the example shown in (C) of FIG. 4, the effective area EF _C of the cathode panel CP are first panel (specifically, three) more getter box 40A of, 40B is bonded In this example, there is one X-axis, Y-axis direction, and coordinates (0, 0, 0). A through hole (not shown) that is closed by the getter boxes 40 and 40B and provided in the cathode panel CP is provided in a portion of the support 10 other than the electron emission region.

In the example shown in FIG. 5A, the invalid region NE _C of the cathode panel CP which is the first panel, which is located in the vicinity of one of the two opposing sides of the display device, , A plurality (specifically, four) of getter boxes 40A and 40B are bonded, and the X-axis, Y-axis direction, and coordinates (0, 0, 0) are each one in this example, Exists.

In the example shown in FIG. 5B, there are a plurality of invalid areas NE _C of the cathode panel CP which is the first panel, which are located in the vicinity of two opposing sides of the display device. (Specifically, eight) getter boxes 40A and 40B are bonded, and there are two X-axis and Y-axis directions and two coordinates (0, 0, 0) in this example. .

In the example shown in (C) of FIG. 5, the effective region EF _C of the cathode panel CP are first panel (specifically, four) multiple getters box 40A of, 40B is bonded In this example, there is one X-axis, Y-axis direction, and coordinates (0, 0, 0). A through hole (not shown) that is closed by the getter boxes 40 and 40B and provided in the cathode panel CP is provided in a portion of the support 10 other than the electron emission region.

In the example shown in FIG. 6A, there are a plurality of (specifically) four regions that are ineffective regions NE _C of the cathode panel CP that is the first panel and that are located in the vicinity of the four sides of the display device. 10) getter boxes 40A, 40B, and 40C are bonded, and there are seven X-axis, Y-axis directions, and coordinates (0, 0, 0) in this example, respectively. .

In the example shown in FIG. 6B, the invalid region NE _C of the cathode panel CP which is the first panel, the four regions located in the vicinity of the four sides of the display device, and the effective region EF _A plurality (specifically, 12) of getter boxes 40A, 40B, 40C, and 40D are bonded to C, and the X-axis, Y-axis direction, and coordinates (0, 0, 0) are as shown in this example. There are seven each.

  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, cathode panel and anode panel, cold cathode field emission display device and cold cathode field emission device described in the embodiments are examples, and can be changed as appropriate. Also, methods for manufacturing a cathode panel, a cold cathode field emission display, and a cold cathode field emission device are examples, and can be changed as appropriate. Furthermore, various materials used in the manufacture of the anode panel and the cathode panel are also examples, and can be changed as appropriate. The display device has been described by taking color display as an example, but it may also be a single color display. In some cases, the formation of the focusing electrode can be omitted.

  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 may be provided in the gate electrode, a second opening connected to the plurality of first openings related to the insulating layer may be provided, and one or a plurality of electron emission portions may be provided. .

The electron emission region can also be constituted by an electron emission element commonly called a surface conduction electron emission 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 very 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 anode panel, the phosphor layer is excited to emit light, and a desired image can be obtained. Alternatively, the electron emission region can be formed from a metal / insulating film / metal type element.

FIG. 1 is a conceptual diagram when the first panel (cathode panel) and the second panel (anode panel) constituting the first embodiment and the conventional flat display device are disassembled. FIGS. 2A and 2B are a front view and a left side view, respectively, when the flat display device of Example 1 is supported by a support. FIGS. 3A and 3B are conceptual diagrams of a support and the like for explaining a bending state and the like in the flat display device of the first embodiment. 4A, 4B, and 4C are schematic perspective views of a support and the like in the flat display device of Example 2, respectively. 5A, 5 </ b> B, and 5 </ b> C are schematic perspective views of a support and the like in a modified example of the flat display device of Example 2. FIG. FIGS. 6A and 6B are schematic perspective views of a support and the like in another modification of the flat display device according to the second embodiment. FIG. 7 is a conceptual partial end view of a flat display device including a cold cathode field emission display device having a Spindt-type cold cathode field emission device. FIG. 8 is a conceptual partial end view of a flat display device including a cold cathode field emission display device having a flat type cold cathode field emission device. FIG. 9 is a schematic exploded perspective view of a part of a cathode panel and an anode panel in a cold cathode field emission display. FIG. 10 is a layout diagram schematically showing the layout of the barrier ribs, spacers, and phosphor layers in the second panel constituting the flat display device. FIG. 11 is a layout diagram schematically showing the layout of the barrier ribs, spacers, and phosphor layers in the second panel constituting the flat display device. FIG. 12 is a layout diagram schematically showing the layout of the barrier ribs, spacers and phosphor layers in the second panel constituting the flat display device. FIG. 13 is a layout diagram schematically showing the layout of the barrier ribs, spacers, and phosphor layers in the second panel constituting the flat display device. FIG. 14 is a layout diagram schematically showing the layout of the barrier ribs, spacers, and phosphor layers in the second panel constituting the flat display device. FIG. 15 is a layout diagram schematically showing the layout of the barrier ribs, spacers, and phosphor layers in the second panel constituting the flat display device.

Explanation of symbols

CP ... cathode panel (first panel), AP ... anode panel (second panel), EA ... electron emission region, 10 ... support, 11 ... cathode electrode, 12 ... Insulating layer, 13 ... gate electrode, 14 ... opening, 14A ... first opening, 14B ... second opening, 15, 15A ... electron emission part, 20 ... substrate , 21 ... barrier ribs, 22, 22R, 22G, 22B ... phosphor layer, 23 ... light absorption layer (black matrix), 24 ... anode electrode, 25 ... spacer, 26 ... Frame body 31 ... Cathode electrode control circuit 32 ... Gate electrode control circuit 33 ... Anode electrode control circuit 40 ... Getter box 41 ... Through hole 42 ... Getter 50 ... through hole, 51 ... exhaust pipe, 60A, 0B · · · supporting portion, the center point of the CG · · · getter box end of the EG · · · getter box, the center point of the circle of O · · · radius of curvature r

Claims (1)

A first panel in which a plurality of electron emission regions for emitting electrons are formed on a support; a second panel in which a phosphor layer and an anode electrode on which electrons emitted from the electron emission region collide are formed on a substrate; Is a flat display device in which the space sandwiched between the first panel and the second panel is held in a vacuum, and is joined at their peripheral edges.
The first panel is arranged on two opposite sides a first direction parallel to the support, N pieces communicating with said space (where, N ≧ 3) getter box is bonded,
When the first direction length of the nth getter box is c _n ,
If N is even, a n ≦ (N / 2-1) in _{c n> c (n + 1} ), the (N / 2 + 1) ≦ n ≦ (N-1), c n <c (n + ₁₎
If N is odd, a n ≦ In (N-1) / 2 c n> c (n + 1), the (N + 1) / 2 ≦ n ≦ (N-1), c n <c (n + is _1),
When the end of the support is freely supported by the support that is parallel to the other two opposite sides of the support and arranged along the second direction orthogonal to the first direction,
An axis parallel to the first direction and passing through the center point of each getter box is the X axis,
An axis parallel to the second direction is the Y axis,
When the support is cut along the virtual XZ plane including the X axis, the coordinates of the portion where the support is in contact with one of the support portions are (0, 0, 0) in the portion of the support corresponding to the center point of each getter box When the radius of curvature is r,
The first direction length c of each getter box and each getter box so that the virtual floating amount t obtained by the following formulas (1), (2), and (3) is 3 × 10 ⁻² mm or less. The flat display device is characterized in that the position of is set .

1 / r = M / (E · I) (2)
M = q · L (L−X) / 2 (3)
here,
M: Bending moment
E: Young's modulus of support
I: Sectional moment of inertia
q: Load
L: Length of the support in the X-axis direction
X: X coordinate of the center point of each getter box

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