JP5367343B2 - Cold cathode field emission display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cold-cathode field electron emission display device having a structure and constitution in which electrons emitted from an electron emission part are enabled to surely collide with a desired area of an opposed phosphor area. <P>SOLUTION: In a cathode panel for the display device, a cathode electrode 11 is structured of a cathode electrode-branch wiring 11B and a cathode electrode extension part 11C, while a gate electrode 13 is structured of a gate electrode-branch wiring 13B and a gate electrode extension part 13C, the gate electrode extension part 13C is positioned above the cathode electrode extension part 11C without existence of the gate electrode-branch wiring 13B, the gate electrode extension part 13C does not exist above the cathode electrode-branch wiring 11B, the cathode electrode extension part 11C is positioned below the gate electrode extension part 13C without existence of the cathode electrode-branch wiring 11B, the cathode electrode extension part 11C is positioned below a second opening 18, and a notched part or a cutoff part 11D is provided at least either the cathode electrode-branch wiring 11B or the gate electrode-branch wiring 13B. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a cold cathode field emission display having a focus electrode.

  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-speed response, high-luminance color display, and low power consumption.

  A cold cathode field emission display device (hereinafter sometimes abbreviated as “display device”), which is a flat display device incorporating a cold cathode field emission device as an electron emission device, generally has a plurality of cold cathode field fields. A cathode panel provided with an electron-emitting device (hereinafter sometimes abbreviated as “field-emitting device”), and an anode panel having a phosphor region that emits light when excited by collision with electrons emitted from the field-emitting device; However, the cathode panel and the anode panel are arranged to face each other through a space maintained in a high vacuum, and the cathode panel and the anode panel are joined to each other at the outer peripheral portion via a joining member. Here, the cathode panel has electron emission regions corresponding to the sub-pixels 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. 10 shows a schematic partial end view of a typical display device having a Spindt-type field emission device disclosed in Japanese Patent Application Laid-Open No. 2001-035423, and shows the arrangement relationship between a cathode electrode, a gate electrode, and the like. 14A schematically shows a partial cross-sectional view along the arrow BB in FIG. 14A, and FIG. 14B shows the shapes of the cathode electrode and the gate electrode. This is schematically shown in FIG.

In this display device, a cathode panel CP provided with electron emission areas EA arranged in a two-dimensional matrix on a support 10 and an anode panel AP provided with a phosphor area 22 and an anode electrode 24 are provided. A space SP joined at the outer periphery and sandwiched between the cathode panel CP and the anode panel AP is maintained in a vacuum. And the cathode panel CP is
(A) a cathode electrode 211 formed on the support 10;
(B) the first insulating layer 12 provided on the support 10 and the cathode electrode 211;
(C) a gate electrode 213 formed on the first insulating layer 12;
(D) a second insulating layer 16 formed on the first insulating layer 12 and the gate electrode 13, and
(E) a focus electrode 17 formed on the second insulating layer 16;
It has.

  The cathode electrode 211 includes a cathode electrode / trunk wiring 211A extending in the first direction, a cathode electrode / branch wiring 211B extending from the cathode electrode / main wiring 211A in a second direction different from the first direction, and a cathode electrode. -It is comprised from the cathode electrode extension part 211C extended from the branch wiring 211B. On the other hand, the gate electrode 213 extends in the first direction from the gate electrode / branch wiring 213B, the gate electrode / branch wiring 213B extending from the gate electrode / trunk wiring 213A, and the gate electrode / branch wiring 213B. The gate electrode extending portion 213C is configured.

Furthermore, each electron emission area EA
(F) a first opening 14 provided in the gate electrode extension 213C and the first insulating layer 12,
(G) an electron emission portion 15 formed on the portion of the cathode electrode extension 211C exposed at the bottom of the first opening 14, and
(H) Provided on the focus electrode 17 and the second insulating layer 16, with the gate electrode / branch wiring 213B, the gate electrode extending portion 213C, the first opening 14, the first insulating layer 12 and the electron emitting portion 15 exposed at the bottom. The second opening 18,
It is composed of

  A potential corresponding to an image signal (video signal) (for example, a potential varying from 0 to 18 volts) is applied to the cathode electrode 211, and a constant potential corresponding to a scanning signal (for example, for example, a voltage varying from 0 to 18 volts). 35 volts) is applied. Alternatively, on the contrary, a potential corresponding to an image signal (video signal) (for example, a potential varying from 0 to 18 volts) is applied to the gate electrode 213, and a scanning signal is corresponding to the cathode electrode 211. A constant potential (for example, 35 volts) is applied.

JP 2001-035423 A

  In the conventional display device, the gate electrode extension 213C and the cathode electrode / branch wiring 211B do not overlap. Therefore, due to the potential fluctuation corresponding to the image signal (video signal) applied to the cathode electrode 211, the electric field generated by the cathode electrode / branch wiring 211B changes in the electric field formed by the focus electrode 17. As a result, there is a case where the electrons emitted from the electron emission unit 15 do not collide with a desired region of the facing phosphor region 22 and the shape of the electron beam colliding with the anode electrode 24 is changed. There is. Alternatively, due to the potential fluctuation corresponding to the image signal (video signal) applied to the gate electrode 213, the electric field generated by the focus electrode 17 is changed by the electric field generated in the gate electrode / branch wiring 213B. As a result, there is a case where the electrons emitted from the electron emission unit 15 do not collide with a desired region of the facing phosphor region 22 and the shape of the electron beam colliding with the anode electrode 24 is changed. There is.

  Accordingly, an object of the present invention is to provide a cold cathode field emission display device having a configuration and structure in which electrons emitted from the electron emission portion can reliably collide with a desired region of the opposing phosphor region. is there.

In order to achieve the above object, a cold cathode field emission display device according to the first or second aspect of the present invention (hereinafter sometimes simply referred to as “display device”) is provided on a support. A cathode panel having electron emission regions arranged in a two-dimensional matrix and an anode panel provided with a phosphor region and an anode electrode are joined at the outer periphery, and sandwiched between the cathode panel and the anode panel. A cold cathode field emission display in which the space is maintained in a vacuum,
The cathode panel
(A) a cathode electrode formed on a support;
(B) a first insulating layer provided on the support and the cathode electrode;
(C) a gate electrode formed on the first insulating layer;
(D) a second insulating layer formed on the first insulating layer and the gate electrode, and
(E) a focus electrode formed on the second insulating layer;
It has.

In the display device according to the first aspect of the present invention,
The cathode electrode is composed of a cathode electrode / trunk wiring extending in the first direction, a cathode electrode / branch wiring extending from the cathode electrode / trunk wiring, and a cathode electrode extending portion extending from the cathode electrode / branch wiring,
The gate electrode includes a gate electrode / trunk wiring extending in a second direction different from the first direction, a gate electrode / branch wiring extending from the gate electrode / trunk wiring, and a gate electrode extending portion extending from the gate electrode / branch wiring Consists of
Above the cathode electrode extension, the gate electrode extension is located, and there is no gate electrode / branch wiring,
There is no gate electrode extension above the cathode electrode / branch line,
Below the gate electrode extension, the cathode electrode extension is located, and there are no cathode electrodes / branch wires,
Each electron emission region is
(F) a first opening provided in the gate electrode extension and the first insulating layer;
(G) an electron emission portion formed on the cathode electrode extension exposed at the bottom of the first opening, and
(H) a second electrode provided in the focus electrode and the second insulating layer, the gate electrode / branch wiring, the gate electrode extension, the first opening, and the second opening in which the first insulating layer is exposed at the bottom;
Consists of
The cathode electrode extension is located below the second opening,
At least one of the cathode electrode / branch wiring and the gate electrode / branch wiring is provided with a notch or a cutout.

  Here, in the display device according to the first aspect of the present invention, the cathode electrode / branch wiring is provided with a cutout portion or a cutout portion, and the cathode electrode has a potential (fluctuates) corresponding to an image signal. Potential) is applied, and a potential corresponding to the scanning signal (a constant potential) is applied to the gate electrode. Alternatively, the cathode electrode / branch wiring and the gate electrode / branch wiring are provided with cutouts or cutouts, and a potential corresponding to an image signal (fluctuating potential) is applied to the cathode electrode. A potential (a constant potential) corresponding to the scanning signal may be applied. Alternatively, the gate electrode / branch wiring is provided with a cutout or a cutout, a potential corresponding to a scanning signal (a constant potential) is applied to the cathode electrode, and a potential corresponding to an image signal is applied to the gate electrode. A (variable potential) may be applied.

Further, in the Viewing device of the present invention,
A cathode panel having electron emission regions arranged in a two-dimensional matrix on a support and an anode panel having a phosphor region and an anode electrode are joined at the outer periphery, and the cathode panel and the anode panel A cold cathode field emission display device in which a space sandwiched between is held in a vacuum,
The cathode panel
(A) a cathode electrode formed on a support;
(B) a first insulating layer provided on the support and the cathode electrode;
(C) a gate electrode formed on the first insulating layer;
(D) a second insulating layer formed on the first insulating layer and the gate electrode, and
(E) a focus electrode formed on the second insulating layer;
With
A cathode electrode, the cathode electrode and the main wiring extending in a first direction, the cathode electrode and the branch wirings extending from the cathode electrode and the main wiring to the first direction and a second direction substantially orthogonal, and the cathode electrode and the branch wiring of It consists of a cathode electrode extension extending from the tip ,
The gate electrode, the second gate electrode and the main wiring extending in a direction extending from the gate electrode and the main wiring to the first direction, the leading end a second bending is way extending Ru gate electrode, the branch wiring direction, gate It consists of a gate electrode extension extending from the tip of the electrode / branch wiring, and a gate electrode tip extending from the tip of the gate electrode extension,
A cathode electrode extension is located below the gate electrode extension, and a cathode electrode / branch wire is located below the gate electrode tip,
Each electron emission region is
(F) a first opening provided in the gate electrode extension and the first insulating layer;
(G) an electron emission portion formed on the cathode electrode extension exposed at the bottom of the first opening, and
(H) a second electrode that is provided on the focus electrode and the second insulating layer and has a gate electrode / branch wiring, a gate electrode extension, a gate electrode tip, a first opening, and a second opening from which the first insulating layer is exposed at the bottom;
It is composed of

  Here, in the display device according to the second aspect of the present invention, a potential corresponding to an image signal (fluctuating potential) is applied to the cathode electrode, and a potential corresponding to the scanning signal (constant) is constant to the gate electrode. The potential can be applied.

In the display device according to the first aspect and the second aspect of the present invention including the above preferred form and configuration (hereinafter, these may be collectively referred to simply as “display device of the present invention”), A cold cathode field emission device (hereinafter sometimes abbreviated as “field emission device”)
(A) a cathode electrode extension formed on the support;
(B) a first insulating layer provided on the support and the cathode electrode extending portion;
(C) a gate electrode extension formed on the first insulating layer;
(D) a first opening provided in the gate electrode extension and the first insulating layer;
(E) an electron emission portion formed on the portion of the cathode electrode extension exposed at the bottom of the first opening,
(F) a second insulating layer formed on the first insulating layer and the gate electrode extension,
(G) a focus electrode formed on the second insulating layer, and
(H) a second opening provided in the focus electrode and the second insulating layer, with the gate electrode extending portion, the first opening, the first insulating layer and the electron emitting portion exposed at the bottom;
It is composed of

In the display device of the present invention, the substrate constituting the cathode panel or the substrate constituting the anode panel may be any glass substrate, as long as the surfaces of these substrates facing each other are composed of insulating members. Examples include a glass substrate with an insulating coating formed on the surface, a quartz substrate, a quartz substrate with an insulating coating formed on the surface, and a semiconductor substrate with an insulating coating formed on the surface. 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, 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.

  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 extension portion located at the bottom of the first opening) or , Flat field emission devices (field emission devices in which a substantially planar electron emission portion is provided on the cathode electrode extension portion located at the bottom of the first opening). In the cathode panel, the projection image of the cathode electrode / trunk wiring and the projection image of the gate electrode / trunk wiring are orthogonal to each other, that is, the first direction and the second direction are orthogonal to each other. This is preferable from the viewpoint of simplification of the structure. Here, the gate electrode / main line may extend in the row direction (X direction), and the cathode electrode / main line may extend in the column direction (Y direction).

  In the display device, when an actual display operation is performed, a strong electric field generated by a voltage applied to the gate electrode and the cathode 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 anode panel, and collide with the phosphor region. As a result of the collision of electrons with the phosphor region, the phosphor region emits light and can be recognized as an image.

In the display device, the cathode electrode is connected to the cathode electrode control circuit, the gate electrode is connected to the gate electrode control circuit, the anode electrode is connected to the anode electrode control circuit, and the focus electrode is connected to the focus electrode control circuit. Note that these control circuits can be constituted by known circuits. During actual display operation, the voltage (anode voltage) V _A applied to the anode electrode from the anode electrode control circuit is normally constant, and can be set to, 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. At the time of actual display operation of the display device, for example, with respect to the voltage V _C applied to the cathode electrode and the voltage V _G applied to the gate electrode, a voltage modulation method or a pulse width modulation method can be adopted as the gradation control method.

A field emission device can be generally manufactured by the following method.
(1) forming a cathode electrode including a cathode electrode extension on a support;
(2) forming a first insulating layer on the entire surface (on the support and the cathode electrode);
(3) forming a gate electrode including a gate electrode extension on the first insulating layer;
(4) A first opening is formed in a portion of the gate electrode extension and the first insulating layer in a region where the cathode electrode extension and the gate electrode extension overlap, and the cathode electrode extension is formed at the bottom of the first opening. Exposing the existing part,
(5) forming an electron emission portion on the cathode electrode extension portion located at the bottom of the first opening,
(6) A step of forming a second insulating layer having a second opening and forming a focus electrode on the second insulating layer.

Alternatively, the field emission device can be manufactured by the following method.
(1) forming a cathode electrode including a cathode electrode extension on a support;
(2) forming an electron emission portion on the cathode electrode extension portion;
(3) forming a first 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 including a gate electrode extension on the first insulating layer;
(5) A first opening is formed in the gate electrode extension and the first insulating layer in a region where the cathode electrode extension and the gate electrode extension overlap, and an electron emission portion is formed at the bottom of the first opening. Exposing the process,
(6) A step of forming a second insulating layer having a second opening and forming a focus electrode on the second insulating layer.

As constituent materials for the gate electrode, cathode electrode, and focus electrode, chromium (Cr), aluminum (Al), tungsten (W), niobium (Nb), tantalum (Ta), molybdenum (Mo), copper (Cu), gold ( Various metals including metals such as Au), silver (Ag), titanium (Ti), nickel (Ni), cobalt (Co), zirconium (Zr), iron (Fe), platinum (Pt), zinc (Zn); Alloys (for example, MoW) or compounds (for example, TiW; nitrides such as TiN and WN; silicides such as WSi ₂ , MoSi ₂ , TiSi ₂ , and TaSi ₂ ); semiconductors such as silicon (Si); Examples thereof include carbon thin films such as diamond; conductive metal oxides such as ITO (indium oxide-tin), indium oxide, and zinc oxide. The gate electrode, the cathode electrode, and the focus electrode can have a single layer structure or a stacked structure of these materials. In addition, as a method for forming these electrodes, for example, various physical vapor deposition methods (PVD methods) including vacuum deposition methods such as electron beam deposition method and hot filament deposition method, sputtering methods, ion plating methods, and laser ablation methods. Various chemical vapor deposition methods (CVD method); various printing methods including screen printing method, ink jet printing method, metal mask printing method; plating method (electroplating method and electroless plating method); lift-off method; sol-gel The method etc. can be mentioned, The combination of these methods and an etching method can also be mentioned. Here, by appropriately selecting a formation method, it is possible to directly form a patterned strip-like cathode electrode, gate electrode, and focus electrode.

  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 various PVD methods such as a sputtering method and a vacuum deposition method, and various CVD methods.

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. Good. 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.

  When the first opening is cut in a virtual plane parallel to the support surface (first opening A formed in the gate electrode, first A opening formed in the first insulating layer, first B opening formed in the first insulating layer) Can be any shape such as a circle, an ellipse, a rectangle, a polygon, a rounded rectangle, or 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 A opening can also be formed directly. The formation of the first B opening can also be performed by, for example, anisotropic etching, isotropic etching, or a combination of anisotropic etching and isotropic etching. The formation of the second opening provided in the focus electrode and the second insulating layer can also be performed in a similar manner.

  In the field emission device, depending on the structure of the field emission device, one electron emission portion may exist in one first opening, or a plurality of electron emission portions exist in one first opening. Alternatively, a plurality of first A openings are provided in the gate electrode extension, and one first B opening that communicates with the first A openings is provided in the first insulating layer and provided in the first insulating layer. One or a plurality of electron emission portions may be present in the single first B opening.

In the field emission device, a resistor thin film may be formed between the cathode electrode extension portion and the electron emission portion. By forming the resistor thin film, it is possible to stabilize the operation of the field emission device, make the electron emission characteristics uniform, and suppress the leakage current between the cathode electrode extension portion and the gate electrode extension portion. As a material constituting the resistor thin film, a carbon resistor material such as silicon carbide (SiC) or SiCN, a semiconductor resistor material such as SiN or amorphous silicon, a high melting point such as ruthenium oxide (RuO ₂ ), tantalum oxide, or tantalum nitride. Examples thereof include metal oxides and refractory metal nitrides. Examples of the method of forming the resistor thin film include various printing methods such as a sputtering method, various CVD methods, and a screen printing method. The electric resistance value per one electron emitting portion may be about 1 × 10 ⁵ to 1 × 10 ¹¹ Ω, preferably several MΩ to several tens of gigaΩ.

The first insulating layer, as the constituent material of the second 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 material An insulating resin such as polyimide can be used alone or in appropriate combination. For forming the first insulating layer and the second insulating layer, known processes such as various printing methods such as various CVD methods, coating methods, sputtering methods, and screen printing methods can be used.

In the display device, as a configuration example of the anode electrode and the phosphor region,
(1) A configuration in which an anode electrode is formed on a substrate and a phosphor region is formed on the anode electrode. (2) A configuration in which a phosphor region is formed on the substrate and an anode electrode is formed on the phosphor region. 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 region. In the configuration (2), a metal back film may be formed on the anode electrode. The metal back film can also serve as 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 an anode electrode resistor layer. The material constituting the anode electrode resistor layer includes carbon-based materials such as carbon, silicon carbide (SiC), and SiCN; SiN-based materials; ruthenium oxide (RuO ₂ ), tantalum oxide, tantalum nitride, chromium oxide, titanium oxide, and the like. Examples thereof include melting point metal oxides and high melting point metal nitrides; 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 anode electrode resistor layer include 1 × 10 ⁻¹ Ω / □ to 1 × 10 ¹⁰ Ω / □, preferably 1 × 10 ³ Ω / □ to 1 × 10 ⁸ Ω / □. it can. The number of anode electrode units [UN] may be two or more. For example, when the total number of phosphor regions arranged in a straight line is [un], [UN] = [un], or , [Un] = u · [UN] (u is an integer of 2 or more, preferably 10 ≦ u ≦ 100, more preferably 20 ≦ u ≦ 50), or spacers arranged at a constant interval. The number of pixels can be a number obtained by adding 1, or the number of pixels or the number of subpixels can be matched, or the number of pixels or the number of subpixels can be an integer. 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. An anode electrode resistor layer may be formed on one anode electrode as a whole. As described above, if the anode electrode is divided into anode electrode units having a smaller area, instead of being formed over almost the entire effective area, the static electricity between the anode electrode unit and the electron emission area is formed. The electric capacity can be reduced. As a result, the occurrence of discharge can be reduced, and the occurrence of damage to the anode electrode and the electron emission region due to the discharge can be effectively reduced.

  When the anode electrode is composed of an anode electrode unit and a partition wall (described later) is formed, the anode electrode unit may be formed so as to extend from each phosphor region to the partition wall side surface. it can. The anode electrode unit may be formed from each phosphor region to the middle of the side wall of the partition wall.

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, vacuum deposition methods such as electron beam deposition method and hot filament deposition method, various PVD methods such as sputtering method, ion plating method and laser ablation method; various CVD methods; various methods including screen printing method Examples thereof include printing method; metal mask printing method; lift-off method; sol-gel method. That is, a conductive material layer is formed, and based on lithography technology and etching technology, this conductive material layer can be patterned to form an anode electrode. Alternatively, the anode electrode can be obtained by forming a conductive material based on various PVD methods or various printing methods through a mask or screen having an anode electrode pattern. The anode electrode resistor layer can also be formed by the same or similar method as the anode electrode. That is, an anode electrode resistor layer may be formed from a resistor material, and the anode electrode resistor layer may be patterned based on a lithography technique and an etching technique, or a mask or a screen having an anode electrode resistor layer pattern. The anode electrode resistor layer can be obtained by forming the resistor material through various PVD methods and various printing methods. 3 × 10 ⁻⁸ m (30 nm) to 1 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 ⁻⁶ m (1 μm), preferably 5 × 10 ⁻⁸ m (50 nm) to 5 × 10 ⁻⁷ m (0.5 μm).

As the constituent material of the anode electrode, aluminum (Al), molybdenum (Mo), 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 , TaSi _2, etc.); silicon (Si), semiconductors; diamond, graphite and other carbon thin films; ITO (indium oxide-tin), indium oxide, zinc oxide, etc., conductive metal oxides Can be illustrated. When the anode electrode resistor layer is formed, the anode electrode is preferably made of a conductive material that does not change the electric resistance value of the anode electrode resistor layer. For example, the anode electrode resistor layer is made of silicon carbide (SiC). When comprised, it is preferable to comprise an anode electrode from molybdenum (Mo) or aluminum (Al).

  The phosphor region may be composed of monochromatic phosphor particles or may be composed of three primary color phosphor particles. The arrangement pattern of the phosphor regions is, for example, a dot shape. Specifically, when the display device performs color display, examples of the arrangement and arrangement of the phosphor regions include a delta arrangement, a stripe arrangement, a diagonal arrangement, and a rectangle arrangement. That is, one row of the phosphor regions arranged in a straight line is occupied by the row occupied by the red light emitting phosphor region, the row occupied by the green light emitting phosphor region, and the blue light emitting phosphor region. May be composed of a row in which a red light-emitting phosphor region, a green light-emitting phosphor region, and a blue light-emitting phosphor region are sequentially arranged. Here, the phosphor region is defined as a phosphor region that generates one bright spot on the anode panel. One pixel (one pixel) is composed of a set of one red light emitting phosphor region, one green light emitting phosphor region, and one blue light emitting phosphor region, and one subpixel is one phosphor. The region is composed of one red light emitting phosphor region, one green light emitting phosphor region, or one blue light emitting phosphor region. A gap between adjacent phosphor regions may be filled with a light absorption layer (black matrix) for the purpose of improving contrast.

  For the phosphor region, a luminescent crystal particle composition prepared from luminescent crystal particles is used. For example, a red photosensitive luminescent crystal particle composition (red light-emitting phosphor slurry) is applied to the entire surface and exposed. And developing to form a red light emitting phosphor region, and then applying a green photosensitive luminescent crystal particle composition (green light emitting phosphor slurry) to the entire surface, exposing and developing, and then producing a green light emitting phosphor. A region is formed, and further, a blue photosensitive luminescent crystal particle composition (blue light emitting phosphor slurry) is coated on the entire surface, exposed and developed to form a blue light emitting phosphor region. be able to. Alternatively, each phosphor region may be formed by a screen printing method, an ink jet printing method, a float coating method, a sedimentation coating method, a phosphor film transfer method, or the like. Although the average thickness of the phosphor region on the substrate is not limited, it is desirably 3 μm to 20 μm, preferably 5 μm to 10 μm. The phosphor material constituting the luminescent crystal particles can be appropriately selected and used 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.

  It is preferable from the viewpoint of improving the contrast of the display image that the light absorption layer that absorbs light from the phosphor region is formed between adjacent phosphor regions or between a partition wall and a substrate described later. Here, the light absorption layer functions as a so-called black matrix. As a material constituting the light absorption layer, it is preferable to select a material that absorbs 90% or more of light from the phosphor region. 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. The light absorption layer depends on the material used, for example, a combination of a vacuum deposition method, a sputtering method and an etching method, a combination of a vacuum deposition method, a sputtering method, a spin coating method and a lift-off method, various printing methods, a lithography technique, etc. Thus, it can be formed by a method selected as appropriate.

  In order to prevent an electron recoiled from the phosphor region or a secondary electron emitted from the phosphor region from entering another phosphor region, so-called optical crosstalk (color turbidity) is generated. 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) is a method of forming a partition wall forming material layer by extruding a partition wall forming material made of a paste-like organic material or inorganic material onto a substrate from a mold (cast), and then forming the partition wall. In this method, the forming material layer is fired. The sand blast forming method is, for example, a method for forming a partition wall forming material layer on a substrate using a screen printing method, a metal mask printing method, a roll coater, a doctor blade, a nozzle discharge type coater, etc. In this method, the portion of the partition wall forming material layer to be formed is covered with a mask layer, and then the exposed portion 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. Further, a part of the partition may function as a spacer holding portion.

  As a planar shape of the part surrounding the phosphor region in the partition wall (corresponding to the inner contour line of the projected image of the partition wall side surface and a kind of opening region), a rectangular shape, a circular shape, an elliptical shape, an oval shape, a triangular shape, Examples include pentagonal or more polygonal shapes, rounded triangular shapes, rounded rectangular shapes, rounded polygons, etc., and linear shapes extending parallel to two sides of the phosphor region (Rod-like shape). 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 cathode panel and the anode panel are joined at the outer periphery, but the joining may be performed using an adhesive layer as a joining member, or a rod-like or frame-like (frame-like) insulation such as glass or ceramics. You may carry out using the joining member which consists of the frame body comprised from material and an adhesive layer. When using a joining member consisting of a frame and an adhesive layer, the height of the frame is appropriately selected, so that the cathode panel and the anode panel are compared with the case where a joining member consisting only of the adhesive layer is used. It is possible to set the facing distance between the longer. As a constituent material of the adhesive layer, frit glass such as B ₂ O ₃ —PbO-based frit glass and SiO ₂ —B ₂ O ₃ —PbO-based frit glass is generally used, but the melting point is about 120 to 400 ° C. A so-called low melting point metal material may be used. As such low melting point metal materials, In (indium: melting point 157 ° C.); indium-gold low melting point alloy; Sn ₈₀ Ag ₂₀ (melting point 220 to 370 ° C.), Sn ₉₅ Cu ₅ (melting point 227 to 370 ° C.) Tin (Sn) 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.) (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 ° C.) Examples thereof include tin-lead based 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 three members of the cathode panel, the anode panel, and the joining member, the three members may be joined at the same time, or in the first stage, either the cathode panel or the anode panel and the joining member are joined, In the second stage, the other of the cathode panel or the anode panel and the joining member may be joined. If the three-party simultaneous bonding or the second stage bonding is performed in a high vacuum atmosphere, the space surrounded by the cathode panel, the anode panel, and the bonding member becomes a vacuum simultaneously with the bonding. Alternatively, after the three members are joined, the space surrounded by the cathode panel, the anode panel, and the joining member can be evacuated to create a vacuum. When exhausting after joining, the atmosphere pressure during joining may be either normal pressure or reduced pressure, and the gas constituting the atmosphere may be nitrogen gas or a gas belonging to Group 0 of the periodic table (for example, Ar gas) ) Is preferable, but it can also be performed in the atmosphere.

  When exhaust is performed, the exhaust can be performed through an exhaust pipe called a tip pipe connected in advance to the cathode panel and / or the anode 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 wt% chromium (Cr)], and the above-mentioned frit glass or After being joined using a low melting point metal material and the space has reached a predetermined degree of vacuum, it is sealed off by thermal fusion or sealed by crimping. Note that it is preferable that the entire display device is once heated and then cooled before being sealed because residual gas can be released into the space and the residual gas can be removed out of the space by exhaust.

Since the space between the cathode panel and the anode panel is maintained in a vacuum state, a spacer is locally provided between the cathode panel and the anode panel so that the display device is not damaged by atmospheric pressure. It is preferable to arrange them. One row of spacers may be composed of a single spacer or a plurality of spacers. That is, the number of spacers along the X direction may be one or two or more, and depends on the specifications of the display device. The spacer base | substrate which comprises a spacer can be comprised from ceramics or glass material, for example. When the spacer substrate is composed of ceramics, the ceramics include aluminum silicate compounds such as mullite, aluminum oxides such as alumina, barium titanate, lead zirconate titanate, zirconia (zirconium oxide), cordiolite, borosilicate barium, Examples thereof include iron silicate, glass ceramic materials, titanium oxide, chromium oxide, magnesium oxide, iron oxide, vanadium oxide, nickel oxide added to these, and for example, JP 2003-524280 A The materials described in (1) can also be used. In this case, a spacer substrate can be manufactured by forming a so-called green sheet, firing the green sheet, and cutting the fired green sheet product. Glass materials include 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 ), Examples thereof include stellite (2MgO · SiO ₂ ), lead glass (Na ₂ O · PbO · SiO ₂ ), and crystalline glass. In addition, it is preferable to chamfer the end portion of the spacer to remove the protruding portion. For example, the spacer may be fixed by being sandwiched between partition walls provided in the anode panel, or, for example, a spacer holding portion may be formed on the anode panel and / or the cathode panel and fixed by the spacer holding portion. do it.

An antistatic film, a resistor film, or the like may be provided on the side surface of the spacer (more specifically, the side surface of the spacer base). The material constituting the antistatic film preferably has a secondary electron emission coefficient close to 1. As the material constituting the antistatic film, a semiconductor such as Si or Ge, a semimetal such as graphite, an oxide, or a boride , Carbides, sulfides, nitrides, and the like can be used. Specifically, for example, compounds containing a metalloid element such as a semi-metal and MoSe _x such as _{graphite, CrO x, NdO x, CrAl} x O y, manganese _{oxide, La x Ba 2-x CuO} 4, La x Y Oxides such as _1-x CrO ₃ , borides such as AlB _x and TiB _x , carbides such as SiC, sulfides such as MoS _x and WS _x , and compounds of tungsten nitride and germanium nitride, BN, TiN, AlN In addition, for example, materials described in JP-T-2004-500688 and the like can also be used. Examples of the material constituting the resistor film include ruthenium oxide (RuO _x ) and cermet. The film provided on the surface of the spacer such as an antistatic film may be made of a single type of material or may be made of a plurality of types of materials. For example, the film may have a single-layer structure, and the layer may be composed of a plurality of types of materials, or the film is formed by laminating a plurality of layers, and each layer is composed of different materials. Also good. These films can be formed by well-known methods such as various PVD methods such as sputtering and vacuum deposition, various CVD methods, and screen printing methods. Moreover, what is necessary is just to set arbitrarily the film thickness of these films | membranes as needed.

  In the present invention, when the number of pixels is M × N, as (M, N), specifically, VGA (640, 480), S-VGA (800, 600), XGA (1024, 768), APRC (1152,900), S-XGA (1280,1024), U-XGA (1600,1200), HD-TV (1920,1080), Q-XGA (2048,1536), (1920,1035), Some of the image display resolutions such as (720, 480) and (1280, 960) can be exemplified, but are not limited to these values.

  In the cold cathode field emission display according to the first aspect of the present invention, the gate electrode extension is located above the cathode electrode extension, and the gate electrode / branch wiring is present. Not. Also, no gate electrode extension exists above the cathode electrode / branch wiring. Furthermore, the cathode electrode extension is located below the gate electrode extension, and there is no cathode electrode / branch wiring. In addition, the cathode electrode extension is located below the second opening. At least one of the cathode electrode / branch wiring and the gate electrode / branch wiring is provided with a notch or a cutout. Therefore, it is possible to reliably suppress the change in the electric field formed by the focus electrode due to the potential fluctuation of the cathode electrode / branch wiring or the gate electrode / branch wiring. As a result of the above, electrons emitted from the electron emission portion can be reliably collided with a desired region of the opposing phosphor region, and the shape of the electron beam colliding with the anode electrode is changed. Therefore, a cold cathode field emission display device having high image display quality can be provided.

  In the cold cathode field emission display according to the second aspect of the present invention, the tip end portion of the gate electrode extends to above the cathode electrode / branch line so as to cover the cathode electrode / branch line. Therefore, for example, even when a fluctuating potential corresponding to an image signal is applied to the cathode electrode, the change in the electric field formed by the focus electrode can be suppressed because the tip of the gate electrode functions as a kind of shield. it can. Therefore, the electrons emitted from the electron emission portion can be reliably collided with a desired region of the opposing phosphor region, and a change in the shape of the electron beam colliding with the anode electrode is suppressed. Therefore, it is possible to provide a cold cathode field emission display device having high image display quality.

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

  Hereinafter, the present invention will be described based on examples with reference to the drawings. Prior to that, a common outline of cold cathode field emission display devices (hereinafter simply referred to as display devices) in the first to fourth embodiments will be described. Is described below.

  A schematic partial end view of the display device in the example is the same as that shown in FIG. In the display device of the embodiment, a cathode panel CP provided with an electron emission region EA arranged in a two-dimensional matrix on a support 10 and an anode panel AP provided with a phosphor region 22 and an anode electrode 24 are arranged on the outer periphery. The space SP sandwiched between the cathode panel CP and the anode panel AP is held in a vacuum.

And the cathode panel CP is
(A) Cathode electrodes 11, 111 formed on the support 10;
(B) a first insulating layer 12 provided on the support 10 and the cathode electrodes 11 and 111;
(C) gate electrodes 13 and 113 formed on the first insulating layer 12;
(D) a second insulating layer 16 formed on the first insulating layer 12 and the gate electrodes 13 and 113, and
(E) a focus electrode 17 formed on the second insulating layer 16;
It has.

  Here, in the display devices according to the first to fourth embodiments, the cathode electrodes 11 and 111 have cathode electrodes and trunk wires 11A and 111A extending in the first direction (column direction, Y direction), cathode electrodes and Cathode electrode / branch wires 11B, 111B extending from the trunk wires 11A, 111A (specifically, extending in a second direction (row direction, X direction) different from the first direction), and cathode electrodes / branch wires The cathode electrode extending portions 11C and 111C (specifically, extending in the second direction) extending from 11B and 111B are configured. On the other hand, the gate electrodes 13 and 113 include gate electrodes and trunk wirings 13A and 113A extending in the second direction, and gate electrodes and branch wirings 13B and 113B extending from the gate electrodes and trunk wirings 13A and 113A. And further extending in the second direction), and gate electrode extending portions 13C and 113C (specifically extending in the first direction) extending from the gate electrode / branch wires 13B and 113B. Has been. In the display device according to the fourth embodiment, the gate electrode 113 is further configured by a gate electrode tip portion 113E extending from the gate electrode extension portion 113C. The extending direction of the cathode electrode extending portions 11C and 111C and the gate electrode extending portions 13C and 113C is not limited to this. That is, the cathode electrode extends in the second direction from the cathode electrode / main line, and further extends in the first direction, and extends from the cathode electrode / branch line in the first direction. The gate electrode is composed of a gate electrode / branch line extending in the first direction from the gate electrode / main line and a gate electrode extending part extending in the first direction from the gate electrode / branch line. You can also.

Furthermore, each electron emission area EA
(F) First opening 14 provided in gate electrode extension portions 13C and 113C and first insulating layer 12 (provided in first A opening portion 14B and first insulating layer 12 provided in gate electrode extension portion 13C) 1B opening 14C),
(G) an electron emission portion 15 formed on the cathode electrode extension portions 11C and 111C exposed at the bottom of the first opening 14, and
(H) Provided on the focus electrode 17 and the second insulating layer 16, the gate electrode / branch wires 13 </ b> B and 113 </ b> B, the gate electrode extending portions 13 </ b> C and 113 </ b> C, the first opening 14, the first insulating layer 12, and the electron emission at the bottom A second opening 18 where the portion 15 is exposed,
It is composed of In the fourth embodiment, the gate electrode tip 113E is further exposed at the bottom of the second opening 18. Reference numeral 14A indicates a region where the first opening 14 is to be formed.

Here, the display device according to the embodiment includes an effective area EF and an invalid area NF surrounding the effective area EF. The effective area EF is a display area located substantially in the center that performs a practical image display function as a display device. The effective area EF is surrounded by an ineffective area NF that surrounds the frame. The space SP sandwiched between the cathode panel CP, the anode panel AP, and the joining member 26 is maintained in a vacuum (pressure: for example, 10 ⁻³ Pa or less). The ineffective area NF of the cathode panel CP is provided with a through hole (not shown) for evacuation, and in this through hole, an exhaust pipe (not shown) called a chip tube that is sealed after evacuation. Is attached. A spacer 27 is disposed along the row direction (X direction) between the cathode panel CP and the anode panel AP, and the spacer 27 is held by the spacer holding portion 25.

In the embodiment, the field emission element constituting the electron emission region is constituted by, for example, a Spindt type field emission element. Spindt-type field emission devices
(A) a cathode electrode extension portion 11C formed on the support 10;
(B) a first insulating layer 12 provided on the support 10 and the cathode electrode extension portion 11C;
(C) a gate electrode extension 13C formed on the first insulating layer 12,
(D) The first opening 14 (the first A opening 14B provided in the gate electrode extending portion 13C and the first insulating layer 12) provided in the gate electrode extending portion 13C and the first insulating layer 12 portion. 1B opening 14C provided in the
(E) an electron emitting portion 15 formed on the portion of the cathode electrode extending portion 11C exposed at the bottom of the first opening 14;
(F) a second insulating layer 16 formed on the first insulating layer 12 and the gate electrode extension 13C;
(G) the focus electrode 17 formed on the second insulating layer 16, and
(H) Provided on the focus electrode 17 and the second insulating layer 16, the gate electrode / branch wiring 13B, the gate electrode extending portion 13C, the first insulating layer 12, the first opening 14 and the electron emitting portion 15 are exposed at the bottom. The second opening 18,
It is composed of Here, the shape of the electron emission portion 15 is a conical shape.

  In the display device of the embodiment, the cathode electrode / stem wiring 11A, 111A and the gate electrode / stem wiring 13A, 113A are in directions in which projection images of these wirings 11A, 111A, 13A, 113A are orthogonal to each other (column direction and row). In the direction). A region where the projection images of the cathode electrode extending portions 11C and 111C and the gate electrode extending portions 13C and 113C overlap corresponds to a region of one subpixel (subpixel). In the electron emission area EA, a large number of electron emission portions 15 are provided. For simplification of the drawing, FIG. 10 shows two electron emission portions 15 in each electron emission area EA. The electron emission areas EA are usually arranged in a two-dimensional matrix as described above in the effective area EF (area that functions as an actual display portion) of the cathode panel CP. Here, the electron emission portion assembly is composed of a plurality of electron emission portions 15, but the region occupied by the electron emission portion assembly is, for example, an oval (two semicircles are connected by two line segments). In the first to fourth embodiments, an oval long axis (an axis parallel to two line segments connecting two semicircles) or an elliptical shape is used. The major axis and the longitudinal direction of the elongated polygon are parallel to the first direction.

  The anode panel AP includes a substrate 20, a phosphor region 22 formed on the substrate 20 and having a predetermined pattern, and an anode electrode 24 formed thereon. One sub-pixel (one sub-pixel) includes an electron emission area EA and a phosphor area 22 on the anode panel side facing the electron emission area EA. In the effective area EF, the sub-pixels are arranged on the order of several hundred thousand to several million, for example. A light absorption layer (black matrix) 23 is formed on the substrate 20 between the phosphor region 22 and the phosphor region 22 in order to prevent color turbidity of the display image and occurrence of optical crosstalk. ing. The anode electrode 24 is made of aluminum (Al) having a thickness of about 0.3 μm, is in the form of a thin sheet that covers the effective region EF, and is provided so as to cover the phosphor region 22. In the case of a color display device, one pixel (one pixel) is composed of a set of one red-emitting phosphor region, one green-emitting phosphor region, and one blue-emitting phosphor region. . A grid-like partition wall 21 surrounding each phosphor region 22 is formed on the substrate 20. Each phosphor region 22 is surrounded by a partition wall 21. The planar shape (corresponding to the inner contour line of the projected image of the partition wall side surface and a kind of opening region) of the portion surrounding the phosphor region 22 in the lattice-shaped partition wall 21 is a rectangular shape (rectangle), and these planes The shape (planar shape of the opening region) is arranged in a two-dimensional matrix (more specifically, a cross beam), and a lattice-like partition wall 21 is formed. A part of the partition functions as the spacer holding part 25.

In the display device according to the embodiment, the cathode electrode is connected to the cathode electrode control circuit 31, the gate electrode is connected to the gate electrode control circuit 32, the focus electrode 17 is connected to the focus electrode control circuit 33, and the anode electrode 24 is the anode electrode. It is connected to the control circuit 34. At the time of actual display operation of the display device, the anode voltage V _A applied to the anode electrode 24 from the anode electrode control circuit 34 is usually constant, for example, 5 to 15 kilovolts, specifically, for example, 9 kilovolts. (For example, d ₀ = 2.0 mm). On the other hand, regarding the voltage V _C applied to the cathode electrode and the voltage V _G applied to the gate electrode during the actual display operation of the display device,
(Α) 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 (β) A voltage V _G applied to the gate electrode by changing the voltage V _C applied to the cathode electrode (Γ) The method of changing the voltage V _C applied to the cathode electrode and the method of changing the voltage V _G applied to the gate electrode may be adopted. Details will be described later.

During actual display operation of the display device, a relatively negative voltage (V _C ) is applied to the cathode electrode from the cathode electrode control circuit 31, and a relatively positive voltage (V _G ) is applied to the gate electrode of the gate electrode control circuit 32. For example, 0 V is applied to the focus electrode 17 from the focus electrode control circuit 33, and a positive voltage (anode voltage V _A ) higher than that of the gate electrode is applied to the anode electrode 24 from the anode electrode control circuit 34. The In such a display device, when displaying an image by a line sequential drive method, for example, a potential corresponding to an image signal (video signal) is applied to the cathode electrode from the cathode electrode control circuit 31 and the gate electrode control circuit 32 is applied to the gate electrode. A potential corresponding to the scanning signal is applied. When the cathode electrode is a scanning electrode and the gate electrode is a data electrode, a potential corresponding to a scanning signal is applied to the cathode electrode from the cathode electrode control circuit 31, and an image signal is applied to the gate electrode from the gate electrode control circuit 32. A potential corresponding to (video signal) may be applied. An electric field generated when a voltage is applied between the cathode electrode and the gate electrode causes electrons to be emitted from the electron emission portion 15 based on the quantum tunnel effect, and the electrons are attracted to the anode electrode 24 and pass through the anode electrode 24. And collide with the phosphor region 22. As a result, the phosphor region 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 and the voltage V _C applied to the cathode electrode. The cathode electrode is driven by a cathode electrode driver, and the gate electrode is driven by a gate electrode driver. The cathode electrode control circuit 31, the gate electrode control circuit 32, the focus electrode control circuit 33, the anode electrode control circuit 34, and the drive driver can be configured from well-known circuits.

  Example 1 relates to a cold cathode field emission display according to a first aspect of the present invention. FIG. 1A schematically shows the positional relationship between the cathode electrode 11 and the gate electrode 13 in the display device of Example 1, and a schematic partial cross section along the arrow BB in FIG. The figure is shown in FIG. 1B, and the shapes of the cathode electrode 11 and the gate electrode 13 are schematically shown in FIG.

  In the display device of Example 1, or Example 2 and Example 3 described later, the gate electrode extension 13C is located above the cathode electrode extension 11C, and the gate electrode / branch The wiring 13B does not exist. Also, the gate electrode extension 13C does not exist above the cathode electrode / branch wiring 11B. Furthermore, the cathode electrode extension portion 11C is located below the gate electrode extension portion 13C, and the cathode electrode / branch wiring 11B does not exist. Further, the cathode electrode extension portion 11 </ b> B is located below the second opening 18.

  In the display device according to the first embodiment, the cutout portion 11D is provided in the cathode electrode / branch line 11B.

  In the first embodiment, a potential corresponding to an image signal (fluctuating potential) is applied to the cathode electrode 11, and a potential corresponding to a scanning signal (a constant potential) is applied to the gate electrode 13. That is, the above-described method (β) is adopted.

  As described above, in the display device according to the first embodiment, the cut-out portion 11D is provided in the cathode electrode / branch wiring 11B. Therefore, it is possible to reliably suppress a change in the electric field formed by the focus electrode 17 due to a change in the potential of the cathode electrode / branch wiring 11B. As a result, the electrons emitted from the electron emitter 15 can be reliably collided with a desired region of the opposing phosphor region 22, and the shape of the electron beam colliding with the anode electrode 24 is changed. Therefore, a display device having high image display quality can be provided. In addition, since the capacitance formed by the gate electrode extension 13C, the cathode electrode extension 11C, and the cathode electrode / branch wire 11B can be reduced, the load on the drive driver can be reduced. However, high-speed driving is possible.

  The second embodiment is a modification of the first embodiment. 3A schematically shows the positional relationship between the cathode electrode 11 and the gate electrode 13 in the display device of Example 2, and is a schematic partial cross section taken along the arrow BB in FIG. The figure is shown in FIG. 3B, and the shapes of the cathode electrode 11 and the gate electrode 13 are schematically shown in FIG.

  In the display device according to the second embodiment, the extraction portion 13D is provided in the gate electrode / branch wiring 13B. In the second embodiment, a potential corresponding to the scanning signal (a constant potential) is applied to the cathode electrode 11, and a potential corresponding to the image signal (a variable potential) is applied to the gate electrode 13. That is, the above-described method (α) is adopted.

  As described above, in the display device according to the second embodiment, the extraction portion 13D is provided in the gate electrode / branch wiring 13B. Therefore, it is possible to reliably suppress a change in the electric field formed by the focus electrode 17 due to a change in the potential of the gate electrode / branch wiring 13B. As a result, the electrons emitted from the electron emitter 15 can be reliably collided with a desired region of the opposing phosphor region 22, and the shape of the electron beam colliding with the anode electrode 24 is changed. Therefore, a display device having high image display quality can be provided.

  The third embodiment is also a modification of the first embodiment. FIG. 5A schematically shows the positional relationship between the cathode electrode 11 and the gate electrode 13 in the display device of Example 3, and a schematic partial cross section taken along the arrow BB in FIG. The figure is shown in FIG. 5B, and the shapes of the cathode electrode 11 and the gate electrode 13 are schematically shown in FIG.

  In the display device of Example 3, the cathode electrode / branch line 11B is provided with a cut-out part 11D, and the gate electrode / branch line 13B is provided with a cut-out part 13D. In the third embodiment, a potential corresponding to an image signal (fluctuating potential) is applied to the cathode electrode 11, and a potential corresponding to a scanning signal (a constant potential) is applied to the gate electrode 13. That is, the above-described method (β) is adopted.

  As described above, in the display device according to the third embodiment, the cutout portion 11D is provided in the cathode electrode / branch wiring 11B. Therefore, it is possible to reliably suppress a change in the electric field formed by the focus electrode 17 due to a change in the potential of the cathode electrode / branch wiring 11B. In addition, a cutout 13D is provided in the gate electrode / branch wiring 13B. Therefore, it is possible to reliably suppress a change in the electric field formed by the focus electrode 17 due to a change in the potential of the gate electrode / branch wiring 13B. As a result of the above, the electrons emitted from the electron emission portion 15 can be reliably collided with a desired region of the opposing phosphor region 22, and the shape of the electron beam colliding with the anode electrode 24 is changed. Therefore, it is possible to provide a display device having high image display quality.

  Example 4 relates to a display device according to the second aspect of the present invention. FIG. 7A schematically shows the positional relationship between the cathode electrode 111 and the gate electrode 113 in the display device of Example 4, and is a schematic partial cross section taken along the arrow BB in FIG. The figure is shown in FIG. 7B, and the shapes of the cathode electrode 111 and the gate electrode 113 are schematically shown in FIG.

  In the display device of Example 4, the cathode electrode extension 111C is located below the gate electrode extension 113C, and the cathode / branch wire 111B is located below the gate electrode tip 113E. doing. Also in the fourth embodiment, a potential corresponding to an image signal (fluctuating potential) is applied to the cathode electrode 111, and a potential corresponding to a scanning signal (a constant potential) is applied to the gate electrode 113.

  As described above, in the display device according to the fourth embodiment, the gate electrode tip portion 113E extends to above the cathode electrode / branch line 111B so as to cover the cathode electrode / branch line 111B. Therefore, a varying potential corresponding to an image signal is applied to the cathode electrode 111, but a constant potential is applied to the gate electrode 113, and the gate electrode tip portion 113E functions as a kind of shield. The change in the electric field formed by the electrode 17 can be suppressed. Therefore, the electrons emitted from the electron emission portion 15 can be reliably collided with a desired region of the opposing phosphor region 22, and the shape of the electron beam colliding with the anode electrode 24 is changed. Since it can suppress, the display apparatus which has high image display quality can be provided.

  FIG. 11A shows the result of simulating the position of the electron beam that collides with the anode electrode 24 in the display device of Example 4 when it is assumed that 0 volt is applied to the cathode electrode 111 and 35 volt is applied to the gate electrode 113. Shown in FIG. 11B shows the result of simulating the position of the electron beam that collides with the anode electrode 24 in the conventional display device described with reference to FIG. In FIG. 11, a region indicated by light gray and having a side indicated by “A” is a portion of the target anode electrode 24. Black dots indicate electrons that have collided with the anode electrode 24. From FIG. 11A and FIG. 11B, in the display device of Example 4, the electron beam collides with the target region of the anode electrode 24, whereas in the conventional display device. It can be seen that the electron beam collides with the right side of the target area of the anode electrode 24.

  The field emission devices in Examples 1 to 4 can be manufactured, for example, by the following method described with reference to FIGS. 12 and 13. However, only one field emission device is shown. The Spindt-type field emission device can be basically obtained by a method in which the conical electron emission portion 15 is formed by vertical vapor deposition of a metal material. That is, the vapor deposition particles are perpendicularly incident on the first A opening 14B provided in the gate electrode extension 13C, but are shielded by the overhanging deposit formed near the opening end of the first A opening 14B. Utilizing the effect, the amount of vapor deposition particles reaching the bottom of the first B opening 14C is gradually reduced, and the electron emission portion 15 which is a conical deposit is formed in a self-aligning manner. Here, a method of forming the peeling layer 40 in advance on the gate electrode extension 13C and the first insulating layer 12 in order to facilitate removal of unnecessary overhanging deposits will be described.

[Step-A]
First, a cathode electrode 11 (cathode electrode / trunk wiring 11A, cathode electrode / branch wiring 11B, cathode electrode extension portion 11C) made of chromium (Cr) is formed on a support 10 made of glass, for example, and then formed on the entire surface. A first insulating layer 12 made of SiO ₂ is formed, and further, a gate electrode 13 made of chromium (Cr) (gate electrode / trunk wiring 13A, gate electrode / branch wiring 13B, gate electrode extension 13C, if necessary) Further, a gate electrode tip) is formed on the first insulating layer 12. These various electrodes can be formed based on, for example, a sputtering method, a lithography technique, and a dry etching technique.

[Step-B]
Next, a resist layer functioning as an etching mask is formed on the gate electrode extension 13C and the first insulating layer 12 by lithography. Thereafter, the first A opening 14B is formed in the gate electrode extension 13C by the RIE (reactive ion etching) method, and the first B opening 14C is further formed in the first insulating layer 12. A part of the cathode electrode extending portion 11C is exposed at the bottom of the first opening 14 thus obtained. Thereafter, the resist layer is removed by an ashing technique. Thus, the structure shown in FIG. 12A can be obtained.

[Step-C]
Next, the electron emission portion 15 is formed on the cathode electrode extension portion 11 </ b> C exposed at the bottom of the first opening portion 14. Specifically, first, the release layer 40 is formed by obliquely depositing aluminum. At this time, by selecting a sufficiently large incident angle of the vapor deposition particles with respect to the normal line of the support 10, the gate electrode including the gate electrode extension portion 13 </ b> C can be obtained without substantially depositing aluminum at the bottom of the first opening 14. 13 and the peeling layer 40 can be formed on the first insulating layer 12. The release layer 40 protrudes from the opening end of the first opening 14 in a bowl shape, and thereby the first opening 14 is substantially reduced in diameter (see FIG. 12B).

[Step-D]
Next, for example, molybdenum (Mo) is vertically deposited on the entire surface. At this time, as shown in FIG. 12C, as the conductive material layer 41 made of molybdenum having an overhang shape grows on the release layer 40, the substantial diameter of the first opening 14 gradually decreases. Therefore, the vapor deposition particles that contribute to the deposition at the bottom of the first opening 14 are gradually limited to those that pass near the center of the first opening 14. As a result, a conical deposit is formed at the bottom of the first opening 14, and this conical molybdenum deposit becomes the electron emitting portion 15.

[Step-E]
Thereafter, the peeling layer 40 is peeled off from the surfaces of the first insulating layer 12 and the gate electrode 13 by an electrochemical process and a wet process, and the conductive material layer 41 above the first insulating layer 12 and the gate electrode 13 is selectively removed. To do. As a result, as shown in FIG. 13A, the conical electron emission portion 15 can be left on the cathode electrode extension portion 11C located at the bottom of the first opening portion 14. Thereafter, it is preferable that the first insulating layer 12 is isotropically etched to recede the side surface of the first opening 14 to expose the end of the first A opening 14B provided in the gate electrode extension 13C. (See FIG. 13B). Isotropic etching can be performed by dry etching using radicals as the main etching species, such as chemical dry etching, or wet etching using an etchant. As an etchant, for example, a 1: 100 (volume ratio) mixture of a 49% hydrofluoric acid aqueous solution and pure water can be used.

[Step-F]
Thereafter, a photosensitive polyimide resin is formed on the first insulating layer 12 and the gate electrode 13 by, for example, a printing method, and then the photosensitive polyimide resin is exposed and developed to provide the second opening 18. In addition, the second insulating layer 16 can be obtained. Thereafter, the focus electrode 17 is formed on the top surface portion of the second insulating layer 16 by oblique vacuum deposition. The focus electrode 17 is not formed on the bottom of the second opening 18.

[Step-G]
Next, the display device shown in FIG. 10 is assembled. Specifically, the spacer 27 is attached to the spacer holding portion 25 provided in the anode panel AP, and the anode panel AP and the cathode panel CP are arranged so that the phosphor region 22 and the electron emission region EA face each other. The anode panel AP and the cathode panel CP (more specifically, the support 10 and the substrate 20) are connected to each other at the outer peripheral portion via a joining member 26 made of a frame body having a height of about 2 mm made of ceramics or glass. Join. At the time of joining, frit glass as an adhesive layer is applied to the joining part between the joining member 26 and the anode panel AP and the joining part between the joining member 26 and the cathode panel CP, and the frit glass is dried by preliminary firing. Then, the anode panel AP, the cathode panel CP, and the bonding member 26 are bonded together, and the main baking is performed at about 450 ° C. for 10 to 30 minutes. Thereafter, the space SP surrounded by the anode panel AP, the cathode panel CP, and the joining member 26 is exhausted through a through hole (not shown) and an exhaust pipe (not shown), and the pressure of the space SP is 10 ⁻⁴ Pa. When the temperature reaches a certain level, the exhaust pipe is sealed by heat melting or pressure welding. In this manner, the space SP surrounded by the anode panel AP, the cathode panel CP, and the bonding member 26 can be evacuated. Alternatively, for example, the bonding member 26, the anode panel AP, and the cathode panel CP may be bonded together in a high vacuum atmosphere. Alternatively, depending on the structure of the display device, the anode panel AP and the cathode panel CP may be bonded together by using only an adhesive layer without a frame. Thereafter, wiring connection with necessary external circuits is performed, and the display device of the embodiment can be completed.

  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 cold cathode field emission display device, the cathode panel, the anode panel, and the cold cathode field emission device described in the embodiments are 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 the field emission device, the configuration in which one electron emission portion corresponds to one first opening has been described. However, depending on the structure of the field emission device, a plurality of electron emission portions may be provided in one first opening portion. Or a form in which one electron emission portion corresponds to the plurality of first openings. Alternatively, a plurality of first A openings are provided in the gate electrode, a first B opening communicated with the plurality of first A openings in the first insulating layer is provided, and one or a plurality of electron emission portions are provided. You can also. In the embodiment, the example in which the cutout portion is provided exclusively has been described, but the cutout portion may be provided. In the display device of Example 1, an example in which a notch portion 11D ′ is provided instead of the cutout portion is shown in FIG. 9 schematically showing the arrangement relationship between the cathode electrode and the gate electrode. Needless to say, the notch can be applied to the display devices described in the second and third embodiments.

FIGS. 1A and 1B are diagrams schematically showing the arrangement relationship between the cathode electrode and the gate electrode in the cold cathode field emission display device of Example 1, and FIG. It is a typical partial sectional view along arrow BB. FIG. 2 is a diagram schematically illustrating the arrangement relationship between the cathode electrode and the gate electrode in the cold cathode field emission display according to the first embodiment. 3A and 3B are diagrams schematically showing the arrangement relationship between the cathode electrode and the gate electrode in the cold cathode field emission display device of Example 2, and FIG. It is a typical partial sectional view along arrow BB. FIG. 4 is a diagram schematically showing the arrangement relationship between the cathode electrode and the gate electrode in the cold cathode field emission display according to the second embodiment. FIGS. 5A and 5B are diagrams schematically showing the arrangement relationship of the cathode electrode and the gate electrode in the cold cathode field emission display device of Example 3, and FIG. It is a typical partial sectional view along arrow BB. FIG. 6 is a diagram schematically illustrating the arrangement relationship between the cathode electrode and the gate electrode in the cold cathode field emission display according to the third embodiment. FIGS. 7A and 7B are diagrams schematically showing the positional relationship between the cathode electrode and the gate electrode in the cold cathode field emission display device of Example 4, and FIG. It is a typical partial sectional view along arrow BB. FIG. 8 is a diagram schematically showing the arrangement relationship between the cathode electrode and the gate electrode in the cold cathode field emission display according to the fourth embodiment. FIG. 9 is a diagram schematically illustrating the arrangement relationship between the cathode electrode and the gate electrode in a modification of the cold cathode field emission display according to the first embodiment. FIG. 10 is a schematic partial end view of a cold cathode field emission display having a Spindt type cold cathode field emission device. 11A and 11B show that, in the cold cathode field emission display device of Example 2 and the conventional cold cathode field emission display device, 0 volt was applied to the cathode electrode and 35 volts was applied to the gate electrode. It is a figure which shows the result of having simulated the position of the electron beam which collides with an anode electrode when assumed. 12A to 12C are schematic partial end views of a support and the like for explaining a method of manufacturing a Spindt-type cold cathode field emission device. FIGS. 13A and 13B are schematic partial end views of a support and the like for explaining the manufacturing method of the Spindt-type cold cathode field emission device following FIG. 12C. . FIGS. 14A and 14B are diagrams schematically showing the positional relationship between the cathode electrode and the gate electrode in the conventional cold cathode field emission display, and arrow B in FIG. It is a typical partial sectional view along -B. FIG. 15 is a diagram schematically showing the shapes of the cathode electrode and the gate electrode in the conventional cold cathode field emission display.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Support body, 11, 111 ... Cathode electrode, 11A, 111A ... Cathode electrode and trunk wiring, 11B, 111B ... Cathode electrode / branch wiring, 11C ... Cathode electrode extension part, 11D, 13D ... extracted part, 11D '... notched part, 12 ... first insulating layer, 13 ... gate electrode, 13A, 113A ... gate electrode / main wiring, 13B, 113B ... Gate electrode / branch wiring, 13C, 113C ... gate electrode extension, 113E ... gate electrode tip, 14, 14B, 14C ... first opening, 14A ... first opening A region to be formed, 15 ... an electron emission portion, 16 ... a second insulating layer, 17 ... a focus electrode, 18 ... a second opening, 20 ... a substrate, 21 ... a partition, 22 ... phosphor region, 23 ... light absorption layer 24) anode electrode, 25 ... spacer holding part, 26 ... bonding member, 27 ... spacer, 31 ... cathode electrode control circuit, 32 ... gate electrode control circuit 33 ... focus electrode control circuit, 34 ... anode electrode control circuit, 40 ... peeling layer, 41 ... conductive material layer, CP ... cathode panel, AP ... anode panel, EA ..Electron emission area, EF ... effective area, NF ... ineffective area

Claims (2)

A cathode panel having electron emitting regions arranged in a two-dimensional matrix on a support, and the anode panel having phosphor areas and an anode electrode is provided which is joined at the outer peripheral portion, the said cathode panel anode A cold cathode field emission display device in which a space sandwiched between panels is maintained in a vacuum,
The cathode panel is
(A) formed on the support a cathode electrode,
(B) the support and the first insulating layer provided on the cathode electrode,
(C) said first gate electrode formed on the insulating layer,
(D) said first insulating layer and a second insulating layer formed on the gate electrode, and,
(E) said second focusing electrode formed on the insulating layer,
With
The cathode electrode, the cathode electrode and the main wiring extending in a first direction, the cathode electrode and the branch wirings extending from the cathode electrode and the main line in a second direction substantially orthogonal to the first direction, and said cathode electrode It consists of a cathode electrode extension that extends from the tip of the branch wiring,
The gate electrode, the second gate electrode and the main wiring extending in a direction, the gate extending from the electrode-main lines in the first direction, a gate electrode Ru extending as the tip is bent in the second direction · branch wiring, the gate electrode extending portion extending from the distal end of the gate electrode and the branch wirings, and are composed of the gate electrode tip extending from the distal end of the gate electrode extending portion,
Wherein below the gate electrode extending portion located said cathode electrode extending portions, and, on the lower side of the gate electrode tip is positioned said cathode electrode, the branch wiring,
Each electron emission region is
(F) a first opening portion formed on the gate electrode extending portion and the first insulating layer,
(G) an electron emitting portion formed on the cathode electrode extending portion exposed in the bottom portion of the first opening, and,
(H) provided on the focus electrode and the second insulating layer, the gate electrode and the branch wiring to the bottom, the gate electrode extending portion, said gate electrode tip, the first opening and the first insulating layer The exposed second opening,
A cold cathode field emission display comprising: Wherein the cathode electrode is applied a potential corresponding to an image signal, the said gate electrode cold cathode field emission display according to claim 1, potential corresponding to a scanning signal is applied.