JP3095876B2 - Flat color display and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat type color display and a method for manufacturing the same.

[0002]

2. Description of the Related Art A conventional color cathode ray tube has a face plate provided with a dot-like or stripe-like fluorescent film made of phosphors of red, green, and blue emission colors, which is arranged to face an electron gun. . In this color cathode ray tube, in order to improve the display contrast, the spaces between the fluorescent films are coated with a black pigment such as carbon black to form a black matrix. In particular, a color cathode ray tube applies a high voltage of 10 to 20 KV to the electron gun to generate a cathode ray and irradiates the fluorescent film to emit light. However, when the fluorescent film is charged up, light emission is hindered. Was. Therefore, a thin film of aluminum called an aluminum back is provided on the back surface of the phosphor film, and carbon black having good conductivity is used for the black stripe.

On the other hand, there has been proposed a vacuum micro device in which a micro electron gun having a depth of several microns is tightly integrated on a phosphor screen, and a phosphor opposed to the micro electron gun is irradiated with electrons to emit light. FIG. 3 is a sectional view of the vacuum micro device. Transparent electrode 15 and phosphor layer 1 on transparent substrate 14
6 is formed, and a light emitting portion A comprising
A cathode 18 is formed by connecting to the electrode on the gate 7 and a gate (grid) 19 is attached around the cathode while maintaining an insulating state with respect to the electrode, to form a cathode portion B.
The space between the light emitting section A and the cathode section B is evacuated and sealed, and electrons emitted from the tip of the cathode 18 of the cathode section B are used as transparent electrodes 15 functioning as collectors.
And emits light by irradiating the phosphor during that time. The electrons from the cathode 18 are controlled by the potential of the collector transparent electrode 15 and the potential of the gate (grid) 19, and irradiate the required fluorescent film with a predetermined strength. A color display using such a vacuum micro element has a visibility comparable to that of a cathode ray tube and can provide a flat color display having a thickness of 1 cm or less.

[0004]

This type of flat type color display employs a system in which electrons from a micro electron gun are attracted to a collector electrode, so that another fluorescent film is not accidentally irradiated. , The contrast of the display may be reduced due to external light, or the edges of the display may be unclear,
There is a problem that a cascade (small light emission of another color) is generated, and it is difficult to avoid cross contamination in which different phosphors are mixed into adjacent phosphor layers when forming the phosphor layers. Therefore, in the present invention, the above-mentioned problems are solved, a high contrast of a display and a high definition can be easily obtained, and a flat type which can easily avoid cross contamination at the time of forming a phosphor layer. An object of the present invention is to provide a color display and a method of manufacturing the same.

[0005]

SUMMARY OF THE INVENTION The present invention provides a transparent electrode provided on a transparent substrate, a light emitting portion having blue, green and red light emitting phosphor layers provided on each transparent electrode, and a light emitting portion provided on the light emitting portion. In a flat color display having a cathode ray emitting cathode portion disposed to face and evacuating and sealing a gap between the light emitting portion and the cathode portion, a gap between each phosphor layer of the light emitting portion is provided. A flat color display characterized by disposing an insulative black inorganic pigment, and providing a transparent electrode on a transparent substrate, forming an insulative black inorganic pigment layer in a region other than the phosphor layer forming region of the light emitting portion. Next, a light emitting portion composed of a blue, green, and red light emitting phosphor layer is formed on each transparent electrode, and a cathode ray emitting cathode portion is provided opposite to the light emitting portion, and a gap between the light emitting portion and the cathode portion is provided. To evacuate and seal It is a manufacturing method of a flat type color display according to symptoms.

The type of the black inorganic pigment used in the present invention is not limited as long as its body color is black. The conductive inorganic pigment such as carbon black needs to be provided with an insulating property by coating the surface of the conductive inorganic pigment (for example, a silicon-based substance) with water glass or a silicon emulsion. Specifically, Fe ₃ O ₄ , FeCr ₂ O ₄ , FeAl ₂ O
₄ , (Fe, Mg) TiO ₃ , MgFe ₂ O ₄ , (F
e, Mn) WO ₄ , CaFeSi ₂ O ₆ , and Fe,
Iron black (a black pigment containing iron in the composition) such as a composite oxide containing Cr and Co as main components and optionally adding Mn, Ni, Cu and the like; carbon black; Zr
O ₂ , ZnAl ₂ O ₄ , MnO ₂ , Mg ₃ Al ₂ SiO
_{12 and the} like.

The phosphor used in the present invention is blue, green
And red light-emitting phosphors are used.
Above, typical ones are as follows. (Blue light emitting phosphor) ZnS: Ag, CaWO_Four, Ln_Two
SiO_Five: Ce, ZnS: [Zn] (green emitting phosphor) ZnS: Cu, ZnO: Zn, Zn
_TwoSiO_Four: Mn, Ln _TwoO_TwoS: Tb, Ln_ThreeAl_Five
O₁₂,: Ce, Ln_ThreeAl_FiveO₁₂,: Tb, InB
O_Three: Tb (red light emitting phosphor) Ln_TwoO_TwoS: Eu, Ln_TwoO_Three:
Eu, LnVO_Four: Eu, Zn_Three(PO_Four)_Two: Mn (where Ln is at least one of Y, Gd, La and Lu)
One type) In the present invention, the contrast of the display unit is reduced.
Has a body color similar to each emission color to improve
Well-known pigmented phosphor with inorganic pigment attached to phosphor surface
Can also be used.

[0008]

FIGS. 1 and 2 are cross-sectional views of a flat type color display according to an embodiment of the present invention. FIG. On the other hand, FIG. 2 shows an example in which one cascade is provided for a set of light emitting units of a blue light emitting phosphor (B), a green light emitting phosphor (G), and a red light emitting phosphor (R). The light emitting part A of FIG. 1 is provided with a transparent electrode 2 made of indium oxide, tin oxide or a mixed oxide thereof (hereinafter, referred to as ITO) functioning as a collector on a transparent substrate 1 such as glass.
The black inorganic pigment layer 3 is formed in a portion other than the region where the phosphor layer 4 is grown, and then the phosphor layer 4 is formed. In the cathode section B of FIG. 1, a cathode 5 is provided on a substrate 8 so as to face each phosphor layer 4, an insulating member 7 is arranged between the cathodes 5, and a gate (grid) 6 is provided at the tip. . Then, a cell including the light emitting section A and the cathode section B is manufactured, and the inside of the cell is evacuated and sealed to complete a color display. This color display controls the irradiation of electrons to the phosphor layer 4 by applying or interrupting a voltage between the cathode 5 provided for each phosphor layer 4 and the transparent electrode (collector) 2.

In the light emitting portion A of FIG. 2, a relatively low black inorganic pigment layer 10 is provided at the boundary between the light emitting phosphor layers of each color. In order to prevent a malfunction such as a talk, a relatively high black inorganic pigment layer 9 is provided, and a cathode portion B is provided with one cathode 11 corresponding to a set of three color light emitting regions, and a gate is provided around the cathode 11. 12, a cell was produced, and the inside of the cell was evacuated and sealed as in FIG. In this color display, electrons are emitted from one cathode 5 provided for a pair of light emitting regions of three colors, and the phosphor of the electrode 2 loaded with a positive potential in the transparent electrode 2 of the light emitting region is used. The electrons are emitted only to the layer 4 to emit light. Although FIGS. 1 and 2 illustrate a cathode section having a cathode and a gate, the cathode section may have a conventional structure for emitting hot cathode rays.

The black inorganic pigment layer can be formed into a paste or slurry by mixing with a binder, and can be formed by a slurry method or an optical printing method.
It can be formed by a slurry method, a dusting method, a photo-adhesion method, a printing method, an electrophoresis method, an electrophotographic method, or the like. Among the above phosphor layer forming methods, an electrophoresis method, a slurry method, and an electrophotographic method are particularly preferable, and among them, the electrophoresis method is recommended. In addition, it is also possible to transfer a black pigment layer and a phosphor layer previously formed on a film to a transparent substrate.

By the way, a flat type color display is
Cathode rays emitted from the cathode part are attracted to the transparent electrode, which is electrically maintained to the opposite polarity (plus), and collide with the phosphor film on the surface of the transparent electrode to emit light. If there is shading, there is a problem that the cathode ray is strongly attracted to the portion, which causes a decrease in light emission luminance. Therefore, in a flat-panel color display, it is particularly important to form a fluorescent film in an electrically uniform barrier state without pinholes or shading of the film.

Although there has been no practical application of electrophoresis or electrophotography for producing a fluorescent film of a flat color display, an electric attraction force is applied to a transparent electrode by electrophoresis or electrophotography. When a fluorescent film is formed by acting, a pinhole portion of the fluorescent film or a thin portion of the film has a larger electric attraction force, so that a fluorescent film having an electrically uniform barrier property can be easily manufactured. Therefore, it is a very suitable method for forming the fluorescent film of the present invention. Among them, the electrophoresis method is suitable. In order to form a phosphor layer by electrophoresis or the like, a portion other than the display portion on the surface of the transparent electrode, that is, a lead line portion or the like is provided at an edge portion of the transparent electrode. Requires an electrical mask. However, since the insulating black inorganic pigment layer filling between the phosphor layers plays the role of the electric mask as in the present invention, there is no need to provide an electric mask again. In addition, when the fluorescent film is formed by the electrophoresis method as described above, if the edge portion of the transparent electrode is exposed, the potential of the edge portion becomes high, and it is difficult to form a phosphor layer having a uniform thickness. However, by covering the edge portion with the insulating black inorganic pigment layer, the exposed surface of the transparent electrode can be maintained at substantially the same potential, so that a phosphor layer having a uniform thickness can be formed by electrophoresis. It can be easily formed. As a result, when the phosphor is excited, uniform light emission can be obtained for each picture element.

[0013] The phosphor layer of the present invention is preferably formed on a transparent electrode and imparts a weak electrical conductivity from the point of electrically attracting electrons. Specifically, there is a method in which conductive fine particles or a conductive thin film is provided on the phosphor surface, or a small amount of conductive fine particles is added to the phosphor slurry. As the conductive substance, an oxide composed of at least one of indium, tin, zinc, tungsten and the like is preferable.

[0014]

(Example 1) A black inorganic pigment slurry in which carbon black, which has been previously subjected to an insulating treatment with potassium water glass, is dispersed in a mixed aqueous solution of polyvinyl alcohol and dichromate, and ZnS: Zn blue Luminescent phosphor, Z
nS: Cu, Al green light emitting phosphor and (Zn, Cd)
S: A small amount of indium oxide was adhered to each of the Ag red light emitting phosphors to prepare phosphor slurries in which each phosphor was suspended in a solution containing Al ³⁺ . Then, a transparent electrode pattern was formed on the glass substrate with indium oxide, and a black inorganic pigment layer was formed by a slurry method by applying a black inorganic pigment slurry to portions of the glass substrate other than the pattern and edges of the pattern. Next, the glass substrate on which the black inorganic pigment layer is formed is immersed in the phosphor slurry,
A voltage is applied so that the transparent electrode in the area where the phosphor is to be applied is negative, and three colors of phosphors are sequentially attached by electrophoresis. Then, the glass substrate is dried and then fired at a furnace temperature of 450 ° C. The organic substance was decomposed and removed to obtain a light emitting portion. The cathode portion was arranged opposite to the light emitting portion, sealed to form a cell, heated and evacuated, and then the exhaust port was sealed to complete a flat color display. This flat type color display was excellent in visibility, and was able to confirm a display with extremely good contrast and color purity.

Example 2 Iron trioxide (Fe ₃ O ₄ ), a kind of iron black, was used in place of the carbon black of Example 1, and ZnS: Ag was used instead of the ZnS: Zn blue light emitting phosphor. , Al blue light emitting phosphor and CaWO
₄ The mixed phosphor of the blue light emitting phosphor is ZnS: Cu, Al
Instead of the green light emitting phosphor, Y ₃ (Al, Ga) ₅ O ₁₂ :
Ce green light-emitting phosphor, and (Zn, Cd) S: Ag
Instead of the red light emitting phosphor, a mixed phosphor of Y ₂ O ₃ : Eu red light emitting phosphor and Y ₂ O ₂ S: Eu red light emitting phosphor is used, and the phosphor layer is formed by a slurry method instead of the electrophoresis method. A flat-panel color display was produced in the same manner as in Example 1 except for using. The obtained flat type color display was excellent in visibility, and it was possible to confirm a display with extremely good contrast and color purity.

[0016]

According to the present invention, it is possible to provide a flat type color display capable of obtaining a display excellent in contrast and sharpness by adopting the above-mentioned structure.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a flat-panel color display as one specific example of the present invention.

FIG. 2 is a cross-sectional view of a flat color display according to another embodiment of the present invention.

FIG. 3 is a diagram for explaining a configuration of a conventional vacuum micro device.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01J 31/12 H01J 9/227

Claims (2)

(57) [Claims] 1. A transparent electrode provided on a transparent substrate, a light emitting section having blue, green, and red light emitting phosphor layers provided on each transparent electrode, and a cathode ray emission disposed opposite to the light emitting section. In a flat-panel color display having a cathode portion and the gap between the light-emitting portion and the cathode portion being evacuated and sealed, an insulating black inorganic pigment is arranged between the phosphor layers of the light-emitting portion. A flat color display characterized by the following: 2. A transparent electrode is provided on a transparent substrate, an insulative black inorganic pigment layer is formed in a region other than a phosphor layer forming region of a light emitting portion, and then blue, green and red are formed on each transparent electrode. A light-emitting portion comprising a light-emitting phosphor layer, a cathode portion for emitting cathode rays provided opposite to the light-emitting portion, and a gap between the light-emitting portion and the cathode portion is evacuated and sealed; Manufacturing method of color display.