JPH10321170A - Color luminescence display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the chroma, the hue, and the color purity of display color, and prevent insulation breakage between adjoining phosphor layers in display elements provided with field emission elements, color filters, and phosphor layers. SOLUTION: On a light transmissive front substrate 3 of an envelope 4, respective red, green, and blue filters R, G, B, a light non-penetration layer 5 are formed, and a white phosphor layer 8 formed by mixing plural kinds phosphors emitting light in respective colors of red, green, and blue is plane-like continuously formed thereon. Field emission elements 10 are formed on the cathode substrate 2 of the envelope. On the field emission elements, a second insulation layer 18 is formed on gates 14 surrounding emitters 16, and space charge areas 19 are formed above the emitters. Focusing electrodes 20 are formed on the second insulation layer 18. The chroma, the hue, and the color purity of display color are improved. No possibility of insulation breakage is allowed in the whole face solid white phosphor layer 8. Because of the space charge areas 19, electron emission by the field emission elements 10 is stable, and the light emission of an anode is stable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a field emission device which is an electron source, an RGB color filter, and a color light emitting display device having a phosphor layer which emits white light.

[0002]

2. Description of the Related Art As a color light emitting display device using a phosphor for a light emitting portion, there is known a device provided with a light emitting display portion having a structure as shown in FIG. Translucent front plate 100
Color filters R, G, and B, which transmit light of each color of red (R), green (G), and blue (B) well, are separated from each other by a predetermined pattern such as a dot shape or a stripe shape. Is formed. On each of the color filters R, G, B, an anode conductor 101 made of a transparent conductive film is formed independently of each other in the same pattern as the color filters R, G, B. Then, on each anode conductor 101, a phosphor layer 102 made of a ZnO: Zn phosphor is respectively applied, and an anode 103 having a predetermined pattern is formed.

The front plate 100 faces a cathode substrate (not shown), and a field emission device as an electron source is formed on the inner surface of the cathode substrate. The space between the front plate 100 and each outer peripheral portion of the cathode substrate is sealed by a spacer member, thereby forming an envelope whose inside is in a high vacuum state.

When an appropriate drive signal is applied to the anode conductor 101 and the field emission device, the anode 10 at a desired position is provided.
3 can be selected to emit light. The ZnO: Zn phosphor has a relatively wide emission spectrum, and can emit light of each color of red, green, and blue selectively by being combined with color filters R, G, and B. I have.

[0005]

However, in the above-mentioned conventional color light-emitting display device, when a relatively high voltage of about 400 to 600 V is applied to the anode conductor 101 for the purpose of obtaining a sufficient light emission luminance or the like, each fluorescent light is not emitted. The body layer 102 is formed in an independent pattern for each of the color filters R, G, and B. Since each of the phosphor layers 102 having a predetermined pattern has a sharp corner, the adjacent phosphor layers 102, 10
Discharge occurred between the corners of No. 2 and dielectric breakdown easily occurred.

Further, in the above-mentioned conventional color light-emitting display device, it is intended to emit light of each color of R, G and B with one kind of phosphor. The ZnO: Zn phosphor has a relatively wide emission spectrum, but did not provide sufficient saturation, hue, and color purity as a color display device. In particular, Zn
Although the O: Zn phosphor has a weak red component, it is conceivable to provide a phosphor emitting red light only in the portion of the R color filter. However, the work of separately applying a different type of phosphor only to a specific portion is complicated. However, even in such a case, sufficient saturation, hue, and color purity as a color display device cannot always be obtained.

According to the present invention, a field emission device as an electron source
In a color light-emitting display device having a GB color filter and a phosphor layer, the saturation, hue, and color purity of display colors are improved, dielectric breakdown in the phosphor layer is prevented, and the color filter and the electrode are aligned. It is intended to simplify the process by eliminating the need.

[0008]

According to a first aspect of the present invention, there is provided a color light emitting display device comprising: an envelope in which a cathode substrate and a light-transmitting front substrate are arranged at a predetermined interval; and an inner surface of the cathode substrate. And the red, green, and blue filters provided in a predetermined pattern on the inner surface of the front substrate, and provided on a portion of the inner surface of the front substrate where the filters are not provided. A light-transmissive layer, a light-transmissive anode conductor continuously attached to the inner surface of each of the filters and the inner surface of the light-impermeable layer, and red light continuously adhered to the inner surface of the anode conductor. And a white phosphor layer formed by mixing a plurality of types of phosphors having light emission components of green and blue.

According to a second aspect of the present invention, there is provided the color light emitting display device according to the first aspect, wherein the field emission element is formed on a cathode conductor formed on an inner surface of a cathode substrate, and on the cathode conductor. A first insulating layer formed on the first insulating layer; a gate electrode formed on the first insulating layer; and a cathode conductor inside the holes formed in the gate electrode and the first insulating layer. A second insulating layer formed on the gate so as to surround the emitter and having a groove or a hole that forms a space charge region above the emitter; And a focusing electrode formed on the second insulating layer so as to surround the space charge region.

According to a third aspect of the present invention, there is provided a color light emitting display device according to the second aspect, wherein the cathode conductor and the gate electrode are each formed in a strip shape.
In addition, they are arranged so as to cross each other so as to form a matrix.

A color light-emitting display device according to claim 4.
Is the color light emitting display device according to claim 1,
The phosphor that emits red light is Y_TwoO_Three: Eu³⁺, Zn
_Three(PO _Four)_Two: Mn²⁺, (Zn, Cd) S: Ag, Y
VO_Four: Eu³⁺, Y_TwoO_TwoS: Eu³⁺, Y_TwoO_Three: Eu
³⁺One or more phosphors selected from the group consisting of
The phosphor that emits light is LaPO_Four: Ce³⁺, Tb³⁺, La_Two
O_Three・ 0.2SiO_Two・ 0.9P_TwoO_Five: Ce³⁺, Tb
³⁺, CeMgAl₁₁O₁₉: Tb³⁺, GdMgB_FiveO _Ten:
Ce³⁺, Tb³⁺, ZnSiO_Four: Mn²⁺, (Zn, C
d) S: Ag, (Zn, Cd) S: Cu, Al, Zn
S: selected from Au, Cu, Al and ZnS: Cu, Al
One or more phosphors that emit blue light.
But Sr_Ten(PO _Four)₆Cl_Two: Eu²⁺, (Sr, C
a)_Ten(PO_Four)₆Cl_Two: Eu²⁺, (Sr, Ca)_Ten
(PO_Four)₆Cl_Two・ NB_TwoO_Three: Eu²⁺, BaMg
_TwoAl₁₆O₂₇: Eu²⁺, ZnS: 1 selected from Ag
It is characterized by being the above phosphor.

A color light-emitting display device according to claim 5.
Is the color light emitting display device according to claim 4, wherein
Sr, a phosphor that emits blue light_Ten(PO_Four)₆C
l_Two: Eu²⁺, (Sr, Ca)_Ten(PO_Four)₆Cl_Two:
Eu²⁺, (Sr, Ca)_Ten(PO _Four)₆Cl_Two・ NB_Two
O_Three: Eu²⁺, BaMg_TwoAl₁₆O₂₇: Eu²⁺To the
It is characterized by mixing electric materials.

According to a sixth aspect of the present invention, there is provided the color light emitting display device according to the fifth aspect, wherein the conductive material is selected from the group consisting of In ₂ O ₃ , ZnO and SnO _2. And

A color light-emitting display device according to claim 7.
Is the color light emitting display device according to claim 4, wherein
Sr, a phosphor that emits blue light_Ten(PO_Four)₆C
l_Two: Eu²⁺, (Sr, Ca)_Ten(PO_Four)₆Cl_Two:
Eu²⁺, (Sr, Ca)_Ten(PO _Four)₆Cl_Two・ NB_Two
O_Three: Eu²⁺, BaMg_TwoAl₁₆O₂₇: Eu²⁺Surface
Is coated with an oxide.

The color light emitting display device according to claim 8 is the color light emitting display device according to claim 7, wherein the oxide is at least one oxide selected from the group consisting of BaO and SrO. Features.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A color light-emitting display device 1 according to an embodiment of the present invention will be described with reference to FIG. FIG.
As shown in FIG. 1, the color light-emitting display element 1 has an envelope 4 in which an insulating cathode substrate 2 and a translucent and insulating front substrate 3 are arranged at predetermined intervals. Although not shown, a space between the outer peripheral portions of the cathode substrate 2 and the front substrate 3 is sealed by a spacer member. The inside of the envelope 4 is evacuated to a high vacuum state.

On the inner surface of the front substrate 3, red, green, and blue filters R, G, and B are provided in a predetermined pattern such as a dot shape or a stripe shape. Each filter R,
G and B are formed separately from each other at a predetermined interval. Each of the filters R on the inner surface of the front substrate 3
A black light-impermeable layer 5 is provided in a portion where G and B are not provided. The surface of each of the filters R, G, B and the surface of the light-impermeable layer 5 are configured to be substantially coplanar. An insulating separation layer 6 is formed on the surface of each of the filters R, G, B and the surface of the light impermeable layer 5 so as to form one continuous surface. The separation layer 6 is made of, for example, SiO ₂ or SiN. A transparent anode conductor 7 is formed on the surface of the separation layer 6 so as to form one continuous surface.
Is attached. The anode conductor 7 is made of, for example, ITO (Indiu
m Tin Oxide). On the surface of the anode conductor 7,
The white phosphor layer 8 is formed so as to form one continuous surface. The white phosphor layer 8 is formed of a phosphor obtained by mixing at least three kinds of phosphors having red, green, and blue light-emitting components. Although the white phosphor layer 8 emits white light as a whole, it contains red, green, and blue color components, and transmits red, green, and blue filters, and transmits red, green, and blue filters with excellent saturation, hue, and color purity. Emission of each color of green and blue can be obtained.

As the phosphor emitting red light, Y ₂
O ₃ : Eu ³⁺ , Zn ₃ (PO ₄ ) ₂ : Mn ²⁺ , (Zn,
Cd) S: Ag, YVO ₄ : Eu ³⁺ , Y ₂ O ₂ S: Eu
³⁺ , Y ₂ O ₃ : Eu ^{3+ and the} like can be used.

The phosphor emitting green light is La.
PO_Four: Ce³⁺, Tb³⁺, La_TwoO _Three・ 0.2SiO_Two
・ 0.9P_TwoO_Five: Ce³⁺, Tb³⁺, CeMgAl₁₁O
₁₉: Tb³⁺, GdMgB_FiveO_Ten: Ce³⁺, Tb³⁺, Zn
SiO_Four: Mn²⁺, (Zn, Cd) S: Ag, (Zn,
Cd) S: Cu, Al, ZnS: Au, Cu, Al, Z
nS: Cu, Al, etc. can be used.

The phosphor emitting blue light is Sr
₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ , (Sr, Ca) ₁₀ (P
O ₄ ) ₆ Cl ₂ : Eu ²⁺ , (Sr, Ca) ₁₀ (PO ₄ )
₆ Cl ₂ · nB ₂ O ₃ : Eu ²⁺ , BaMg ₂ Al ₁₆ O
₂₇ : Eu ²⁺ , ZnS: Ag and the like can be used.

One or more phosphors are selected for each color, and a total of three or more phosphors are mixed to form the white phosphor layer 8.

When the electric resistance of the phosphor is high, it becomes conductive.
Substances may be mixed to improve conductivity. For example,
Sr, a phosphor that emits blue light_Ten(PO_Four)₆C
l_Two: Eu²⁺, (Sr, Ca)_Ten(PO_Four)₆Cl_Two:
Eu²⁺, (Sr, Ca)_Ten(PO _Four)₆Cl_Two・ NB_Two
O_Three: Eu²⁺, BaMg_TwoAl₁₆O₂₇: Eu²⁺Is a comparison
High resistance, In_TwoO_Three, ZnO, SnO_TwoEtc.
A conductive material may be mixed.

Further, S, which is the phosphor emitting blue light,
r ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ , (Sr, Ca)
₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ , (Sr, Ca) ₁₀ (P
O ₄ ) ₆ Cl ₂ .nB ₂ O ₃ : Eu ²⁺ , BaMg ₂ A
l ₁₆ O ₂₇ : The surface of Eu ²⁺ is exposed to BaO which emits secondary electrons.
If coated with an oxide such as SrO or SrO, the anode conductor 7
Even when the voltage applied to the light emitting device is relatively low, practically sufficient emission luminance can be obtained.

Next, a field emission device 10 as an electron source is provided on the inner surface of the cathode substrate 2. The field emission device 10 includes a cathode conductor 1 formed on an inner surface of a cathode substrate 2.
1 and a resistance layer 12 formed on the cathode conductor 11
And a first insulating layer 13 formed on the resistance layer 12
A gate electrode 14 formed on the first insulating layer 13, and a hole 15 formed in the gate electrode 14 and the first insulating layer 13 and provided on the resistance layer 12. And an emitter 16.

In this embodiment, the cathode conductor 11 and the gate electrode 14 are strip-shaped, and are arranged so as to intersect each other so as to form a matrix. At a number of intersections between the cathode conductor 11 and the gate electrode 14 constituting the matrix, a group 17 composed of a large number of the above-described emitters 16 is formed. Each group 17 is located at a position corresponding to each of the filters R, G, and B described above. While scanning one of the cathode conductor 11 and the gate electrode 14,
If a selection signal is given to the other in synchronization with this, the group 17 of the emitters 16 at a desired position at the intersection of the two can be selected and driven to emit electrons.

Further, a second insulating layer 18 is formed on the gate electrode 14 so as to surround the emitter 16. The second insulating layer 18 has a groove or a hole provided above the emitter 16 and forms a space charge region 19. That is, the space charge region 19 is a space in which a part of the space above the emitter 16 that emits electrons is surrounded by the second insulating layer 18. Due to the presence of the space charge region 19, emission of electrons by the emitter 16 is stabilized.
A focusing electrode 20 is formed on the second insulating layer 18 so as to surround the space charge region 19.
The intensity and diffusion of the emitted electron current can be controlled by adjusting the potential of the focusing electrode.

The driving of the color light emitting display element 1 of this embodiment will be described. A relatively high voltage of, for example, about 400 V to 1 kV is constantly applied to the anode conductor 7. One of the cathode conductor 11 and the gate electrode 14 is scanned, and a selection signal is supplied to the other in synchronization with the scanning. Group 1 of emitters 16 at the intersection of cathode conductor 11 and gate electrode 14 forming a matrix
7, a group 17 at a desired position is selected, and
A number of emitters 16 emit electrons. The electrons impinge on the opposing white phosphor layer 8 to emit light. The white light is emitted to the outside of the front substrate 3 via the filter located at the position, and light of a color corresponding to the color of the filter is obtained. ,

An appropriate negative voltage is applied to the converging electrode 20, whereby the flow of electrons emitted from the emitter 16 is converged and applied to the filters R, G, B of the solid white phosphor layer 8. Electrons hit the corresponding position.

[0029]

According to the present invention, in a color light emitting device having red, green, and blue filters, a white phosphor layer in which a plurality of kinds of phosphors that emit red, green, and blue light are mixed is solid. , The saturation, hue, and color purity of the display color are improved, and no discharge occurs in the phosphor layer to prevent dielectric breakdown.

Further, in the present invention, if a space charge region surrounded by a focusing electrode and an insulating layer is provided above the emitter of the field emission device, the emission of electrons by the field emission device is stabilized, and the emission of the anode is stabilized. I do.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a color light-emitting element which is an example of an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view near an anode in an example of a conventional color light emitting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Color light emitting display element 2 Cathode substrate 3 Front substrate 4 Enclosure 5 Light opaque layer 7 Anode conductor 8 White phosphor layer 10 Field emission device 11 Cathode conductor 13 First insulating layer 14 Gate electrode 15 Void 16 Emitter 18 Second insulating layer 19 Space charge region 20 Focusing electrode R, G, B filter

Claims (8)

[Claims] 1. An envelope in which a cathode substrate and a translucent front substrate are arranged at a predetermined interval; a field emission element provided on an inner surface of the cathode substrate; Red, green, and blue filters provided in a pattern, a light-opaque layer provided on a portion of the inner surface of the front substrate where the filters are not provided, an inner surface of the filters, and the light-impermeable layer A light-transmitting anode conductor continuously applied to the inner surface of the layer, and a plurality of types of phosphors having red, green, and blue light-emitting components continuously applied to the inner surface of the anode conductor. A color light-emitting display device having a white phosphor layer formed by mixing. 2. The field emission device includes a cathode conductor formed on an inner surface of a cathode substrate, a first insulating layer formed on the cathode conductor, and formed on the first insulating layer. A gate electrode, and an emitter provided in conduction with the cathode conductor inside a hole formed in the gate electrode and the first insulating layer, and further including the emitter so as to surround the emitter. A second insulating layer formed on a gate and having a groove or a hole forming a space charge region above the emitter, and formed on the second insulating layer so as to surround the space charge region; The color light-emitting display device according to claim 1, further comprising a focusing electrode. 3. The color light-emitting display device according to claim 2, wherein said cathode conductor and said gate electrode are each formed in a strip shape and intersect with each other so as to form a matrix. 4. The phosphor which emits red light is Y
₂ O ₃ : Eu ³⁺ , Zn ₃ (PO ₄ ) ₂ : Mn ²⁺ , (Z
n, Cd) S: Ag, YVO ₄ : Eu ³⁺ , Y ₂ O ₂ S:
Eu ³⁺ , Y ₂ O ₃ : One or more phosphors selected from Eu ³⁺ , wherein the phosphor emitting green light is LaPO ₄ : Ce ³⁺ , T
b ³⁺ , La ₂ O ₃ .0.2SiO ₂ .0.9P ₂ O ₅ :
Ce ³⁺ , Tb ³⁺ , CeMgAl ₁₁ O ₁₉ : Tb ³⁺ , GdM
^{_{gB 5 O 10: Ce 3+,}} Tb 3+, ZnSiO 4: Mn 2+,
(Zn, Cd) S: Ag, (Zn, Cd) S: Cu, A
1, one or more phosphors selected from ZnS: Au, Cu, Al and ZnS: Cu, Al, and the phosphor emitting blue light is Sr ₁₀ (PO ₄ ) ₆ Cl.
₂ : Eu ²⁺ , (Sr, Ca) ₁₀ (PO ₄ ) ₆ Cl ₂ : E
u ²⁺ , (Sr, Ca) ₁₀ (PO ₄ ) ₆ Cl ₂ .nB ₂ O
₃ : Eu ²⁺ , BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ , Zn
2. S: One or more phosphors selected from Ag.
A color light-emitting display device according to claim 1. 5. Sr ₁₀ which is the phosphor emitting blue light
(PO ₄ ) ₆ Cl ₂ : Eu ²⁺ , (Sr, Ca) ₁₀ (PO
₄ ) ₆ Cl ₂ : Eu ²⁺ , (Sr, Ca) ₁₀ (PO ₄ ) ₆
Cl ₂ · nB ₂ O ₃ : Eu ²⁺ , BaMg ₂ Al
₁₆ O _27: the Eu ^2+, a color light-emitting display device according to claim 4, wherein a mixture of conductive material. 6. The conductive material is In ₂ O ₃ , ZnO, S
color luminescent display device of claim 5, wherein selected from the group consisting nO _2. 7. The phosphor emitting blue light, Sr ₁₀
(PO ₄ ) ₆ Cl ₂ : Eu ²⁺ , (Sr, Ca) ₁₀ (PO
₄ ) ₆ Cl ₂ : Eu ²⁺ , (Sr, Ca) ₁₀ (PO ₄ ) ₆
Cl ₂ · nB ₂ O ₃ : Eu ²⁺ , BaMg ₂ Al
₁₆ O _27: color luminescent display device of claim 4, wherein the surface of the Eu ²⁺ was coated with oxide. 8. The color light emitting display device according to claim 7, wherein said oxide is at least one oxide selected from the group consisting of BaO and SrO.