JP2000323042A - Discharge type flat display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge type flat display device capable of improving light emitting efficiency of a phosphor and displaying a visible image of high brightness and high quality. SOLUTION: A light emitting substrate 30 includes ribs 37 of a strip shape. A plurality of pixel regions of a stripe shape surrounded with the ribs 37 are divided by the predetermined number of pixels with a protrusion 21 provided on a front surface substrate 10. With this structure, crosstalk between adjacent pixel regions is reduced, degradation of image quality of a visible image displayed on a screen is prevented, and a high quality visible image is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge type flat panel display, and more particularly to a structure capable of improving the image quality of a plasma display panel for obtaining a visible image by using discharge plasma.

[0002]

2. Description of the Related Art EL (Electro Luminescence) panels,
LEDarray (Light Emission Diode array) panel, PDP (Plasma Display Panel), FL (Fluoresc
ent Light) panel and LCD (Liquid Crystal Di
splay) Panels can be made small, portable and mobile devices,
It is widely used as a display device for office equipment and computers.

[0003] Among them, PDPs (plasma display panels) are used for large-screen televisions because they have a wide viewing angle and do not require a light source or the like.

A PDP fills a discharge gas between two opposing insulating substrates, applies a voltage between the two substrates to generate a discharge plasma, generates ultraviolet light, and uses the ultraviolet light. The phosphor emits light to obtain a visible image.

Usually, a mixed gas of Ne (neon) and Xe (xenon) is used as a discharge gas.

[0006]

SUMMARY OF THE INVENTION However, PDP
Although a wide viewing angle can be obtained as compared with an LCD panel, there is a problem that the luminance of a screen is low because the luminous efficiency is low as compared with a CRT (Cathode Ray Tube).

Further, even if discharge plasma is generated in a region corresponding to one pixel, the ultraviolet light generated by the discharge plasma causes the phosphor of the adjacent pixel to emit light, or the visible light emitted by the phosphor emits the adjacent plasma. The crosstalk caused by emission from the pixels that cause a problem that the image quality of the visible image displayed on the screen deteriorates occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a discharge type flat display device capable of displaying a high-quality visible image with reduced crosstalk between adjacent pixels. To provide.

[0009]

According to a first aspect of the present invention, there is provided a discharge type flat panel display device comprising: a first electrode in a stripe shape; and a first electrode disposed on the first electrode. A first electrode substrate having a first dielectric layer on a main surface thereof, a second electrode having a stripe shape, and a second dielectric layer disposed on the second electrode on a main surface; A discharge-type flat panel display device comprising: a second electrode substrate having two electrodes opposed to each other at a predetermined interval so as to be substantially orthogonal to the first electrode; and a discharge gas sealed in the gap. Stripe-shaped ribs protruding in the direction of the second electrode substrate are arranged between the first electrodes adjacent to one electrode substrate,
In addition, on one of the first electrode substrate and the second electrode substrate, at least one of ultraviolet light and visible light is located between the adjacent second electrodes and protrudes toward the other substrate. A shielding projection is arranged.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the discharge type flat panel display according to the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view schematically showing a structure of an opposed discharge AC type flat display device (hereinafter, referred to as a plasma display panel or PDP) 1 utilizing discharge plasma.

That is, the PDP 1 is formed of a material that transmits light, and has a front substrate 10 as a second electrode substrate that emits display light (visible light) corresponding to an input image signal to an observer side; A light emitting substrate 30 is disposed opposite to the front substrate 10 at a predetermined interval and serves as a first electrode substrate that generates visible light.

FIG. 2 is a plan view schematically showing the structure of the light emitting substrate 30. FIG. 3 is a diagram showing a PD taken along line AA in FIG.
It is sectional drawing which shows roughly the cross section when P is cut | disconnected. FIG. 4 is a sectional view schematically showing a section when the PDP is cut along the line BB in FIG. FIG. 5 is a cross-sectional view schematically showing a cross section when the PDP is cut along the line CC in FIG.

That is, the front substrate 10 and the light emitting substrate 30
Has, for example, glass substrates 11 and 31 as a material that is light-transmissive and stable under high temperature conditions generated by discharge plasma.

The distance between the front substrate 10 and the light emitting substrate 30 is defined to be, for example, 200 μm in this embodiment.

Between the front substrate 10 and the light emitting substrate 30,
A mixed gas 51 for ultraviolet discharge in which Xe (xenon) as a main discharge gas and Ne (neon) as a discharge control gas are mixed at a predetermined ratio is injected at a predetermined pressure P.
Note that He (helium) can also be used as the discharge control gas. The pressure P of the mixed gas 51 is represented by P · d, where d is the distance between the surface of the front substrate 10 facing the light emitting substrate 30 and the surface of the light emitting substrate 30 facing the front substrate 10. It is set so as to satisfy ≧ 7.5 (torr · cm). Specifically, the mixed gas 5
The pressure P of 1 is set, for example, to a pressure lower than 760 torr, preferably 500 torr.

The partial pressure of the xenon gas as the main discharge gas is preferably set to 15% or more, that is, 30%.
Thereby, the excimer emission wavelength is positively used as the ultraviolet light, and the utilization efficiency is improved.

On the surface of the front substrate 10 on the side of the glass substrate 11 facing the light emitting substrate 30, a plurality of substrates extending in the first direction, ie, the X-axis direction, and formed of a metal material such as silver (Ag) are provided. Are arranged at predetermined intervals in the second direction, that is, the Y-axis direction. This display electrode 13
Corresponds to a stripe-shaped second electrode.

The display electrodes 13 are arranged vertically, that is, in "columns".
This defines the address in the direction, and is governed by the size of the display area of the PDP 1 and the required resolution.
National Televi 2 inch and 16: 9 aspect ratio
Video g of sion System Committee (NTSC) mode
When conforming to the raphics Array (VGA) standard, about 1.
There are 480 electrodes at an interval of 08 mm (corresponding electrodes in the “row” direction are provided on the light emitting substrate 30 side as described below).
52 sets are provided). This display electrode 13 has about 12
It has a width of 0 μm and a thickness of about 7 μm.

The front substrate 1 on the side where the display electrodes 13 are provided
A light-transmitting dielectric layer 15 made of low-melting glass or the like, which functions as a dielectric layer, covers the portion where the front substrate 10 is exposed and the display electrode 13. That is, the surface of the display electrode 13 on the side facing the light emitting substrate 30 is protected by the dielectric layer 15 from ions generated by the discharge plasma. This dielectric layer 15 has about 3
It has a thickness of 0 μm.

On the entire surface of the dielectric layer 15, a UV (ultraviolet) reflection layer 1 that reflects ultraviolet light mainly having an excimer emission wavelength generated by discharge plasma toward the light emitting substrate 30.
7 are provided. The UV reflection layer 17 is a dielectric multilayer film, reflects a predetermined wavelength component of ultraviolet light generated by electric discharge, and transmits visible light to be transmitted through the front substrate 10.

The UV reflective layer 17 has at least one layer made of YF ₃ (yttrium fluoride) having a small absorptivity to ultraviolet light emitted from Xe ^* and Xe ₂ ^* ( ^* indicates an excited state). Contains. This UV reflection layer 17
Each layer has a film thickness defined by (λ / 4), where λ is the wavelength of main ultraviolet light to be reflected.

On the UV reflection layer 17, the display electrode 13
When viewed from the direction in which the image of the front substrate 10 is emitted, that is, when viewed from the display surface 10a, in the vicinity of the display electrode 13 and in the vicinity thereof, in other words, the surface of the dielectric layer 15 on the light emitting substrate 30 side In a region facing the display electrode 13, a protective film 19 that prevents ions generated by the discharge plasma from reaching the display electrode 13 is provided.
For the protective film 19, for example, MgO (magnesium oxide) having a large secondary electron emission efficiency (secondary electron emission coefficient) for emitting ions generated by discharge as elementary elements is used. Protective film 19 selectively provided corresponding to the display electrode
Is defined, for example, in the range of 100 nm to 1000 nm, more preferably 500 nm to 1000 nm, and in this embodiment, is set to 500 nm.

The protective film 19 has a width corresponding to the display electrode 13, in this example, a display electrode 1 having a width of about 120 μm.
3 has a width of about 180 μm, which is slightly larger than
The protective film 19 can be uniformly provided on the dielectric layer 15. In this case, the protective film 19 is formed into a thin film to suppress undesired absorption of visible light and ultraviolet light by the protective film and a decrease in transmittance. Need to be formed.

On the surface of the light emitting substrate 30 facing the front substrate 10 of the glass substrate 31, a second direction orthogonal to the direction in which the display electrodes 13 of the front substrate 10 extend, that is, the Y-axis direction, is provided. A plurality of opposing electrodes 33 formed of a metal material such as silver are arranged at predetermined intervals in the X-axis direction. The counter electrode 33 corresponds to a stripe-shaped first electrode that is arranged to be substantially orthogonal to the display electrode 13 as a second electrode. The counter electrode 33 is connected to the display electrode 13.
A predetermined voltage is applied between the light emitting substrate 30
Ultraviolet rays are generated from the mixed gas 51 injected between the substrate and the front substrate 10.

The counter electrode 33 is formed on the display electrode 13 of the front substrate 10 when the front substrate 10 is viewed from the display surface 10a side.
R (red), G (green) and B
The discharge chamber 39 corresponding to any one of (blue) is selectively driven. In addition, the counter electrode 33 corresponds to each of the three primary colors R (red), G (green), and B (blue) per pixel so that a color image can be displayed by additive color mixing. 852 × 3 = 2556 (for a panel having a display area of the size described above)
This is arranged.

In this case, the pitch is ／ of one pixel (approximately 1.08 mm assuming that the pixel is substantially square), so that the pitch is approximately 0.36 mm. The width between the opposing electrodes 33 is set to be smaller than at least the distance between the ribs (partitions) 37 described below. In this embodiment, the counter electrode 33 has a width of about 120 μm and a thickness of about 7 μm.

On the entire surface of the light emitting substrate 30 facing the front substrate 10, a low melting point glass provided to cover each of the exposed portion of the light emitting substrate 30 and the counter electrode 33 (entire surface of the light emitting substrate). A dielectric layer 35 is provided. The dielectric layer 35 has a thickness of about 30 μm, so that the surface of the counter electrode 33 facing the front substrate 10 is protected by the dielectric layer 35 from ions generated at the time of discharge. .

On the surface of the light emitting substrate 30 facing the front substrate 10, a plurality of stripe-shaped partitions or ribs 37 arranged at predetermined intervals are provided in parallel with the counter electrode 33. In the panel having the display area of the size described above, the number of ribs 37 is 852 × 3 + 1 = 2557 with the center-to-center distance in the X-axis direction being 0.36 mm.

Each of the ribs 37 provides a discharge chamber 39 between adjacent ribs 37. In the discharge chamber 39,
The counter electrodes 33 are located one by one. This rib 37
About 200 μm height corresponding to the substrate gap, and about 60 μm
m.

In this example, the top of the rib 37, that is, the surface of the rib 37 facing the observer is blackened by applying, for example, a black paint 37a to improve the display contrast. Shaded). As a method of improving the display contrast, in addition to blackening the tops of the ribs 37, the ribs 37 themselves are blackened, or a black paint is applied to a region of the front substrate 10 facing the ribs 37, for example. It may be.

On the surface of the light emitting substrate 30 facing the front substrate 10, a discharge chamber 3 is provided in a direction substantially orthogonal to the counter electrode 33.
A projection 21 having a triangular cross section is provided so as to divide 9 in correspondence with each pixel. The protrusion 21 has a height substantially equal to that of the rib 37, and prevents ultraviolet light generated by discharge and visible light converted by a fluorescent layer described later in order to prevent crosstalk between adjacent pixels. Both prevent reaching the adjacent discharge chamber 39 and act to reflect further.

On the inner wall of the discharge chamber 39, including the rib 37 and the side wall of the protrusion 21, a fluorescent layer 41 which emits visible light by being excited by the ultraviolet rays generated by Xe.
Are formed. This fluorescent layer 41 has an average particle size of 3 μm.
An arbitrary number of substantially spherical spherical phosphors having a thickness of not less than m and not more than 5 μm, for example, 3 μm, are laminated to a predetermined thickness. More specifically, the thickness of the fluorescent layer 41 provided in each of the discharge chambers 39R, 39G, and 39B is adjusted according to the emission characteristics of the phosphor for each color. Is set to 20 μm in the discharge chamber 39R emitting green light, 40 μm in the discharge chamber 39G emitting green (G), and 30 μm in the discharge chamber 39B emitting blue light.

Each of the discharge chambers 39 (R, G,
The fluorescent layers 41R, 41G and 41B provided in B)
Are covered with a fluorescent layer protective film containing MgO, not shown. The thickness of the fluorescent layer protective film in each discharge chamber 39 is, for example, 50 nm in the fluorescent layer protective film corresponding to the red (R) fluorescent layer 41R, 30 nm in the fluorescent layer protective film corresponding to the fluorescent layer 41G, and Layer 41B
Is set to 40 nm in the fluorescent layer protective film corresponding to. As described above, by adjusting the thickness of the fluorescent layer protective film for each discharge chamber 39 and adjusting the transmission amount of ultraviolet light reaching the fluorescent layer 41, light emission can be adjusted for each color.

The spherical phosphor used for the fluorescent layer 41 has a surface containing at least MgO (magnesium oxide), protects the spherical phosphor from a discharge plasma generated in the discharge chamber 39, and emits the visible light emitted by each phosphor. It is also possible to use one coated with a fluorescent layer protective film that transmits light. In this case, there is no need to separately provide a fluorescent layer protective film on the fluorescent layer surface, and a wider discharge space can be secured.

The visible light generated by the fluorescent layers 41R, 41G and 41B constituting the fluorescent layer 41 is transmitted between the inner wall of the discharge chamber 39 and the fluorescent layer 41, including the side walls of the ribs 37 and the projections 21. Visible light reflecting layer 43 that reflects light toward
Are formed. The visible light reflecting layer 43 is provided in each discharge chamber 39.
Is prevented from passing through the light emitting substrate 30 and being emitted to the direction opposite to the display surface 10a of the front substrate 10, that is, to the rear surface of the light emitting substrate 30, so that the display on the front substrate 10 is efficiently performed. The display light is extracted from the surface 10a to the observer side, for example, Al ₂ O ₃ (alumina),
A fine particle reflector such as TiO ₂ (titania), MgO or MgF ₂ (magnesium fluoride) can be used, and in this embodiment, Al ₂ O ₃ (alumina) is used.

The thickness of the visible light reflecting layer 43 is preferably a specific thickness defined based on the light emission characteristics (especially, light emission intensity) of the fluorescent layers 41R, 41G and 41B provided in the corresponding discharge chamber. ing. That is, the visible light reflecting layer 4
A thickness of 3 governs the reflectivity, for example, 10
When the thickness is larger than 0 nm, the content is 50% or more.
It is desirable that the film be thicker than nm. However,
The thickness of the visible light reflecting layer 43 is preferably thinner in the discharge chamber 39.
And the luminous efficiency is improved.

For this reason, according to this embodiment, the thickness of the visible light reflecting layer 43 is 200 nm in the discharge chamber 39R emitting red light and 300 nm in the discharge chamber 39G emitting green light. In the discharge chamber 39B that emits blue light, the wavelength was set to 200 nm. It should be noted that green (G) is perceived as being dark even if the luminance slightly changes compared to other colors because of high visibility. For this reason, as described above, the thickness of the back reflection layer provided in the discharge chamber 39G that emits a phosphor having low luminous efficiency, that is, green (G), is a discharge chamber that emits red (R) and blue (B). The thickness is set to about 1.5 times the thickness of the back reflection film provided on each of 39R and 39B.

As described above, by setting the thickness of the visible light reflecting layer 43 optimally in accordance with the color of the light to be emitted by each discharge chamber, the brightness uniformity of each color viewed from the display surface 10a can be improved. Can be improved.

Between the visible light reflecting layer 43 and the dielectric layer 35,
A MgO layer 45 having a thickness of about 500 nm is provided as a protective film between the visible light reflecting layer 43 and the side wall of the rib 37 and the protrusion 21. That is, MgO
Has a function of lowering the discharge voltage, and therefore, by providing an MgO layer also on the discharge chamber side of the light emitting substrate 30, the luminous efficiency can be further increased. Rib 37 and projection 2
Since the fluorescent layer 41 and the protective film are further disposed on the respective side walls of the light emitting device 1, the MgO film 45 does not need to be separately disposed for the purpose of increasing the discharge space.

Further, in the PDP 1 shown in FIGS. 1 to 5, the light emitting substrate 30
A rectangular opening 47 is provided in a part of the fluorescent layer 41 and the visible light reflecting layer 43 in FIG. That is, the opening 47 is provided with the display electrode 13 extending along the X-axis direction.
Are projected on the counter electrode 33 extending along the Y-axis direction, and are provided corresponding to the intersection regions formed on the counter electrode 33.

That is, the opening 47 has a side of about 100
It is formed in a rectangular shape of about 200 μm. More specifically,
In this embodiment, the length m of the opening 47 along the display electrode 13 is set to 180 μm, which is slightly larger than the electrode width of 120 μm, which is the electrode width of the counter electrode 33, and is set to 180 μm. The length l along the display electrode 1
The width is set to 180 μm which is slightly larger than 120 μm which is the electrode width of No. 3 in consideration of the positional deviation.

The size of the opening 47 is such that, when the display electrode 13 is projected onto the counter electrode 33, the area that exposes the intersection region formed on the counter electrode 33 with respect to the positional shift that occurs during its formation. It is necessary to keep the discharge start voltage fluctuation constant, and the lengths m and l of the openings 47 may be smaller than the widths of the corresponding electrodes 13 and 33. . However, in consideration of the discharge efficiency, it is desirable to set such a large value as in this embodiment.

As a method of forming the opening 47, a material having high water repellency such as F (fluorine) is applied in advance before the step of applying or depositing the fluorescent layer 41 in a region where the counter electrode 33 is to be exposed. However, it can be manufactured by partially eliminating the fluorescent layer 41.

As described above, according to the structure of this embodiment, the projections 21 for partitioning the discharge chambers 39 are provided between adjacent pixels, and the visible light reflecting film 43 and the fluorescent layer 41 are provided on the side surfaces of the projections 21. They are arranged in layers.

As a result, the ultraviolet light generated in each discharge chamber 39 is converted into visible light by the fluorescent layer 41 on the side wall of the projection 21, and is further converted by the visible light reflecting film 43 into the front substrate 1.
It is reflected to the 0 side. Thereby, the influence of crosstalk due to ultraviolet light and visible light generated in the adjacent discharge chamber 39 is reduced, and a good display image can be secured.

In particular, according to this configuration, since the projections 21 are formed in a triangular cross section, visible light can be reflected toward the front substrate 10 by the side walls of the projections 21 and the visible light utilization efficiency can be improved. Be increased.

Further, according to the above configuration, the opening 47 is provided on the counter electrode 33, so that the discharge starting voltage can be reduced. Further, the discharge plasma generated between the display electrode 13 and the counter electrode 33 causes Damage to the layer 41 can be prevented.

Further, in this PDP 1, Xe
Of the main discharge gas X with respect to the partial pressure of the discharge control gas Ne
By increasing the proportion of e to 30%, which is in the range of 15% to 100%, Xe ₂ ^* in addition to the Xe ^* resonance line of 147 nm, which is the Xe ^* resonance line of the ultraviolet light generated in the known PDP ^. Ultraviolet light having a wavelength of 172 nm due to excimer light emission is positively obtained.

That is, by increasing the partial pressure of Xe in the mixed gas G, conventionally, e + Xe → e + Xe ^* Xe ^* → Xe + ultraviolet rays having a wavelength of 147 nm are extracted by using ultraviolet rays having a wavelength of 147 nm. by ultraviolet _{^{Xe * + 2Xe → Xe 2 *}} + Xe Xe 2 * → 2Xe + wavelength 172 nm, it is possible to obtain the ultraviolet ray having a wavelength of 172 nm.

The energy for exciting each phosphor of the fluorescent layer 41 is the wavelength 17 generated by the Xe ₂ ^* excimer emission.
Since the ultraviolet light of 2 nm is lower than the ultraviolet light of 147 nm, the luminous efficiency is increased.

When the partial pressure of Xe is 10%, ultraviolet rays having a wavelength of 172 nm are also generated.
m, so that the partial pressure of Xe is 1
It is preferably at least 5%. In addition, since the discharge starting voltage increases as the partial pressure of Xe increases, Xe
Is set to 70% or less, more preferably 60% or less, and preferably 40% or less.

For example, regarding the relationship between the partial pressure of Xe of the mixed gas 51 and the luminous efficiency, by setting the degree of the partial pressure of Xe to 15% or more, the light emission becomes higher than when the partial pressure of Xe is 10%. It is observed that the efficiency is improved by a factor of approximately two. Increasing the partial pressure of Xe increases the discharge starting voltage. However, by setting the discharge type to the counter electrode type as in this embodiment, the discharge starting voltage can be suppressed to, for example, 350 V or less. To

With respect to the reflection characteristics of the dielectric multilayer film used for the UV reflection layer 17 of the front substrate 10 of the PDP 1 shown in FIGS. 1 to 5, the UV reflection layer 17 has an angle of incidence of ultraviolet rays to the reflection layer 17 itself. In the normal direction (θ = 0 °) and 30 ° from the normal (θ = 30 °),
It can provide the maximum reflectance for ultraviolet light of about 172 nm.

The incident angle is 45 ° normal (θ = 45 °).
°), the reflection wavelength peaks at 172 nm.
However, it is recognized that it is useful to increase the reflectance of all the ultraviolet energy generated by the discharge. By arranging the UV reflection film 17 on the surface of the front substrate 10 on the light emitting substrate 30 side, the total ultraviolet energy directed to the light emitting substrate 30 is increased by 15% or more.

In the PDP 1 shown in FIGS. 1 to 8,
By providing the UV reflection film 17 having the above-described reflection characteristics, the luminous efficiency of visible light radiated from the discharge chamber 39 is improved. For example, if the partial pressure of Xe of the mixed gas is 1
When it is 5%, the luminous efficiency is increased by about 25% by adding the UV reflection layer 17. For example, if the partial pressure of Xe is 40%, the luminous efficiency is approximately 50%.
Be increased.

In this PDP 1, that of the discharge chamber 39
Of the visible light generated by each,
Ratio and visible light formed on the light emitting substrate 30 side of the discharge chamber 39
The relationship between the reflectance of the reflective layer 43 and the reflectance of the visible light
43, for example, Al₂O ₃White by (alumina) etc.
By coloring in color, compared to untreated
1.5 times the amount of visible light is obtained.

In this PDP 1, the front substrate 1
The intensity distribution of visible light radiated from the fluorescent layer 41 due to discharge in the space between the 0 display electrode 13 and the opposing electrode 33 of the light emitting substrate 30 will be briefly described with reference to FIG.

In the space between the display electrode 13 and the counter electrode 33, the intensity distribution of the visible light emitted from the fluorescent layer 41 due to the discharge between the electrodes is such that the emitted visible light has a An arbitrary point when it is assumed to be generated from a point has a distribution as indicated by an area α according to the cosine law.

That is, of the visible light provided from an arbitrary point by the discharge between the two electrodes, the visible light of the portion indicated by the region β is covered by the display electrode 13 when viewed from the display surface 10a side. You will not be able to see it.

Accordingly, the range of the extraction area γ where the visible light is emitted toward the display surface 10a is a section indicated by the arc δ. Here, assuming that the angle between any one point and the discharge center is θ, the angle is generated between the two electrodes and the display electrode 1
3, the extraction efficiency η excluding the visible light component that cannot be seen from the display surface 10a side.
_ex2 is represented by {1 / 2πcosω · dωdθ (1).

At this time, the emission intensity I is given by: I = f · D _disp · η _ex1 · η _ex2 · η _UV · η _phos · WD (2) where f is the pulse frequency (usually 100 kHz) in the display period.
z) D _disp is the duty ratio of the display period (usually 10%) WD = Cg (V ² −Ve ² ); V is the applied voltage, and Ve is the end voltage. W is the width of the display electrode 13 (inter-rib direction), and D is the distance between the surface of the front substrate 10 opposite to the display surface 10a and the surface of the light emitting substrate 30 on the front substrate 10 side. .

Note that D _disp is set in consideration of high definition.
By setting the address period D _address to 90%, the address period is set to 10%. In addition, η _ex1 is the normal extraction efficiency, and η _ex2 is the extraction efficiency excluding visible light that cannot be seen from the display surface 10a side due to the shadow of the front electrode 13. Further, η _phos is the luminous efficiency of the phosphor used alone for the fluorescent layer 41, η _phos
UV is the UV emission efficiency. At this time, the power consumption per pulse is represented by Cg = εS / d
(S: area of front electrode 13, d: glass (front substrate) 1
0), and when the applied voltage is V, Cg (V
² is a -Ve ^2).

The relationship between the extraction efficiency and the light intensity of the visible light emitted from each discharge chamber, that is, the luminance, is set such that the discharge is performed when 0.5 ≦ W / D ≦ 2.4 is satisfied. Even if the visible light emitted in the chamber 39 is blocked by the display electrode 13 made of a metal material or the like that is opaque to visible light,
Luminance of 0 candela (cd / m ² ) or more and extraction efficiency of 50% or more can be secured.

By the way, in consideration of outdoor use, for example, a luminance higher than 1000 (cd / m ² ) is often required.

In this case, WD shown in the equation (2), ie, S in Cg (V ² −Ve ² ), ie, the display electrode 1
By increasing the area of No. 3, it is possible to increase the luminance.

However, increasing the area of the display electrode 13 reduces the extraction efficiency η _ex2 .

For this reason, the display electrode 13 is made of, for example, a transparent conductive film such as ITO or IZO (Indium Zinc Oxide) transparent to the wavelength of visible light radiated from the fluorescent layer 41 by discharge, or a metal wiring and a transparent conductive film. As a combination with a film, the luminance can be secured by increasing the extraction efficiency while increasing the area of the display electrode 13. In this case, the opening 47 is desirably formed corresponding to the size of the transparent conductive film.

FIG. 7 is a block diagram showing an example of a drive circuit for displaying an image on the PDP 1 shown in FIGS.

As shown in FIG. 7, the PDP 1 has the same configuration as the column drive circuit 101 which supplies a predetermined voltage to the display electrodes 13 in the order corresponding to the image signals in the X-axis direction under the control of the main control circuit 111. Drive circuit 1 for supplying a predetermined voltage to the counter electrode 33 at a position corresponding to the image signal in the Y-axis direction
03 and a frame memory 107 for storing an image signal supplied from the outside. Note that an image signal is input to the frame memory 107 via a video interface 109 that receives an image signal from the outside.

The main control circuit 111 stores driving conditions and control data specific to the PDP 1.
An OM (program memory) 113, a clock generation circuit 115 for generating a basic clock, and a vertical synchronization signal generation circuit 117 for generating a vertical synchronization signal V-sync for synchronizing the image signals stored in the frame memory 107 in the vertical direction. , A horizontal synchronization signal H-sync for horizontal synchronization with the image signal stored in the frame memory 107
A well-known image display circuit group such as a horizontal synchronizing signal generation circuit 119 for generating the image signal is connected.

Column drive circuit 101 and row drive circuit 10
Under the control of the main control circuit 111, each of the discharge chambers 3 controls a voltage for image display for each of a plurality of subfields divided into a predetermined number according to a known subfield method.
9 is applied to the display electrode 13 and the counter electrode 33 that specify the pixel 9.

That is, a predetermined voltage is applied to each of the arbitrary display electrodes 13 on the front substrate 10 and any of the opposing electrodes 33 (R, G, and B) on the light emitting substrate 30, so that each electrode is placed on the front surface. A discharge corresponding to the image information is generated at a position where the substrate 10 intersects when viewed from the display surface 10a side, and the fluorescent layers 41 (R, G, and B) formed in each discharge chamber 39 by the ultraviolet light generated by the discharge. Emits visible light of a predetermined color.

By applying a drive voltage to each of the column drive circuit 101 and the row drive circuit 103,
In each discharge chamber 39, the sustain discharge and the write discharge are repeated at a predetermined timing.

Further, each of the column driving circuit 101 and the row driving circuit 103 has a rising time of the driving pulse.
It is configured to be able to generate a pulse shorter than the duration of Xe ₂ ^* (the lifetime of metastable atoms in an excited state). The rise time of the pulse, defined as the time required for the magnitude of the pulse to change from 10% to 90%, is set to 200 to 10 ns.

As described above, the luminous efficiency can be improved by setting the rise time of the image display pulse applied in the subfield short.

As described above, the PD shown in FIGS.
In P1, the light emitting substrate 30 projects in the direction toward the front substrate 10, converts the ultraviolet light into visible light, and reflects the converted visible light toward the front substrate 10 side.
Is provided at a substantially center between adjacent display electrodes 13 as shown in FIGS. 2 and 5.

As a result, crosstalk between adjacent pixels is reduced as compared with the related art, and good image reproducibility can be secured.

In this embodiment, as shown in FIG. 5, a plurality of pixel regions extending in the Y-axis direction surrounded by ribs 37 extending in a stripe shape in the Y-axis direction are divided into one pixel region. As described above, the projections 21 are arranged between all the display electrodes 13, but it is not always necessary to arrange the projections so as to divide every pixel, but to divide every plurality of pixels, for example, every three pixels, Alternatively, the plurality of display electrodes 13 may be arranged between adjacent projections.

Since the projection 21 has substantially the same structure as the rib 37, no special manufacturing process is required.

However, this projection 21 is
It can also be manufactured by a separate manufacturing process. For example, black carbon or the like is mixed to reduce the visible light transmittance by about 30%.
The crosstalk can be reduced by forming the ribs 37 of preferably 10% or less. However, in this case, the undesired visible light is absorbed instead of being reused, so that the visible light use efficiency is not improved as in the above embodiment.

In this embodiment, the projections 21 and the ribs 37 are formed at substantially the same height. However, if each discharge chamber is to be exhausted uniformly and sufficiently, one of them is lower than the other. It is effective to form, for example, the protrusions 21 in the range of 0.3 × d to 0.7 × d with respect to the substrate gap d.

If the projections 21 and the ribs 37 are formed in substantially the same process, the projections 2 and the ribs 37 are formed as shown in FIG.
1 can also be formed in substantially the same shape as the rib 37.
In this case, it is effective to apply a black paint 21a or the like similar to that arranged on the rib 37 on the projection 21.

In the above embodiment, the projection 21 is provided on the light emitting substrate 30 side, but may be provided on the front substrate 10 side as shown in FIG. In this case, the projections 21 are formed to have a transmittance of visible light of about 30% or less, preferably 10% or less by mixing black carbon or the like.

By forming the projections 21 on the dielectric layer 15 and covering the surface with the UV reflection layer 17, it is possible to prevent ultraviolet light generated by discharge from entering the adjacent discharge chamber. .

Further, a visible light reflecting film and a fluorescent layer may be arranged on the projection 21. As a result, the efficiency of converting ultraviolet light into visible light can be increased, visible light can be effectively prevented from entering the adjacent discharge chamber, and light can be effectively emitted from the front substrate 10 side.

As described above, according to the PDP of this embodiment, the luminance of the screen can be improved by reducing the discharge starting voltage and improving the luminous efficiency of the fluorescent layer. In addition, by providing a projection that divides a plurality of stripe-shaped pixel regions surrounded by ribs, crosstalk between adjacent pixel regions is reduced to prevent a reduction in image quality of a visible image displayed on a screen, It is possible to display a high-quality visible image.

Although the above embodiments have been described by taking the opposing discharge type as an example, a surface discharge type in which a pair of electrodes for generating a surface discharge is arranged on the front substrate side with respect to each electrode on the light emitting substrate side. Can also be suitably used.

[0089]

As described above, according to the present invention, it is possible to provide a discharge-type flat display device capable of improving the luminous efficiency of a phosphor and displaying a high-luminance and high-quality visible image. it can.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a structure of a PDP according to an embodiment using discharge plasma of the present invention.

FIG. 2 is a plan view schematically showing a structure of a light emitting substrate 30 of the PDP shown in FIG.

FIG. 3 is a sectional view schematically showing a section when the PDP is cut along the line AA in FIG. 2;

FIG. 4 is a sectional view schematically showing a section when the PDP is cut along the line BB in FIG. 2;

FIG. 5 is a sectional view schematically showing a section when the PDP is cut along the line CC in FIG. 2;

FIG. 6 is a sectional view schematically showing a section of a PDP according to a modification of the present invention.

FIG. 7 is a block diagram showing an example of a drive circuit for displaying an image on the PDP 1 shown in FIGS. 1 to 5;

FIG. 8 is a perspective view schematically showing a structure of a PDP according to a modification of the present invention.

FIG. 9 is a diagram for explaining the intensity distribution of visible light in a discharge space.

DESCRIPTION OF SYMBOLS 1 ... PDP 10 ... Front substrate 11 ... Glass substrate 13 ... Display electrode 15 ... Dielectric layer 17 ... UV reflection layer 19 ... Protective film 21 ... Protrusion 30 ... Light emitting substrate 31 ... Glass substrate 33 ... Counter electrode 35 ... Dielectric layer 37 ... Rib 39 ... Discharge chamber 41 (R, G, B) ... Fluorescent layer 43 (R, G, B) ... Visible light reflective layer 45 ... Protective film 47 ... Opening 51 ... Discharged mixed gas

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeo Ito 1-9-2 Hara-cho, Fukaya-shi, Saitama F-term in Fukaya Plant, Toshiba Corporation (reference) 5C040 FA01 GB03 GB14 GF02 GF12 MA02 5C094 AA06 AA09 AA10 AA24 BA12 BA31 CA19 CA24 DA13 DB04 EA04 EA06 EB02 EC03 EC04 ED11 ED15 FA01 FA02 FB15

Claims (14)

[Claims] A first electrode substrate provided on a main surface with a first electrode in a stripe shape and a first dielectric layer disposed on the first electrode; a second electrode in a stripe shape; A second electrode substrate provided on the main surface with a second dielectric layer disposed on the two electrodes, the second electrode substrate being opposed to the first electrode at a predetermined interval so as to be substantially orthogonal to the first electrode; A discharge-type flat panel display device having a discharge gas sealed in a gap, wherein a stripe-shaped rib protruding in the direction of the second electrode substrate is arranged between the first electrodes adjacent to the first electrode substrate. And, on one of the first electrode substrate and the second electrode substrate, located between the adjacent second electrodes, protruding toward the other substrate, at least ultraviolet light and visible light Discharge characterized in that a projection for shielding one side is arranged Flat panel display. 2. The discharge type flat display device according to claim 1, wherein the projection is provided on the second electrode substrate and protrudes toward the first electrode substrate. 3. The discharge type flat display device according to claim 1, wherein the projection is provided on the first electrode substrate and protrudes in a direction of the second electrode substrate. 4. The discharge type flat display device according to claim 1, wherein the protrusion has a triangular cross section whose top portion protrudes toward the other substrate. 5. The discharge type flat display device according to claim 1, wherein a phosphor is disposed on a main surface of the projection. 6. The discharge type flat display device according to claim 1, wherein a visible light reflecting layer is disposed on a surface of each of the protrusions. 7. The discharge type flat display device according to claim 1, wherein the projection has an ultraviolet reflecting layer disposed on a surface thereof. 8. The discharge type flat display device according to claim 1, wherein said projections are arranged so as to include a plurality of said second electrodes between adjacent projections. 9. The flat panel display according to claim 1, wherein the first electrode substrate includes a phosphor layer provided on the first dielectric layer. 10. The discharge type flat display device according to claim 9, wherein said phosphor layer has an opening in a region where said first electrode and said second electrode are orthogonal to each other. 11. The first electrode substrate includes a phosphor layer provided on the first dielectric layer, and a visible light that reflects the visible light between the phosphor layer and the first dielectric layer. The discharge type flat panel display according to claim 1, further comprising a light reflection film. 12. The discharge type flat display device according to claim 11, wherein the first electrode substrate further comprises a protective film. 13. The discharge type flat display device according to claim 1, wherein the second electrode substrate includes an ultraviolet reflecting film that transmits the visible light and reflects the ultraviolet light. 14. The flat panel display according to claim 1, wherein the second electrode includes at least a pair of electrodes corresponding to each of the first electrodes.