JPH1131460A - Discharge type plane display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve light emitting efficiency and screen brightness of a plasma discharge type plane display device. SOLUTION: A plasma discharge type plane display device 1 with the partial pressure of Xe in mixture gas G being 15% or more has a display electrode 12a on a surface substrate 11 and a counter electrode 23 on an emission substrate 21. The phosphor layer 28 of a discharge chamber 26 for the emission substrate contains small-side spherical phosphors whose outside is covered with a reflecting layer 27. The display electrode of the surface substrate is protected by a protecting film 15 formed on the side face of the discharge chamber, an ultraviolet reflecting film 14 and a dielectric layer 13. In this way, the plasma discharge type display device with a high screen brightness is provided, in which the display of an image is started with low discharge starting voltage and emission efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a flat panel display device, and more particularly to a display device using plasma discharge with improved luminous efficiency.

[0002]

2. Description of the Related Art Display devices such as an electroluminescence panel, a light emitting diode panel, a plasma discharge display device, a fluorescent display device, and a liquid crystal display device can have a thin display portion. Applications for office equipment and terminal display devices such as computers are increasing.

In particular, a plasma discharge type flat panel display is
Since the viewing angle is wide and it does not require light source optics, etc.
Application to large-screen televisions has been put to practical use. A plasma discharge type flat display device fills a discharge gas between two insulating substrates facing each other, generates ultraviolet light by gas discharge between the two substrates, and emits a phosphor using the ultraviolet light, An image is displayed.

Usually, a mixed gas of Ne (neon) and Xe (xenon) is used as a discharge gas. The mixing ratio of each was 9 for Ne and 9 for Xe.
It is about.

[0005]

However, although the plasma discharge type flat display device described above can have a wider viewing angle than a liquid crystal display device, it is called a CRT (cathode ray tube, usually a cathode ray tube), However, there is a problem that the brightness of the screen is low (that is, the luminous efficiency is low) as compared with a cathode ray tube used as a picture tube of a television. Further, there is a problem that the life is shorter than that of a CRT or a liquid crystal display device. An object of the present invention is to improve luminous efficiency,
An object of the present invention is to provide a discharge type flat display device capable of ensuring high display luminance.

[0006]

SUMMARY OF THE INVENTION The present invention has been made based on the above-mentioned problems, and includes a pair of substrates arranged to face each other, a discharge gas sealed between the substrates, and a pair of substrates. A discharge type flat display device, comprising: an excitation unit configured to excite the discharge gas to generate ultraviolet rays by exciting the discharge gas; and a light conversion unit configured to emit predetermined visible light based on the ultraviolet rays. The present invention provides a discharge type flat display device characterized in that the pressure is adjusted so as to emit excimer light based on the excitation means.

Further, according to the present invention, a pair of substrates disposed to face each other, a discharge gas sealed between the substrates, and a discharge gas disposed between the pair of substrates to excite the discharge gas to generate ultraviolet rays. A discharge-type flat panel display device comprising: an exciting unit that emits light; and a light converting unit that emits a predetermined visible light based on the ultraviolet light. An object of the present invention is to provide a discharge-type flat panel display device having an ultraviolet reflecting film for reflecting ultraviolet light on a side of the light converting means on a substrate remote from the converting means.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic diagram showing an example of a discharge type flat display device, that is, a plasma discharge type flat display device according to an embodiment of the present invention.

As shown in FIG. 1, a plasma discharge type flat display device (hereinafter, simply referred to as a discharge type display device) 1 is
A front substrate 11 formed of, for example, glass and the like having high heat resistance and transmitting light, and emitting display light (visible light) corresponding to an input image signal, a predetermined distance from the front substrate 11, for example, 200 micrometers. (Hereinafter, referred to as μm), and a light-emitting substrate 21 that emits visible light corresponding to display light displayed by the front substrate 11. In addition, between the front substrate 11 and the light emitting substrate 21, a mixed gas G 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. Also,
When the distance between the surface of the front substrate 11 facing the light emitting substrate 21 and the surface of the light emitting substrate 21 facing the front substrate 11 is d, the pressure p of the mixed gas G is p · d ≧ 7.5 (torr · cm). Note that the pressure p is preferably set to a pressure lower than 760 torr, and more preferably to approximately 500 torr.

FIG. 2 is an enlarged partial sectional view of one pixel of the discharge type display device 1 shown in FIG. As shown in FIG. 2, a surface of the front substrate 11 facing the light emitting substrate 21 includes:
For example, a metal electrode formed of a transparent material such as ITO and integrally formed with a plurality of display electrodes 12a extending in a first direction (here, the X-axis direction shown in FIG. 1). A bus 12b is arranged. The display electrode 1
A predetermined number of 2a and the buses 12b are arranged at a pitch defined based on the size and the resolving power of the discharge display device 1, for example, a diagonal of 42 inches and an aspect ratio of 16:
In the 9 NTSC / VGA (video graphic array), for example, 480 pixels are arranged at a pitch of 1.08 mm in order to provide pixels of 852 × 480 dots.

The display electrode 12a and the bus bar 12b are covered with a dielectric layer 13 for protecting each electrode from ultraviolet rays radiated from Xe by discharge. The dielectric layer 13 is provided with an ultraviolet reflective coating (hereinafter abbreviated as a UV (ultraviolet) reflective layer) 14 that reflects ultraviolet light generated by Xe toward the light emitting substrate 21. The UV reflection layer 14 is a dielectric multilayer film,
A characteristic is provided that reflects much of the ultraviolet light of a predetermined wavelength generated by e and transmits visible light that should pass through the front substrate 11. The UV reflection layer 14 has reflection characteristics of Xe ^* and Xe ₂ ^* ( ^*) in order to efficiently reflect the wavelength of ultraviolet light generated by the discharge gas Xe ^.
Contains YF ₃ (yttrium fluoride), which is good (has a small absorptance) with respect to that in the excited state.

The UV reflective layer 14 has a high emission efficiency (secondary electron emission coefficient) of secondary electrons emitted by ions generated by the discharge, and furthermore, the front substrate 11 and the light emitting substrate 21
A protective film 15 is formed to protect the UV reflection layer 14 from a discharge generated between the two. In addition, as the protective film 15, for example, MgO (magnesium oxide) is used. Further, the thickness of the protective film 15 is set to, for example, 40 nm or less, preferably 20 nm.

A surface of the light emitting substrate 21 facing the front substrate 11 has a second direction orthogonal to the first direction (here, FIG. 1).
And a predetermined voltage is applied between the display electrode 12a of the front substrate 11 and the mixed gas G injected into the light emitting substrate 21 and the front substrate. (Counter) electrode 2 for generating ultraviolet light from
3 are provided. The counter electrode 23 is provided on the front substrate 1.
In a state where 1 is viewed from the display surface 11a side, a corresponding display color (any one of R, G, and B) of each dot located at a point intersecting with the bus bar 12b of the front substrate 11 is selectively driven. In addition,
The counter electrode 23 is used to display a color image.
Three pixels, one for R (red) display, one for G (green) display, and one for B (blue) display, are arranged per pixel. In a panel of the above size, 852 × 3 = 2556 lines are arranged. In this case, since the pitch is 1/3 of one pixel, it is 0.36 mm.

The opposing electrodes 23 are also separated by barriers 24 extending in parallel with the respective electrodes, thereby forming discharge chambers 26 with the front substrate 11, respectively. The height of the barrier 24, that is, the length from the light-emitting substrate 21 is, as described later with reference to FIG.
μm or more, it is about 70% and barrier 2
The width of 4 is set to a predetermined width defined according to the pixel density and the screen size.

The inside of the discharge chamber 26, that is, the side surfaces of the two barriers 24 separating one counter electrode 23 and the surface of the light emitting substrate 21 sandwiched between the barriers 24 facing the front substrate 11,
The visible light generated by the fluorescent screen described below is applied to the front substrate 11.
A back reflection layer 27 that reflects light toward is formed. The back reflection layer 27 can increase the amount of display light that can be viewed from the display surface 11a of the front substrate 11 by preventing visible light generated by the phosphor screen from passing through the light emitting substrate 21. Al ₂ O ₃ (alumina), TiO ₂ (titania), MgO or MgF ₂
(Magnesium fluoride) or the like is used. The back reflection layer 27 has a main purpose of reflecting visible light, and may be, for example, white paint.

Inside the discharge chamber 26, the back reflection layer 27
A fluorescent screen 28 made of a fluorescent material that emits visible light when excited by ultraviolet rays that generate Xe is formed in the region where is formed or the entire region that covers the barrier 24. The phosphor screen 28 has an average particle diameter of 3 μm or less, preferably 2 μm, using a manufacturing method described in detail later with reference to FIG.
Hereinafter, a plurality of spherical phosphors formed into a spherical shape of 1 μm or less are preferably used. The thickness of the phosphor screen 28 is, for example, 5 μm by using the phosphor described above.
Is set to

As described above, when the thickness of the phosphor screen is set to 5 μm using a phosphor having a small particle diameter, the space between the two barriers 24, that is, the discharge space can be enlarged, and the plasma loss is reduced. As a result, the luminous efficiency can be improved. Note that the size of the discharge space cannot be given a specific numerical value because it depends on the pixel pitch, that is, the resolution and the size of the screen. For example, the pitch of one pixel is 0.66 mm.
When the distance between the discharge chambers 26 is 0.22 mm, the luminous efficiency can be increased by about 20% as compared with the case where a conventionally used phosphor having a coating thickness of 20 μm is used.

The fluorescent screen 28 is covered with a fluorescent screen protective film 29 containing, for example, MgO and MgF ₂ . Note that the phosphor screen protecting film 29 may be coated on the outer peripheral surface of each of the spherical phosphor particles constituting the phosphor screen 28.

FIG. 3 is a block diagram showing an example of a driving circuit for displaying an image on the discharge type display device 1 shown in FIGS. As shown in FIG. 3, the discharge type display device 1 has a display electrode 12a corresponding to an image signal in the X-axis direction.
And column drive circuit 2 for supplying a predetermined voltage to bus 12b
01, a row drive circuit 203 for supplying a predetermined voltage to the counter electrode 23 in response to an image signal in the Y-axis direction, and a frame memory 207 for storing an externally supplied image signal. The frame memory 207 has a video interface 20 for receiving an image signal from the outside.
An image signal is input via the terminal 9.

Column drive circuit 201 and row drive circuit 20
Under the control of the main control circuit 211, each of the column drive circuit 201 and the row drive circuit 203 controls the discharge voltage for image display for each of a plurality of subfields divided into a predetermined number according to a known subfield method. Is applied to the discharge chamber 26. The main control circuit 211 includes a ROM (program memory) 213 storing driving conditions and control data specific to the discharge type display device 1, a basic clock generation circuit 215 for generating a basic clock, and a frame memory 207. A vertical synchronizing signal generating circuit 217 for generating a vertical synchronizing signal V-sync for synchronizing the stored image signal in the vertical direction, and a horizontal synchronizing signal for synchronizing the image signal stored in the frame memory 207 in the horizontal direction. Horizontal synchronizing signal generating circuit 21 for generating signal H-sync
9 and other well-known image display circuits.

Column drive circuit 201 and row drive circuit 203
Respectively, the rise time of the drive pulse is Xe ₂
^A pulse that is shorter than the duration of ^* (the life of the metastable atom in the excited state) is generated, and the rise time of the pulse is preferably as described later with reference to FIG.
It is set to 200 to 10 nanoseconds (hereinafter referred to as ns). Note that the rise time of the pulse indicates a time required for the magnitude of the pulse to change from 10% to 90%.

FIG. 4 is a graph showing the wavelength distribution of ultraviolet rays generated in each discharge chamber 26 in the discharge type display device 1 shown in FIGS. In FIG. 4,
The scale indicating the intensity is normalized by setting the peak value to 1.

As is clear from FIG. 4, FIGS.
5, the partial pressure of Xe, that is, the ratio of the main discharge gas Xe to the discharge control gas Ne is 15% to 10%, as described below with reference to FIG.
Since it is increased in the range of 0%, in addition to the ultraviolet ray having a wavelength of 147 nanometers (hereinafter referred to as nm) which is a Xe ^* resonance line among the ultraviolet rays generated by the known discharge display device, 172 nm by Xe ₂ ^* excimer emission
UV light having a wavelength of

That is, by increasing the partial pressure of Xe in the mixed gas G, conventionally, ultraviolet rays having a wavelength of 147 nm were obtained by e + Xe → e + Xe ^* Xe ^* → Xe + ultraviolet rays having a wavelength of 147 nm. Xe ^* + 2Xe → Xe ₂ ^* + Xe Xe ₂ ^* → 2Xe + Ultraviolet light having a wavelength of 172 nm can provide ultraviolet light having a wavelength of 172 nm.

The energy for exciting the phosphor on the phosphor screen 28 is a wavelength 172 generated by Xe ₂ ^* excimer emission.
Since the ultraviolet light of nm is lower than the ultraviolet light of 147 nm, the luminous efficiency is increased. In addition, as shown in FIG. 4, when the partial pressure of Xe is 10%, 147 nm
And the partial pressure of Xe is preferably higher than 15%.

FIG. 5 is a graph showing the relationship between the partial pressure of Xe in the mixed gas G and the luminous efficiency. In FIG. 5, the scale indicating the efficiency is an arbitrary scale. As shown in FIG. 5, it is recognized that the luminous efficiency is almost doubled by increasing the degree of the partial pressure of Xe to more than 15%. It should be noted that increasing the partial pressure of Xe increases the discharge starting voltage. However, as in the above-described embodiment, by setting the discharge type to the counter electrode type, the discharge starting voltage can be increased to, for example, 350 volts (hereinafter, referred to as “voltage”). V).

FIG. 6 shows each discharge chamber 26 of the discharge type display device 1, that is, the display electrode 1 of the front substrate 11 by the column drive circuit 201 and the row drive circuit 203 shown in FIG.
4 is a graph showing the relationship between the rise time of a pulse of an image display pulse applied in a subfield between 2a and the bus bar 12b and the display electrode 23 of the light emitting substrate 21 and luminous efficiency. In FIG. 6, the scale indicating the efficiency is an arbitrary scale.

FIG. 7 is a graph showing the reflection characteristics of the dielectric multilayer film used for the UV reflection layer 14 of the front substrate 11 of the discharge display device 1 shown in FIGS. Note that at least one YF ₃ layer is formed in the dielectric multilayer film as described above.

As shown in FIG. 7, the UV reflection layer 14
Can provide the maximum reflectance with respect to the ultraviolet ray of about 172 nm when the incident angle of the ultraviolet ray on the reflection layer 14 itself is the normal direction (0 °) and 30 ° from the normal line. When the incident angle is 45 ° normal, the peak of the reflection wavelength is a wavelength other than 172 nm. However, it is recognized that the reflection wavelength is useful for increasing the reflectance of all the ultraviolet energy generated by the discharge. In addition,
By arranging the UV reflection film 14 on the surface of the front substrate 11 on the light emitting substrate 21 side, the total ultraviolet energy directed to the light emitting substrate 21 side is increased by 15% or more.

FIG. 8 shows the discharge type display device 1 shown in FIGS. 1 and 2 having the reflection characteristic shown in FIG.
6 is a graph showing how the luminous efficiency of visible light emitted from the discharge chamber 26 is improved by providing the reflective film 14. In FIG. 8, the scale indicating the luminous efficiency is an arbitrary scale.

As shown in FIG. 8, for example, when the partial pressure of Xe in the mixed gas is 15%, the luminous efficiency is increased by about 25% by adding the UV reflection layer 14. For example, if the partial pressure of Xe is 40%, the rate of increase of the reflection efficiency is approximately 20%. As described above, in the discharge display device 1 shown in FIGS. 1 and 2, the protective film 15 having a thickness of 20 μm is provided on the surface of the UV reflective film 14 on the light emitting substrate 21 side. From this, it has been recognized that the luminous efficiency at each partial pressure is further increased by about 20%.

FIG. 9 shows the ratio of visible light generated in each discharge chamber 26 to the outside and the light emission of each discharge chamber 26 in the discharge type display device 1 shown in FIGS. 4 is a graph showing a relationship with the reflectance of a back reflection layer 27 formed on the substrate 21 side. In FIG. 9, the scale indicating the ratio of the extracted light is an arbitrary scale.

As shown in FIG. 9, the back reflection layer 27 is colored white with, for example, Al ₂ O ₃ (alumina), so that it is untreated (0.4 on the vertical axis in FIG. 9). , The visible light amount is approximately twice (0.8 on the vertical axis in FIG. 9).

FIG. 10 shows a front substrate 1 for each discharge chamber 26 in the discharge type display device 1 shown in FIGS.
6 is a graph showing a relationship between a voltage applied to one display electrode 12a and a bus bar 12b and a display electrode 23 of a light emitting substrate 21 and a partial pressure of Xe.

As shown in FIG. 10, when the partial discharge of Xe in the mixed gas is substantially lower than 60%, the discharge starting voltage can be set to a voltage lower than 350 V by setting the discharge type to the counter discharge. Is recognized. Therefore, Xe
Is preferably 15% to 60% from the viewpoint of lowering the firing voltage. Note that the discharge start voltage of the well-known surface discharge type display device under the same conditions exceeds 400 V even when the partial pressure of Xe is about 15%. Must be used.

FIG. 11 shows a barrier 24 forming each discharge chamber 26 in the discharge type display device 1 shown in FIGS.
4 is a graph showing the relationship between the height of the light and the luminous efficiency. In addition,
In FIG. 11, the scale indicating the luminous efficiency is an arbitrary scale. Further, the result shown in FIG.
9 was measured in a state accompanied by 9.

As shown in FIG. 11, when the discharge type is the counter discharge, the height of the barrier 24 and the luminous efficiency are reduced.
It is recognized that they are roughly proportional. Therefore, from the viewpoint of improving the luminous efficiency, the effective distance between the light emitting substrate 21 and the front substrate 11 is preferably set to 150 μm or more. The height of the barrier 24 is desirably 70% or more of the effective distance between the light emitting substrate 21 and the front substrate 11 in order to reduce crosstalk.

FIG. 12 is a schematic diagram showing an embodiment of a surface discharge type flat display device different from the opposed discharge type display device shown in FIGS. . The same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description will be omitted. The characteristics of each element described with reference to FIGS. 4 to 11 are assumed to be common.

As shown in FIG. 12, the discharge type display device 101 has a partial pressure of Xe with respect to Ne of 15 to 40%.
The front substrate 111 and the light-emitting substrate 121 for sealing the mixed gas G set in the above.

On the surface of the front substrate 111 facing the light emitting substrate 121, X display electrodes 112 formed of a material transparent to the wavelength of visible light and extending a predetermined number in the first direction.
a and a metal bus electrode 112b integrally formed with the X display electrode 112a and a material transparent to the wavelength of visible light, similarly to the X display electrode 112a, and extending a predetermined number in parallel with the X display electrode 112a. Outgoing Y display electrode 113
a and a metal bus electrode 113b formed integrally with the Y display electrode 113a. The bus 112b of the X display electrode and the bus 113b of the Y display electrode are
Each is connected to a drive circuit by a row drive line (not shown).

The dielectric layer 13 is formed on the exposed portion of the front substrate 111 where the X display electrode 112a and the bus bar 112b and the Y display electrode 113a and the bus bar 113b are not formed.

The dielectric layer 13 includes Xe ^* and Xe ₂ ^*
A UV reflecting layer 14 is formed, which includes YF ₃ exhibiting a high reflection efficiency with respect to the light-emitting substrate 121 and reflects ultraviolet rays generated by Xe toward the light emitting substrate 121. The UV reflection layer 14 enhances the utilization efficiency of ultraviolet rays generated in the discharge chamber 126 described below, and is useful for improving the luminous efficiency.

The UV reflection layer 14 is provided on the UV reflection layer 14 from discharge generated between the front substrate 111 and the light emitting substrate 121.
Is formed. In addition, as the protective film 15, for example, MgO is used.

On the surface of the light emitting substrate 121 facing the front substrate 111, for example, a plurality of X display electrodes 112 extending in parallel with the Y display electrodes 113 a and provided on the front substrate 111 are provided.
Prior to the discharge caused by the application of a predetermined voltage to the a and Y display electrodes 113a, a preliminary discharge is performed in a discharge chamber 126 described below, and the X display electrodes 112a and the Y display electrodes 113a for displaying images are used. An address electrode 122 for selecting a discharge chamber 126 in which ultraviolet light is to be generated from the mixed gas G injected between the light emitting substrate 121 and the front substrate 111 by discharge is formed. The address electrode 122 also has a corresponding display color (R,
G or B) is prepared for each pixel.

On both sides of the address electrodes 122, barriers 24 extending in parallel with the respective electrodes are arranged at predetermined intervals. That is, the address electrode 122 is divided by the two barriers 24 to form the discharge chamber 126 with the front substrate 111, respectively. In addition, barrier 2
4, that is, the length from the light emitting substrate 121 is preferably an effective distance between the light emitting substrate 121 and the front substrate 111, as described above with reference to FIG.
When set within 0 μm, the interval is set to approximately 70% of the interval, and the width of the barrier 24 is set to a predetermined width defined according to the density of pixels and the screen size.

The inside of the discharge chamber 126, that is, the address 12
2, the discharge chamber 126 is provided on the side surface of the two barriers 24 separating the two and the surface facing the front substrate 111 of the light emitting substrate 121 sandwiched between the barriers 24, as already described with reference to FIG.
Inside, a fluorescent screen 28 that generates fluorescence (visible light) of a predetermined wavelength by ultraviolet light generated from the mixed gas G and a rear reflective layer 27 that reflects the visible light generated by the fluorescent screen 28 toward the front substrate 111 are formed. ing.

FIG. 13 shows one pixel of a barrier rib type discharge type display device which is further different from each of the opposed discharge type display device shown in FIGS. 1 and 2 and the surface discharge type display device shown in FIG. FIG. The same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description is omitted. The characteristics of each element described with reference to FIGS. 4 to 11 are assumed to be common.

As shown in FIG. 13, the discharge type display device 301 has a front substrate 311 and a light emitting substrate 321. The partial pressure of Xe to Ne is 15 between the two substrates.
The mixed gas G set at% to 60% is sealed.

On the surface of the front substrate 311 facing the light emitting substrate 321, a plurality of transparent electrodes 312 extending in the surface direction are provided.
a and a bus 312b. This transparent electrode 31
2a is used as an address electrode.

A dielectric layer 13 is formed on an exposed portion of the front substrate 311 where the transparent electrode 312a, the bus 312b, and the electrode are not provided. A visible light transmitting phosphor layer 330 including a phosphor that transmits visible light is disposed on the dielectric layer 13. The visible light transmitting phosphor layer 3
30 includes YF ₃ exhibiting a high reflection efficiency with respect to Xe ^* and Xe ₂ ^* , and a UV reflective layer 314 or a front substrate 311 for reflecting ultraviolet rays generated by Xe toward the light emitting substrate 321, and between the light emitting substrate 321. At least one of the protective films 315 that protects the phosphor layer 330 from the discharge generated in the step (a) is formed. In addition, as the protective film 315, for example, MgO is used. It goes without saying that both the UV reflection layer 314 and the protection layer 315 may be used.

The visible light transmitting phosphor layer 330 is fluoresced (visible light) by the ultraviolet light generated by the mixed gas G in the discharge chamber 326 having a configuration similar to the discharge chamber 26 or 126 already described in FIG. 2 or FIG. Which causes
Until now, even in the front substrate, which only transmitted the visible light generated by the light emitting substrate, the light reaching by the discharge can be directly made visible light. Therefore, the discharge chamber 3
The utilization efficiency of the ultraviolet light and the fluorescence generated in 26 is further increased, and the luminous efficiency is further improved. When the visible light transmitting phosphor 330 is disposed on the front substrate 311, the visible light transmitting phosphor 330 is disposed so that the partition 324 described below does not reach the front substrate 311. Since there is a possibility that irregular reflection may occur at an end of the 324 (a region parallel to the front substrate 311), the visible light transmitting fluorescent layer 330 is formed on the front substrate 311.
In the case of using, a material having a low reflectance, for example, a black paint (not shown) is preferably applied to the top of the partition 324. Also, instead of applying black paint on the top of the partition 324, the front substrate 311 is placed in a state where the front substrate 311 is viewed in a planar direction, that is, from the display surface 311a.
The filter member 3 is provided on the protective layer 315 of the front substrate 311 facing the region through which the partition 24 can be seen, that is, the top of the partition 324.
35 may be arranged.

The transparent substrate 312 a of the front substrate 311 extends in a second direction orthogonal to the first direction in which the transparent substrate 311 extends, and emits light from the light emitting substrate 321 toward the front substrate 311. A plurality of barriers 324 extending three per pixel are formed substantially vertically from the substrate 321. The area divided by the two barriers 324 provides a discharge chamber 326 between the area and the front substrate 311.

The two barriers 324 are opposed to each other, that is, the inner wall of the discharge chamber 326, and are arranged substantially in the center of the barrier 324 in the height direction or on the light emitting substrate 321 so as to form a pair for each discharge chamber 326. First and second discharge electrodes 33
1 and 332 are provided. The first and second discharge electrodes 331 and 332 are respectively connected to the display electrode 12a in the panel device shown in FIGS.
(Bus 12b) and the counter electrode 23, and the corresponding display color (R, G, B) at a position where an arbitrary row and column are designated by a control circuit (not shown) using the address electrode 312a together. Is selectively displayed. In addition, the first and second discharge electrodes 331 and 332 correspond to FIG.
By setting the discharge interval provided by the bus bar 12b and the display electrode 12a and the display electrode 23 in the panel device shown in FIG. 2 to be the same as that in the counter discharge shown in FIG. In addition to what can be done with a proper discharge start voltage, the discharge start voltage can be further reduced by applying a preliminary discharge by the address electrode.

The inside of the discharge chamber 326, that is, the surface on which the respective discharge electrodes 331 and 332 of each barrier 324 partitioning the first and second discharge electrodes 331 and 332 are disposed and the front substrate 311 of the light emitting substrate 321. A back reflection layer 333 is formed in a portion surrounded by the surface. The back reflection layer 333 prevents visible light generated from a phosphor screen composed of small-diameter spherical phosphor particles formed on the reflection film 333 described below from passing through the light-emitting substrate 321, so that the front reflection substrate 331 is formed. 311 to increase the amount of display light that can be viewed from the display surface 311a.
l ₂ O ₃ , TiO ₂ , MgO, MgF ₂ or the like is used. The particles used for the back reflection layer 333 preferably have a property capable of reflecting the visible light output by the phosphor excited by the ultraviolet light generated by Xe and the ultraviolet light itself generated by Xe. Can be

Inside the discharge chamber 326, the back reflection layer 3
The fluorescent screen 28 is formed in the area where 33 is formed. The phosphor screen 28 has an average particle diameter of 3 μm or less, preferably 2 μm or less, more preferably 1 μm or less, as in the other examples described above.
A plurality of spherical phosphors formed in a small spherical shape of μm or less are used. Note that the thickness of the phosphor screen 28 is a fraction of, for example, 5 μm, compared to the phosphor thickness of a well-known discharge display device.
m. Further, the phosphor screen 28 is coated with a phosphor screen protective film 29 containing, for example, MgO and MgF ₂ , as in the example described above.

FIG. 14 is a schematic view showing a method of manufacturing a phosphor used in the discharge type display device shown in FIG. 1, FIG. 2, FIG. 12, or FIG. As shown in FIG. 14, the phosphor has a spherical shape having an average particle size of approximately 3 μm or less, preferably 2 μm or less, more preferably 1 μm or less under an environment where the maximum temperature is lower than 3000 ° C. by the thermal plasma device 401. Formed. That is, the powder raw material heated by the frame furnace 417 through which the plasma torch 415 can pass is injected into the injection port 419 into the plasma container main body 413 reduced to a predetermined pressure by the exhaust pump 411.
From the plasma container body 413 so as not to come into direct contact with the inner wall thereof. As a result, a spherical phosphor powder having a small particle diameter can be obtained even with a complicated composition.

[0057]

As described above, in the plasma discharge type flat display device of the present invention, the ultraviolet reflecting film for reflecting the ultraviolet light generated by the discharge toward the phosphor provided on the light emitting substrate is provided on the front substrate side. The partial pressure of Xe in the discharge gas is in the range of 15% to 60%, and the display electrodes are arranged to face each other;
By making the average particle diameter of the phosphor in the discharge chamber small, discharge can be started at a low discharge start voltage, and the luminous efficiency is improved.

Further, by covering the wall surface of the discharge chamber with a reflective layer and protecting the phosphor layer and the display electrode with a dielectric protective film, it is possible to extend the life and improve the luminous efficiency. Therefore, a discharge-type flat panel display device having high luminous efficiency and high screen luminance is provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a plasma discharge type flat display device of the present invention.

FIG. 2 is a partial cross-sectional view schematically showing a unit pixel of the display device shown in FIG.

FIG. 3 is a block diagram illustrating an example of a driving circuit of the display device illustrated in FIGS. 1 and 2.

FIG. 4 is a graph showing a wavelength distribution of ultraviolet light generated in each discharge chamber of the display device shown in FIGS. 1 and 2;

5 is a graph showing the relationship between the partial pressure of Xe in the mixed gas and the luminous efficiency of the display device shown in FIGS. 1 and 2. FIG.

6 shows the rise time and light emission of an image display pulse applied in a subfield to each discharge chamber of the display device shown in FIG. 1 by each of the row drive circuit and the column drive circuit shown in FIG. 4 is a graph showing a relationship with efficiency.

FIG. 7 is a graph showing reflection characteristics of a dielectric multilayer film used for a UV reflection layer of a front substrate of the display device shown in FIGS. 1 and 2;

8 shows how the luminous efficiency of visible light emitted from the discharge chamber is improved by using the UV reflective film having the reflection characteristics shown in FIG. 7 in the display device shown in FIGS. 1 and 2; The graph shown.

9 is a graph showing a relationship between a ratio of visible light extracted from each discharge chamber of the display device shown in FIGS. 1 and 2 and a back reflection layer formed on a light emitting substrate side of each discharge chamber.

10 is a graph showing the relationship between the interelectrode voltage applied between the display electrode and the bus bar of the front substrate and the display electrode of the light emitting substrate and the partial pressure of Xe with respect to the discharge chamber of the display device shown in FIGS. Graph showing the relationship.

FIG. 11 is a graph showing a relationship between a luminous efficiency and a barrier in a pixel constituting each discharge chamber of the display device shown in FIGS. 1 and 2;

FIG. 12 is a schematic diagram showing another embodiment different from the display device shown in FIGS. 1 and 2, in which one pixel is taken out and shown as a cross-sectional view.

FIG. 13 is a schematic view showing another embodiment different from the display device shown in FIGS. 1 and 2, in which one pixel is taken out and shown as a cross-sectional view.

FIG. 14 is a schematic diagram showing a thermal plasma device used for manufacturing a spherical small-diameter phosphor used in the display device shown in each of FIGS. 1, 2 and 11;

[Description of Signs] 1 ... discharge type display (plasma discharge type flat display), 11 ... front substrate, 12a ... display electrode, 12b ... bus (metal electrode), 13 ... dielectric layer, 14 ... UV reflection layer ( UV protective film, 15: protective film, 21: light emitting substrate, 23: display electrode (counter electrode), 24: barrier, 26: discharge chamber, 27: back reflective layer, 28: fluorescent screen, 29: protective film, 111 ... front substrate, 112a ... X display electrode, 112b ... bus (metal electrode), 113a ... Y display electrode, 113b ... bus (metal electrode), 121 ... light emitting substrate, 122 ... address electrode (third electrode), 126 ... Discharge chamber, 201: column drive circuit, 203: row drive circuit, 207: frame memory, 209: video interface, 211: main control circuit, 213: ROM (program 215, a basic clock generating circuit, 217, a vertical synchronizing signal generating circuit, 219, a horizontal synchronizing signal generating circuit, 301, a discharge type display device, 321, a light emitting substrate, 330, a visible light transmitting phosphor layer, and 331. 1 discharge electrode, 332 ... second discharge electrode, 333 ... back reflection layer, 335 ... black filter.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takaaki Murata 2-1 Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Toshiba Hamakawasaki Plant (72) Inventor Kiyotoshi Terai No. 2, Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 1 Inside Toshiba Hamakawasaki Factory (72) Inventor Yoshikazu Hoshina No. 2-1, Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside Toshiba Hamakawasaki Factory (72) Inventor Masaaki Tamaya Koyuki-ku, Kawasaki-shi, Kanagawa Prefecture No. 1 Muko Toshiba, Toshiba R & D Center (72) Inventor Yuji Okita 2-24-1, Harumi-cho, Fuchu-shi, Tokyo Toshiba FA System Engineering Co., Ltd. (72) Inventor Ryoji Tsuda Kawasaki, Kanagawa 7-1, Nisshincho, Kawasaki-ku, Ichiba Toshiba Electronic Engineering Corporation

Claims (29)

[Claims] 1. A pair of substrates opposed to each other, a discharge gas sealed between the substrates, and an excitation unit disposed between the pair of substrates and exciting the discharge gas to generate ultraviolet rays. A light-converting device that emits predetermined visible light based on the ultraviolet light, wherein the discharge gas is regulated so as to emit excimer light based on the excitation device. A discharge type flat panel display device characterized by the above-mentioned. 2. The discharge gas includes a main discharge gas and a discharge control gas for controlling discharge, and a partial pressure of the main discharge gas is set to 15% or more. 2. The discharge type flat panel display according to claim 1. 3. The discharge gas according to claim 1, wherein the main discharge gas contains Xe, and the discharge control gas contains at least one of Ne and He. Discharge type flat panel display. 4. The discharge type flat display device according to claim 1, wherein a wavelength of excimer light emission by said discharge gas is 172 nm. 5. The apparatus according to claim 1, wherein said excitation means comprises a first electrode and a second electrode which are disposed opposite to the inner main surfaces of each of said pair of substrates.
5. The discharge type flat display device according to claim 1, further comprising an electrode. 6. An apparatus according to claim 1, wherein said excitation means includes an address electrode and a pair of discharge electrodes which are opposed to main inner surfaces of each of said pair of substrates. The discharge type flat display device according to any one of the above. 7. The method according to claim 1, further comprising a plurality of partition walls extending from one of the substrates toward the other substrate between the pair of substrates. 2. The discharge type flat panel display according to item 1. 8. The method according to claim 1, wherein the partition wall is provided between the pair of substrates.
8. The discharge type flat display according to claim 7, wherein a distance between a substrate on which the base of the partition wall is formed and a substrate facing the substrate is approximately 70% of a distance between the pair of substrates. apparatus. 9. The excitation means includes a first electrode and a second electrode formed in each of the plurality of partition walls in pairs with each other.
8. The flat panel display according to claim 7, further comprising an electrode. 10. The discharge type flat display device according to claim 5, wherein said light converting means includes a phosphor layer disposed on said second electrode. 11. The flat panel display according to claim 6, wherein said light conversion means includes a phosphor layer disposed on said address electrode. 12. The discharge type flat display device according to claim 9, wherein said light conversion means includes a phosphor layer disposed on said excitation means formed on said partition. 13. The discharge type flat display device according to claim 10, wherein said phosphor layer is formed by dispersing phosphor particles having an average particle diameter of 3 μm or less. . 14. The discharge type flat display device according to claim 5, further comprising an ultraviolet reflecting film between one of said substrates and said second electrode. 15. The discharge type flat display device according to claim 6, further comprising an ultraviolet reflective film between one of said substrates and said address electrode. 16. The discharge gas pressure p satisfies p · d ≧ 7.5 (torr · cm), where d is the distance between the pair of substrates. Items 1 to 15
Item 10. A discharge type flat panel display according to any one of the above items. 17. A pair of substrates opposed to each other, a discharge gas sealed between the substrates, and an excitation unit disposed between the pair of substrates and exciting the discharge gas to generate ultraviolet rays. A light-converting means for emitting predetermined visible light based on the ultraviolet light; a discharge-type flat display device, wherein the light-converting means is separated from another substrate side or the light-converting means of the pair of substrates. A discharge type flat panel display device comprising an ultraviolet reflecting film for reflecting ultraviolet light on the light conversion means side of the substrate. 18. The discharge-type flat surface according to claim 17, wherein said excitation means includes a first electrode and a second electrode which are disposed opposite to the inner main surfaces of each of said pair of substrates. Display device. 19. The apparatus according to claim 17, wherein said excitation means includes an address electrode and a pair of discharge electrodes disposed opposite to the inner main surfaces of each of said pair of substrates.
Item 8. The discharge type flat panel display device according to item 1. 20. The discharge-type flat display according to claim 17, further comprising a plurality of partition walls extending from one of the substrates toward the other substrate between the pair of substrates. apparatus. 21. The distance between the pair of substrates, the distance between the pair of substrates and the substrate facing the substrate on which the base of the partition is formed is approximately 70 compared to the distance between the pair of substrates.
21. The discharge type flat panel display according to claim 20, wherein 22. The discharge-type flat surface according to claim 21, wherein said excitation means includes a first electrode and a second electrode formed in pairs with each other on each of said plurality of partition walls. Display device. 23. The light conversion device according to claim 18, wherein the light conversion means includes a phosphor layer disposed on the second electrode.
Item 8. The discharge type flat panel display device according to item 1. 24. The discharge type flat display device according to claim 19, wherein said light converting means includes a phosphor layer disposed on said address electrode. 25. The flat panel display according to claim 20, wherein said light conversion means includes a phosphor layer disposed on said excitation means formed on said partition. 26. The discharge type flat display device according to claim 18, wherein said phosphor layer is formed by dispersing phosphor particles having an average particle diameter of 3 μm or less. . 27. The discharge type flat display device according to claim 18, further comprising an ultraviolet reflection film between one of said substrates and said second electrode. 28. The discharge type flat display device according to claim 19, further comprising an ultraviolet reflecting film between one of said substrates and said address electrode. 29. When the distance between the pair of substrates is d, the pressure p of the discharge gas satisfies p · d ≧ 7.5 (torr · cm). Clause 16 or 2
Item 9. A discharge type flat panel display according to any one of items 8 to 10.