JP2773393B2 - Color discharge display panel and method of manufacturing the same - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color discharge display panel used for information display and television image display, and more particularly to a color discharge display panel with improved emission luminance and a method of manufacturing the same. Things.

[Prior Art] Discharge display panels emit light using gas discharge, and have excellent features such as a large non-linearity of discharge phenomena, high-speed response, and a unique memory effect.
It is widely used for information display devices and the like. at present,
Practically used are those that display red and orange in a single color due to the discharge emission of Ne, but use a discharge gas that generates ultraviolet rays such as Xe, and apply a fluorescent substance applied to the inner wall of the discharge cell. , Blue, etc., full color display can be realized.

Although such a color discharge display panel has various structures, it can be classified into a transmission type and a reflection type according to the application position of the phosphor powder. The transmissive type is a panel in which a phosphor is applied to a front substrate side which is a display surface, and a light emitting display is viewed through a phosphor layer. On the other hand, in the reflection type, a phosphor is applied to the inner wall of the rear substrate or the partition wall for separating the discharge cells on the display rear side. The reflection type has a higher dot brightness than the transmission type because the light emission of the phosphor is directly viewed through the transparent front substrate, and is advantageous over the transmission type if some measures are taken to increase the aperture ratio.

However, even in such a reflection type, light generated from the phosphor is emitted in all directions, so that the amount of light extracted to the display side and contributing to display is considerably reduced. In order to improve this, a method employing a white glaze layer has been used.

FIG. 3 is a partial sectional view of a panel showing an example of a reflection type. White glaze layer 36 and phosphor layer on rear substrate 31
35 are formed. A discharge cell 33 defined by the front substrate 32 and the partition 34 is formed. A discharge gas containing Xe is sealed in the discharge cells 33. The electrode structure includes a DC type and an AC type using an electrode covered with a dielectric layer. Although there are various types such as a surface discharge configuration and a one-pixel three-electrode structure, the present invention is not directly related to the electrode structure.
FIG. 3 shows a state in which the electrodes are omitted for simplification.

The phosphor layer 35 generates visible light by the ultraviolet light generated by the discharge. Light emitted upward from the phosphor layer 35 is effectively extracted as display light, but light emitted downward from the phosphor layer 35 is emitted to the rear surface almost as it is without the white glaze layer 36 and contributes to display. do not do. When there is a white glaze layer 36 as shown in FIG. 3, a part of the light is diffusely reflected and returned to the display side, and the luminance is improved. Such a white glaze layer is mainly composed of lead glass having a low softening point, and a fine powder such as alumina or titanium oxide having a different refractive index from the glass component is dispersed therein, and is formed by screen printing. The white glaze layer often has a diffuse reflection function by whitening the glaze layer formed as an AC-type dielectric layer or an interlayer insulating layer having a multilayer electrode structure.

[Problems to be Solved by the Invention] As described above, the display brightness is improved by disposing the white glaze layer below the phosphor layer, but the useless light emitted to the rear side is also reduced. There are still many, and the improvement effect is not enough. This is because the reflection performance of the white glaze layer is not so good. Factors that determine the performance of such diffuse reflection include the difference in refractive index between the dispersed powder and the glass medium, the particle diameter of the dispersed powder, the packing density, and the like. In the white glaze layer, the refractive index of lead glass is quite large, about 1.7,
The difference in refractive index from the dispersed powder cannot be made large. In addition, when the amount of the dispersed powder is increased, a good layer cannot be formed without reflow even at the sintering temperature, so that the amount of the mixed powder cannot be increased. For these reasons, the reflectivity of the white glaze layer is not so large, and the luminance is not sufficiently improved. In addition, aside from the case where the white glaze layer is used also as the dielectric layer of the AC type panel and the like, if it is newly formed as a reflective layer, there is a problem that the manufacturing cost is greatly increased.

The present invention has been made in view of such a conventional situation, and has an object to provide a color discharge display panel in which the reflectance under the phosphor is improved, the manufacturing cost is low, and the display luminance is high. I do.

Means for Solving the Problems The present invention relates to a color discharge display panel having a discharge cell defined by a partition wall between a rear substrate and a front substrate serving as a display side, wherein at least the rear wall of the inner wall of the discharge cell Has a reflective layer made of white pigment powder formed thereon, and a phosphor layer is formed on the reflective layer.

Further, in the manufacturing method, a step of screen-printing and drying a white pigment powder paste on at least the rear substrate of the inner wall of the discharge cell, and a step of screen-printing a phosphor paste on the dried white pigment powder layer, A white pigment powder layer and the phosphor paste are simultaneously fired to form a reflective layer made of white pigment powder and a phosphor layer formed on the reflective layer.

Furthermore, according to the present invention, in a color discharge display panel including a discharge cell defined by a partition wall between a rear substrate and an entire substrate serving as a display side, a discharge cell inner wall is formed on a rear substrate and on a side surface of the partition wall. A color discharge display panel is also obtained in which a reflection layer made of a white pigment powder is formed, and a phosphor layer is formed on the reflection layer.

[Operation] The diffuse reflection layer formed below the phosphor layer of the present invention is made of fine white pigment powder. As the white pigment, various oxides such as titanium oxide, barium oxide, lead oxide, magnesium oxide, and aluminum oxide; sulfides such as zinc sulfide; and fine white powders of nitrides and fluorides may be used. it can. Among them, titanium oxide is most practical because it can be obtained at a high refractive index and at a low price. Since this white pigment layer is different from the white glass layer and is merely a powder layer, the refractive index difference from the refractive index (about 1) of the discharge gas is large, and a fine powder layer densely packed may be used. High reflection performance because it can. Such a structure can be easily realized by applying a white pigment powder by a similar method before applying the phosphor powder.

Example Next, an example of the present invention will be described in detail.

FIG. 1 is a partial sectional view of an example of a color discharge display panel according to the present invention. The method of manufacturing this discharge display panel is as follows.
First, a writing electrode 7 is formed on a glass back substrate 1.
Thereafter, a paste made of fine powder of titanium oxide having an average particle diameter of 0.3 μm, a binder, a solvent and the like was printed in a predetermined dot shape by screen printing to form a white pigment layer 9. 120 ° C
After drying, a paste consisting of a blue phosphor powder (BaMgAl ₁₄ O ₂₃ : Eu), a binder, a solvent and the like is screen-printed on one-third of the titanium oxide dots, and dried to form a phosphor layer 10.
a.

Further, the paste of the green phosphor powder (Zn ₂ SiO ₄ : Mn) and the paste of the red phosphor powder ((Y, Gd) BO ₃ : Eu) were shifted by one third in the same manner as the blue phosphor powder. The phosphor layers 10b and 10c were printed on the titanium oxide dots. This substrate was baked at 500 ° C. to remove the binder component and complete the rear substrate portion on which the titanium oxide white pigment layer 9 and the blue, green, and red phosphor layers 10a to 10c were formed. The thickness of each phosphor layer was about 10 μm.

On the other hand, a surface discharge electrode 6 designed to have a sufficient opening is formed on the front substrate 2, and a glass layer formed by a thick film technique and a magnesium oxide surface protection film formed by vacuum deposition are formed thereon. A dielectric layer 8 made of a layer is formed. A center sheet glass plate having a large number of fine holes was sandwiched between a front substrate portion and a rear substrate portion as a partition wall 4, and discharge cells 3 were formed and the whole was sealed to complete a panel. A He-Xe mixed gas containing 1% of Xe was sealed as a discharge gas. When this panel was illuminated, the brightness on the white surface was 110 cd /
A luminance of m ² was obtained.

On the other hand, to prepare a free panel with white pigment layer 9, was measured the brightness at the same driving conditions as above, was 75 cd / m ^2, the effect of the white pigment layer was confirmed. When the white pigment layer of titanium oxide is thin, the reflection effect is small, and when the thickness is large, the reflection performance is saturated, but a manufacturing problem occurs,
It is preferable that the thickness be approximately 1 μm to 30 μm.

FIG. 2 is a partial sectional view of a panel showing a second embodiment in which a white pigment layer and a phosphor layer are also formed on a partition wall portion. The structure of this panel is substantially the same as that of FIG. 1, but in the present embodiment, a partition 24 is directly formed on a back substrate 21 to constitute a discharge cell 23. The partition wall 24 is a black insulator in which low-melting glass and fine powder such as aluminum oxide and iron oxide are mixed, and is formed by a thick film technique. A paste composed of fine powder of titanium oxide and a water-insoluble binder was uniformly applied and dried on the entire surface. Then, apply a photosensitive paste composed of phosphor powder and PVA, and dry,
Exposure and development were repeated for blue, green, and red phosphors, and then baked at 500 ° C.

Since the white pigment layer 29 and the phosphor layers 25a, 25d, and 25c are also formed on the partition wall portion of the rear substrate portion, the discharge cell 23 thus obtained has higher luminance.

In the above embodiment, the titanium oxide powder was used as the white pigment layer, but other materials can be used as long as the powder has a high refractive index. Further, in order to improve the adhesion strength of the white pigment layer, a small amount of a glass component may be mixed to crosslink particles.

[Effects of the Invention] As described above, according to the present invention, there is provided a color discharge display panel with improved light emission luminance of a color plasma display. Further, the discharge display panel of the present invention,
Since the reflection layer can be formed in the same process as the application of the phosphor powder layer, no new equipment is required, and the process is simple, so that there is little influence on the cost. Further, according to the configuration of the present invention, there is an advantage that the phosphor layer can be thinned, and the amount of expensive phosphor material used can be reduced.

[Brief description of the drawings]

1 and 2 are partial cross-sectional views of one embodiment of the present invention, and FIG. 3 is a partial cross-sectional view of an example of a conventional color discharge display panel. 1,21,31 ... Back substrate 2,22,32 ... Front substrate 3,23,33 ... Discharge cell 4,24,34 ... Partition wall 6,26 ... Surface discharge electrode 7,27 ... Write electrode 8,28 dielectric layer 9,29 white pigment layer 10a, 10b, 10c, 25a, 25b, 25c, 35 phosphor layer 36 white glaze layer

Claims (4)

(57) [Claims] 1. A color discharge display panel having a discharge cell defined by a partition wall between a rear substrate and a front substrate serving as a display side, wherein at least the rear substrate on the inner wall of the discharge cell is made of a reflection of white pigment powder. A color discharge display panel comprising a layer, and a phosphor layer formed on the reflective layer. 2. A color discharge display panel having discharge cells defined by partitions between a rear substrate and a front substrate serving as a display side, wherein a white pigment is formed on the rear substrate of the inner walls of the discharge cells and on the side surfaces of the partitions. A color discharge display panel, wherein a reflective layer made of a powder is formed, and a phosphor layer is formed on the reflective layer. 3. A color discharge display panel according to claim 1, wherein said reflective layer has a thickness of 1 μm to 30 μm. 4. The color discharge display panel according to claim 1, wherein said partition is a black insulator.