JP2003317630A - Plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma display panel with a smaller characteristics difference of initialization discharge in each discharge cell for red color, green color and blue color. <P>SOLUTION: By placing a front face substrate 1 as a first substrate and a back face substrate 6 as a second substrate with a phosphor layer 10r, 10g, and 10b emitting light of red, green and blue color in opposition, discharge cells 11r, 11g, and 11b for red color, green color and blue color are formed each in correspondence with a red-color, green-color and blue-color phosphor layer 10r, 10g, 10b. As for at least one-color discharge cell 11g out of the red- color, green-color and blue-color discharge cells 11r, 11g, and 11b, a distance 18 from the surface of the back face substrate 6 to the underside of the phosphor layer is made larger than those of the discharge cells 11r, 11b of other colors and yet a thickness 16g of the phosphor layer 10g is made smaller. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a large screen, thin type,
The present invention relates to a plasma display panel known as a lightweight display device.

[0002]

2. Description of the Related Art In recent years, a plasma display panel has attracted attention as a thin display device having excellent visibility, and high definition and large screen have been promoted.

This plasma display panel is roughly classified into an AC type and a DC type in terms of driving, and there are two types of discharge types, a surface discharge type and a counter discharge type, but high definition, large screen and manufacturing. Because of its simplicity, the AC type surface discharge type plasma display is now predominant.

FIG. 3 is a perspective view showing a main part of a typical plasma display panel. The structure and operation will be described below. A plurality of scan electrodes 2 and sustain electrodes 3 are formed in pairs on the front substrate 1, and a transparent dielectric layer 4 is formed on these electrodes. A protective layer 5 made of magnesium oxide is formed on the dielectric layer 4, and its thickness is considerably smaller than that of the dielectric layer 4. The dielectric layer 4 has a current limiting function peculiar to the AC type plasma display panel, which is a factor that can prolong the life as compared with the DC type.

A plurality of address electrodes 7 are formed on the rear substrate 6 facing the front substrate 1 so as to be orthogonal to the scan electrodes 2 and the sustain electrodes 3, and cover the address electrodes 7 to form a base layer 8. Are formed. A partition 9 is provided on the underlying layer 8 between the address electrodes 7, and a phosphor layer 10 that emits red, green, or blue is sequentially formed on the underlying layer 8 between the partitions 9. A plurality of discharge cells 11 are formed between the front substrate 1 and the rear substrate 6 that face each other, and a red phosphor layer 10r is provided in the red discharge cell 11r.
The green discharge cell 11g is provided with a green phosphor layer 10g, and the blue discharge cell 11b is provided with a blue phosphor layer 10b.
Is provided. In the discharge cell 11, a mixed gas of neon (Ne) and xenon (Xe) as a discharge gas is about 6
It is filled at a pressure of 6.5 kPa (500 Torr).

FIG. 4 shows an example of a standard drive waveform of the plasma display panel. As shown in FIG. 4, the drive waveform is composed of four operation periods including an initialization period, a writing period, a sustaining period, and an erasing period. In the initializing period, an initializing discharge for forming initializing charges (a predetermined amount of wall charges required during the writing operation) and generating priming particles is performed between the scan electrode 2 and the address electrode 7, and the writing period Then, in the discharge cell where the sustain discharge should be performed in the sustain period, the write discharge is selectively performed between the scan electrode 2 and the address electrode 7 and between the scan electrode 2 and the sustain electrode 3.
In the sustain period, the sustain discharge is performed between the scan electrode 2 and the sustain electrode 3 in the discharge cell in which the write discharge is selectively performed in the write period. In the erasing period, the wall charges generated by the sustain discharge are erase-discharged between the scan electrodes 2 and the sustain electrodes 3. Therefore, in order to surely perform the writing discharge, the sustaining discharge, and the erasing discharge after the initialization period, it is necessary to appropriately form the initialization charges necessary for the series of discharges between the scan electrode 2 and the address electrode 7. It is important to perform the initializing discharge.

FIG. 5 shows a simple equivalent circuit in the initialization discharge between the scan electrode 2 and the address electrode 7 of the discharge cell 11. The simple equivalent circuit is formed by the electrostatic capacity 12 by the dielectric layer 4 and the protective layer 5, the electrostatic capacity by the base layer 8 and the phosphor layer 10 (hereinafter referred to as the electrostatic capacity of the phosphor layer) 13, and the discharge space. It The discharge space is the Zener voltage Vb1, V
It is replaced with the Zener diode of b2, the Zener voltage Vb1 is the discharge start voltage when the dielectric layer 4 becomes the cathode, and the Zener voltage Vb2 corresponds to the discharge start voltage when the phosphor layer 10 becomes the cathode. . The capacitance 13 of the phosphor layer is red, green, or blue phosphor layer 10.
r, 10g, 10b, 13r,
13g and 13b. The electrostatic capacitance (electrostatic capacitance of the discharge cell) 14 between the scan electrode 2 and the address electrode 7 becomes a combined capacitance of the dielectric layer 4 and the protective layer 5, the discharge space, and the phosphor layer.

[0008]

By the way, in the initialization period
The initializing discharge in the scan electrode 2 and the address electrode 7 is
Between, that is, the base layer 8 and the phosphor layer 10 on the rear substrate 6 side,
Discharge space through the dielectric layer 4 and the protective layer 5 on the front substrate 1 side
Between the red, green, and blue phosphor layers 10.
of the phosphor materials used for r, 10g, and 10b, respectively.
Due to the difference, there is a difference in the capacitance 13 of the phosphor layer of each color.
In the discharge space where the phosphor layers of each color are formed.
There is a difference in voltage and current characteristics during initializing discharge.
For example, as a red phosphor material (Y₂Gd) BO₃: Eu
Zn as a green phosphor material ₂SiO_Four: Mn
As a blue phosphor material
_TenO₁₇: When using Eu, especially the green discharge cell 11
The discharge starting voltage of the initializing discharge of g is a red discharge cell 11r.
And higher than the discharge starting voltage of the blue discharge cell 11b
Tends to become. In addition, the discharge current in the initializing discharge
Even with the green discharge cell 11g, the discharge cell 11r and
It is smaller than 11b, and in the green discharge cell 11g
Sufficient initializing discharge compared to the discharge cells 11r and 11b
It is difficult to do so, and it has bad write characteristics after the initialization period.
Tend to have an impact.

The present invention has been made to solve the above problems, and an object thereof is to provide a plasma display panel having a smaller difference in the characteristics of the initializing discharge in each of red, green and blue discharge cells. And

[0010]

In order to achieve the above object, a plasma display panel of the present invention comprises a first substrate and a second substrate having a phosphor layer for emitting red, green and blue light. The red, green and blue phosphor layers respectively corresponding to the red, green and blue between the substrates by facing each other,
Green and blue discharge cells are formed, and in at least one color discharge cell among red, green and blue discharge cells, a phosphor is formed from the surface of the second substrate as compared with discharge cells of other colors. The distance to the lower surface of the layer is increased and the thickness of the phosphor layer is decreased. With this configuration, it is possible to reduce the difference in discharge characteristics among the red, green, and blue discharge cells.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION That is, according to the invention described in claim 1 of the present invention, a discharge space is provided between the first substrate and the red color,
A red, green and blue discharge cell corresponding to each of the red, green and blue phosphor layers is formed between the substrates by arranging a second substrate on which a phosphor layer emitting green and blue is formed so as to face each other. In the discharge cell of at least one color among red, green and blue discharge cells,
The plasma display panel is characterized in that the distance from the surface of the second substrate to the lower surface of the phosphor layer is increased and the thickness of the phosphor layer is decreased as compared with discharge cells of other colors.

Further, according to a second aspect of the present invention, a dielectric layer is provided between the second substrate and the phosphor layer in at least one color discharge cell among red, green and blue discharge cells. It is characterized in that the distance from the surface of the second substrate to the lower surface of the phosphor layer is made larger than that of the color discharge cell.

According to another aspect of the present invention, a plurality of address electrodes are provided on the second substrate and a base layer is formed so as to cover the address electrodes, and among the red, green and blue discharge cells, By providing a dielectric layer between the underlayer and the phosphor layer in at least one color discharge cell, the distance from the surface of the second substrate to the bottom surface of the phosphor layer is different from that of discharge cells of other colors. The feature is that the distance is increased.

Further, in claim 4, the dielectric layer is
It is characterized in that it is made of a material having a high reflectance for ultraviolet rays and visible light, and in claim 5, the dielectric layer is made of a dielectric containing titanium dioxide.

Further, in claim 6, among the constituent members formed on the first substrate, the distance from the surface of the constituent member in contact with the discharge space to the surface of the phosphor layer is red, green and blue discharge cells. Is almost the same in.

An embodiment of the present invention will be described below with reference to the drawings. The same parts as those shown in FIG. 3 are designated by the same reference numerals.

FIG. 1 is a sectional view showing a main part of a plasma display panel according to an embodiment of the present invention. In this plasma display panel, a discharge space is provided between the front substrate (first substrate) 1 and the rear substrate (second substrate).
6 and 6 are arranged so as to face each other. Similar to the plasma display panel shown in FIG. 3, a plurality of scan electrodes 2 and sustain electrodes 3 are arranged in pairs on the front substrate 1, and a dielectric is formed so as to cover the scan electrodes 2 and the sustain electrodes 3. A layer 4 is formed, and a protective layer 5 is further formed on the dielectric layer 4. A plurality of address electrodes 7 are arranged on the rear substrate 6, and a base layer 8 is formed so as to cover the address electrodes 7. Partition walls 9 parallel to the address electrodes 7 are formed between the address electrodes 7 on the base layer 8. In the space partitioned by the partition wall 9, phosphor layers 10r, 10g, 10b that emit red, green or blue light are provided.
And a dielectric layer 15 is provided between the base layer 8 and the green phosphor layer 10g.

The front substrate 1 and the rear substrate 6 are the scanning electrodes 2
Further, the sustain electrodes 3 and the address electrodes 7 are arranged so as to be orthogonal to each other and the periphery thereof is hermetically sealed, and the discharge space between the front substrate 1 and the rear substrate 6 has a discharge gas mixture of Ne and Xe. Are filled at a predetermined pressure and mixing ratio.
Discharge cells 11 corresponding to the phosphor layers of each color are formed at the intersections of the scan electrodes 2 and the sustain electrodes 3 and the address electrodes 7. That is, a red discharge cell 11r is formed between the front substrate 1 and the rear substrate 6 corresponding to the red phosphor layer 10r, and a green discharge cell 11g is formed corresponding to the green phosphor layer 10g. The blue discharge cell 11b is formed corresponding to the blue phosphor layer 10b. Then, by using the above-described conventional driving method, sustain discharge is generated in each discharge cell 11 to cause the phosphor layer 10 to emit light, thereby displaying an image.

In the plasma display panel of the present embodiment, the thickness 16r of the red phosphor layer 10r and the thickness 16b of the blue phosphor layer 10b are set to be substantially the same, and the thicknesses 16r, 16b are set. The thickness 16g of the green phosphor layer 10g is smaller than that of the above, and the dielectric layer 15 is formed below the green phosphor layer 10g. Here, the thickness of the phosphor layer 10 of each color is the bottom surface of the phosphor layer 10, that is, the surface of the base layer 8 in contact with the phosphor layer 10 (in the case of the red and blue phosphor layers 10r and 10b) or the dielectric. It is the thickness of the phosphor layer 10 measured from the surface of the body layer 15 (in the case of the green phosphor layer 10 g). As shown in FIG. 1, the phosphor layer 10 is formed so as to be thin in the central portion of the discharge cell 11 and thicker on the side of the barrier ribs 9.
Thickness of green and blue phosphor layers 16r, 16g, 16b
Is the value at the thinnest portion of the phosphor layer 10 of each color from the bottom surface. The thickness 16 of the phosphor layer can be adjusted by the viscosity of the phosphor material applied when forming the phosphor layer 10, the coating amount, the resin content, and the like.

Next, the thickness 16r of the red phosphor layer 10r
Also, regarding the plasma display panel in which the thickness 16b of the blue phosphor layer 10b is 30 μm and the thickness of the dielectric layer 15 and the thickness 16g of the green phosphor layer 10g are changed, the electrostatic discharge per discharge cell is The capacity and the discharge start voltage of the initializing discharge were examined. Here, as a red phosphor material
(Y ₂ Gd) BO ₃ : Eu was used, Zn ₂ SiO ₄ : Mn was used as the green phosphor material, and BaMgAl ₁₀ O ₁₇ : Eu was used as the blue phosphor material. Dielectric layer 15
Examples of the low melting point glass and titanium dioxide (TiO ₂ ) containing lead oxide (PbO), bismuth oxide (Bi ₂ O ₃ ) or zinc oxide (ZnO) as a main component have a relative permittivity sufficiently larger than that of the phosphor layer 10. Although a dielectric material containing as a main component may be used, titanium dioxide (TiO ₂ ) is used here. Further, the distance 17 from the surface of the protective layer 5 formed on the front substrate 1 to the surface of the phosphor layer 10 is set to be substantially the same in the discharge cells of each color. The capacitance of the discharge cell 14
Was obtained as follows. That is, a voltage equal to or higher than the discharge starting voltage is applied between the scan electrode 2 and the address electrode 7, and the discharge current flowing into the address electrode 7 at that time is applied to the scan electrode 2 and the address electrode 7 in series. It was measured by reading the voltage fluctuations at both ends, and the capacitance per discharge cell was roughly estimated from the relationship between the measured discharge current and the voltage applied between the scan electrode 2 and the address electrode 7. In this way, the green phosphor layer 10
Table 1 shows the capacitance per green discharge cell 11g and the discharge start voltage of the initializing discharge in the green discharge cell 11g when the thickness 16g of g and the thickness of the dielectric layer 15 are changed.

[0021]

[Table 1]

A dielectric layer 15 is provided under the green phosphor layer 10g.
In the conventional panel in which the thickness 16g of the green phosphor layer is 30 μm, which is the same as the thicknesses 16r and 16b of the red and blue phosphor layers without forming the above, the capacitance of the red, green, and blue discharge cells is 14r. , 14g, 14b are 0.00135 respectively
The pF, 0.00127 pF, and 0.00136 pF were obtained, and there was a 7% difference in the electrostatic capacity of the discharge cells of each color. On the other hand, as shown in Table 1, by increasing the thickness of the dielectric layer 15, the capacitance 14g of the green discharge cell increases, and in particular, the thickness of the dielectric layer 15 and the thickness of the green phosphor layer 16g are increased. Is 15 μm, the capacitance of the green discharge cell is 1
4g becomes 0.00136pF, and the capacitance of red and blue discharge cells is 0.00135pF, 0.00136pF.
It can be almost the same as F.

The red, green and blue discharge cells 11 are also provided.
The discharge start voltage of the initializing discharge between the scan electrode 2 and the address electrode 7 in each of r, 11g, and 11b is 218V, 233V, and 216V in the conventional panel, and the discharge start voltage in the green discharge cell is The discharge start voltage of the discharge cell is higher than that of the discharge cell. On the other hand, as shown in Table 1, the dielectric layer 15
The discharge starting voltage of the green discharge cells is reduced by increasing the thickness of the discharge cells, and the discharge starting voltages of the red and blue discharge cells are decreased.
It approaches 8V and 216V. Particularly, when the thickness of the dielectric layer 15 and the thickness 16 g of the green phosphor layer are set to 15 μm, the discharge start voltage of the green discharge cells becomes 217V, which is almost the same as the discharge start voltages 218V and 216V of the red and blue discharge cells. Can be Further, it was confirmed from the waveform of the discharge current that the discharge currents of the initializing discharges in the red, green, and blue discharge cells were more uniform than in the conventional panel by increasing the thickness of the dielectric layer 15.

As described above, by providing the dielectric layer 15 under the green phosphor layer 10g, the bottom surface of the back plate 6 in the green discharge cell 11g is smaller than that in the red and blue discharge cells 11r and 11b. By increasing the distance 18 from the lower surface of the green phosphor layer 10g to the thickness 16g of the green phosphor layer, it is possible to adjust the electrostatic capacitance 14g of the green discharge cell, and discharge of each color. It is possible to reduce the characteristic difference between the voltage and the current of the initializing discharge in the cell.
It is considered that this is because the effective cell voltage applied to the discharge space becomes more uniform in the discharge cells of each color.
As a result, it is possible to realize a plasma display panel having a larger driving margin.

Further, in the panel of the present embodiment,
Of the constituent members formed on the front substrate 1, the distance 17 from the surface of the protective layer 5, which is the constituent member in contact with the discharge space, to the surface of the phosphor layer 10 is made substantially the same in the discharge cells of each color. Therefore, it is possible to obtain a plasma display panel having more uniform initializing discharge characteristics in the discharge cells of each color without affecting the characteristics of sustaining discharge other than initializing discharge and other discharge characteristics.

In this embodiment, the thickness of the green phosphor layer is 1
Since 6 g is made smaller, the reflectance of the green phosphor layer 10 g is lowered and the emission brightness is lowered.
By increasing the reflectance of the surface of the dielectric layer 15 provided below 0 g so that the dielectric layer 15 also serves as a light reflection layer, the decrease in reflectance of the green phosphor layer 10 g is compensated. be able to. For example, titanium dioxide (TiO ₂ ) having a high reflectance for ultraviolet rays and visible light may be used as the material of the dielectric layer 15.

The dielectric layer 15 may be provided in at least one color discharge cell among red, green and blue discharge cells. For example, as shown in FIG. 2, the dielectric layer 15r is provided between the base layer 8 and the red phosphor layer 10r in the red discharge cell 11r, and the base layer 8 and the green phosphor layer are provided in the green discharge cell 11g. Dielectric layer 1 between 10g
5g can be provided. In this case, the dielectric layer 15r
And the dielectric layer 15g can be formed of different materials,
Moreover, since the thicknesses thereof can also be made different, by appropriately setting the materials and thicknesses of the dielectric layers 15r and 15g, it is possible to provide a plasma display panel having a uniform capacitance between the discharge cells of each color.

[0028]

As is apparent from the above description, according to the plasma display panel of the present invention, it is possible to reduce the characteristic difference between the voltage and the current of the initializing discharge in the discharge cells of each color, and to improve the driving margin. It is possible to realize a large plasma display panel.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of a plasma display panel according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of a modified example of the plasma display panel.

FIG. 3 is a perspective view showing a main part of a conventional plasma display panel.

FIG. 4 is a waveform diagram showing an example of a driving method of the plasma display panel.

FIG. 5 is a simplified equivalent circuit diagram in the discharge between the scan electrode and the address electrode of the plasma display panel.

[Explanation of symbols]

1 Front substrate 2 scanning electrodes 3 sustain electrodes 6 Rear substrate 7 Address electrode 8 Underlayer 10 Phosphor layer 11 discharge cells 15 Dielectric layer 16 Thickness of phosphor layer 17 Distance from the surface of the protective layer to the surface of the phosphor layer

Claims (6)

[Claims] 1. A red substrate, a red substrate, a green substrate, and a second substrate provided with a discharge space therebetween and a second substrate provided with a phosphor layer for emitting red, green, and blue light. It is configured by forming red, green and blue discharge cells corresponding to the respective blue phosphor layers, and at least one color discharge cell among the red, green and blue discharge cells is compared with other color discharge cells. Thus, the plasma display panel is characterized in that the distance from the surface of the second substrate to the lower surface of the phosphor layer is increased and the thickness of the phosphor layer is decreased. 2. A discharge cell of at least one color among red, green and blue discharge cells is provided with a dielectric layer between the second substrate and the phosphor layer, so that discharge cells of other colors are provided. The plasma display panel according to claim 1, wherein the distance from the surface of the second substrate to the lower surface of the phosphor layer is increased. 3. A plurality of address electrodes are provided on a second substrate, and a base layer is formed so as to cover the address electrodes, and at least one of red, green, and blue discharge cells is a discharge cell. By providing a dielectric layer between the underlayer and the phosphor layer, the distance from the surface of the second substrate to the lower surface of the phosphor layer is increased as compared with the discharge cells of other colors. The plasma display panel according to claim 1, which is characterized in that. 4. The plasma display panel according to claim 2, wherein the dielectric layer is made of a material having a high reflectance for ultraviolet rays and visible light. 5. The plasma display panel according to claim 2, wherein the dielectric layer is made of a dielectric material containing titanium dioxide. 6. The distance from the surface of the constituent member in contact with the discharge space to the surface of the phosphor layer among the constituent members formed on the first substrate is substantially the same in the red, green and blue discharge cells. The plasma display panel according to claim 1, wherein: