JP2000156164A - Display panel and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve light-emitting efficiency of a plasma display panel. SOLUTION: Discharge gas to be filled in a discharge space of a cell formed by a protective layer of a front glass substrate, the dielectric layer of a back surface glass board and a partition wall is the mixture gas of three components obtained by adding Ar to two components of Ne, Xe. Mixture ratio α(Xe), α(Ar) or Xe, Ar is set so that partial pressure ratio with respect to a total pressure Pt of the discharge gas satisfy the relation 3%<=α(Xe)<=8%, 0%<α(Ar)<=5%, and a sum (α(Xe)+α(Ar)) of the mixture ratio of Xe, Ar is set to satisfy the relation (α(Xe)+α(Ar))<=9.2%. The total pressure Pt of the discharge gas is set at 300 Torr<=Pt<=760 Torr.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display panel such as a plasma display panel (hereinafter, referred to as PDP) and a display device using the same, and more particularly to a composition of a discharge gas.

[0002]

2. Description of the Related Art In order to realize a display with high luminous efficiency, it is important that electric power supplied to a cell by a driving circuit is efficiently used for generation of ultraviolet rays. In order to generate ultraviolet rays, for example, as disclosed in JP-A-4-332430, it is common to use a mixed gas such as Ne or Xe as a discharge gas.
(A) an excited state of Xe is created by collision between an electron and an Xe atom, and ultraviolet rays are emitted when returning to the ground state; or
(B) It is necessary to consider the following two mechanisms: ionized Xe, that is, an electron is captured by collision of the Xe ion with the electron to form an excited state of Xe, and ultraviolet light is emitted when returning to the ground state.

[0003]

However, assuming the former mechanism (a), compared with the energy required to excite Xe to a state where ultraviolet radiation can be emitted, the average electron energy in the plasma is reduced. Due to the low kinetic energy, most of the electrons did not help to create the excited state of Xe. On the other hand, assuming the latter mechanism (b), the excited state of Xe is higher because the average kinetic energy of electrons in the plasma is higher (electron temperature is higher) than the energy that causes collisions that cause electron capture. There were few electrons making. Therefore, the configuration was not always satisfactory in terms of luminous efficiency.

As described in JP-A-63-205031, Ar is added to two components of Ne and Xe as a gas for generating plasma in a cell of a PDP, and the chromaticity deteriorated by Ne light. Has been carried out, but improvement in luminous efficiency itself has not been suggested.

[0005] An object of the present invention is to provide a PDP which can solve such a problem and can enhance the luminous efficiency.

[0006]

In order to achieve the above object, the present invention provides a method in which Ar is added to a binary gas of Ne and Xe as a discharge gas for generating plasma or the like in a cell.
By specifying a composition range of these three components as a component mixture gas, the luminous efficiency is enhanced. Further, the present invention specifies the total pressure of the three-component mixed gas within a predetermined range.

According to the experiment of the inventor, the mixing ratio of Xe (concentration: α (Xe)) is determined by the ratio of the partial pressure P (Xe) of Xe to the total pressure Pt of the three-component mixed gas, that is, α (Xe). ) = P
(Xe) / Pt, 3% ≦ α (Xe) ≦ 8%, and the mixing ratio of Ar (concentration: α (Ar))
The total pressure Pt of this three-component mixed gas at the partial pressure P (Ar) of Ar
0% <α (Ar) ≦ 5%, expressed as α (Ar) = P (Ar) / Pt, and the sum of the mixing ratio of Xe and Ar (α (Xe) + α)
(Ar)) is set to (α (Xe) + α (Ar)) ≦ 9.2%.

[0008] By selecting such a composition, the total pressure Pt of the three-component mixed gas is increased from 300 Torr to 760 Torr.
It was clarified that, for any of the above ranges, there was a total pressure at which the luminous efficiency was higher when Ar was added than when no Ar was added, for the same Xe concentration.

According to another experiment of the inventor, the mixing ratio of Xe (concentration: α (Xe)) is determined by the ratio of the partial pressure P (Xe) of Xe to the total pressure Pt of the ternary mixed gas, that is, , Α (X
e) = P (Xe) / Pt, 3.8% ≦ α (Xe) ≦ 8%, and the mixing ratio of Ar (concentration: α (Ar))
The total pressure Pt of this three-component mixed gas at the partial pressure P (Ar) of Ar
Where α (Ar) = P (Ar) / Pt, 0% <α (Ar) ≦ 3.2%, and the sum of the mixing ratio of Xe and Ar (α (Xe) + α
(Ar)) is set to (α (Xe) + α (Ar)) ≦ 9.2%.

[0010] By selecting such a composition, the total pressure Pt of the three-component mixed gas is from 420 Torr to 760 Torr.
It was clarified that, for any of the above ranges, there was a total pressure at which the luminous efficiency was higher when Ar was added than when no Ar was added, for the same Xe concentration.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing a part of the structure of an embodiment of a PDP used as a display panel of a display device according to the present invention, where 1 is a front glass substrate, 2-1.
2-2 are X electrodes, 3-1 and 3-2 are Y electrodes, 4-1 and 4-2 are X bus electrodes, and 5-1 and 5-
2,... Are Y bus electrodes, 6 is a dielectric layer, 7 is a protective layer, 8
Is a back glass electrode, 9 is an address electrode, 10 is a dielectric layer, 11 is a partition, 12 is a phosphor layer, and 13 is a discharge space.

In FIG. 1, on the lower surface of a front glass substrate 1, X electrodes 2-1, 2-2,.
.. And Y electrodes 3-1, 3-2 as transparent independent electrodes.
Are alternately provided in parallel with each other, and these X electrodes 2-1, 2-2,...
X bus electrodes 4-1, 4-2,...
And Y bus electrodes 5-1, 5-2,... .., Y electrodes 3-1, 3-2,..., X bus electrodes 4-1 4-2.
.., The Y bus electrodes 5-1, 5-2,... Are covered with a dielectric layer 6, and a protective layer 7 of MgO or the like is further provided thereon.

On the other hand, X electrodes 2-1, 2-2,..., Y electrodes 3-1, 3-2,.
A plurality of address electrodes 9 which are three-dimensionally crossed at right angles to
These address electrodes 9 are covered with a dielectric layer 10.
On the dielectric layer 10, a partition 11 is provided between the address electrodes 9 in parallel with the address electrodes 9, and a concave region formed by the wall surface of the partition 11 and the upper surface of the dielectric layer 10 is provided. Of these, the phosphor layer 12 is formed inside the portion sandwiching the address electrode 9.

The front glass plate 1 and the rear glass plate 8 thus formed are combined to form a PDP such that the top surface of each partition 11 comes into contact with the protective layer 13, and a PDP is formed. The space in which the layer 12 is formed forms a discharge space, and discharge gas is sealed therein.

FIG. 2 is a sectional view of the PDP shown in FIG. 1 as viewed from the direction of arrow D1 (that is, as viewed in the longitudinal direction of X electrodes 2-1, 2-2,...). 2 shows a portion of one cell which is a minimum unit, and 2 denotes the X electrodes 2-1 and 2-2.
-2,..., 3 are Y electrodes 3-1, 3-2,.
,..., 4, 4-2,..., 5-1, 5-2,. Are denoted by the same reference numerals, and redundant description is omitted.

In FIG. 1, two adjacent partitions 11 are 1
The address electrodes 9 define the longitudinal boundaries of the X electrodes 2 of the two cells, and are located between the two adjacent partition walls 11.
That is, it is arranged in the middle of the cell. The discharge space 13 of such a cell is filled with a discharge gas for generating plasma.

The discharge space 13 may be spatially separated by the partition wall 11 or may be spatially continuous by providing a gap between the partition wall 11 and the side of the discharge space of the front glass substrate 1. In some cases.

FIG. 3 is a cross-sectional view of the PDP shown in FIG. 1 viewed from the direction of arrow D2 (that is, viewed in a direction orthogonal to the X electrodes 2-1, 2-2,...). The figure shows two cell parts separated from each other, and the parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

In FIG. 1, X electrodes 2-1, 2-2,...
In the direction orthogonal to..., No partition is provided between the cells, and as shown by a broken line, a region including one adjacent X electrode 2 and one Y electrode 3 constitutes one cell. ing.

FIG. 4 is a timing chart showing the operation in one field period required to display one image on the PDP shown in FIG.

As shown in FIG. 1A, one field period includes a plurality of (for example, eight) subfields SF1 to SF.
Is divided into F8, each subfield, as shown in FIG. 4 (b), it consists a write discharge period T _A which defines the preliminary discharge period T _R and the light emitting cells and the light-emitting display period T _S.

[0022] FIG. 5 is a diagram showing voltage waveforms of each electrode in Figure 1 is applied to the prior art write discharge (address) period T _A.

[0023] In FIGS. 1 and 5, the voltage P _A a voltage V0 (V) applied to the address electrodes 9, the voltage P _X is the voltage V1 (V) applied to the X electrode 2 . The voltages P _Yi and P _{Yi + 1} are V2 (V) voltages applied to the i-th and (i + 1) -th Y electrodes 3, respectively. The scan pulse P _SC is sequentially added to the voltage P _Y applied to the Y electrode 3 in order. In FIG. 5, when the scan pulse P _SC is applied to the i-th Y electrode 3, At this timing, the scan pulse P _SC is applied to the (i + 1) -th Y electrode 3.

[0024] Here, now, when the i-th Y electrode 3 scan pulse P _SC is applied, if the voltage P _A is applied to the address electrodes 9, and the i-th Y electrode 3 address electrodes 9 The address discharge occurs in the cell located at the intersection with. The cell in which the address discharge has occurred is a light emitting cell that emits light by a sustain pulse in the light emitting display period T _S (FIG. 4B). When the scan pulse P _SC is applied to the i-th Y electrode 3 and the voltage P _A is not applied to the address electrode 9 (that is, when the address electrode 9 is at the ground potential), the intersection of these electrodes occurs. No write discharge occurs in the cell of the other cell, and that cell becomes a non-light emitting cell.

As described above, in the address discharge period T _A , the scan pulse P _SC is applied to the Y electrodes 3 one by one, and the scan pulses P _SC are applied to the address electrodes 9.
In response to _SC, voltage P _A of V0 (V) is applied in the light emitting cells, the non-light emitting cell, it is not applied, the ground potential.

In the next light emitting display period T _S (FIG. 4B),
Sustain pulses are alternately applied to the X electrode 2 and the Y electrode 3, and the sustain discharge is performed in the light emitting cells the number of times equal to the number of the supplied sustain pulses to emit light, and the non-light emitting cells do not emit light. Field SF1-SF
By setting the ratio of the number of sustain pulses in the address discharge period T _A of 8 to a predetermined value, gradation display can be performed on the PDP.

FIG. 6 is a ternary composition diagram showing one specific example of the relationship between the composition of the discharge gas filling the discharge space 13 in FIG. 1 and the luminous efficiency. In this specific example, this discharge gas is Ne-Xe-Ar three-component gas mixture,
9 shows the results of experiments on the luminous efficiency η (lm / W) with respect to the composition . The composition is a set of the mixing ratio of each component gas. Here, the mixing ratio of each component gas is the ratio (%) of the partial pressure of each component gas to the total pressure of the discharge gas,
For example, assuming that the total pressure of the discharge gas is Pt and the partial pressure of a certain component gas G in the discharge gas is P (G), the mixture ratio α (G) [%] of this component gas is α (G) = It is represented by P (G) × 100 / Pt. In the Ne-Xe-Ar three-component gas of this specific example, the composition is specified by (α (Ne), α (Xe), α (Ar)), and designates one point on the ternary composition diagram. In addition,
In this specific example, α (Ne) + α (Xe) + α (Ar) = 100%.

Here, the Ar axis represents the mixture ratio α (Ar) of 0 to 10% Ar, the axis Xe represents the mixture ratio α (Xe) of Xe of 0 to 10%, and a line parallel to the Xe axis. Represents a composition line in which the mixture ratio α (Ar) of Ar is constant, and a line parallel to the Ar axis represents a composition line in which the mixture ratio α (Xe) of Xe is constant. On the Ar axis, the mixing ratio of Xe α (Xe)
Is 0, and the mixing ratio α (Ar) of Ar is 0 on the Xe axis. The intersection O between the Ar axis and the Xe axis is a point where the mixture ratio α (Ne) of Ne is 100%,
A line connecting a point a where the mixture ratio α (Ar) of r is 10% and a point b where the mixture ratio α (Xe) of Xe on the Xe axis is 10% is a line where the mixture ratio α (Ne) of Ne is 90% composition line,
The line parallel to this straight line is a composition line in which the mixture ratio α (Ne) of Ne is constant.

Further, the solid line in FIG.
(Lm / W) which is a contour line.
η = 0.47, 0.4935, 0.5, 0.55, 0.5
7, 0.6 and 0.616 contour lines are shown.

FIG. 6 also shows the luminous efficiency η at the main measurement points. Here, the main measurement points shown are points where α (Ar) = 0% and α (Xe) = 2% (η =
0.5046), and the point of α (Xe) = 4% (η = 0.
5388), and the point of α (Xe) = 6% (η = 0.5
8), a point of α (Xe) = 8% (η = 0.648),
α (Ar) = 2% and α (Xe) = 2% (η = 0.474
8) Similarly, a point of α (Xe) = 4% (η = 0.55),
Similarly, a point of α (Xe) = 6% (η = 0.64), a point of α (Xe) = 8% (η = 0.616), and α (A
r) = 4% and α (Xe) = 2% (η = 0.398)
2) Similarly, the point of α (Xe) = 4% (η = 0.493)
5) Similarly, the point of α (Xe) = 6% (η = 0.534)
7). These points are also shown as overlapping measurement points in other ternary composition diagrams described later. In FIG. 6, besides the above points, α (Xe) = 0 when α (Ar) = 6%.
% Point (η = 0.3078) is also shown as the main measurement point.

In this experiment, a 25 inch XGA panel having the structure shown in FIG. 1 was used, the cell pitch was 165 μm, and the total pressure of the discharge gas in the discharge space 13 was 500 Ton.
rr.

According to the experimental results, the mixing ratio α of Xe
When (Xe) is focused on a constant composition line of 6%, α (A
r) = 2%, α (Xe) = 6%, the luminous efficiency η has a maximum value of 0.64 (lm / w), and the luminous efficiency η = 0.58 when Ar is not mixed on this composition line. (lm / W). Focusing on the behavior of the luminous efficiency η = constant contour line, when the composition range CE indicated by hatching with the dashed line as a boundary (however, except for the line where Ar is 0%), Xe
It was found that, when the mixing ratio α (Xe) was the same, the composition when Ar was mixed as the discharge gas could obtain a higher luminous efficiency η than the composition when Ar was not mixed.

In this specific example, the boundary of the composition range CE is indicated by a dashed line indicating α (Xe) = 3.8%, α (Ar) = 3.8%.
Approximation by a dash-dot line indicating 2%, a dash-dot line indicating α (Xe) + α (Ar) = 9.2% and a straight line indicating α (Xe) = 8%,
In this composition range CE, the mixing ratio α of the component gas Xe
(Xe) is 3.8% ≦ α (Xe) ≦ 8% The mixture ratio α (Ar) of the component gas Ar is 0% <α (Ar) ≦
3.2% and the sum of the mixing ratio of Xe and Ar (α
(Xe) + α (Ar)) is set to α (Xe) + α (Ar) ≦ 9.2%. Thereby, 3 of Ne-Xe-Ar
In the component gas, a composition range in which the luminous efficiency η is greatly improved as compared with the binary gas of Ne—Xe has been clarified.

By the way, as described above, the mixing ratio α of Xe
When (Xe) is the same, the composition range CE in which a higher luminous efficiency η can be obtained in the case where the composition is mixed with Ar than in the case where the composition is not mixed with Ar is caused by the total pressure. This is the case where Pt is 420 Torr or more. FIG. 7 is a ternary composition diagram showing the same experimental results as FIG. 6 when the total pressure Pt of the discharge gas is set to 420 Torr. As in the case of FIG. And contour lines.

In the composition diagram shown in FIG. 7, the mixture ratio α of Xe
(Xe) = Ar mixing ratio α on a constant composition line of 6%
The luminous efficiency η when (Ar) = 2% is 0.56 (lm)
/ W), but do not mix Ar (α (Ar)
= 0%), the luminous efficiency η was 0.556 (lm / W). That is, the composition range CE indicated by hatching including this measurement point is a range where a larger luminous efficiency η can be obtained when the composition when Ar is mixed than when the composition without Ar is mixed. Was.

FIG. 8 shows that the total pressure Pt of the discharge gas is 400 Torr.
FIG. 7 is a ternary composition diagram showing the same experimental results as in FIG. 6 when r. In this case, the composition when Ar is mixed is better than the composition when Ar is not mixed.
The composition range CE in which a large luminous efficiency η was obtained was not obtained.

FIG. 9 shows that the total pressure Pt of the discharge gas is 420 Torr.
7 is a ternary composition diagram showing the same experimental results as FIG. 6 when 470 Torr, which is larger than r, is set. In the composition diagram (total pressure Pt = 420 Torr) shown in FIG. 7, α (Ar) =
2%, α (Xe) = 4% (luminous efficiency η = 0.504)
4) is not included in the above composition range CE, but in the case of FIG. 9 in which the total pressure Pt is increased from 420 Torr shown in FIG. 7 to 470 Torr, the luminous efficiency η at this point is η = 0.53.
29, which is included in the composition range CE in which a higher luminous efficiency η can be obtained than in the case of a composition without mixing Ar. That is, the composition range CE is larger than that in FIG.

FIG. 10 shows that the total pressure Pt of the discharge gas is 600 To.
FIG. 7 is a ternary composition diagram showing the same experimental results as FIG. 6 when rr is used. In this case, when Ar is not mixed, X
At each measurement point where the mixing ratio α (Xe) = 4%, 6%, and 8%, the address could not be obtained, and the luminous efficiency η could not be obtained. On the other hand, when Ar was mixed, The address was obtained, and the luminous efficiency η was determined. Although the boundary of the composition range CE is not clearly determined, a higher luminous efficiency η can be obtained than in the case of a composition in which Ar is not mixed with at least the mixing ratio α (Ar) and α (Xe) within the above range. Can be

In general, when the total pressure Pt of the discharge gas increases, the operating voltage becomes excessively high, and at a pressure higher than the atmospheric pressure, the panel is easily broken. From this, the effective upper limit of the total pressure Pt is 760 Torr.
It is about.

As described above, in this embodiment, Ne-
Total pressure Pt of discharge gas, which is a ternary mixed gas of Xe-Ar
Is set to 420 Torr ≦ Pt ≦ to 760 Torr, and X
The mixing ratios α (Ar) and α (Xe) of e and Ar are set in the above range, whereby the luminous efficiency η becomes larger than that in the case where Ar is not mixed, and the discharge gas has a high luminous efficiency η. (The same Xe mixing ratio α (X
In contrast to e), there is an effective total pressure that increases the luminous efficiency when Ar is mixed than when Ar is not mixed).

Next, the discharge starting voltage V _SA in this embodiment is
The following describes the lower limit voltage _Vsl of the sustain voltage range (address valid range, also referred to as margin) at the time of addressing (one point lighting driven by only the sustain voltage).

FIG. 11 is a ternary composition diagram showing the discharge starting voltage V _SA (single-point lighting) when the total pressure Pt of the discharge gas, which is a three-component gas mixture of Ne—Xe—Ar, is 420 Torr. shows its contour and the discharge starting voltage V _SA of the plurality of measurement points indicated by.

The discharge starting voltage V _SA is the basis of the operating voltage, and is discharged to a composition line having a constant mixture ratio of (Ar + Xe) (in FIG. 11, a straight line parallel to the straight line connecting points a and b). If the contours of the starting voltage V _SA are parallel, Ar
Will contribute to the _firing voltage VSA to the same extent as the addition of Xe (that is, the firing voltage _VSA will increase even if the mixing ratio of Xe or Ar increases). If Ar is further added to the mixed gas in which Xe is added at a certain mixing ratio to the Ne gas, the discharge starting voltage _VSA increases, which is not preferable.

However, according to FIG. 11, the discharge starting voltage V
The contour line of _SA is substantially parallel to the composition line in which the mixture ratio α (Xe) of Xe is constant, and therefore, the mixture ratio α which is already in Ne is already present.
The mixed gas to which Xe is added in (Xe),
Be added Ar, it can be seen that the degree of increase of the discharge starting voltage V _SA is small. In particular, the mixing ratio α (Xe) of Xe is 2%
When Ar is added to the mixed gas of the order, V _SA = 181.26 (V) at the Ar mixing ratio α (Ar) = 0%, whereas the Ar mixing ratio α (Ar) = 2 % _VSA = 179.
96 (V), and a decrease in the discharge starting voltage V _SA was observed.
When the mixture ratio of Ar + Xe is seen on a constant composition line, it takes a local minimum value and shows a peculiar behavior by the so-called Penning effect.

FIG. 12 is a ternary composition diagram showing the lower limit voltage V _Sl of the sustain voltage range at the time of addressing when the total pressure Pt of the discharge gas which is a three-component gas mixture of Ne—Xe—Ar is 420 Torr. The lower limit voltage V _Sl at a plurality of measurement points indicated by black circles and their contour lines are shown.

In the same figure, as is clear from the shape of the contour lines shown in the figure, up to the mixing ratio α (Xe) of Xe of about 7%, the mixing of Xe with the mixing ratio α (Xe) already in Ne is performed. the gas, a constant the mixing ratio alpha (Xe), when gradually added Ar, rather the lower limit voltage V _sl sustain voltage range is lowered until the mixing ratio alpha (Ar) of about 2.5% I understand. This is advantageous for low voltage driving.

Similarly, FIG. 13 shows that the total pressure Pt of the discharge gas is 4
FIG. 14 is a ternary composition diagram showing the firing voltage V _SA at 70 Torr, and FIG. 14 is a ternary composition diagram showing the lower limit voltage V _Sl of the sustain voltage range at the time of addressing.
When the total pressure Pt is set to 470 Torr, FIG.
As in the case where the total pressure Pt shown in FIG. 12 is 420 Torr, the same tendency of the discharge starting voltage V _{SA and} the tendency of the lower limit voltage V _Sl of the sustain voltage range at the time of addressing can be obtained.

From the above description of FIGS. 11 to 14, in this embodiment, the mixture ratio α (X
e), within the above range of α (Ar), the discharge starting voltage V _SA and the lower limit voltage V _Sl of the sustain voltage range at the time of addressing
, And does not increase the write voltage of the cell.

Next, as another embodiment, a description will be given of a PDP similar to that described above except for the thickness of the dielectric layer 6 except for the thickness.

FIG. 15 shows that the total pressure Pt of the discharge gas is 600 To.
FIG. 7 is a ternary composition diagram showing the same experimental results as in FIG. 6 when rr is set, and shows main measurement points of luminous efficiency η and contour lines as in FIG. However, in the drawings after FIG. 15, when Ar is not mixed (α (Ar) = 0%), the total pressure Pt = 3 at the mixing ratio α (Xe) = 6% of Xe.
The value of 00 Torr is represented by a normalized value, that is, a normalized efficiency EfN. In FIG. 15, the mixing ratio α of Xe when Ar is not mixed (α (Ar) = 0%)
(Xe) = Normalization efficiency EfN at 5%, Xe mixture ratio when Ar is not mixed α (Xe) = Normalization efficiency EfN at 4% and Xe mixture ratio when Ar is not mixed Interpolated value 1.217 as the average of normalized efficiency EfN = 1.374 at α (Xe) = 6%
5, which is shown in parentheses (1.2175).

In this specific example, as shown in FIG.
On the composition line where the mixing ratio α (Xe) = 3% of e is constant, Ar
Are not mixed (α (Ar) = 0%), the normalized luminous efficiency EfN is 1.1641, whereas the normalized luminous efficiency EfN when the mixture ratio of Ar α (Ar) = 2% is 1.1685, which is slightly, but large. That is, the composition range CE indicated by hatching including this measurement point
Is higher when the composition when Ar is mixed is higher than the composition when Ar is not mixed, that is, in a range where a large luminous efficiency η is obtained,
Compared with the specific examples shown in FIGS. 6 to 14, the composition range CE expands to the side where the mixture ratio α (Xe) of Xe is small, and the composition ratio X (Xe) is constant at 3%. The line is part of the boundary. On the other hand, when the mixing ratio of Xe when Ar is not mixed, the contour line of the normalized efficiency EfN = 1.2055 at the mixing ratio α (Xe) = 4% and the mixing ratio α (Xe of Xe)
e) = intersection with the constant composition line of 4% is the mixing ratio α of Ar
(Ar) = 5%.

The upper limit of the Ar mixing ratio α (Ar) on the composition line where Xe mixing ratio α (Xe) = 4% is constant = 5% is determined thereby, and the Ar mixing ratio α (Ar) in the above composition range CE is determined. Was set as the upper limit.

As described above, in the specific example shown in FIG.
Compared with the specific example shown in FIG. 6, the mixing ratio of Xe
The composition range CE expands to the side where e) is small, and accordingly, the upper limit of the Ar mixing ratio α (Ar) also increases. On the other hand, other boundaries of the composition range CE are the same as in FIG.
That is, the composition range CE is determined by the mixing ratio α (X
e), 3% ≦ α (Xe) ≦ 8% The mixing ratio α (Ar) of the component gas Ar is 0% <α (Ar)
≦ 5% and the sum of the mixing ratio of Xe and Ar (α (X
e) + α (Ar)) is set to α (Xe) + α (Ar) ≦ 9.2%. As a result, the composition range in which the normalized efficiency EfN, that is, the luminous efficiency η, is significantly improved in the Ne-Xe-Ar three-component mixed gas, as compared with the Ne-Xe binary mixed gas, is further clarified.

In the specific example shown in FIG. 15, when the mixing ratio α (Xe) of Xe is the same, the composition when Ar is mixed is more effective than the composition when Ar is not mixed. Large normalized efficiency EfN, that is, large luminous efficiency η
Occurs when the total pressure Pt is 30
This is the case of 0 Torr or more.

FIG. 16 shows that the total pressure Pt of the discharge gas is 500 To.
FIG. 16 is a ternary composition diagram showing the same experimental results as in the specific example of FIG. 15 when rr is set, and as in FIG. 15, the main normalized efficiency EfN, that is, the measurement points of the luminous efficiency η and the contour lines Are shown.

In this specific example, as shown in FIG.
On the composition line where the mixing ratio α (Xe) = 3% of e is constant, Ar
Are not mixed (α (Ar) = 0%), the normalized luminous efficiency EfN is 1.1121, while the normalized luminous efficiency EfN when the mixture ratio of Ar α (Ar) = 2% is 1.0976, which is small but small. X
When the mixing ratio α (Xe) of e is the same, the normalized efficiency EfN, that is, the large luminous efficiency, is higher when the composition is mixed with Ar than when the composition is not mixed with Ar. The boundary of the composition range CE where η can be obtained is shown in FIG.
In the specific example of FIG. 5, the composition line of Xe has a constant composition ratio α (Xe) = 3%, whereas the mixture ratio of Xe α (Xe) = 3.15.
%, And the composition range CE is slightly smaller than the specific example of FIG.

FIG. 17 shows that the total pressure Pt of the discharge gas is 400 To.
15 is a ternary composition diagram showing the same experimental results as in the specific example of FIG. 15 when rr is obtained, and as in the specific example of FIG. 15, the main normalized efficiency EfN, that is, the measurement point of the luminous efficiency η And contour lines.

In this specific example, as shown in FIG.
When the mixing ratio α (Xe) of e is the same, the normalized efficiency EfN, that is, the large luminous efficiency, is higher when the composition is mixed with Ar than when the composition is not mixed with Ar. The boundary of the composition range CE where η can be obtained is shown in FIG.
In the specific example of No. 6, the composition line of Xe was 3.15%, and the composition ratio of Xe was 3.15%. On the other hand, the mixture ratio of Xe was α (Xe) =
The composition line becomes 3.23% constant, and the other boundaries are
In the specific example shown in FIG. 16, the composition line has a constant Ar mixture ratio α (Ar) = 5%, whereas the Ar mixture ratio α (Ar) = 3.
The composition line becomes 6% constant, and the composition range CE is further reduced.

FIG. 18 shows that the total pressure Pt of the discharge gas is 300 To.
15 is a ternary composition diagram showing the same experimental results as in the specific example of FIG. 15 when rr is obtained, and as in the specific example of FIG. 15, the main normalized efficiency EfN, that is, the measurement point of the luminous efficiency η And contour lines.

In this specific example, as shown in FIG.
When the mixing ratio α (Xe) of e is the same, the composition when Ar is mixed is larger than the composition when Ar is not mixed, that is, the normalized efficiency EfN, that is, the luminous efficiency η is larger. Are obtained, the boundaries of the composition range CE where
Although it is not possible to draw a straight line as in FIG. 17, the composition range CE is smaller than that of the specific example of FIG.

FIG. 19 shows that the total pressure Pt of the discharge gas is 200 To.
15 is a ternary composition diagram showing the same experimental results as in the specific example of FIG. 15 when rr is set, and measurement of the main normalized efficiency EfN, that is, the emission efficiency η, as in the specific example of FIG. Points and contour lines are shown.

In this specific example, as shown in FIG.
When the mixing ratio α (Xe) of e is the same, the composition when Ar is mixed is larger than the composition when Ar is not mixed, that is, the normalized efficiency EfN, that is, the luminous efficiency η is larger. Is obtained at only one measurement point, and Ar
Are not mixed (α (Ar) = 0%), the contour line starting from the measurement point of the mixing ratio α (Xe) = 4% of the Xe is bent as shown by the dotted line, and linearly approximated on average. , As indicated by the dashed line, the composition range CE as described above.
It is somewhat difficult to regard it as a boundary. In other words, under these conditions, when the mixing ratio α (Xe) of Xe is the same, the composition when Ar is mixed is larger than the composition without Ar when the normalized efficiency EfN, That is,
This means that the composition range CE in which a large luminous efficiency η can be obtained is not obtained.

As described above, the PDP shown in FIG.
In the condition (1), when the mixing ratio α (Xe) of Xe is the same, the composition when Ar is mixed has a higher Ar
Is larger than the case of the composition without mixing
N, that is, the composition range CE in which a large luminous efficiency η can be obtained occurs when the total pressure Pt is 300 Torr or more, and 420 in the PDP conditions shown in FIGS. 6 to 14.
The pressure range is wider than Torr or higher.
The upper limit of the total pressure Pt of the mixed gas is 760 Torr as in the case of the PDP conditions shown in FIGS.

As described above, in the embodiment shown in FIGS. 15 to 19, the total pressure Pt of the discharge gas, which is a three-component gas mixture of Ne—Xe—Ar, is set to 300 Torr ≦ Pt ≦ 760 T
orr, and the mixture ratio of Xe and Ar α (Xe), α (A
r) is set to a range corresponding to the range shown in FIGS. 15 to 19, whereby the luminous efficiency η becomes larger than the case where Ar is not mixed, and a discharge gas having a high luminous efficiency η can be obtained. (Ie, the same mixing ratio α of Xe)
In contrast to (Xe), the total pressure (effective) at which luminous efficiency is higher when Ar is mixed than when Ar is not mixed
Exists).

Next, with respect to the embodiments described with reference to FIGS. 15 to 19, the discharge start voltage V _SA (single-point driving with only the sustain voltage), the sustain voltage range at the time of address (the range where the address is valid) Te, described the measurement voltage V _m taken at the midpoint of the also called margin).

In FIGS. 20 to 23 used in this explanation, Xe when Ar is not mixed (α (Ar) = 0%)
At a mixing ratio α (Xe) = 6%, the total pressure Pt = 300
The value of Torr is represented by a normalized value, that is, a normalized discharge start voltage VsN or a normalized measurement voltage VmN.

FIG. 20 shows a normalized discharge start voltage VsN when the total pressure Pt of the discharge gas which is a three-component gas mixture of Ne—Xe—Ar is 500 Torr, that is, the discharge start voltage V
FIG. 4 is a ternary composition diagram showing _SA (single-point lighting), showing a normalized discharge start voltage VsN at a plurality of measurement points indicated by black circles and contour lines thereof.

As shown in FIG. 20, in this specific example, as in the case of FIG.
Although there are some undulations in the contour line of sN, (Ar + Xe)
Is far from a constant straight line, and the Xe mixing ratio α (X
e) is nearly parallel to a certain composition line. Therefore, even with the addition of Ar to the gas mixture Xe at a certain mixing ratio Ne alpha (Xe) is added, increased degree of normalized firing voltage VsN, i.e., increased by about the discharge starting voltage V _SA Is small.

FIG. 21 shows a normalized discharge start voltage VsN when the total pressure Pt of the discharge gas, which is a three-component gas mixture of Ne—Xe—Ar, is 300 Torr, that is, the discharge start voltage V
FIG. 4 is a ternary composition diagram showing _SA (single-point lighting), showing a normalized discharge start voltage VsN at a plurality of measurement points indicated by black circles and contour lines thereof.

As shown in FIG. 21, in this specific example, similarly to the specific example shown in FIG. 11, the contour line of the normalized discharge start voltage VsN has some undulations, but (Ar
+ Xe) is not a straight line with a constant mixture ratio, but the mixture ratio α (Xe) of Xe is nearly parallel to a constant composition line. Therefore, N
Even when Ar is added to a mixed gas in which Xe is added to e at a certain mixing ratio α (Xe), the normalized discharge start voltage V
increase of about sN, i.e., increased by about the discharge starting voltage V _SA is seen that small.

FIG. 22 is a ternary composition diagram showing the standardized measurement voltage VmN, that is, the measurement voltage VmN when the total pressure Pt of the discharge gas, which is a three-component gas mixture of Ne—Xe—Ar, is 500 Torr. In addition, a normalized measurement voltage VmN of a plurality of measurement points indicated by black circles and their contour lines are shown.

As shown in FIG. 22, also in this specific example, the contour of the normalized measurement voltage VmN has some undulations, but the mixture ratio of (Ar + Xe) is far from a constant straight line.
The mixture ratio α (Xe) of Xe is nearly parallel to a certain composition line.
In particular, if attention is paid to the composition line of the Xe mixture ratio α (Xe) = 4%, the standardized measurement voltage VmN decreases with the increase of the Ar mixture ratio α (Ar), which is rather advantageous. .

FIG. 23 is a ternary composition diagram showing the normalized measured voltage VmN when the total pressure Pt of the discharge gas, which is a three-component gas mixture of Ne—Xe—Ar, is 300 Torr. 2 shows the normalized measurement voltage VmN of the measurement point and the contour line thereof.

As shown in FIG. 23, also in this specific example, the contour of the normalized measurement voltage VmN has some undulations, but the mixture ratio of (Ar + Xe) is not a straight line, but
Rather, the mixing ratio α (Xe) of Xe is nearly parallel to a constant composition line. In particular, if attention is paid to the composition line of the Xe mixture ratio α (Xe) = 4%, the standardized measurement voltage VmN decreases with the increase of the Ar mixture ratio α (Ar), which is rather advantageous. .

As is clear from the above description of FIGS. 20 to 23, also in the embodiment described with reference to FIGS. 15 to 23, the mixture ratio α (Xe), α (Ar) of Xe and Ar in the discharge gas is determined. Within the above range, the discharge starting voltage _VSA and the measurement voltage Vm at the time of addressing are not particularly increased, and the writing voltage of the cell is not increased.

Although the above description relates to an AC type PDP, it goes without saying that the present invention can be similarly applied to a DC type PDP.

[0077]

As described above, according to the present invention,
Since the mixture ratio of Xe and Ar mixed with Ne is set in a range in which the luminous efficiency η becomes high, the luminous efficiency η of the display panel is improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a part of the structure of one embodiment of a display panel of a display device according to the present invention.

FIG. 2 is a cross-sectional view of the display panel shown in FIG. 1 as seen from a direction of an arrow D1.

FIG. 3 is a cross-sectional view of the display panel shown in FIG. 1 as viewed from a direction of an arrow D2.

FIG. 4 is a diagram showing a configuration of one field period in the embodiment shown in FIG.

FIG. 5 is a diagram showing voltage waveforms of respective electrodes in FIG. 1 during the writing period of FIG. 4 (b).

FIG. 6 shows Ne—Xe filling the discharge space in FIG.
FIG. 4 is a ternary composition diagram showing a specific example of the relationship between the composition of a ternary mixed gas of -Ar and luminous efficiency.

FIG. 7 shows a case where the total pressure is lower than that of the specific example shown in FIG. 6;
FIG. 3 is a ternary composition diagram showing a specific example of the relationship between the composition of a ternary mixed gas of e-Xe-Ar and luminous efficiency.

FIG. 8 shows Ne-Xe when the total pressure is lower than that in FIG. 7;
FIG. 3 is a ternary composition diagram showing a specific example of the relationship between the composition of a ternary mixed gas of -Ar and luminous efficiency.

9 shows a specific example of the relationship between the composition of the ternary gas mixture of Ne—Xe—Ar and the luminous efficiency when the total pressure is close to the middle between the specific examples of FIGS. 6 and 7; It is a system composition diagram.

FIG. 10 shows Ne- when the total pressure is higher than the specific example of FIG.
FIG. 3 is a ternary composition diagram showing a specific example of the relationship between the composition of a three-component mixed gas of Xe—Ar and luminous efficiency.

FIG. 11 is a ternary composition diagram showing a specific example of the relationship between the composition of a ternary mixed gas of Ne—Xe—Ar and the discharge starting voltage V _SA .

FIG. 12 is a ternary composition diagram showing a specific example of the relationship between the composition of a three-component mixed gas composed of Ne—Xe—Ar and the lower limit voltage _Vsl of the sustain margin.

FIG. 13 shows Ne when the total pressure is lower than that of the specific example of FIG.
-Xe-Ar ternary mixed gas composition and firing voltage V
FIG. 3 is a ternary composition diagram showing a specific example of a relationship with _SA .

FIG. 14 shows Ne when the total pressure is lower than the specific example of FIG.
It is a ternary composition diagram showing a specific example of the relationship between the lower limit voltage V _sl composition and sustain margin ternary gas mixture consisting of -xe-Ar.

FIG. 15 shows Ne-X filling the discharge space in FIG.
FIG. 3 is a ternary composition diagram showing a specific example of the relationship between the composition of a three-component mixed gas of e-Ar and normalized luminous efficiency.

FIG. 16 shows Ne when the total pressure is lower than the specific example of FIG.
FIG. 3 is a ternary composition diagram showing a specific example of the relationship between the composition of a ternary mixed gas of —Xe—Ar and normalized luminous efficiency.

FIG. 17 shows Ne when the total pressure is lower than that of the specific example of FIG.
FIG. 3 is a ternary composition diagram showing a specific example of the relationship between the composition of a ternary mixed gas of —Xe—Ar and normalized luminous efficiency.

FIG. 18 shows Ne in the case where the total pressure is lower than the specific example of FIG.
FIG. 3 is a ternary composition diagram showing a specific example of the relationship between the composition of a ternary mixed gas of —Xe—Ar and normalized luminous efficiency.

FIG. 19 is a graph showing Ne when the total pressure is lower than that of the specific example of FIG. 18;
FIG. 3 is a ternary composition diagram showing a specific example of the relationship between the composition of a ternary mixed gas of —Xe—Ar and luminous efficiency.

FIG. 20 shows Ne-X filled in the discharge space in FIG.
FIG. 4 is a ternary composition diagram showing a specific example of a relationship between the composition of a three-component mixed gas of e-Ar and a normalized discharge start voltage VsN.

FIG. 21 is a graph showing Ne- when the total pressure is lower than the specific example of FIG. 20;
FIG. 4 is a ternary composition diagram showing a specific example of the relationship between the composition of a three-component mixed gas of Xe—Ar and a normalized discharge start voltage VsN.

FIG. 22 shows Ne-X filling the discharge space in FIG.
FIG. 4 is a ternary composition diagram showing a specific example of a relationship between a composition of a three-component mixed gas composed of e-Ar and a standardized measurement voltage VmN.

FIG. 23 shows Ne- when the total pressure is lower than the specific example of FIG.
FIG. 4 is a ternary composition diagram showing a specific example of the relationship between the composition of a three-component mixed gas composed of Xe—Ar and a standardized measurement voltage VmN.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front glass substrate 2-1 and 2-2 X electrode 3-1 and 3-2 Y electrode 4-1 and 4-2 X bus electrode 5-1 and 5-2 Y bus electrode 6 Dielectric 7 Protective layer 8 Back surface Glass substrate 9 A electrode 10 Dielectric 11 Partition 12 Phosphor 13 Discharge space

Continued on the front page (72) Inventor Atsushi Yokoyama 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Information Media Business Division of Hitachi, Ltd. (72) Inventor Yusuke Yajima 1-280 Higashi-Koigabo, Kokubunji-shi, Tokyo Inside Hitachi Central Research Laboratory, Inc. (72) Yoshimi Kawanami 1-280 Higashi-Koigabo, Kokubunji-shi, Tokyo Hitachi, Ltd. Central Research Laboratory (72) Inventor Takahisa Mizuta 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref.Information Media Division, Hitachi, Ltd.

Claims (5)

[Claims] 1. A display panel in which a discharge gas is discharged to generate plasma, the plasma generates ultraviolet light, and the ultraviolet light generates visible light, wherein the discharge gas is Ne, Xe, or Ar And a mixture ratio α (Xe) of the Xe gas in the discharge gas as a partial pressure ratio with respect to the total pressure of the discharge gas, 3% ≦ α (Xe)
≦ 8%, and the mixing ratio α (Ar) of the Ar gas in the discharge gas is 0% <α (Ar) as a partial pressure ratio to the total pressure of the discharge gas.
≦ 5%, and the sum of the mixing ratio of the Xe gas and the Ar gas (α (X
e) + α (Ar)): (α (Xe) + α (Ar)) ≦ 9.2%. 2. The display panel according to claim 1, wherein the total pressure Pt of the discharge gas is 300 Torr ≦ Pt ≦ 760 Torr. 3. A display panel in which a discharge gas is discharged to generate plasma, the plasma generates ultraviolet light, and the ultraviolet light generates visible light, wherein the discharge gas includes Ne, Xe, and Ar And a mixture ratio α (Xe) of the Xe gas in the discharge gas as a partial pressure ratio to the total pressure of the discharge gas is 3.8% ≦ α (X
e) ≦ 8%, and the mixing ratio α (Ar) of the Ar gas in the discharge gas is 0% <α (Ar) as a partial pressure ratio to the total pressure of the discharge gas.
≦ 3.2%, and the sum of the mixing ratio of the Xe gas and the Ar gas (α (X
e) + α (Ar)): (α (Xe) + α (Ar)) ≦ 9.2%. 4. The display panel according to claim 1, wherein the total pressure Pt of the discharge gas is 420 Torr ≦ Pt ≦ 760 Torr. 5. A display device comprising the display panel according to claim 1. Description: