JP3126756B2 - DC type discharge panel and display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for driving a color DC discharge type display panel with a pulse memory.

[0002]

2. Description of the Related Art A first conventional example of a color DC discharge type display panel has a structure shown in FIG. (a) is a sectional view thereof, and (b) is a diagram showing a surface plate thereof. Figure F
P, BM, BA, A, Ph, C, D, TH and RP are the front plate (glass), black lattice (black matrix), partition,
Represents anode (indium tin oxide), phosphor, cathode (Ni), dielectric, third electrode and back plate (glass). The details of this panel are described in Publication (1). However, since the XY matrix panel is driven by a single-row (line) simultaneous driving method and flows a relatively large current (about 490 μA), the luminous efficiency is low. It is bad at 0.025lm / W (white) and is not suitable for television receiving panels except for special applications. He (93%)-Kr (5%)-Xe (2%)
0 Torr is used.

A second conventional example has a structure shown in FIG. 21. In the figure, the same elements as those in FIG. 20 are denoted by the same reference numerals, but other elements such as AA, DA, R-Ph , G-Ph, B-Ph, P
S, DC, W and ACE are auxiliary anode, display anode,
Red-phosphor, green-phosphor, blue-phosphor, priming space, display cells, embankments and auxiliary cells,
See Publication (2) for the operation of this panel.

A third conventional example has a structure shown in FIG. 22. In the figure, the same elements as those in FIGS. 20 and 21 are denoted by the same reference numerals. CB, WB, AAL
And DAL are the filter, cathode bus, white background,
It represents an auxiliary anode line and a display anode line, and the description of the reference numerals will be continued. See Publication (3) for details of the third conventional example.

Further, a fourth conventional example of the structure shown in FIG. 23 is (a) a plan view of this panel viewed from the display side, and (b)
Is a cut surface when the panels were cut along the cutting line X ₁ -X ₂ of FIG. (A). The panel having this structure is closest to the configuration of the DC discharge display panel of the present invention to be described below. In the drawing, reference symbols AC, DAB, and R are auxiliary cathodes, respectively.
Represents the indicated anode bus and current limiting resistance, see publications (4) and (5) for details.

The above-described second to fourth prior art examples are each driven by a pulse memory drive system, and the cathodes of these panels are
Ni, Al, is composed of a material such as LaB _6, as the filler gas
He-Xe is used at 1.5 to 5%, and the total gas pressure is used at 200 to 250 Torr.

List of Publications (1) Niwa et al .: "17-inch DC Type High-Definition Color Plasma Display", Journal of the Institute of Television Engineers of Japan, Vol.45, No.5 (19
90), pp. 571-577 (2) Murakami et al .: "20-inch color discharge display panel", Technical Report of the Institute of Television Engineers of Japan, ID88-37 (1988.3) (3) Sakai et al .: "Ultra-low reflectivity color display discharge" Panel (I
V) ”, IEICE Technical Report, EID87-72 (19
88.2.5.) (4) JP-A-60-253131 (Japanese Patent Application No. 59-107687) "Gas discharge display panel" (5) Takano et al .: "Pulse memory drive of discharge display panel with resistance", Television Conference Annual Meeting '90, Proceedings 4-3, pp.
77−78

[0008]

In the first conventional example described above, as described in detail in the publication (1), the peak luminance of the image is as low as about 33 cd / m ² and the luminous efficiency is low. Therefore, it is not suitable as a large television image panel.

Although the life of this panel is not described in the publication, it is presumed that the luminance is low and the life is relatively long because the light emission time ratio, which is inversely proportional to the number of rows of the panel, is as small as 1/480. You. Defining the operating time until the luminance becomes 1/2 of the initial luminance is defined as the lifetime.In general, if the luminance is reduced by lowering the luminous time rate, the life will naturally be extended. X Life needs to be measured.

In the second and third conventional examples, the brightness is increased by the memory effect, the peak brightness is estimated to be 50 to 100 cd / m ² , and the actual life is estimated to be 1000 to 2000 hr (hour). Practically, it is said that the life is required to be about 100 cd / m ² × 10000 hr.

It has been found that the biggest factor that determines the life is that the luminance is reduced by the deposition of the cathode material into the cells by sputtering. It has been found that it is important to reduce the discharge current in order to reduce sputtering.In the second and third conventional examples, the discharge sustaining current was kept at about 100 μA, but the life was still short. I understand.

The fourth prior art is an improvement on this point. Since the maintenance current is further reduced by adding a current limiting resistor, the life is doubled but is still insufficient. .

An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a DC discharge panel whose lifetime is as long as 10,000 hours at a luminance of 100 cd / m ² and a display device using the same. is there.

[0014]

In order to achieve this object, a display device for driving a DC discharge panel by pulse memory according to the present invention has a front plate and a back plate, and discharge cells are arranged in a matrix by spacers or partition walls. A display device for forming and driving a DC-type discharge panel including a phosphor screen that emits a predetermined emission color to each discharge cell and a discharge current limiting element for limiting the discharge current of each discharge cell, using pulse memory. He gas and Xe as filling gas for the panel
When the total partial pressure ratio of the gas occupies at least 95% of the total filled gas pressure, and when the partial pressure ratio of the Xe gas to the total filled gas pressure is x and the total filled gas pressure is p torr, 0.01 ≦ x ≦ 0.5, p ≦
In addition to satisfying the condition of 600, the condition of xp ⁵ (S / I) ² ≧ 6.3 × 10 ⁴ is satisfied when the cathode effective area of the discharge display panel is Smm ² and the discharge sustaining current is IμA. It is characterized by having been constituted.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail by way of embodiments with reference to the accompanying drawings. Prior to this, the history of the present inventors reaching the present invention will be described in detail. That is, the inventors of the present application have considered the life factor of the pulse memory operation in more detail, and confirmed this in several basic experiments.
The experiment was performed using the panel shown in FIG. (a) is a plan view of this panel, a cross-sectional view in (b) is X ₁ -X ₂ cut surface.

The cathode material of this panel is Al, Ni, BaAl ₄
Others were used. For the cathode C, use part of the bus CB directly or
The cathode material was attached or formed on the CB. A white glass material was used for the cell barrier BA and the white background WB. The phosphor Ph is red: (YGd) BO ₃ : Eu, green: Zn ₂ SiO ₄ : Mn, blue: BaM
g Al ₁₄ O ₂₃ : Eu was paste-printed and used.
As a result of various experiments, the present inventors were able to confirm the following facts.

(1) The life of the pulse memory at the time of sustain pulse operation is the same as that at the time of constant current drive, considering the operation time rate D, if the current is the same as that at the time of constant current drive. Of course, the life when driven at a constant current is also a value obtained by dividing the life when D = 1 by the actual value of D.

(2) As shown in FIG.
It can be approximated by p (−bt) + c. Where b and c are constants and t
Is the operating time. In the case of FIG. 4, Al cathode, He-Xe 10%,
This is the time-dependent deterioration characteristics due to a DC discharge at a total gas pressure of 200 torr, a constant current I = 100 μA.

(3) When the operating current increases, the life T
Becomes shorter. For example, it was also found that when the light emission time ratio was 1 and I = 100 μA, T = 100 hr, whereas when I = 300 μA, T = 2 hr.

(4) The life when operated at several different current values could also be estimated. This is because, as the pulse memory, a method of life can be evaluated when a write current I ₁ and the sustain pulse current I ₂ and the size nor different time rates. This can be summarized as follows. Current value I ₁
Life is T ₁ , and I ₂ is T ₂
Assuming that D ₁ and D ₂ are used, the life T when they are mixed is given by T = (D ₁ / T ₁ + D ₂ / T ₂ ) ⁻¹ (1). For example, for pulse memory I ₁ =
_{300 μA, T 1 = 2hr,} D 1 = 1/2000, I 2 = 100 μA, T 2 =
Assuming that 100 hr, D ₂ = 1/60, the life when writing only is T ₁ / D ₁ = 4000 hr, and the life when maintaining only is T ₂ / D ₂ = 60.
Although it is 00 hr, the lifetime T when actually mixed is 2400 hr, which is a very small time rate, but it has been revealed that the lifetime is shortened by a large current at the time of writing.
From these facts, it was found that, in the fourth conventional example, the write current was reduced and the life was extended.
However, the service life is still insufficient, and the present invention has solved this problem for the first time.

The limiting conditions according to the present invention were confirmed by changing the gas composition in a panel having substantially the same configuration as that of the fourth conventional example. For example, He-Xe 10% gas at 300 Torr
It was found that the lifespan was dramatically increased by encapsulation.
This is shown in FIG. The panel used for the measurement is shown in FIG. The cathode material is Al without Hg. From FIG. 5, it was found that the life was nearly doubled even when the pressure was increased only by 10% from 250 Torr, and exceeded 10,000 hours. The luminance is almost constant in this range (200 to 350 Torr).
cd / m ² .

FIG. 6 shows that the current is expressed as a parameter on a logarithmic scale. Life from the slope of this curve group (p-filling pressure) p ⁵ ~p ⁶ was found to be approximately proportional to. In addition, the inventors of the present invention have taken a lot of data. Fig. 7 shows lifetime versus Xe amount (p is a parameter)
8, FIG. 8 shows luminous efficiency vs. current characteristics, FIG. 9 shows voltage-current characteristics, FIGS. 10 and 11 show luminous output vs. current characteristics, FIG. 12 shows luminous efficiency vs. pressure characteristics, and FIG. 13 shows luminous efficiency vs. Xe partial pressure ratio characteristics. Show, figure
14 shows life vs. current characteristics, and FIG. 15 shows data on discharge sustaining voltage vs. pressure characteristics.

FIGS. 6, 7 and 14 show that the life T when D = 1/60 can be approximated by T = 7 × 10 ⁻⁸ xp ⁵ (60 / I) ² [hour] (2) in this panel. Was. Where x is the partial pressure ratio of Xe,
p is the total pressure [Torr] and I is the current value [μA]. Table 1
Figure 2 shows a comparison between measured values and Eq. (2), which is a relatively good evaluation method. Since this panel is normally stable when used at about 60 μA, in order to obtain T exceeding 10,000 hours, it is necessary to fill a gas satisfying xp ⁵ ≧ 1.4 × 10 ¹¹ (3).

[0024]

[Table 1]

It is necessary to consider the value of the discharge current per unit area of the cathode, and for that purpose, it is necessary to consider the effective cathode area. In the case where the distance from the anode is not constant, as in the cathode of the panel shown in FIG. 3, the place where the normal glow discharge actually operates generally depends on the pd product. In this case, the shortest distance d is 1.2 times. To the point. This is because a slightly higher sustaining voltage of, for example, about 20 V is required to operate the remaining portion as a cathode, so that the discharge at the shortest distance d becomes abnormal glow discharge and spatter increases rapidly. this is,
6 and FIG. In the case of the panel of FIG. 3, as shown in FIG. 16, it is about 2/3 of the total cathode area. In this figure, assuming that the anode is one point and dm = 1.2d, the effective cathode area S is

(Equation 1) In this panel, S = 0.04 mm ² . Since the effective area of the cathode has been defined, the current density is calculated and the equation (2) is corrected, so that T = 0.16 × p ⁵ (S / I) ² (4). Here, S is the cathode effective area mm ² .

Regarding the upper limit of the total pressure, the atmospheric pressure (760 Torr)
r), but if the life is sufficient, the lower the better, the more stable the minimum discharge sustaining current increases as the pressure p increases, as shown in FIG. Because it gets worse, the maximum value is set to 600 Torr. In addition, x was set to 0.5 or less from the stability of discharge.

The writing at the time of driving the memory of the panel is as follows.
The voltage must be increased by several tens of volts, for example, 50 volts, than the sustain voltage. However, as shown in FIG. 9, such a write voltage causes a large current to flow and the life is shortened. Therefore, it is necessary to insert some kind of current limiting element in series. Usually, since a resistor is used, it is necessary to attach it as shown in FIG. 23, for example.

From the above, the resistance in the panel is
A display device having a panel satisfying xp ⁵ (S / I) ² ≧ 6.3 × 10 ⁴ and a memory driving method is obtained.

FIG. 18 shows the range in the case where only He-Xe is used under the above conditions. Even if a small amount of rare gas of less than 5%, Ne, Ar, or Kr is added in addition to He-Xe, characteristics that are not much different are obtained.

Although the above description has been made on the case where Al is used as the cathode material, it has been found that almost the same effect can be obtained with other materials.

When the material is Ni, the life versus pressure is as shown in FIG. In the case of Ni, as it is, the life is shorter than that of Al. However, by adding mercury Hg, the life can be extended to about 100 times that before the addition, so that the life is longer than that of Al.

As other materials, BaAl ₄ , LaB ₆ , BaB ₆
Such as boride, Ba (N ₃ ) ₂ , alkali metal, Y ₂ O ₃ , ZnO, RuO
₂ , Cr, Co, graphite, Ca _0.2 La _0.8 CrO ₃ , Mg, BaLa ₂ O
₄ , BaAl ₂ O ₄ and LaCrO ₃ have almost the same effect. The attachment method is applied by a method such as printing, plasma spraying, vapor deposition, and sputtering.

The phosphor is usually Y ₂ O ₃ : Eu, Y for red.
VO ₃ : Eu, YP _0.65 V _0.35 O ₄ : Eu, YBO ₃ : Eu, (YGa) B
O ₃ : Eu, Zn ₂ SiO ₄ : Mn, BaMg ₂ Al ₁₄ O ₂₄ : Eu.
Mn, BaAl ₁₂ O ₁₉ : Mn, for blue Y ₂ SiO ₄ : Ce, YP _0.85
V _0.15 O ₄ : Eu, BaMg ₂ Al ₁₄ O ₂₄ : Eu, BaMgAl ₁₄ O ₂₃ : Eu are used. The adhesion is performed by printing, photo etching, adhesion, spraying, or the like. Depending on the location where the phosphor is attached, it is called a reflection type (back panel or cell wall) or a transmission type (front panel). The position of the resistance must be changed accordingly. When a fluorescent substance is attached to the front panel, a reflection type has a greater degree of freedom because a place for attaching a resistance is limited.

The filter for enhancing the contrast can be incorporated in the panel as described in detail in the technical report of the technical report on television, ED-993 (November 13, 1986).

The resistor-attached panel may be one shown in Documents 4 and 5, but FIG. 1 shows another example. This cell structure is characterized in that a front plate FG is provided with a resistor R, and the rest is almost the same as FIG.

FIG. 2 shows another example in which only the write electrode has a resistance. There is a cathode on the front panel, a writing anode bus (WAB) runs on the rear panel in the vertical direction,
From there, it is connected to the write anode (WA) via a resistor (R). On the other hand, the display anode (DA) protrudes from the bus (DAB) to the center of the cell. DAB is parallel to C, but may be parallel to WAB. Since the sustain discharge is performed between DAB and C, either may be used. In this case, it can be driven only in the pulse memory mode.

The panel with a resistor has the following features.
Front plate or back plate, (2) Electrodes to be attached, anode side, cathode side, or write electrode only, (3) Classification by combination of presence or absence of auxiliary discharge, corresponding to each of the above two examples And other examples are considered as well. DC memory mode and
Although there are two types of pulse memory driving methods, it can be normally used in both modes.

Although the embodiments of the present invention have been described in detail above, it is obvious that the present invention is not limited to these embodiments and that various modifications and changes can be made within the scope of the claims. Will.

[0039]

As has been described in detail in the embodiments of the present invention, when the display device of the present invention is used, the life of the DC discharge panel is greatly increased, and practical use can be expected. Also,
A configuration in which only the write electrode has a resistance as in the panel shown in FIG. 2 has an advantage that luminance unevenness does not occur even if there is some variation in the resistance. Further, in the configuration in which the cathode and the display anode bus are parallel, the power consumption of the sustain pulse is small.

[Brief description of the drawings]

1 (a) is a plan view of a panel with resistance according to the present invention viewed from the display side, and FIG. 1 (b) is a cut surface X ₁ -X _{2 of} FIG. ₁ (a).
FIG.

FIG. 2 (a) is a plan view of another embodiment of a panel with a resistor according to the present invention as viewed from the display side, and FIG. 2 (b) is a cut plane X _{1 of} FIG. 2 (a).
A cross sectional view taken along -X _2.

FIG. 3A is a plan view of a panel configuration used in an experiment for the present invention viewed from the display side, and FIG. 3B is a cut plane X _{1 in} FIG.
A cross sectional view taken along -X _2.

FIG. 4 shows a temporal change in luminance due to DC discharge when the experimental panel shown in FIG. 3 is used.

FIG. 5 shows life versus pressure characteristics for quantitatively explaining the effect of the present invention.

FIG. 6 shows life versus pressure characteristics for quantitatively explaining the effect of the present invention.

FIG. 7 is a graph showing life versus time for quantitatively explaining the effect of the present invention.
The Xe partial pressure ratio characteristics are shown.

FIG. 8 shows luminous efficiency versus current characteristics according to the present invention.

FIG. 9 shows voltage-current characteristics according to the present invention.

FIG. 10 shows light emission output luminance versus current characteristics according to the present invention.

FIG. 11 shows light emission output luminance versus current characteristics according to the present invention.

FIG. 12 shows luminous efficiency versus pressure characteristics according to the present invention.

FIG. 13 shows luminous efficiency versus Xe partial pressure ratio characteristics according to the present invention.

FIG. 14 shows life versus current characteristics for quantitatively explaining the effect of the present invention.

FIG. 15 shows a sustain voltage vs. pressure characteristic according to the present invention.

FIG. 16 is a view for explaining a cathode effective area of the discharge display panel according to the present invention.

FIG. 17 shows a stable minimum discharge sustaining voltage-pressure characteristic according to the present invention.

FIG. 18 shows the range of the pressure to Xe partial pressure ratio when I = 60 μA and S = 0.04 mm ^{2 according to} the present invention.

FIG. 19 shows life versus pressure characteristics for quantitatively explaining the effect of the present invention when Ni is used as a cathode material.

20 (a) is a cross-sectional view of a first conventional example of a discharge display panel, and FIG. 20 (b) is a plan view as viewed from the display side thereof.

FIG. 21 shows a configuration of a second conventional example of a discharge display panel.

FIG. 22 shows a configuration of a third conventional discharge display panel.

23 (a) is a plan view of a fourth conventional example of a discharge display panel as viewed from the display side, and FIG. 23 (b) is a cross-sectional view taken along a cut plane X ₁ -X ₂ of FIG. 23 (a).

[Explanation of symbols]

 FP Front plate RP Back plate BM Black lattice BA Partition DCE Display cell ACE Auxiliary cell A Anode DA Display anode DAB Display anode bus DAL Display anode wire AA Auxiliary anode AAL Auxiliary anode wire C Cathode AC Auxiliary cathode CB Cathode bus DC display cathode Ph Fluorescent Body W Embankment WB White back WW White wall material R Resistance D Dielectric TH Third electrode PS Priming space WA Write anode WAB Write anode bus

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-253131 (JP, A) JP-A-2-133855 (JP, U) Akio Niwa, 5 others, “17 inch DC type high definition color” Plasma Display ", Journal of the Institute of Television Engineers of Japan, 1990, Vol. 45, No. 5, p. 571-577 (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01J 17/20 H01J 17/49

Claims (1)

(57) [Claims] 1. A discharge panel comprising a front plate and a back plate, wherein discharge cells are formed in a matrix by spacers or partitions, and a discharge screen for emitting a predetermined luminescent color to each discharge cell and a discharge current of each discharge cell are limited. In a display device that drives a DC discharge panel having a discharge current limiting element for performing pulse memory, a sum of partial pressure ratios of He gas and Xe gas as filling gas of the panel is at least 95% of the total filling gas pressure.
%, And the partial pressure ratio of Xe gas to the total filled gas pressure is x,
When the total gas pressure is p torr, 0.01 ≦ x ≦ 0.5,
The condition that p ≦ 600 is satisfied, the effective area of the cathode of the discharge display panel is Smm ² , and the discharge sustaining current is Iμ.
A, a DC-type discharge pump characterized by satisfying the condition xp ⁵ (S / I) ² ≧ 6.3 × 10 ⁴
A display device that drives a channel with pulse memory .