KR20010001936A - display apparatus using gas discharge - Google Patents

Abstract

PURPOSE: A PDP(Plasma Display Panel) is provided to maximize the discharging efficiency and to satisfy with a large life length, a low operating voltage, an emitting brightness and a color purity. CONSTITUTION: A discharging area filling a discharging gas is formed by sealing around parallel the first and second substrates. An electrode for discharging the discharging gas is equipped inside one substrate between the first and second substrates. A fluorescent layer is excited by ultraviolet rays. The ultraviolet rays are generated by discharging the discharging gas. The discharging gas comprises a three primary mixed gas of He, Ne and Xe and a two primary mixed gas of Ne and Xe. The Xe gas is contained 0.1-10wt%. The three primary mixed gas comprises He:Ne(3:7)-6% Xe. The two primary mixed gases are comprised of Ne-10% Xe.

Description

Display apparatus using gas discharge

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas discharge display device, and in particular, a plasma display panel suitable for improving reliability of a product by mixing two or three kinds of gases in a specific ratio and filling the discharge region. The present invention relates to a gas discharge display device.

In general, a gas discharge display device is classified into a DC type, an AC type, and a hybrid type in which a DC type and an AC type are combined according to the structure of the electrode. The difference between the direct current type and the alternating current type is distinguished by whether the electrode is directly exposed to the discharge plasma or indirectly by the dielectric layer. In the case of a direct current type PDP, an electrode is directly exposed to a discharge plasma. In the case of an alternating current type PDP, an electrode is indirectly coupled with the plasma through a dielectric. Such a difference shows a difference in discharge phenomenon, and in the case of an alternating current type, charged particles formed by the discharge are accumulated in the dielectric layer. In other words, electrons are accumulated in the dielectric layer on the positively charged electrode, and ions are accumulated in the dielectric layer on the negatively charged electrode. The potential formed through such a phenomenon is called a wall potential, and since the wall potential is formed to be opposite to the potential applied from the outside, the potential applied to the gas in the cell decreases when the wall potential starts to form. Therefore, when a sufficiently large wall potential is formed, the discharge is canceled because the potential applied to the gas decreases below the potential capable of sustaining the discharge.

However, if the potential of the potential applied to the external electrode is applied after the wall potential is formed, driving by the memory function that discharge is possible even when a low externally applied potential is added by adding the potential by the wall potential and the externally applied potential. Do it.

The AC PDP has a memory function effect due to the wall potential accumulated in the dielectric. That is, the dielectric in the cell in which the discharge was previously formed may cause the discharge to be discharged at a lower voltage than in the case where the charged particles form a wall potential in the dielectric and have no wall potential. This memory function is very useful for driving a large panel of a PDP, which is a gas discharge display device employing a row driving method.

In the case of the DC-type PDP, unlike the AC-type PDP, the DC-type PDP does not have a function of forming a wall potential by a dielectric and thus does not have a unique memory function. That is, since the electrode is directly exposed to the discharge region, the charged particles formed by the discharge flow through the electrodes having opposite polarities to the external circuit and do not accumulate on the electrode surface. However, in the case of the direct current type PDP, the pulse memory function using the charged particle supply effect is used.

The pulse memory function refers to the principle that when the discharge pulse is applied again before the charged particles and the quasi-neutral particles formed in the discharge are attenuated, the discharge is formed under a lower voltage than in the absence of such charged particles. This memory function is an essential feature that enables driving without deterioration of luminance when driving a large panel in a row driving method, and such a characteristic is also necessary in terms of electrode structure.

1 and 2 are cross-sectional views showing basic electrode structures of a DC type PDP and an AC type PDP.

As shown in FIG. 1, the basic electrode structure of the DC-type PDP includes the anode electrode 3 and the cathode electrode 4, the partition wall 5, and the phosphor layer formed on the front substrate 1 and the back substrate 2. It consists of (6).

The anode 3 and the cathode 4 form a current path for discharge formation. The barrier rib 5 determines the distance between electrodes for forming the discharge, and prevents crosstalk due to discharge occurring in adjacent cells. The electrode material mainly used in the DC-type PDP has a high secondary electron emission coefficient so as to have a low discharge voltage characteristic, and nickel, which is excellent in sputtering characteristics that can withstand sputtering by ions, is mainly used.

In the AC PDP shown in FIG. 2, the dielectric layer 10 for forming the capacitively coupled discharge covers the sustain electrodes 7 and 8 and the address electrode 9. The commonly used dielectric uses boronsilicate series, and has a low secondary electron emission coefficient and a short lifetime due to sputtering by ions generated during plasma formation. Therefore, magnesium oxide (MgO) is used to protect the dielectric from plasma. An oxide-based thin film such as) is coated on the dielectric layer 10 using the protective film 11.

The magnesium oxide (MgO) exhibits low voltage discharge characteristics because of its good sputter resistance and high secondary electron emission coefficient. However, since the thickness of the MgO layer must be thin and the surface characteristics must be excellent, it is difficult to form through thick film printing and is usually manufactured by a thin film process by vacuum deposition.

In the case of the partition 5, a height of about 100 to 200 mu m is required to form a discharge distance and a volume. Since the thickness of the thick film printing method is several tens of micrometers, the barrier rib 5 is formed through multilayer printing.

In addition, as a requirement for forming a discharge, an electrode structure having two electrodes or generally three electrodes is mainly used. In case of DC type PDP, an auxiliary cathode is added to form an auxiliary discharge. In case of an AC type PDP, the sustain electrode (7) (8) and the selective discharge and the sustain discharge are separated to address speed. An address electrode 9 is introduced to improve the efficiency. Therefore, the electrode structure may be classified into a two-electrode structure and a three-electrode structure according to the number of electrodes. In addition, according to the arrangement of the electrodes forming the discharge can be classified into a counter electrode structure and a surface discharge electrode structure. In the case of the counter electrode structure, two sustain electrodes forming a discharge are positioned on the front substrate and the back substrate, respectively, and the discharge is formed on the vertical axis of the panel. In the case of the surface discharge electrode structure, the discharge is formed. Refers to an electrode structure in which two sustain electrodes are positioned on the same substrate so that a discharge is formed on one plane of the panel.

In addition, Figure 3 is a perspective view showing an AC type PDP according to the prior art, it is formed to have a predetermined interval in the horizontal direction on the front substrate (1) made of glass, the upper side surface of the front substrate (1) to facilitate light transmission In order to maintain the discharge voltage, a sustain electrode (7) (8) consisting of a transparent electrode and a metal electrode is formed on the front surface of the front substrate (1) including the sustain electrode (7) (8) and sustain electrode (7) (8). To protect the dielectric layer 10, to extend the lifetime of the dielectric layer 10, to improve the secondary electron emission effect, and to reduce the change in the discharge characteristics, the protective layer 11, the back substrate (2), the An underlayer 12 formed on the upper surface of the rear substrate 2, an address electrode 9 formed on the upper side of the underlayer 12 at regular intervals in a direction orthogonal to the sustain electrodes 7 and 8, and the address The white back 13 formed on the entire surface of the base film 12 including the electrode 9, the front facer In order to maintain the gap between the substrate 1 and the back substrate 2 and to prevent mis-discharge between the cells, the partition wall 5 formed in parallel with the address electrode 9 with each address electrode 9 therebetween interposed therebetween, It consists of phosphor layers 6 of red, green and blue (R, G, B) formed between each partition 5.

As such, when the manufacturing of the front substrate 1 and the rear substrate 2 is completed, an exhaust hole is formed in the rear substrate 2 to fill a desired discharge gas in a vacuum state.

Subsequently, after applying the bonding frit to the periphery of the front substrate 1 and the rear substrate 2 and completing the bonding, a discharge region is formed between the front substrate 1 and the rear substrate 2.

Then, after the discharge gas is injected and sealed according to the desired optical characteristics through the exhaust hole, the entire process of manufacturing the PDP is completed.

On the other hand, the colorization of PDP employs a method of exciting phosphors like CRT. CRT uses electro-luminescence, which is excited by electrons accelerated to several tens of keVs, whereas PDP uses photo-luminescence, in which phosphors are excited by ultraviolet rays formed by gas discharge. Light emission is adopted. In particular, 147 nm vacuum ultraviolet rays of xenon (Xe) gas are mainly used. Therefore, a phosphor is applied to the electrode structure of the PDP for colorization.

In addition, the electrode structure of the PDP is classified into a transmission type and a reflection type structure by the application position of the phosphor. The transmissive electrode structure has the advantage of being easy to fabricate, but has a disadvantage in that the variation is large due to the printing surface state of the phosphor. In the case of the reflective structure, the luminance can be increased by enlarging the coating area of the phosphor. Although it has, there is a difficulty in the phosphor coating technology. In addition, the reflective electrode structure has higher luminance characteristics than the transmissive electrode structure, and the phosphor coating technology has been solved by the development of thick film printing technology and the development of new process technology such as sandblast. have.

As described above, the gas discharge display device mainly applied to the PDP utilizes the penning effect of the discharge gas as a core technology for image display. The phenning effect is to promote the ionization reaction through metastable particle species with very large impact areas, which enhances the Townsend α-process.

For example, the penning reaction of He + Xe and Ne + Xe is as follows.

He ^* + Xe → Xe + + e + He

Ne ^* + Xe → Xe + + e + Ne

Where He and Ne are the main constituent gases, Xe is the additive gas, and He ^* and Ne ^* are each metastable or excited particles. Particles in this excited state have a relatively long life time and have a large collision cross-sectional area, so the probability of collision with other particles is greater, and when He and Ne gas are added as compared with Xe gas, The effect of neutral excitons is to promote ionization.

In addition, the secondary electron emission from the surface of the material in contact with the plasma plays a very important role in determining the discharge characteristics of the PDP. In particular, the secondary electrons are emitted by the plasma from the dielectric-covered electrode, such as AC-type PDP may be a direct ion impact, surface reaction of the excitable species, and light reaction. The most common of these is the reaction by ion bombardment. Neon ions with an ionization energy of 21.6 eV enter and neutralize by combining with one electron in the valence band, and the surplus energy releases electrons in the other valence band to the surface.

The kinetic energy of the electron is obtained by subtracting the band gap energy of magnesium oxide (MgO) and the surface work-function energy from the energy of the incident ions. The electrons are accelerated by the electric field again and generate ions and electrons in the plasma state again through collision.

Next, VUV (vacuum ultra violet) in the gas discharge display device will be described.

The VUV refers to UV having a short wavelength of 200 nm or less even in UV (ultra violet). VUV cannot pass through these gases if the pressure of the mother gas is high or contains oxygen, and strong absorption occurs in the gases. The wavelength and intensity of the VUV in the PDP is an important factor in determining the luminance of the light emitted from the panel.

Ultraviolet rays emitted from xenon (Xe) have a wavelength in the region of 140 nm to 180 nm, and overlap with the wavelength region where the fluorescent materials for R, G, and B exhibit the best efficiency. Among the inert gases, helium (He) and neon (Ne) have a short wavelength of 100 nm or less, and thus are not suitable for use for UV for stimulating a phosphor and emitting visible light. Xenon (Xe) gas seems to be suitable considering the intensity and wavelength of UV light emitted. However, in order to use it as a PDP gas, the driving voltage and the lifetime of the electrode must be considered at the same time. Mixed gas is used.

A typical case of the binary mixed gas is to add xenon (Xe) gas to helium (He) or neon (Ne) to lower the driving voltage and improve the UV efficiency.

As mentioned above, the use of helium (He) or neon (Ne) as the main gas has higher electron temperature in these gases than pure xenon (Xe) gas, so that the excitation of xenon is effective and the penning effect with xenon is used. It is for. In addition, even in the case of mixed gas, the conditions for producing the maximum UV efficiency may vary depending on the mixing ratio or other discharge conditions.

When the above-mentioned single discharge gas is used, since the discharge start voltage is high, the discharge start voltage is lowered by using the binary mixed gas or the ternary mixed gas, but there is a problem in that the luminance characteristics are deteriorated. The display device using the mixed gas has a problem that the display device using the CRT is less than the display device in terms of brightness.

In addition, in terms of ultraviolet rays, xenon (Xe) gas, which generates ultraviolet rays having the longest wavelength among inert gases, cannot be used alone due to too high discharge initiation voltage. Thus, neon or helium (He) is mixed. Although the discharge start voltage was lowered by using the source gas, color purity and lifetime were deteriorated.

As shown in FIG. 4, in the case of neon (Ne) + 4% xenon (Xe), the color coordinate shows 'X' axis '0.6' due to the orange visible light of neon (Ne), and thus the color purity is lowered and helium (He) + In the case of 4% Xenon (Xe), it shows a problem of shortening the life, so [Helium: Neon (7: 3)] + 4% Xenon (He): Neon (Ne) (8: 2)] + 4% xenon (Xe) was used to try to improve the color purity.

However, as shown in FIG. 5, the discharge brightness variation is as follows. [Helium (He): Neon (Ne) (8: 2)] + 4% xenon (Xe) has a discharge brightness of about 6 (cd / m ^2). In the case of [Helium (Ne) (Ne) (7: 3)] + 4% Xenon (Xe), the discharge luminance is about 12 (cd / m ² ), which improves color purity more than a certain level. You can't expect it.

Thus, in order to improve the problem of deterioration of color purity when using two-way gas in the conventional PDP, a discharge gas containing helium (He) as a main component of ternary mixed gas consisting of helium (He), neon (Ne), and xenon (Xe) However, there is a problem in that low discharge start voltage, high luminance light emission, color purity improvement, and long life, which are essential conditions of the plasma display panel, are not simultaneously satisfied.

In addition, the conventional PDP has a problem in that visual contour noise appears at the boundary line of each gray scale due to an abnormal luminance phenomenon due to a difference in discharge luminance.

The present invention has been made to solve the problems of the conventional gas discharge display device as described above, the object of the present invention is to maximize the discharge efficiency by differently adjusting the mixing ratio of at least one discharge gas of the ternary mixed gas The present invention provides a gas discharge display device capable of simultaneously satisfying long life, low operating voltage, light emission luminance and color purity characteristics.

1 is a cross-sectional view showing the electrode structure of a discharge cell of a conventional DC PDP;

2 is a cross-sectional view showing the electrode structure of a discharge cell of a conventional AC PDP;

3 is a perspective view showing an AC PDP according to the prior art;

Figure 4 is a graph showing the color coordinate characteristics of the pressure of the conventional three-way mixed gas (He + Ne + Xe),

5 is a graph showing the discharge luminance characteristics of the conventional ternary mixed gas (He + Ne + Xe),

6 is a graph showing discharge luminance characteristics of binary mixed gas (Ne + Xe) and ternary mixed gas (He + Ne + Xe) according to the present invention.

Explanation of symbols for main parts of the drawings

1: Front board 2: Back board

3: anode electrode 4: cathode electrode

5: bulkhead 6: phosphor layer

7, 8: sustain electrode 9: address electrode

10 dielectric layer 11: protective film

12: base film 13: white back

The gas discharge display device of the present invention seals the periphery of the first and second substrates parallel to each other to form a discharge region filled with discharge gas, and discharge gas discharge is formed on an inner surface of at least one of the first and second substrates. A plasma display panel having a dedicated electrode and having a fluorescent layer excited by ultraviolet light generated by the discharge of the discharge gas, the helium (He), neon (Ne), and xenon (Xe) filled in the discharge region. Xenon (Xe) gas of the ternary mixed gas of the ()) and binary mixed gas of neon (Ne) and xenon (Xe) is a discharge gas having a composition ratio of 0.1% to 10% of the total mass.

Hereinafter, a preferred embodiment of the discharge gas display device according to the present invention with reference to the accompanying drawings will be described in detail.

First, the characteristics of each single gas among the discharge gases used in the gas discharge display device will be briefly described for better understanding of the present invention, and the discharge characteristics by mixing these gases will be described.

Gas discharge display devices using phosphors generally use vacuum ultraviolet rays emitted in an excited state of xenon (Xe). However, since xenon gas alone cannot realize sufficient discharge characteristics, a mixture of neon and xenon or helium and xenon is used. In most cases, if xenon is added to neon gas or xenon to helium hex, the emission of vacuum ultraviolet rays increases initially depending on the content of xenon, and then exceeds the proper mixing ratio. It tends to decrease.

In addition, in the ternary mixed gas (He + Xe + Ar or Ne + Xe + Ar), it can be seen that the emission amount and the discharge start voltage of vacuum ultraviolet rays vary according to the content of argon gas (Ar), and another ternary mixed gas In (He + Ne + Xe), it can be seen that the discharge start voltage varies depending on the mixing ratio of xenon (Xe).

In the case of the binary mixed gas or the ternary mixed gas, there is a mixing ratio of an appropriate additive (Xe or Ar), and since the maximum light emission occurs at the maximum efficiency, it is very important to identify the optimum mixing ratio.

The present invention is a ternary mixed gas in which helium (He) and neon (Ne) are mixed at an optimum ratio of 3: 7 or 7: 3, and xenon (Xe) is mixed at 0.1 to 10% with the mixed gas. In addition, the present invention is further limited to the mixing ratio of xenon (Xe) to be specified in 6% and 4%.

6 is a view illustrating an embodiment of the present invention, in which helium (He) and neon (Ne) are mixed at an optimum ratio to indicate an optimum efficiency of discharge gas at 400 to 700 Torr pressure, and then to the mixed gas. Experimental results for a ternary mixed gas containing 6% and 4% of xenon (Xe) and a binary mixed gas containing 10% of xenon (Xe) in neon (Ne), respectively, at 400 to 700 Torr pressure. Shows the time versus charge density (10 ^-9 C / cm).

Therefore, according to the experimental results of the present invention, the discharge time with respect to the reaction rate of the gas in the discharge region is delayed in the order of 6% and 4% of the added amount of xenon (Xe) gas, and the amount of added xenon gas to the neon (Ne) gas. It can be seen that the discharge time is further delayed at this 10%.

In addition, although the discharge brightness change characteristic of the present invention is not shown in the drawing, in the case of [Helium (Ne) (Ne) (3: 7)] + 6% Xenon (Xe), the discharge brightness is about 5.18 (cd / m ^2). In the case of [Helium (Ne) (Ne) (7: 3)] + 4% Xenon (Xe), the discharge luminance is about 4.77 (cd / m ² ), which improves color purity by a certain level or more. You can expect

In addition, the present invention can remove the moving image pseudo contour noise at the boundary line of each gray scale by reducing the change in the discharge luminance difference.

As described in detail above, the gas discharge display device according to the present invention has the following effects.

The present invention has the effect of improving the luminance characteristics of the gas discharge display device by mixing xenon (Xe) in a specific ratio so as to show the optimum efficiency to the binary mixture gas (He + Ne) as the panning gas of the gas discharge display device.

Third, the present invention reduces the abnormal luminance variation occurring in the conventional PDP by adding xenon gas having a specific mixing ratio to the mixed gas or neon gas, thereby improving the long life, low voltage operation, high luminance emission, and color purity improvement of the gas discharge display device. Satisfying at the same time has the effect of maximizing the reliability of the product.

Claims (5)

A periphery of the first and second substrates parallel to each other is formed to form a discharge region filled with discharge gas, and a discharge gas discharge electrode is provided on an inner surface of at least one of the first and second substrates. In a plasma display panel having a fluorescent layer excited by ultraviolet light generated by a gas discharge, a ternary mixed gas and neon of helium (He), neon (Ne), and xenon (Xe) filled in the discharge region are formed. A xenon (Xe) gas in the binary mixed gas of (Ne) and xenon (Xe) is a discharge gas having a composition ratio of 0.1% to 10% of the total mass. The gas discharge display device according to claim 1, wherein the ternary mixed gas has a composition ratio of helium (He): neon (Ne) (3: 7) -6% xenon (Xe). The gas discharge display device according to claim 1, wherein the ternary mixed gas has a composition ratio of helium (He): neon (Ne) (7: 3) -4% xenon (Xe). The gas discharge display device according to claim 1, wherein the binary mixed gas has a composition ratio of neon (Ne) -10% xenon (Xe). The gas discharge display device according to any one of claims 1 to 4, wherein the mixed gas is filled in a panel at a pressure of 400 to 700 Torr.