JP3726667B2 - AC type plasma display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an AC type plasma display device used for image display of a television receiver and an information display terminal.
[0002]
[Prior art]
Conventionally, the panel structure of a plasma display device is configured as shown in FIG. That is, as shown in FIG. 8, a scan electrode 23 and a sustain electrode 24 covered with a dielectric layer 22 are paired in parallel with each other on the front substrate 21, and on the dielectric layer 22 A protective film 25 which is an easily dischargeable insulating film is formed. A data electrode 28 covered with an insulating layer 27 is provided on the back substrate 26, and a partition wall 29 is provided in parallel with the data electrode 28 on the insulating layer 27 between the data electrodes 28. Further, a phosphor layer 30 is provided from the surface of the insulator layer 27 to the side surface of the partition wall 29, and the front substrate 21 and the rear substrate 26 are in a discharge space so that the scan electrode 23, the sustain electrode 24, and the data electrode 28 intersect. 31 are arranged opposite to each other. In the discharge space 31, at least one of helium, neon, and argon and xenon are sealed as a discharge gas. Further, one discharge cell 32 is formed at the intersection of the scan electrode 23 and the sustain electrode 24 and the data electrode 28 which are sandwiched between two adjacent barrier ribs 29 and form a pair. That is, a plurality of discharge cells 32 are arranged in a plane between the front substrate 21 and the rear substrate 26.
[0003]
Next, a method for driving the panel will be described. First, an initializing discharge is generated between all pairs of scan electrodes 23 and sustain electrodes 24 to accumulate wall charges on the surface of the protective film 25. Subsequently, a scan pulse voltage is applied to one scan electrode 23 and a write pulse voltage is applied to the data electrode 28 corresponding to the discharge cell 32 for writing display data, thereby generating a write discharge in the discharge cell 32. To perform the write operation. This writing operation is sequentially performed on all the scanning electrodes 23. After the write operation is completed for all the scan electrodes 23, a pulse voltage is alternately applied to all the scan electrodes 23 and the sustain electrodes 24, and a discharge is generated in the discharge cells where the write discharge is performed, so that the phosphor layer 30 is formed. Display is performed by emitting light.
[0004]
[Problems to be solved by the invention]
However, when an image is displayed on a conventional panel, it has been found that non-lighting cells due to defective writing operation occur randomly in the panel surface, causing a reduction in display quality. This is considered to be due to a discharge delay phenomenon which is a general property of the discharge phenomenon.
[0005]
In general, after applying a voltage equal to or higher than the discharge start voltage between the discharge gaps, the time until discharge occurs is called a discharge delay, but this discharge delay has a formation delay determined by the discharge cell structure and the constituent material of the panel, There is a statistical delay that reflects the probabilistic factors of the occurrence of discharge. Among these, the statistical delay is larger than the microsecond order and the formation delay, which is the main cause of defective writing operation. In order to perform the writing operation reliably, the writing time per scan electrode needs to be as long as several μsec, and the time occupied by the writing operation in the driving waveform becomes long. In this case, or when driving a large panel with a large number of scanning lines, how to shorten the writing time becomes a big problem.
[0006]
The present invention has been made to solve such a problem. By shortening the discharge delay in the write operation, the write operation can be reliably performed to improve the display quality and the write time can be shortened. The purpose is to provide a panel.
[0007]
[Means for Solving the Problems]
In the plasma display apparatus of the present invention, two substrates are provided to face each other across a plurality of discharge cells arranged in a plane, and the discharge cells have an ignition gap for generating a seed discharge for inducing a main discharge. It is what you have. With this configuration, it is possible to generate a write discharge using the discharge generated in the ignition gap as a seed.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
According to a first aspect of the present invention, there is provided a seed discharge for providing a plurality of discharge cells by opposingly arranging a pair of substrates having at least a transparent front side, and inducing a main discharge in each of the plurality of discharge cells. Is provided with an ignition gap.
[0009]
According to the first aspect of the present invention, a plurality of discharge cells are formed by disposing a pair of substrates transparent at least on the front side so that a discharge space is formed between the substrates and partitioning the discharge space by partition walls. In a plasma display device provided with an electrode on a substrate so that a main discharge is generated in the discharge cell, a gap is formed between the side surface of the partition and the surface of the substrate on which the electrode for generating the main discharge is formed. Thus, a conductive phosphor layer is formed, and an ignition gap is formed between the phosphor layer and the substrate.
[0010]
As the conductive phosphor layer, a layer containing zinc oxide is used. Furthermore, by providing an electrically floating conductor on the substrate that forms the ignition gap with the conductive phosphor layer, a sufficient wall charge can be supplied to the ignition gap.
[0011]
According to a fourth aspect of the present invention, a plurality of columns of display electrodes are arranged in a stripe pattern, and a dielectric layer is formed so as to cover the display electrodes, and an easily dischargeable insulation is formed on the dielectric layer. A transparent front substrate on which a film is formed, and a plurality of rows of data electrodes arranged in a direction perpendicular to the display electrodes, so as to form a discharge space between the front substrate and the front substrate. An electrode that generates a main discharge on the side surface of the partition wall, and a partition wall that provides a plurality of discharge cells by partitioning the discharge space between the data electrodes on the back side substrate. A conductive phosphor layer is formed so that a gap is formed between the substrate and the surface of the substrate, and an electrically floating conductor is formed between the dielectric layer and the easily dischargeable insulating film. An ignition gap between the conductor and the phosphor layer Are those that you configured. And like the structure demonstrated above, the electroconductive fluorescent substance layer uses what contains zinc oxide.
[0012]
Hereinafter, a plasma display device according to an embodiment of the present invention will be described with reference to FIGS.
[0013]
(Embodiment 1)
FIG. 1 shows an example of a panel structure in a plasma display device according to an embodiment of the present invention, and FIG. 2 shows a cross section taken along the line AA ′ of FIG. As shown in the figure, a plurality of pairs of stripe-like display electrodes 4 that are paired with a scanning electrode 2 and a sustaining electrode 3 are formed on a transparent front substrate 1 such as a glass substrate. A light shielding layer 5 is disposed between adjacent display electrodes 4. The scan electrode 2 and the sustain electrode 3 are respectively composed of transparent electrodes 2a and 3a and buses 2b and 3b made of silver or the like electrically connected to the transparent electrodes 2a and 3a. A dielectric layer 6 is formed on the substrate 1 on the front side so as to cover the plurality of pairs of electrodes, and a protective film 7 which is an easily dischargeable insulating film is formed on the dielectric layer 6. ing.
[0014]
A plurality of stripes covered with an insulating layer 9 are arranged on the back substrate 8 facing the front substrate 1 in a direction perpendicular to the display electrodes 4 of the scan electrodes 2 and the sustain electrodes 3. A data electrode 10 is formed. On the insulating layer 9 between the data electrodes 10, a plurality of stripe-shaped partition walls 11 are arranged in parallel with the data electrodes 10.
[0015]
Further, a conductive phosphor so that a gap is formed between the surface 11a between the partition walls 11 and the surface of the insulator layer 9 with the surface of the substrate 1 on which the display electrode 4 for generating the main discharge is formed. Layer 12 is formed.
[0016]
The substrate 1 and the substrate 8 are arranged to face each other with a minute discharge space so that the scan electrode 2 and the sustain electrode 3 and the data electrode 10 are orthogonal to each other, and the periphery is sealed, and the discharge One or a mixed gas of helium, neon, argon, and xenon is sealed in the space as a discharge gas. In addition, the discharge space is divided into a plurality of sections by partition walls 11 to provide a plurality of discharge cells 13 at which the intersections of the display electrodes 4 and the data electrodes 10 are located. The phosphor layers 12 are sequentially arranged one by one so as to be blue.
[0017]
Here, the phosphor layer 12 is made of a material obtained by mixing an insulating phosphor material and a conductive material, and has conductivity. As the conductive material, powdered or whisker (dendritic) zinc oxide (ZnO) is used.
[0018]
That is, a gap between the top 14 of the phosphor layer 12 applied to the side wall of the partition wall 11 and the protective film 7 of the substrate 1, that is, a formed body (dielectric layer 6, scan electrode 2) formed on the substrate 1. An ignition gap 15 is formed between the surfaces of the sustain electrode 3 and the protective film 7) and the phosphor layer 12 adjacent to the surfaces.
[0019]
FIG. 3A is a potential distribution diagram in the discharge cells 13 of the panel of this embodiment, and FIG. 3B is a potential distribution diagram in the discharge cells 32 of the conventional panel. Since the phosphor layer is an insulator in the conventional panel, the potential distribution has a shape as shown by a broken line in FIG. 3B. However, the potential distribution in the panel of this embodiment is that the phosphor layer is conductive. Therefore, the potential distribution in the conventional panel is clearly different from that of the conventional panel, as shown by the broken line in FIG. A strong electric field concentration is generated between the top portion 14 of the phosphor layer 12 applied to the side surface of the partition wall 11 and the protective film 7, and this is an ignition gap 15 having a substantially extremely short discharge gap. Become.
[0020]
A very strong electric field concentration occurs in the ignition gap 15 when a write pulse voltage is applied, and a voltage substantially larger than the discharge start voltage of the ignition gap 15 is applied. For this reason, the discharge is started in the ignition gap 15 with almost no large discharge delay, and the charged particles generated by this discharge become a seed fire, and become the main discharge in the discharge cell 13 with almost no statistical delay. Write discharge is performed.
[0021]
FIG. 4 shows the result of measuring the statistical delay of the discharge during the write discharge using an actual panel. Note that Y ₂ O ₃ : Eu was used for the red phosphor layer, and BaMg ₂ Al ₁₄ O ₂₄ : Eu was used for the blue phosphor layer. For the green phosphor layer, a mixture of Zn ₂ SiO ₄ : Mn and ZnO was used. Further, the statistical delay of the discharge was obtained by measuring the current waveform flowing during the write discharge with an oscilloscope for 100 discharge cells among the discharge cells in which the phosphor layers of the respective colors were formed. The write discharge was generated with a scan pulse voltage of 70 V, a write pulse voltage of 60 V, and a pulse width of these pulse voltages of 1.5 μsec. In one discharge cell, a panel having lengths of 1080 μm and 360 μm in a direction parallel to and perpendicular to the barrier ribs 11 and a barrier rib height of 120 μm was used. The vertical axis in FIG. 4 is the statistical delay of discharge in the discharge cell in which the green phosphor layer is formed, and the horizontal axis is the weight mixing ratio of ZnO to Zn ₂ SiO ₄ : Mn (green phosphor).
[0022]
When ZnO was not mixed, the green discharge cell had the largest statistical delay and was the main cause of the write operation failure. According to the results shown in FIG. 4, by mixing ZnO with the green phosphor, Statistical delay can be shortened, and writing discharge can be reliably performed. In addition, the time required for the write operation can be shortened.
[0023]
(Embodiment 2)
FIG. 5 is a cross-sectional view of a main part of the panel according to the second embodiment of the present invention.
[0024]
The panel of FIG. 5 differs from the panel configuration of the first embodiment in that a floating conductor 16 that is in an electrically floating state is formed between the dielectric layer 6 and the protective film 7 at the position of the ignition gap 15. That is. The floating conductor 16 can be formed of a transparent material such as indium tin oxide (ITO) or tin oxide (SnO ₂ ), or an opaque material such as silver (Ag). The floating conductor 16 may be formed on the surface of the protective film 7 as shown in FIG. Further, the protective film 7 may be omitted if the dielectric layer 6 is made of a material that is resistant to ion sputtering during discharge and has a high secondary electron emission coefficient.
[0025]
FIG. 7 is a schematic configuration diagram showing a planar positional relationship between the scan electrode 2, the sustain electrode 3, the partition wall 11, and the floating conductor 16, and FIGS. 7A to 7C show the shape and position of the floating conductor. This is a changed example.
[0026]
As shown in FIGS. 7A to 7C, the floating conductors 16a, 16b and 16c are provided close to the position of the ignition gap. In the configuration of FIG. 7B, when the scanning electrode 2 is composed of the transparent electrode 2a and the opaque metal bus 2b, the floating conductor 16b is provided below the metal bus 2b. Even if 16b is formed of an opaque material, the visible light transmittance does not change and does not cause a decrease in luminance. In the configuration of FIG. 7C, since the floating conductors 16c are arranged in a direction perpendicular to the partition wall 11, the front substrate 1 and the rear substrate 8 are bonded to each other as compared with the configuration of FIG. Position alignment becomes easy.
[0027]
Next, the function of the floating conductor 16 will be described.
[0028]
As described in the first embodiment, a very strong electric field concentration occurs in the ignition gap 15 between the top portion 14 of the phosphor layer 12 applied to the side surface of the barrier rib 11 and the protective film 7 when a write pulse is applied. In this ignition gap 15, since a voltage much higher than the discharge start voltage is applied, the discharge starts without causing a large discharge delay. However, if the amount of wall charge accumulated on the surface of the protective film 7 made of an MgO thin film is not sufficient before the write discharge, the discharge generated in the ignition gap 15 is very small and sufficient charged particles are generated without the floating conductor 16. In some cases, the discharge cell 13 does not cause an address discharge because the process ends without performing the process. This is because the MgO thin film is generally excellent in insulation, and the electric field is relaxed by discharging slight wall charges on the surface of the MgO thin film.
[0029]
The function of the floating conductor 16 is to supply the ignition gap 15 with an electric charge for generating a seed fire discharge sufficient to shift to the main discharge. That is, when the floating conductor 16 is provided between the dielectric layer 6 and the protective film 7 as shown in FIG. 5, when discharge occurs in the ignition gap 15, the floating conductor 16 passes through the protective film 7. Thus, electric charge is supplied to the ignition gap 15. As shown in FIG. 6, when the floating conductor 16 is provided on the protective film 7, when discharge occurs in the ignition gap 15, electric charge is supplied from the floating conductor 16 to the ignition gap 15. As a result, the discharge can be continued until the discharge generated in the ignition gap becomes a seed discharge sufficient to shift to the main discharge.
[0030]
As a result, it is possible to supply sufficient charged particles by the discharge of the ignition gap 15, and the charged particles generated by the discharge generated in the ignition gap 15 become a igniter and generate the write discharge which is the main discharge with almost no statistical delay. Can be made. For this reason, the display quality of the panel of this embodiment is improved as compared with the conventional panel.
[0031]
In the above embodiment, the write discharge has been described as an example of the main discharge. However, the same applies to the case where the main discharge is generated by applying a voltage between the data electrode and the scan electrode or the sustain electrode. An effect can be obtained.
[0032]
In addition, although the case where ZnO is used as the conductive material has been described, in addition to ZnO, indium oxide (In ₂ O ₃ ), tin oxide (SnO ₂ ), indium tin oxide (ITO), or the like is also used. The effect can be obtained, and the phosphor material is not limited to that shown in the above embodiment. Furthermore, the same effect can be obtained even when a red phosphor layer or a blue phosphor layer is mixed with a conductive material.
[0033]
【The invention's effect】
As described above, according to the AC type plasma display apparatus of the present invention, for each discharge cell, a substantially very small discharge gap is formed between the top of the phosphor coated on the side wall of the barrier rib and the front substrate. Therefore, a very strong electric field concentration occurs in the ignition gap when a write pulse is applied, and discharge starts with almost no large discharge delay. The charged particles generated by the discharge generated here act as a igniter, and writing discharge is performed with almost no statistical delay. As a result, an unlit cell due to a defective writing operation is eliminated, and an AC type plasma display device without image quality deterioration can be realized. Further, the time required for the writing operation can be shortened, which is advantageous for a large panel or a high definition panel in which the number of scanning lines is increased.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a panel structure of a plasma display device according to an embodiment of the present invention with a part cut away. FIG. 2 is a cross-sectional view of the main part of the panel. FIG. 4 is a graph showing the measurement results of the statistical delay of discharge in the panel according to the first embodiment of the present invention. Sectional view [FIG. 6] Cross-sectional view of a main part showing another example of the panel according to the second embodiment of the present invention. [FIG. FIG. 8 is a perspective view of a panel of a conventional plasma display device with a part cut away.
DESCRIPTION OF SYMBOLS 1 Front side board | substrate 2 Scan electrode 3 Sustain electrode 4 Display electrode 6 Dielectric layer 7 Protective film 8 Back side board 9 Insulator layer 10 Data electrode 11 Partition 12 Phosphor layer 13 Discharge cell 14 Top part 15 of phosphor layer Ignition gap 16 Floating conductor

Claims (4)

A plurality of discharge cells are provided by disposing a pair of substrates transparent at least on the front side so that a discharge space is formed between the substrates and partitioning the discharge space with a partition wall, and a main discharge is generated in the discharge cell. In the plasma display device in which electrodes are arranged on the substrate, a conductive phosphor layer is formed on the side surface of the partition so that a gap is formed between the surface of the substrate on which the electrode for generating main discharge is formed. AC type plasma display device to be formed . 2. The AC type plasma display device according to claim 1, wherein the conductive phosphor layer contains zinc oxide . 2. The AC type plasma display device according to claim 1, wherein an electrically floating conductor is provided on a substrate that forms an interval with the conductive phosphor layer . A transparent front substrate having a plurality of rows of display electrodes arranged in stripes and a dielectric layer formed so as to cover the display electrodes and an easily dischargeable insulating film formed on the dielectric layer; A back-side substrate provided with a plurality of rows of data electrodes arranged in a direction orthogonal to the display electrodes, so as to form a discharge space between the front-side substrate and the back-side substrate. A partition wall for providing a plurality of discharge cells by partitioning the discharge space between the data electrodes on the substrate, and a gap between the side surface of the partition wall and the surface of the substrate on which an electrode for generating a main discharge is formed. An AC type plasma display device in which a conductive phosphor layer is formed so that an electrically floating conductor is provided between the dielectric layer and an easily dischargeable insulating film .

Images