KR100326858B1 - Plasma Display Panel Driving with Radio Frequency Signal - Google Patents

Abstract

The present invention relates to a high frequency plasma display panel capable of lowering high frequency driving voltage and power consumption for generating sustain discharge.

The high frequency plasma display panel according to the present invention is characterized in that the data electrode is formed to have a larger line width than the scan electrode.

As a result, the discharge area and the amount of charged particles generated during address discharge are increased, thereby lowering the driving voltage and power consumption necessary for sustain discharge.

Description

High Frequency Plasma Display Panel {Plasma Display Panel Driving with Radio Frequency Signal}

The present invention relates to a high frequency plasma display panel capable of lowering high frequency driving voltage and power consumption for generating sustain discharge.

Plasma Display Panel (hereinafter referred to as 'PDP') is a display device using visible light generated from a phosphor when ultraviolet rays generated by gas discharge excite the phosphor. PDP is thinner and lighter than Cathode Ray Tube (CRT), which has been the mainstay of display means, and it has the advantage of being able to realize high-definition large screen and having a wide viewing angle. The PDP is composed of discharge cells arranged in a matrix. In the PDP, by adjusting the number of sustain discharges generated in each discharge cell, stepwise brightness required for image display, that is, gray scale, is realized. In the actual AC drive type PDP, in order to perform sustain discharge, a rectangular pulse of 200 mW to 300 mW is periodically applied to the discharge sustaining electrode periodically. In AC-driven PDP, the discharge occurs only once at a very short time for one spherical pulse, and most of the discharge time is consumed as a step of forming wall charge and preparing for the next discharge, thereby lowering the discharge efficiency. In order to solve this problem, a PDP (hereinafter referred to as an RF PDP) in which a discharge is caused by a high frequency has been proposed. In the RF PDP, electrons vibrating by the high frequency signal continuously ionize the discharge gas in the discharge region, so that discharge is continuously performed for most of the discharge time.

1 is a cross-sectional view illustrating a longitudinal cross-sectional structure of a discharge cell in a conventional RF PDP. Referring to FIG. 1, the upper plate 60 and the lower plate 62 are provided in parallel with a predetermined distance. A high frequency signal is supplied to the rear surface of the upper substrate 64 constituting the upper plate 60 so that the high frequency electrodes 66 forming high frequency sustain discharge are formed side by side for each discharge cell. The upper dielectric layer 68 formed on the high frequency electrode 66 has a function of accumulating charges during discharge. The upper protective layer 70 coated on the upper dielectric layer 68 may protect the high frequency electrode 66 and the upper dielectric layer 68 from sputtering shocks of charged particles during discharge to extend the life of the discharge cell. On the lower substrate 72 constituting the lower plate 62, a data electrode 74 for address discharge is formed to cross at right angles with the high frequency electrode 66 of the upper plate 60. On the data electrode 74, the scan electrode 78 is formed in a direction orthogonal to the data electrode 74 with the first dielectric layer 76 interposed therebetween. The scan electrode 78 and the high frequency electrode 66 of the upper plate 60 are parallel to each other. The scan electrode 78 generates an address discharge together with the data electrode 74 and also generates a high frequency sustain discharge together with the high frequency electrode 66. The second dielectric layer 80 and the lower passivation layer 82 are sequentially formed on the scan electrode 78. In addition, the partition wall 84 is formed vertically between the upper plate 60 and the lower plate 62. The partition wall 84 forms a discharge region 86 of the cell together with the upper plate 60 and the lower plate 62, and distinguishes the discharge cells from each other to block electrical and optical interference between neighboring cells. The discharge region 86 is filled with a mixed gas of He + Xe or Ne + Xe that generates ultraviolet rays during discharge. On the second dielectric layer 80 of the lower plate 62, a phosphor 88 which is excited by ultraviolet rays generated during discharge and generates visible light is coated.

When the discharge process of the RF PDP is schematically described, an AC driving signal is supplied between the data electrode 74 and the scan electrode 78 of the lower plate 62 so that an address discharge occurs between the two electrodes 74 and 78. In this process, charged particles such as electrons are generated in the discharge region 86. Then, the direction of the electric field is alternately changed in the discharge region 86 by the high frequency signal supplied to the high frequency electrode 66 of the upper plate 60. Accordingly, the electrons generated in the discharge region 86 continuously generate a sustain discharge while vibrating up and down between the high frequency electrode 66 and the scan electrode 78. Thus, when the distance between the electrodes in the glow discharge is long, the effect is like a positive column that the discharge efficiency is very high. The vibrating electrons excite and ionize the discharge gas continuously during most discharge times. Ultraviolet rays generated in this process excite the phosphor 88 to generate visible light, thereby realizing an image of the PDP.

In this RF PDP, the sustain discharge efficiency is improved compared to the conventional AC surface discharge PDP, but there are still problems in address discharge for cell selection and charged particle generation. These problems will be described in conjunction with FIGS. 2A and 2B.

Figure 2a shows in detail the longitudinal cross-sectional structure of the bottom plate to make the address discharge in the conventional RF PDP. As shown in FIG. 2A, a first dielectric layer 76 for electrical insulation is formed between the scan electrode 78 and the data electrode 74 formed on the lower substrate 72 of the panel, and the second dielectric layer is formed thereon again. 80 is formed. The protective layer and the phosphor formed on the second dielectric layer 80 are omitted in FIG. 2A. In the RF PDP, the thickness t1 + t2 of the dielectric layer formed on the data electrode 74 is different from the thickness t1 of the dielectric layer formed on the scan electrode 78. That is, the first and second dielectric layers 76 and 80 are formed on the data electrode 74 to have a thickness of t1 + t2, and only the second dielectric 80 is formed on the scan electrode 78 to have a thickness of t1. do. Accordingly, when voltage is applied to the scan electrode 78 and the data electrode 74 during the address discharge, the discharge voltage applied to the actual discharge region 86 varies depending on the position due to the difference in the voltage drop in the dielectric layer. Occurs unevenly. In particular, since the dielectric layer thickness t1 + t2 is very thick on the data electrode 74, the voltage drop is more severe. Accordingly, the driving voltage higher than the discharge voltage required for the actual discharge must be supplied to the data electrode 74. However, when the driving voltage of the data electrode 74 is increased, the address discharge pattern is formed long in the longitudinal direction of the data electrode 74. As a result, diffusion and movement of charged particles into adjacent cells becomes severe, and mutual interference between adjacent cells occurs. This problem severely affects the overall discharge uniformity and driving voltage margin of the panel. In addition, in the RF PDP, unnecessary energy consumption occurs due to the parasitic capacitance component C2 between the data electrode 74 and the scan electrode 78, resulting in a decrease in discharge efficiency. The parasitic capacitance component C2 is decreased by increasing the thickness t2 of the first dielectric layer 76. However, when the thickness of the first dielectric layer 76 is increased, the voltage drop in the dielectric layer is increased, which causes the data electrode 74 to increase. This causes a problem of increasing the driving voltage to be supplied.

Another problem with the address discharge structure of the RF PDP relates to the electrode structure. 2B is a plan view of the lower plate 62 showing the structure of the scan electrode 78 and the data electrode 74 causing the address discharge. As shown in the figure, in the conventional RF PDP, the address discharge is concentrated only at a narrow point where the scan electrode 78 and the data electrode 74 cross each other. That is, the discharge field 90 in which charged particles such as electrons are generated in the discharge cell is narrowly formed only in a specific part in the discharge cell, so that the discharge uniformity is reduced. In addition, since the total amount of charged particles generated in the discharge cell is small, the sustain discharge voltage must be increased in the sustain discharge using these charged particles as an initial seed. Accordingly, as the high frequency power consumption increases, the discharge efficiency is lowered, and the burden of the high frequency driving circuit is increased.

Accordingly, an object of the present invention is to provide a high frequency plasma display panel capable of lowering high frequency driving voltage and power consumption for generating sustain discharge.

Another object of the present invention is to provide a high frequency plasma display panel in which unnecessary power loss in the dielectric layer is reduced.

Another object of the present invention is to provide a high frequency plasma display panel which can lower the driving voltage during address discharge.

1 is a cross-sectional view illustrating a longitudinal cross-sectional structure of a discharge cell in a conventional high frequency plasma display panel.

Figure 2a is a longitudinal cross-sectional view showing in detail the bottom plate structure shown in FIG.

2B is a plan view showing an electrode structure and an address discharge structure of a lower plate in a conventional high frequency plasma display panel.

3A is a plan view illustrating an electrode structure of a lower plate in a high frequency plasma display panel according to an exemplary embodiment of the present invention.

3B is a plan view illustrating an address discharge structure in a high frequency plasma display panel according to an exemplary embodiment of the present invention.

4A and 4B are longitudinal cross-sectional views of a lower plate showing a cross section taken along lines A-A 'and B-B', respectively, shown in FIG. 3A;

<Description of Symbols for Main Parts of Drawings>

60: top plate 62: bottom plate

64: upper substrate 66: high frequency electrode

68: upper dielectric layer 70: upper protective layer

72,110: lower substrate 74,102: data electrode

76,112: first dielectric layer 78,100: scan electrode

80,114: second dielectric layer 82: lower protective layer

84,108 bulkhead 86 discharge area

88 phosphor 90116 discharge field

104: narrow part 106: wide part

In order to achieve the above object, the high frequency plasma display panel of the present invention is characterized in that the data electrode is formed to have a larger line width than the scan electrode.

Other objects and features of the present invention in addition to the above object will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 3A to 4B.

3A is a plan view illustrating an electrode structure of a lower plate in an RF PDP according to an exemplary embodiment of the present invention. As shown in FIG. 3A, in the RF PDP of the present invention, a data electrode 102 formed in a direction orthogonal to the scan electrode 100 with a dielectric layer not shown in the figure interposed therebetween, A narrow portion 104 is formed to be thin in the direction orthogonal to 100, and a wide portion 106 is formed to be wide in the direction parallel to the scan electrode in the discharge cell. That is, the data electrode 102 is formed to extend in a direction parallel to the scan electrode 100 at a portion that intersects the scan electrode 100 and to have a shape wider than the width of the scan electrode 100. The longitudinal cross-sectional structure of the lower plate having such an electrode structure is as shown in FIGS. 4A and 4B. A data electrode 102 is formed on the lower substrate 110, a first dielectric layer 112 is formed between the data electrode 102 and the scan electrode 100, and a second dielectric layer (2) is again formed on the scan electrode 100. 114) is formed. The lower protective layer and the phosphor which are not shown in the figure are sequentially formed on the second dielectric layer 114. In order to form the data electrode 102 in the form as shown in FIG. 3A, a mask pattern is first formed such that all regions on the lower substrate 110 are masked except for the region where the electrode is to be printed. Then, the electrode material may be printed on a portion which is not masked by the mask pattern by screen printing or the like. Through this method, it is possible to easily form the electrode structure of the desired shape.

When an address discharge occurs between the data electrode 102 and the scan electrode 100 formed as described above, as shown in FIG. 3B, at the point where the wide portion 106 of the data electrode 102 and the scan electrode 100 cross each other. The discharge field 116 is formed to be wide. In the conventional structure, the discharge field 90 is strongly formed in a narrow area where the scan electrode 78 and the data electrode 74 intersect, whereas in the structure of the present invention, the scan electrode 100 and the data electrode 102 are discharged. Since they are formed in parallel in the cell, the discharge field 116 is uniformly formed in a relatively wide area. As the discharge area becomes wider, the amount of charged particles such as electrons generated during address discharge increases. Accordingly, it is possible to lower the sustain driving voltage for stably causing the sustain discharge for each discharge cell. In addition, since the generated charged particles are widely and uniformly distributed in the discharge region, the discharge uniformity during the sustain discharge is improved.

Meanwhile, in the electrode structure illustrated in FIG. 3A, as the area of the wide part 106 included in the data electrode 102 increases, a capacitance value existing between the data electrode 102 and the scan electrode 100 increases. There are disadvantages. Similar to the problem of the conventional structure, when the capacitance value between the scan and data electrodes 100 and 102 is increased, the displacement current between the scan and data electrodes 100 and 102 is increased, thereby increasing unnecessary power loss. The power loss due to the displacement current can be reduced by increasing the thickness of the first dielectric layer 112 between the scan and data electrodes 100 and 102 to reduce the capacitance value. However, when the thickness of the first dielectric layer 112 is increased, the voltage drop in the dielectric layer increases during address discharge as in the conventional case, which causes a problem in that the driving voltage needs to be increased.

In order to solve these problems, in the present invention, the first dielectric layer 112 between the data electrode 102 and the scan electrode 100 is sufficiently thick and formed on the first dielectric layer 112 and the scan electrode 100. The second dielectric layer 114 formed is patterned as shown in FIGS. 4A and 4B. 4A and 4B are longitudinal cross-sectional views of a lower plate showing a cross section taken along lines A-A 'and B-B', respectively, shown in FIG. 3A. As shown in the figure, all other portions except for the portion of the second dielectric layer 114 on the scan electrode 100 are patterned to be removed. In this structure, since the thickness of the first dielectric layer 112 between the data electrode 102 and the scan electrode 100 is sufficiently thick, the capacitance value between the scan and the data electrodes 100 and 102 can be lowered and unnecessary power consumption can be reduced. Will be. In addition, since the thickness of the dielectric layer formed on the data electrode 102 becomes thinner by the thickness d, as shown in FIG. 4B, the voltage drop problem in the dielectric layer may be simultaneously solved.

As the method for patterning the dielectric layer, there may be various methods such as etching the photosensitive glass and printing the dielectric layer. In order to pattern a dielectric layer using the etching method of photosensitive glass, as a material of a dielectric layer, the photosensitive glass which has the characteristic which the characteristic changes in response to an ultraviolet-ray is used. First, a mask pattern is formed on a lower substrate 110 on a lower substrate in which a data electrode 102, a first dielectric layer 112, a scan electrode 100, and a second dielectric layer 14 are sequentially formed. When the lower plate is irradiated with ultraviolet rays for a predetermined time and heat-treated, the dielectric layer portion irradiated with ultraviolet rays and the dielectric layer portion not irradiated with ultraviolet rays are systematically different from each other. The lower plate is then precipitated in the etchant for a predetermined time to remove the portion exposed or not exposed to the ultraviolet rays. At this time, whether the exposed portion is removed or the unexposed portion is removed depends on the energy of the irradiated ultraviolet rays and the heat treatment temperature during heat treatment. In the step of forming the mask pattern, the mask pattern should be formed in consideration of the characteristics of the etching method and the portions to be removed through etching.

In the method of patterning a dielectric layer by using a dielectric layer printing method, the data electrode 102, the first dielectric layer 112, and the scan electrode 100 are sequentially formed on the lower substrate 110, and then the scan electrode ( A mask pattern is formed on the first dielectric layer 112 to mask all regions except for the scan electrode 100. The second dielectric layer 114 may be formed only on the scan electrode 100 in the form as shown in FIGS. 4A through 4B by printing a dielectric material on the unmasked scan electrode 100.

As described above, in the high frequency plasma display panel according to the present invention, the electrode area of the data electrode is widened at the intersection with the scan electrode of the data electrode, thereby increasing the discharge area and the amount of charged particles during the address discharge. have. Accordingly, it is possible to reduce the high frequency driving voltage and the power consumption to enable the sustain discharge to occur stably, thereby improving the discharge efficiency and reducing the burden on the high frequency driving circuit. In addition, the charged particles generated during the address discharge are uniformly distributed in a large area within the discharge cell, thereby improving the uniformity of discharge during sustain discharge.

In addition, the thickness of the dielectric layer between the scan electrode and the data electrode is sufficiently thick to reduce the capacitance value between the two electrodes, thereby effectively preventing an increase in unnecessary power consumption caused by the shape deformation of the data electrode. On the other hand, by patterning the dielectric layer formed on the data electrode, the voltage drop in the dielectric layer can be suppressed to lower the driving voltage during address discharge. Thus, interference between adjacent cells is reduced, and the overall discharge uniformity of the panel is improved.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (4)

A high frequency plasma display panel comprising a scan electrode for line scanning of a panel, a data electrode formed in a direction orthogonal to the scan electrode to cause an address discharge together with the scan electrode, and a high frequency electrode to generate a high frequency sustain discharge. And the data electrode is formed to have a larger line width than the scan electrode. The method of claim 1, And the data electrode has a larger line width at the center of the display cell formed at a point crossing the scan electrode and a smaller line width at both ends. The method of claim 2, And a first dielectric layer formed between the data electrode and the scan electrode. The method of claim 3, wherein And a second dielectric layer formed on the first dielectric layer and the scan electrode and patterned to be formed only around the scan electrode.