KR100421476B1 - Electrode Structure in Plasma Display Panel - Google Patents

Abstract

The present invention relates to an electrode structure of a plasma display panel capable of improving contrast.

The plasma display panel according to the present invention has a scan electrode formed on an upper substrate, a periphery of one side of the discharge cell, and receives a scan pulse for selecting the discharge cell, and a width corresponding to the width of the scan electrode between the scan electrode and the upper substrate. A second holding layer formed between the black layer to be formed, the first sustaining electrode formed on the other side of the discharge cell, and the first sustaining electrode and the scanning electrode to generate the first sustaining electrode and the sustain discharge in the selected discharge cell; An electrode is provided.

Description

Electrode Structure in Plasma Display Panel

The present invention relates to an electrode structure of a plasma display panel, and more particularly, to an electrode structure of a plasma display panel capable of improving contrast.

Plasma Display Panel (hereinafter referred to as "PDP") is a display device using visible light generated from a phosphor when vacuum 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 has the advantage of being able to realize high definition large screen. PDP is composed of a plurality of discharge cells arranged in a matrix form, one discharge cell constitutes a pixel of the screen.

1 is a perspective view showing a discharge cell structure of a conventional three-electrode AC surface discharge type PDP.

Referring to FIG. 1, a discharge cell of a conventional three-electrode AC surface discharge type PDP includes a scan / sustain electrode 12Y and a common sustain electrode 12Z formed on an upper substrate 10, and a lower substrate 18. The address electrode 20X is formed. The scan / sustain electrode 12Y and the common sustain electrode 12Z are transparent electrodes formed of indium tin oxide (ITO). Since ITO has a high resistance value, bus electrodes 13Y and 13Z are formed side by side on the back surface of the scan / sustain electrode 12Y and the common sustain electrode 12Z. The bus electrodes 13Y and 13Z receive a driving signal from the outside and supply the supplied driving signal to the scan / sustain electrode 12Y and the common sustain electrode 12Z so that a uniform voltage is applied to each of the discharge cells. . The black layer 30 may be formed between the bus electrodes 13Y and 13Z, the scan / sustain electrode 12Y, and the common sustain electrode 12Z as shown in FIG. 2 to improve contrast. The black layer 30 is formed of an electrically conductive material. The upper dielectric layer 14 and the passivation layer 16 are stacked on the upper substrate 10 having the scan / sustain electrode 12Y and the common sustain electrode 12Z side by side. In the upper dielectric layer 14, wall charges generated during plasma discharge are accumulated. The protective layer 16 prevents damage to the upper dielectric layer 14 due to sputtering generated during plasma discharge and increases discharge efficiency of secondary electrons. As the protective film 16, magnesium oxide (MgO) is usually used.

The lower dielectric layer 22 and the partition wall 24 are formed on the lower substrate 18 on which the address electrode 20X is formed, and the phosphor layer 26 is coated on the surfaces of the lower dielectric layer 22 and the partition wall 24. The address electrode 20X is formed in the direction crossing the scan / sustain electrode 12Y and the common sustain electrode 12Z. The partition wall 24 is formed in parallel with the address electrode 20X to prevent ultraviolet rays and visible light generated by the discharge from leaking to the adjacent discharge cells. The phosphor layer 26 is excited by ultraviolet rays generated during plasma discharge to generate visible light of any one of red, green, and blue. Inert gas for gas discharge is injected into the discharge space provided between the upper substrate 10 / lower substrate 18 and the partition wall 24.

The AC surface discharge type PDP is driven by dividing one frame into several subfields having different discharge times in order to express gray level of an image. Each subfield is further divided into a reset period for uniformly causing discharge, an address period for selecting a discharge cell, and a sustain period for expressing gray scale according to the number of discharges. For example, when the image is to be displayed with 256 gray levels, the frame period (16.67 ms) corresponding to 1/60 second is divided into eight subfields. Each of the eight subfields is further divided into an address period and a sustain period. Here, the reset period and the address period of each subfield are the same for each subfield, while the sustain period is 2 ⁿ (n = 0,1,2,3,4,5,6,7) in each subfield. Is increased. In this way, since the sustain period is different in each subfield, the gray level of the image can be expressed.

3 is a view showing a waveform diagram according to a conventional method for driving a PDP.

Referring to FIG. 3, in the reset period, a reset discharge for initializing the discharge cells is generated by the reset pulse Vr supplied to the common sustain electrode 12Z. The reset pulse Vr may be supplied to the scan / sustain electrode 12Y. In the address period, the scan pulse (-Vs) is sequentially supplied to the scan sustain electrode 12Y, and the data pulse Vd synchronized with the scan pulse (-Vs) is supplied to the address electrode 20X. At this time, an address discharge occurs in the discharge cell supplied with the data pulse Vd. In the sustain period, the sustain pulse Vsus is alternately supplied to the scan / sustain electrode 12Y and the common sustain electrode 12Z to generate sustain discharge in the discharge cells selected by the address discharge.

However, in the conventional PDP, the black layer 30 is formed only on the bus electrodes 13Y and 13Z. Therefore, when the black image is displayed on the PDP, the light incident from the outside cannot be blocked by the upper substrate, thereby reducing the contrast. In addition, there is a problem that light is generated by a reset discharge generated in the reset period, and the contrast is reduced by this light. On the other hand, in order to solve this problem, the size of the black layer 30 can be increased, but as the size of the black layer 30 becomes larger, the luminance decreases.

Accordingly, an object of the present invention relates to an electrode structure of a plasma display panel capable of improving contrast.

1 is a perspective view showing a conventional three-electrode AC surface discharge type plasma display panel.

FIG. 2 is a diagram illustrating a black layer formed between the transparent electrode and the bus electrode illustrated in FIG. 1.

3 is a waveform diagram illustrating a driving waveform supplied to the electrodes illustrated in FIG. 1.

4 is a cross-sectional view showing a plasma display panel according to an embodiment of the present invention.

FIG. 5 is a waveform diagram illustrating driving waveforms supplied to electrodes illustrated in FIG. 4. FIG.

<Description of Symbols for Main Parts of Drawings>

10,40: upper substrate 12Y, 42Y: scan / sustain electrode

12Z, 42Z: Common sustain electrode 13Y, 13Z, 48Y, 48Z: Bus electrode

14,22,54 dielectric layer 16: protective film

18,53: lower substrate 20X, 52X: address electrode

24: partition 26: phosphor layer

30, 44, 46: black layer 42S: scanning electrode

In order to achieve the above object, the plasma display panel of the present invention includes a scan electrode formed on an upper substrate, a periphery of one side of the discharge cell, receiving scan pulses for selecting a discharge cell, and a scan electrode between the scan electrode and the upper substrate. The first sustain electrode and the sustain discharge in the selected discharge cell formed between the black layer formed with the width corresponding to the width, the first sustain electrode formed at the periphery of the other side of the discharge cell, and the first sustain electrode and the scan electrode. And a second sustaining electrode for generating the same.

Other objects and features of the present invention in addition to the above objects will become 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. 4 to 5.

4 is a cross-sectional view illustrating a plasma display panel according to an embodiment of the present invention.

Referring to FIG. 4, the PDP according to the embodiment of the present invention includes the scan electrode 42S, the first sustain electrode 42Y, the second sustain electrode 42Z, and the lower substrate 53 formed on the upper substrate 40. Is provided on the address electrode 52X. The first sustain electrode 42Y and the second sustain electrode 42Z are transparent electrodes formed of ITO. Bus electrodes 48Y and 48Z are formed on the rear surfaces of the first sustain electrode 42Y and the second sustain electrode 42Z. The bus electrodes 48Y and 48Z receive a driving signal from the outside, and supply the supplied driving signals to the first and second sustain electrodes 42Y and 42Z. A first black layer 46 made of a conductive material is formed between the first and second sustain electrodes 42Y and 42Z and the bus electrodes 48Y and 48Z to improve contrast. The first and second sustain electrodes 42Y and 42Z generate sustain discharge in the sustain period. Meanwhile, the first black layer 46 formed between the first and second sustain electrodes 42Y and 42Z and the bus electrodes 48Y and 48Z may be omitted. The scan electrode 42S formed at one peripheral portion of the discharge cell receives the scan pulse in the address period. The scan electrode 42S is formed of a conductive material, for example, silver (Ag). A second black layer 44 is formed between the scan electrode 42S and the upper substrate 40. The second black layer 44 blocks light incident from the outside to improve the contrast of the PDP. On the other hand, the scan electrodes 42S and the first sustain electrodes 42Y are formed at intervals within 100 μm, and the first sustain electrodes 42Y and the second sustain electrodes 42Z are formed at intervals of 100 μm or more. That is, since the interval between the first sustain electrode 42Y and the second sustain electrode 42Z is set wide, the discharge efficiency during the sustain discharge can be improved. In addition, the width of the scan electrode 42S is formed to be wider than that of the first and second sustain electrodes 42Y and 42Z in order to effectively block light incident from the outside. An upper dielectric layer 50 and a passivation layer 51 are stacked on the upper substrate 40 on which the scan electrode 42S, the first sustain electrode 42Y, and the second sustain electrode 42Z are formed side by side. Wall charges generated during plasma discharge are accumulated in the upper dielectric layer 50. The passivation layer 51 prevents damage to the upper dielectric layer 50 due to sputtering generated during plasma discharge and increases discharge efficiency of secondary electrons. As the protective film 51, magnesium oxide (MgO) is usually used.

The lower dielectric layer 54 and the partition wall (not shown) are formed on the lower substrate 53 on which the address electrode 52X is formed, and the phosphor layer (not shown) is applied to the lower dielectric layer 54 and the partition wall surface. The address electrode 52X is formed in the direction crossing the scan electrode 42S, the first sustain electrode 42Y, and the second sustain electrode 42Z. The partition wall is formed in parallel with the address electrode 52X to prevent ultraviolet rays and visible light generated by the discharge from leaking to the adjacent discharge cells. The phosphor layer is excited by ultraviolet rays generated during plasma discharge to generate visible light of any one of red, green, and blue. Inert gas for gas discharge is injected into the discharge space provided between the upper substrate 40 and the lower substrate 53 and the partition wall.

FIG. 5 is a waveform diagram illustrating a method of driving the PDP shown in FIG. 4.

Referring to FIG. 5, in the driving method according to an exemplary embodiment of the present invention, one frame is driven by dividing a frame into several subfields having different discharge times. Each subfield is further divided into a reset period for uniformly causing discharge, an address period for selecting a discharge cell, and a sustain period for expressing gray scale according to the number of discharges. In the reset period, the reset pulse Vr is supplied to the scan electrode 42S to cause a reset discharge for initializing the discharge cells. At this time, most of the light generated by the reset discharge is blocked by the second black layer 44. In the address period, the scan pulse (-Vs) is sequentially supplied to the scan electrode 42S, and the data pulse Vd synchronized with the scan pulse (-Vs) is supplied to the address electrode 52X. At this time, an address discharge occurs in the discharge cell supplied with the data pulse Vd. In the sustain period, sustain pulses Vsus are alternately supplied to the first and second sustain electrodes 42Y and 42Z to cause sustain discharge in discharge cells selected by the address discharge. At this time, since the scan electrode 42S is not formed between the first and second sustain electrodes 42Y and 42Z, it is possible to prevent a decrease in luminance caused by the scan electrode 42S.

As described above, according to the electrode structure of the plasma display panel according to the present invention, a scan electrode having a wide width is formed on one side periphery of the discharge cell, and a width corresponding to the width of the scan electrode is formed between the scan electrode and the upper substrate. By forming the black layer, the branch can block light incident from the outside and light generated by the reset discharge, thereby improving contrast.

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 (5)

Upper substrate, A scan electrode formed at one periphery of the discharge cell and receiving a scan pulse for selecting the discharge cell; A black layer formed between the scan electrode and the upper substrate to have a width corresponding to the width of the scan electrode; A first sustain electrode formed at a peripheral portion of the other side of the discharge cell; And a second sustain electrode formed between the first sustain electrode and the scan electrode to generate a sustain discharge with the first sustain electrode in the selected discharge cell. The method of claim 1, Wherein the scan electrode and the second sustain electrode are formed at intervals of 100 μm or less, and the second sustain electrode and the first sustain electrode are formed at intervals of 100 μm or more. The method of claim 1, And the scan electrodes have a width wider than that of the first and second sustain electrodes. The method of claim 1, And the scan electrode is supplied with a reset pulse in a reset period for initializing a discharge cell. The method of claim 1, And sustain pulses are alternately applied to the first and second sustain electrodes during a sustain period for discharging the selected discharge cells.