KR20000055528A - Plasma Display Panel with ElectroMagnetic Wave Shielding Layer - Google Patents

Abstract

PURPOSE: A plasma displaying device with electromagnetic wave screen layer is provided to enable users to effectively screen electromagnetic waves by attaching a screen layer. CONSTITUTION: A plasma displaying device with electromagnetic wave screen layer includes the following components. A lower screen layer(48) is formed under a lower plate(32). A primary dielectric layer(38) is formed on the lower plate(32). A RF electrode(50) is attached to a primary dielectric layer(38). A secondary dielectric layer(40) is formed on the address electrode(50), scan electrode(44), and a plate(34). An upper screen layer(46) is equipped to the middle part of the secondary dielectric layer(40) and the upper plate(34). The device enables users to reduce electromagnetic interference by forming an electromagnetic wave screen layer.

Description

Plasma display device with electromagnetic shielding layer {Plasma Display Panel with ElectroMagnetic Wave Shielding Layer}

The present invention relates to a plasma display device, and more particularly, to a plasma display device having an electromagnetic shielding layer configured to shield electromagnetic waves.

Recently, a liquid crystal display (hereinafter referred to as "LCD"), a field emission display (hereinafter referred to as "FED") and a plasma display panel (hereinafter referred to as "PDP") Flat display devices such as PDP have been actively developed. Among them, PDP is able to realize large screen of 40 inches or more as well as ease of fabrication by simple structure, excellent brightness and luminous efficiency, memory function and wide viewing angle of 160 ° or more. Has the advantage.

Referring to FIG. 1, an AC PDP according to the related art has a lower substrate 14 on which an address electrode 2 is mounted, and a lower dielectric formed by coating a predetermined thickness on an upper portion of the lower substrate 14 to form wall charges. A thick film 18, a sustain electrode pair 4 formed transparently on the upper substrate 16 to drive the discharge, and a predetermined thickness on the upper substrate 16 and the sustain electrode pair 4; The upper dielectric thick film 12 is applied to form a wall charge. The conventional PDP structure will be described in detail. A stripe-shaped partition wall 8 is formed between the lower substrate 14 and the upper substrate 16 to divide each discharge cell. In addition, on the upper substrate 16, a pair of sustain electrodes 4, that is, scan and sustain electrodes and a sustain electrode are arranged side by side. On the upper dielectric thick film 12, a protective layer 10 is applied to protect the upper dielectric thick film 12 from sputtering by plasma discharge. On the other hand, the address substrate 2 is disposed on the lower substrate 14 so as to be orthogonal to the sustain electrode pair 4. On the upper portion of the lower dielectric thick film 18, a partition 8 is formed at a predetermined height (for example, 150 to 180 mu m). The phosphor 6 coated on the partition 8 and the lower dielectric thick film 18 is excited by vacuum ultra-violet (UVU) to generate visible light. Meanwhile, a driving method of the PDP will be described. When a predetermined driving voltage (for example, 200 V) is applied between the address electrode 6 and the sustain electrode pair 8, plasma discharge is caused by electrons emitted from the address electrode 6 inside the discharge cell. The vacuum ultraviolet rays generated in this process excite the phosphors of red (hereinafter referred to as "R"), green (hereinafter referred to as "G") and blue (hereinafter referred to as "B"). Light of R, G, and B emitted from the phosphor passes through the protective layer 10, the upper dielectric thick film 12, and the sustain electrode pair 4 toward the front of the upper substrate 16 to display characters or graphics. Done. In this case, by adjusting the number of sustain discharges, stepwise brightness necessary for displaying an image, that is, gray scale, is realized. Accordingly, the number of sustain discharges is recognized as an important factor for determining the brightness and discharge efficiency of the PDP. In fact, in the AC type PDP, in order to perform sustain discharge, a spherical pulse of 10-100 Hz is periodically applied. In this case, the sustain discharge occurs only once at an extremely short instant per sustain pulse. In addition, the charged particles generated by the sustain discharge move the discharge path formed in the sustain electrode pair 4 along the polarity of the electrode, so that wall charges are formed in the dielectric layer inside the cell and the voltage by the wall charge is applied. In addition to the voltage, the sustain can be maintained at a voltage lower than the discharge start voltage. As described above, the sustain discharge caused by the sustain pulse occurs only once at a very short time every pulse, and most of the other time is consumed in the preparation of the wall charge and the next discharge, thereby lowering the discharge efficiency of the PDP. . In order to improve such a reduction in discharge efficiency, studies are being actively conducted to raise the sustain discharge frequency to a radio frequency (for example, several MHz to several hundred MHz). Hereinafter, a plasma display device for radio frequency (hereinafter referred to as "RF") will be described with reference to FIGS. 2 to 3.

Referring to FIG. 2, the RF plasma display device includes a first dielectric layer 26 formed on the lower substrate 14 ′, an RF electrode 20 mounted on the first dielectric layer 26, and a first dielectric layer ( A partition 8 'vertically formed on the upper portion of the upper surface 26, a phosphor 6' applied to the inner wall of the partition 8 ', and a second dielectric layer 28 stacked on the upper substrate 16'. And an address electrode 24 and a scan electrode 22 mounted on the second dielectric layer 28. The RF PDP is formed such that the partition wall 24 has a predetermined height in order to apply an RF pulse to perform sustain discharge. The driving of the RF plasma display device will be described. Each of the address electrodes 24 and the scan electrodes 22 arranged so as to be perpendicular to each other on the upper substrate 16 'has a driving voltage having a voltage level higher than a discharge start as shown in FIGS. 3A and 3B, respectively. When applied, it causes an address discharge. In this case, wall charges are formed in the selected cell. In addition, when the RF signal is applied to the RF electrode 20 disposed on the lower substrate 14 ′ orthogonal to the address electrode 24, only the cells in which the wall charges are formed in the address electrode 24 and the scan electrode 22 are discharged. To generate this, a drive voltage slightly lower than the discharge start voltage level is applied to generate charged particles. At this time, RF discharge is maintained by the formed charged particles.

In this case, a rectangular pulse (or sine wave) of several MHz to several tens of MHz, that is, an RF pulse is applied to the RF electrode 20 to perform sustain discharge. In addition, when sustain discharge by RF pulse is performed, the vibration amplitude of charged particles and ions is designed to be smaller than the height of the partition wall so that the charged particles and ions generated in the cell do not directly collide with the partition wall 8 'by the discharge. Instead, it exists in a quasi-stational state inside the discharge cell, thereby reducing the amount of charged particles lost in the partition 8 '. On the other hand, the frequency region of the sustain pulse during the RF discharge of the RF plasma display device is several tens of MHz, in which case energy proportional to the square of the frequency is emitted to the outside in the form of electromagnetic waves. Accordingly, electromagnetic waves radiated to the front surface of the PDP adversely affect the human body, and electromagnetic waves radiated to the rear surface of the PDP affect the circuit part, thereby making it difficult to operate normally.

Accordingly, an object of the present invention is to provide a plasma display device having an electromagnetic shielding layer configured to shield electromagnetic waves.

1 is a diagram showing a configuration of a conventional plasma display device.

2 is a cross-sectional view showing the configuration of an RF plasma display.

3 is a view showing a driving waveform for driving FIG.

4 illustrates a plasma display device having an electromagnetic shielding layer according to the present invention.

5 is a plan view showing the shape of the electromagnetic shielding layer of FIG.

<Description of the code | symbol about the principal part of drawing>

2,24,40: address electrode 4: transparent electrode

6,6 ', 42: phosphor 8,8', 36: partition

10: protective film 12,18: dielectric thick film

14,14 ', 32: Lower board 16,16', 34: Upper board

20,50 RF electrode 22,44 Scan electrode

26, 28 dielectric layer 46 upper shielding layer

48: lower shielding layer

In order to achieve the above object, a plasma display device having an electromagnetic shielding layer according to the present invention includes an electromagnetic shielding layer for shielding electromagnetic waves generated from the display device.

Other objects and features of the present invention other than the above object will become apparent from the description of the embodiments with reference to the accompanying drawings.

A preferred embodiment of the present invention will be described with reference to FIGS. 4 to 5.

Referring to FIG. 4, the plasma display device having the electromagnetic shielding layer according to the present invention includes a lower shielding layer 48 formed under the lower substrate 32 and a first dielectric layer 38 formed on the lower substrate 32. ), An RF electrode 50 mounted on the first dielectric layer 38, a partition 36 vertically formed on the upper portion of the first dielectric layer 38, and a phosphor 42 coated on an inner wall of the partition 36. ), The second dielectric layer 40 formed on the upper substrate 34, the address electrode 50 and the scan electrode 44 mounted on the second dielectric layer 40, the upper substrate 34 and the second substrate. An upper shielding layer 46 attached between the dielectric layers 40. In the plasma display device having the electromagnetic shielding layer according to the present invention, a shielding layer for shielding electromagnetic waves is provided under the upper substrate 34 and the lower substrate 32. Since other configurations and operations are the same as those of FIG. 2, detailed descriptions thereof will be omitted. The upper shielding layer 46 is formed between the upper substrate 34 and the dielectric layer 40 using a sputtering method or a printing method, and one side thereof is connected to the ground voltage source GND. In this case, the upper shielding layer 46 is formed in a lattice shape as shown in FIG. 5A to shield electromagnetic waves leaking to the entire surface of the plasma display device. In addition, the upper shielding layer 46 may perform a function of a black matrix to prevent optical interference between adjacent cells. That is, when the upper shielding layer 46 is formed in a metal grid to separate cells from cells, light crosstalk between neighboring cells is absorbed by the metal material to perform the function of the black matrix. On the other hand, the lower shielding layer 48 is formed by sputtering or printing a metal material that reflects visible light on the entire surface of the lower substrate 32, and one side is connected to the ground voltage source GND. In this case, the lower shielding layer 48 is formed as shown in FIG. 5B to shield the electromagnetic waves leaking to the rear surface of the plasma display device. In addition, the lower shielding layer 48 performs a function of reflecting housekeeping rays traveling to the rear surface of the plasma display device. That is, the lower shielding layer 48 shields electromagnetic waves leaking to the rear surface of the plasma display device and reflects visible light traveling to the rear surface. In this case, the position of the lower shielding layer 48 may be provided between the lower substrate 32 and the first dielectric layer 38 according to the designer's intention. In addition, the upper and lower shielding layers 46 and 48 are made of a metal plate to shield electromagnetic waves, and one side is connected to the ground voltage source GND.

As described above, the plasma display device having the electromagnetic shielding layer according to the present invention forms an electromagnetic shielding layer for shielding the leakage of electromagnetic waves inside the plasma display device (ElectroMagnetic Interference; hereinafter referred to as "EMI") There is an advantage to reduce.

In addition, since the electromagnetic shielding layer of the plasma display device having the electromagnetic shielding layer according to the present invention is a black matrix layer on the upper plate, and a visible light reflecting layer on the lower plate does not need to configure a separate black matrix layer and the visible light reflecting layer. There is an advantage to simplify the configuration of the device.

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 (9)

In the plasma display device, And an electromagnetic shielding layer for shielding electromagnetic waves generated from the display device. The method of claim 1, The plasma display device further comprises a high frequency voltage driving electrode. The method of claim 1, The electromagnetic shielding layer, And an electromagnetic shielding layer formed on the upper substrate and the lower substrate of the plasma display device, respectively. The method of claim 3, wherein And an electromagnetic shielding layer formed on the upper substrate to shield electromagnetic waves leaking to the front surface of the plasma display device and to absorb light generated from the cell. The method of claim 3, wherein The electromagnetic shielding layer formed on the lower substrate is a plasma display device having an electromagnetic shielding layer, characterized in that the shielding electromagnetic waves leaking to the rear surface of the plasma display device and at the same time reflects visible light traveling to the front side toward the front surface. . The method of claim 3, wherein And the electromagnetic shielding layer has a lattice shape. The method of claim 2, And the electromagnetic shielding layer is made of a metal material. The method of claim 3, wherein And the electromagnetic shielding layer of the lower substrate is formed on the entire surface of the lower substrate. The method of claim 3, wherein And the electromagnetic shielding layer of the lower substrate is formed between the lower substrate and the dielectric layer.