KR19990016068A - PDP 4-electrode driving device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PDP driving apparatus of a PDP-TV (Plasma Display Panel-Television), and more particularly, to a voltage consumed to cause discharge between electrodes in a PDP panel. In general, a PDP panel having a three-electrode structure forms a discharge between the X electrode and the Y electrode. As the PDP panel is enlarged, a distance between the X electrode and the Y electrode is widened, and a high voltage is applied during the discharge. Accordingly, the present invention discloses a four-electrode driving apparatus of a PDP that enables the voltage to be lowered by adding one more electrode in the conventional three-electrode structure. That is, the driving apparatus of the PDP having the four-electrode structure is composed of an S ₁ electrode, an S ₂ electrode, a Y electrode, and an addressing electrode, and a first discharge is formed between the S ₁ electrode and the Y electrode, and the Y electrode and the S electrode. A second discharge is formed between the _two electrodes, and the first discharge and the second discharge occur alternately. As the first discharge and the second discharge are alternately formed, the driving voltage of the PDP having the 4-electrode structure is lower than the driving voltage of the PDP having the 3-electrode structure, _{and the} discharge occurs even when the writing voltage V _W is low. It can also reduce the burden on other peripheral circuits. In addition, the number of sustain pulses can be increased compared to the three-electrode method, thereby making it brighter in terms of luminance.

Description

PDP 4-electrode driving device

The present invention relates to a PDP driving device of a PDP-TV (Plasma Display Panel-Television), and more particularly, a high voltage required for driving a PDP by implementing a four-electrode PDP by adding one more electrode to a conventional three-electrode PDP. The present invention relates to a four-electrode driving device (PDP) of the PDP, which makes it possible to lower the conventional three-pole method.

In general, the electrode structure of a PDP is classified into a DC type, an AC type, and a hybrid type in which a DC type and an AC type are combined. In the case of a direct current type PDP, an electrode is directly exposed to the discharge plasma. In the case of an AC type PDP, the electrode is indirectly coupled with the plasma through a dielectric. As described above, the discharge type represents the direct current type and the alternating current type, and in the case of the AC type, charged particles formed by the discharge are accumulated in the dielectric layer. In other words, electrons are accumulated by 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 this 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 is started again. Therefore, when a sufficiently large wall potential is formed, the discharge is erased because the potential applied to the gas decreases below the potential at which discharge can be maintained. However, if the potential of the potential applied to the external electrode is applied after the wall potential is formed, the potential by the wall potential and the external applied potential are added to discharge even when a low external applied potential is applied. This phenomenon is called a memory function. The AC PDP has a memory function effect due to the wall potential accumulated in the dielectric. In other words, the dielectric in the cell where the discharge was previously formed may cause the charged particles to form a wall potential at the dielectric, thereby causing the discharge at a lower voltage than in a cell without the wall potential.

1 is a cross-sectional view of a conventional three-electrode PDP cell. As shown in FIG. 1, a cross-sectional view of a three-electrode PDP cell includes a front substrate 10, a rear substrate 12, an X electrode 24, a Y electrode 26, a dielectric layer 22, a magnesium oxide 20, The phosphor layer 28, the addressing electrode 14, and the partition 16 are comprised.

On the rear substrate 12, a dielectric layer 22 for forming a capacitively coupled discharge covers the electrode, and two electrodes of the X electrode 24 and the Y electrode 26 are disposed on one substrate, and the X electrode ( A discharge is formed between the 24 and the Y electrode 26. On the other hand, since the discharge occurs on one substrate, there is no ion bombardment in the phosphor layer 18, and there is an advantage that magnesium oxide is not used as the protective layer. However, since the two electrodes of the X electrode 24 and the Y electrode 26 which form a discharge on the same substrate are respectively covered by the dielectric layer 22, the parasitic coupling capacitor value formed on each electrode and the dielectric becomes large. In general, the time constant of the resistor and the capacitor (RC) is increased, the operation speed is lowered, but it is solved by introducing three electrodes that can separate the address operation and the sustain operation.

A necessary condition for forming a discharge is two electrodes, and an electrode structure having three electrodes is mainly used. In the case of the direct current type, an auxiliary anode for forming the auxiliary discharge is added, and in the case of the AC type, the addressing electrode 14 is introduced to separate the selective discharge and the sustain discharge to improve the address speed. 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, a barrier rib shown in a cross-sectional view of the three-electrode PDP cell determines the distance between electrodes for forming a discharge, and serves to prevent crosstalk due to discharge occurring in adjacent cells.

In general, the dielectric material used is boric silicate (borosilicate) series, magnesium oxide (MgO) to protect the dielectric from the plasma because the secondary electron emission coefficient is low and the life is shortened by sputtering by ions generated during plasma formation An oxide thin film as described above is used as a protective film on the dielectric layer 22. The magnesium oxide 20 covered on the dielectric layer exhibits low-voltage discharge characteristics because of good sputter resistance and high secondary electron emission coefficient. However, since the thickness of the magnesium oxide layer should be as thin as thousands of, and the surface characteristics should be excellent, it is difficult to form through thick film printing, and is usually manufactured by a thin film process by vacuum deposition.

The driving operation of the PDP having the electrode structure as described above uses a row driving method using a strong nonlinearity characteristic of gas discharge, unlike a cathode ray tube in which an electron gun sequentially scans pixel by pixel. In addition, the PDP is generally driven by a continuous pulse having a constant voltage, and the gray scale display is implemented by digital rather than analog. However, since gas discharge usually requires a relatively high voltage of several hundred volts, the video signal is amplified and driven.

In addition, the driving operation of the PDP is classified into three types and will be described below for better understanding. Firstly, an addressing or writing mode is a driving operation required for initial discharge formation. In the case of the He + Xe and Ne + Xe penning mixtures commonly used in PDPs, potentials of 240 to 280 volts are applied. The AC type composed of the third electrode reduces the high current caused by the parasitic capacitor caused by the sustain electrode and the dielectric, and adopts a driving method that separates the selection operation from the holding operation.

Secondly, a sustain operation is a driving operation in which the discharge is maintained by a sustain pulse having a lower voltage than the selection pulse by using the memory function characteristic of the gas discharge. In the case of an alternating PDP, a memory driving effect by wall charge is used, and a memory driving method capable of separating a selection operation and a holding operation by using the memory function is used to implement a high quality display device of a large PDP. Provided is a driving method capable of operating without high luminance in high gradation display.

Third, erasing mode (Erasing mode) is an operation mode for erasing the discharge in the case of the AC PDP neutralizes the wall charge to form a discharge at a low voltage to prevent the wall charge is formed sufficiently, or erase with a short pulse width The wall charge is removed by applying a pulse to prevent the wall charge from reaching a steady state.

On the other hand, the driving technology of the PDP is an active light emitting display device in which ultraviolet rays generated from gas discharge excite a fluorescent film to implement an image. That is, since the PDP uses ultraviolet light emission by gas discharge as a light source corresponding to each pixel, the driving circuit merely functions to form or erase gas discharge for each pixel in order to implement a display image. The driving circuit includes an image signal and signal control unit for each pixel constituting an image, and a high speed high voltage switching control unit that can form or eliminate ultraviolet rays generated from each pixel.

In addition, the row driving method refers to a method of simultaneously driving one line of cathode rays. That is, because of the characteristics of the nonlinear line, if a scan pulse is applied to one cathode line and then a data pulse is applied to all the lines of the anode line, the voltage between the selected cathode line and the anode line does not reach the discharge formation voltage, and thus, one pixel scanning method. Compared with the horizontal resolution, the brightness and efficiency are improved. In other words, the row driving method is an essential method for driving a large display, and PDP is advantageous in size because it has a stronger nonlinearity than other display devices.

In the conventional three-electrode PDP panel as described above, the spacing between the electrodes becomes wider as the PDP-TV becomes larger. For example, in a PDP panel having a resolution of 853 x 480, the distance between electrodes becomes 40 inches wider than that of 30 inches. Therefore, when the distance between the electrodes of the PDP panel increases, there is a problem that the voltage to be applied when driving the PDP increases.

The present invention has been made to solve the above problems, an object of the present invention is to have a S ₁ electrode, Y electrode, S ₂ electrodes and addressing electrode in the conventional three-electrode structure having an X electrode, a Y electrode and an addressing electrode The four-electrode structure is used to generate sustain discharge between the S ₁ electrode and the Y electrode of the four-electrode structure, and to generate the sustain discharge between the Y electrode and the S ₂ electrode. It is to provide a four-electrode driving device of the PDP to apply a low driving voltage.

1 is a cross-sectional view showing a three-electrode method of a conventional PDP cell.

2 is a block diagram of a four-electrode PDP and a peripheral circuit of the present invention.

3 is a cross-sectional view of a four-electrode method of the PDP cell shown in FIG.

4 is a waveform diagram according to a driving operation of an AC PDP;

＊ Explanation of symbols on main parts of drawing

50: S ₁ electrode drive unit 60: S ₁ electrode holding drive IC unit

70: S ₂ electrode drive unit 80: S ₂ electrode holding drive IC unit

90: Y electrode driving unit 100: 4 electrode discharge cell

110: addressing driving IC section 120: control circuit section

100a: front substrate 100b: back substrate

100c: address electrode 100d: phosphor layer

110e: bulkhead 100f: magnesium oxide

100g: dielectric layer 100h: S ₁ electrode

100i: Y electrode 100j: S ₂ electrode

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

2 is a block diagram of a peripheral circuit of a PDP and a cell having four electrodes according to the present invention. 2 is a control circuit section for controlling a signal by the system of the present invention;

S ₁ electrode driving portion and connected to the control circuit, the driving electrode S _1;

S ₁ is connected to the electrode and the driving, S and sustain drive IC of the _first electrode portion to the discharge sustain drive operation S ₁ for the electrodes;

S ₂ electrode driving portion and connected to the control circuit, the driving electrode S _2;

Wherein S ₂ is connected to the electrode driver, the sustain electrode S ₂ of the discharge sustain drive operations for the S ₂ sub-electrode driving IC;

A Y electrode driver connected to the control circuit unit to drive a Y electrode;

An addressing driving IC unit connected to the control circuit unit and configured to selectively write on the panel by raising a data stream for image information to an appropriate voltage level; And

S ₁ electrode, S _2-electrode sustain-drive-S ₂ electrode, Y 4 electrode cells of the addressing electrode to be connected to the Y electrode and the addressing drive IC unit which is connected to the electrode driver is connected to the IC unit which is connected to the S _1-electrode sustain-drive-IC unit It provides a four-electrode drive device of the PDP.

According to the invention, the control circuit 120 is applied to the S ₁ electrode driver 50 and the S ₂ electrode drive 70 as a control signal suitable for electrode S ₁ and S ₂ electrode driving. The control signals applied to the S ₁ electrode driver 50 and the S ₂ electrode driver 70 are converted into a predetermined drive signal and applied to the S ₁ electrode holding driver IC unit 60 and the S2 electrode holding driver IC unit 60. do. In addition, the control circuit unit 120 applies a control signal for driving the Y electrode to the Y electrode driver 90, and a control signal for selective writing of the addressing electrode is applied to the addressing driving IC unit 110.

The S _1-electrode sustain-drive-IC unit 60 and the S ₂ and sustain drive IC unit 80 of the electrode is to be applied to a sustain pulse alternately between S ₁ and Y electrodes and the Y and S ₂ electrode, wall charges The driving of the discharge of the formed pixel is started and maintained. In addition, the addressing driving IC unit 110 sequentially receives image data to be written to the PDP panel, and shifts in parallel, thereby loading one line of image data. Since the process should be the same as the input mode operation time of the other temporary storage area, the input mode should be operated at twice the frequency of the output mode.

On the other hand, the S connected to the S ₁ electrode (100h), the first output terminal (80a) of the S _2-electrode sustain-drive-IC unit 80 connected to the first output terminal (60a) of the S _1-electrode sustain-drive-IC unit 60 A cell having four electrodes composed of the _second electrode 100j, the Y electrode 100i connected to the Y electrode driver 90, and the first output terminal 110a of the addressing drive IC unit 110 is displayed in the display area of the PDP panel. Is displayed on the device.

3 is a cross-sectional view of a PDP cell having four electrodes. A cross-sectional view of the four electrodes with respect to the PDP cell of FIG. 3 includes a front substrate 100a, a back substrate 100b, an addressing electrode 100c, a phosphor layer 100d, a magnesium oxide 100f, a dielectric layer 100g, and S. consists of a _first electrode (100h), Y electrodes (100i), S ₂ electrode (80j) and the partition (100e).

In the electrode structure of the AC type PDP shown in FIG. 3, the S ₁ electrode, the Y electrode, and the S ₂ electrode are formed on the back substrate 100a, and the dielectric layer 100g for forming the capacitively coupled discharge is the S ₁ electrode 100h. ), The Y electrode 100i and the S ₂ electrode 80j are covered. In general, the dielectric material used is a borosilicate series, and has a low secondary electron emission coefficient and a short lifetime due to sputtering by ions generated during plasma formation. Is deposited on the dielectric layer 100g as a protective film. In addition, the addressing electrode 100c improves the address speed by separating the selective discharge and the sustain discharge, and employs a method of exciting the phosphor like a cathode ray tube to colorize the PDP. Therefore, the phosphor layer 100d is applied to color the electrode structure of the PDP. Meanwhile, the barrier rib 100e determines the distance between electrodes for forming the discharge and prevents crosstalk due to discharge occurring in adjacent cells.

The four-electrode structure of the PDP configured as described above has a much shorter distance between electrodes than the three-electrode structure, and the four-electrode discharge cell 100 has a first discharge formed between the S ₁ electrode 100h and the Y electrode 100i. In addition, a second discharge is formed between the Y electrode 100i and the S ₂ electrode 100j, and the processes of the first discharge and the second discharge are alternately performed.

4 shows waveforms in which wall potentials are formed in accordance with an applied voltage pulse. 4, V _W represents a write voltage, V _S represents a sustain voltage, and V _a represents an addressing voltage.

On the other hand, the write pulse shown in Fig. 4 may be applied with a sufficient potential equal to or more than the discharge start voltage sufficient to cause gas discharge. However, the method of increasing the applied voltage increases the price due to the increase in power consumption and the high breakdown voltage of the driving circuit element, so it is necessary to select an appropriate voltage for all the pixels of the entire panel. However, when the wall charge is present, the electric potential applied to the external electrode and the electric potential due to the wall charge are added together, so that a discharge is formed at a low voltage. Therefore, the operation (addressing) of discharging without the help of wall charges and the operation (sustain) of discharging at low potentials with the help of wall charges can be separated. In addition, the S ₂ electrode not selected in the waveform diagram consisting of four electrodes continues to maintain the sustain voltage.

As can be seen from the above description, the present invention adopts a four-electrode method of S ₁ electrode, Y electrode and S ₂ electrode in the conventional three-electrode method composed of the X electrode and the Y electrode, which is much shorter than the distance between the conventional three electrodes. do. Therefore, there is an effect that discharge can occur even when the write voltage V _W is low, and the burden on other peripheral circuits can be reduced. In addition, since more sustain pulses can be applied than the three-electrode method, the brightness becomes much brighter.

Claims (3)

In a PDP driving apparatus for displaying an image by applying a discharge sustain signal, an addressing signal, and a discharge voltage to one 4-electrode discharge cell in accordance with a control signal of the control circuit unit 120, The four-electrode discharge cell 100 includes an S ₁ electrode 100h applied from the first output terminal 60a of the S ₁ electrode holding driver IC unit 60 controlled according to the driving signal of the S ₁ electrode driver 50. , S ₂ electrode drive 70 is S ₂ electrode (100j) that is from the first output terminal (80a) of the S _2-electrode sustain-drive-IC unit 80 is controlled according to a drive signal with, The Y electrode 100i applied from the Y electrode driver 90 positioned between the S ₁ electrode 100h and the S ₂ electrode 100j; Crosses the S ₁ electrode 100h, the S ₂ electrode 100j, and the Y electrode 100i at right angles to the addressing electrode 100c applied from the first output terminal 110a of the addressing driving IC unit 110. Done, The control signals of the S ₁ electrode driver 50, the S ₂ electrode driver 70, the Y electrode driver 90, and the addressing driving IC unit 110 are generated by the control circuit unit 120. PDP 4-electrode driver. The method of claim 1, wherein the S ₁ electrode holding driving IC unit 60 and the S ₂ electrode holding driving IC unit 80 are each of n output terminals, that is, (60a, 60b, 60c, ...; 80a, 80b, 80c, ...), wherein the four-electrode driving device of the PDP, characterized in that two electrodes are outputted from each output terminal. The method of claim 1, wherein the four-electrode discharge cell 100 has a first discharge formed between the S ₁ electrode 100h and the Y electrode 100i, and between the Y electrode 100i and the S ₂ electrode 100j. The second discharge is formed in the four-electrode driving apparatus of the PDP, characterized in that the first discharge and the second discharge occurs alternately.