KR20080044704A - Plasma display, and driving device and method thereof - Google Patents

Abstract

A plasma display device and a method and an apparatus for driving the plasma display device are provided to prevent damage to a scan IC by enabling a switching process to normally generate voltage to be delivered to a scan electrode. A plasma display device includes plural first electrodes, a scan circuit(430), first and second capacitors(C1,C2), and a first transistor(Ysc). The scan circuit is connected to the first electrodes. The scan circuit selectively applies first voltages to some of the first electrodes, and applies second voltages to the rest. The first capacitor is charged with a third voltage. A second capacitor is charged with a second voltage from the scan circuit. The first transistor includes a first electrode connected to first terminals of the first and second capacitors, and a second terminal connected to a first voltage source. When the voltage charged in the second capacitor reaches a second voltage, the first transistor performs a switching process so that a charging path is formed and the first capacitor is charged through the charging path.

Description

Plasma display device, its driving device and driving method {PLASMA DISPLAY, AND DRIVING DEVICE AND METHOD THEREOF}

1 is a diagram illustrating a plasma display device according to an exemplary embodiment of the present invention.

2 illustrates a driving waveform of a plasma display device according to an exemplary embodiment of the present invention.

3 is a view illustrating a driving circuit of the scan electrode driver 400 according to an exemplary embodiment of the present invention.

4 is a diagram illustrating waveforms of voltages VscH and VCCF and voltage VCCF2 generated by the operation of a transistor in a scan driver according to an exemplary embodiment of the present invention.

The present invention relates to a plasma display device, a driving device thereof and a driving method.

The plasma display device is a display device using a plasma display panel that displays text or an image by using plasma generated by gas discharge. In the plasma display panel, a plurality of discharge cells are arranged in a matrix form.

In the plasma display device, a plurality of subfields having respective weights are divided and driven. In the address period of each subfield, a scan pulse is sequentially applied to a plurality of scan electrodes to select a cell to be turned on and a cell not to be turned on. In the sustain period, the high level voltage of the sustain discharge pulse Alternately applying a low level voltage performs sustain discharge on the cells to be turned on to actually display the image.

In such a plasma display device, in order to apply scan pulses to a plurality of scan electrodes, a scan integrated circuit (IC) is connected to each scan electrode, and between the ground of the scan integrated circuit and a power supply for supplying a voltage of the scan pulse. The transistor is connected. And the low level of the sustain discharge pulse through the body diode of the transistor connected to the power supply supplying the low level voltage of the sustain discharge pulse when the transistor connected between the ground of the scan integrated circuit and the power supply supplying the voltage of the scan pulse is turned on. Transistors are also formed to block the current path from the power supply for supplying the voltage to the power supply for supplying the voltage of the scan pulse. In this case, the plasma display device uses a DC-DC converter to supply the ground voltage and the scan pulse voltage. When the plasma display device is initially driven, a voltage transmitted from the output terminal of the DC-DC converter may not rise to a constant level. Then, when using the voltage which does not rise to a fixed level, there exists a possibility that the element using this voltage may be damaged. That is, a signal of non-rated level is input to the scanning direct circuit, and there is a risk of damage.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a plasma display device capable of preventing damage to a scan integrated circuit of a plasma display device, a driving device thereof, and a driving method thereof.

According to one aspect of the present invention, a plasma display device is provided. The plasma display device is connected to a plurality of first electrodes and the plurality of first electrodes, respectively, and selectively applies a first voltage to a corresponding first electrode of the plurality of first electrodes during an address period, and then applies the remaining first electrodes. A scan circuit for applying a second voltage to an electrode, a first capacitor for charging a third voltage, a second capacitor for charging a second voltage of the scan circuit, a first terminal at a first end of the first capacitor and the second capacitor And a first transistor having an electrode connected thereto and a second end connected to a first power source, wherein the first transistor starts a switching operation before the voltage charged in the second capacitor becomes the second voltage, thereby charging A path is formed to charge the first capacitor. The scan circuit includes a second transistor and a third transistor, wherein a second voltage is transmitted to a first electrode of the second transistor, and a first voltage is transferred to a second electrode of the third transistor. An intersection point between the second electrode of the two transistors and the first electrode of the third transistor is connected to the first electrode. The charging path further includes a diode having an anode connected to the second power supply and a cathode connected to a second end of the first capacitor. The third voltage is supplied to a driving voltage of the scan circuit. An input terminal is connected to a second end of the first capacitor and an output terminal is connected to the scan circuit. The regulator unit receives the third voltage and scans the third voltage. Adjust the drive voltage to the normal range of the circuit. The first voltage is lower than the second voltage.

According to another feature of the present invention, there is provided a driving device of a plasma display device. A driving apparatus of a plasma display device including a plurality of scan electrodes, the apparatus comprising: a first power source, a first transistor having a first electrode connected to the first power source, and a first end connected to a second electrode of the first transistor And a first capacitor charged with a first voltage, a second capacitor charged with a second voltage, and the first voltage as a driving voltage by a charging path generated according to the switching operation of the first transistor. And a scan circuit for selectively transferring the voltage of the first power supply or the second voltage to a scan electrode, wherein the switching operation of the first transistor begins before the voltage charged in the second capacitor becomes a second voltage. . The scan circuit includes a second transistor and a third transistor, wherein a second voltage is transmitted to a first electrode of the second transistor, a third voltage is transferred to a second electrode of the third transistor, An intersection point between the second electrode of the two transistors and the first electrode of the third transistor is connected to the scan electrode. The charging path further includes a diode having an anode connected to the second power supply and a cathode connected to a second end of the first capacitor. An input terminal is connected to a second end of the first capacitor and an output terminal is connected to the scan circuit. The regulator unit receives the first voltage and converts the first voltage into the scan circuit. Adjust the drive voltage to the normal range. The third voltage is lower than the second voltage

According to still another aspect of the present invention, a method of driving a plasma display device is provided. A driving method of a plasma display device including a plurality of first electrodes and a scanning circuit connected to the plurality of first electrodes, the method comprising: a) charging a first capacitor to a first voltage according to a switching operation of a first transistor; And b) charging a second capacitor having a first end connected to a first input terminal of the scanning circuit, wherein a) is performed in b) in which the second capacitor is connected to a second voltage. Characterized by starting before. The scan circuit further includes driving using the first voltage and selectively transferring the second voltage or the third voltage to the scan electrode. The third voltage is lower than the second voltage.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification. In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

In addition, the wall charge in the present invention refers to a charge formed close to each electrode on the wall (eg, the dielectric layer) of the cell. And the wall charge is not actually in contact with the electrode itself, but is described here as "formed", "accumulated" or "stacked" on the electrode. In addition, the wall voltage refers to the potential difference formed in the wall of the cell by the wall charge.

A plasma display device according to an exemplary embodiment of the present invention will be described in detail with reference to FIG. 1.

1 is a diagram illustrating a plasma display device according to an exemplary embodiment of the present invention.

As shown in FIG. 1, a plasma display device according to an exemplary embodiment of the present invention includes a plasma display panel 100, a controller 200, an address electrode driver 300, a scan electrode driver 400, and a sustain electrode driver 500. It includes.

The plasma display panel 100 includes a plurality of address electrodes (hereinafter referred to as "A electrodes") A1 to Am extending in the column direction, and a plurality of sustain electrodes extending in pairs with each other in the row direction (hereinafter, " X electrodes "(X1 to Xn) and scan electrodes (hereinafter referred to as" Y electrodes ") (Y1 to Yn). In general, the X electrodes X1 to Xn are formed corresponding to each of the Y electrodes Y1 to Yn, and the display for displaying an image in the sustain period between the X electrodes X1 to Xn and the Y electrodes Y1 to Yn. Perform the action. The Y electrodes Y1 to Yn and the X electrodes X1 to Xn are disposed to be orthogonal to the A electrodes A1 to Am. At this time, the discharge space at the intersection of the A electrodes A1 to Am and the X and Y electrodes X1 to Xn and Y1 to Yn forms the cell 12. The structure of the plasma display panel 100 is an example, and a panel having another structure to which the driving waveform described below may be applied may also be applied to the present invention.

The controller 200 receives an image signal from the outside and outputs an A electrode driving control signal, an X electrode driving control signal, and a Y electrode driving control signal. The controller 200 divides and drives one frame into a plurality of subfields, and each subfield is composed of a reset period, an address period, and a sustain period.

The address electrode driver 300 receives an A electrode driving control signal from the controller 200 and applies a display data signal for selecting a discharge cell to be displayed to each A electrode.

The scan electrode driver 400 receives a Y electrode driving control signal from the controller 200 and applies a driving voltage to the Y electrode.

The sustain electrode driver 500 receives the X electrode driving control signal from the controller 200 and applies a driving voltage to the X electrode.

2 illustrates a driving waveform of a plasma display device according to an exemplary embodiment of the present invention. In the following description, only the driving waveforms applied to the Y electrode, the X electrode, and the A electrode forming one cell will be described.

As shown in Fig. 2, in the rising period of the reset period, the voltage of the Y electrode gradually increases from the voltage Vs to the voltage Vset while the X electrode is held at the reference voltage (0 V in Fig. 2). In FIG. 2, the voltage of the Y electrode is shown to increase in the form of a lamp. Then, while the voltage of the Y electrode is increased, a weak discharge (hereinafter referred to as "weak discharge") occurs between the Y electrode and the X electrode and between the Y electrode and the A electrode, and a negative wall charge is applied to the Y electrode. And a positive wall charge is formed on the X and A electrodes.

In the falling period of the reset period, the voltage of the Y electrode gradually decreases from the Vs voltage to the Vnf voltage while the Ve voltage is applied to the X electrode. Then, while the voltage of the Y electrode decreases, a weak discharge occurs between the Y electrode and the X electrode, and between the Y electrode and the A electrode, and the negative wall charges formed on the Y electrode and the positive wall charges formed on the X electrode and the A electrode. Is erased to initialize the discharge cells. In general, the magnitude of the (Vnf-Ve) voltage is set near the discharge start voltage between the Y electrode and the X electrode. As a result, the wall voltage between the Y electrode and the X electrode becomes almost 0 V, whereby a cell that does not have an address discharge in the address period can be prevented from being erroneously discharged in the sustain period.

In the address period, in order to select discharge cells to emit light, scan pulses having a VscL voltage are sequentially applied to a plurality of Y electrodes while a Ve voltage is applied to the X electrodes. Here, the VscL voltage is also called a scan voltage. In this case, Va voltage is applied to the A electrode passing through the cell to be turned on among the plurality of discharge cells formed by the Y electrode and the X electrode to which the VscL voltage is applied. Then, an address discharge occurs between the A electrode to which the Va voltage is applied and the Y electrode to which the VscL voltage is applied, and the Y electrode to which the VscL voltage is applied, and the X electrode to which the Ve voltage is applied, thereby causing a positive wall charge, A, to the Y electrode. Negative wall charges are formed on the electrode and the X electrode, respectively. Here, the VscL voltage may be set at a level equal to or lower than the Vnf voltage. The VscH voltage higher than the VscL voltage is applied to the Y electrode to which the VscL voltage is not applied, and the reference voltage is applied to the A electrode of the discharge cell that is not selected.

Meanwhile, in order to perform this operation in the address period, the scan electrode driver 400 selects a Y electrode to which a scan pulse having a VscL voltage is applied among the Y electrodes Y1 to Yn. For example, in the single drive, the Y electrodes can be selected in the order arranged in the vertical direction. When one Y electrode is selected, the address electrode driver 300 selects a discharge cell to be turned on among discharge cells formed by the corresponding Y electrode. That is, the address electrode driver 300 selects a cell to which an address pulse of Va voltage is applied among the A electrodes A1 to Am.

In the sustain period, a sustain discharge pulse having a high level voltage (Vs voltage in FIG. 2) and a low level voltage (0V in FIG. 2) is applied to the Y electrode and the X electrode in the opposite phase, between the Y electrode and the X electrode of the discharge cell to be turned on. Sustain discharge occurs. Thereafter, the process of applying the sustain discharge pulse to the Y electrode and the X electrode is repeated a number of times corresponding to the weight indicated by the corresponding subfield.

Hereinafter, a scan electrode driver according to an exemplary embodiment of the present invention will be described.

3 is a view illustrating a driving circuit of the scan electrode driver 400 according to an exemplary embodiment of the present invention.

As shown in FIG. 3, the driving circuit of the scan electrode driver 400 includes a DC-DC converter 410, a regulator 420, a scan circuit 430, a transistor Ysc, a capacitor C1, and a capacitor C2. ), Diode D1 and diode D2. A transistor according to an embodiment of the present invention has a gate electrode as a control electrode and a source and drain electrode as two electrodes.

The DC-DC converter 410 receives a voltage Vs transmitted from a switching module power supply (SMPS) and the like, and is connected to a power supply VscL supplying a voltage VscL. Then, the first voltage VscH and the second voltage Vccf are generated using the voltage Vs and the voltage VscL.

The scanning circuit 430 has a first input terminal and a second input terminal, and the output terminal is connected to the Y electrode, and the voltage of the first input terminal and the voltage of the second input terminal to the corresponding Y electrode to select a cell to be turned on in the address period. Optionally applied. In FIG. 3, one scan circuit 430 connected to one Y electrode is illustrated, but there are a plurality of scan circuits 430 respectively connected to the plurality of Y electrodes Y1 to Yn. In addition, a predetermined number of scan circuits may be formed as one integrated circuit (IC), so that a plurality of output terminals of the scan integrated circuit may be connected to a predetermined number of Y electrodes, respectively. In this case, in addition to the predetermined number of scan circuits, the scan integrated circuit is provided with a shift register (not shown) for sequentially outputting control signals to the scan circuits.

The scanning circuit 430 includes transistors Sch and Scl. The source of the transistor Sch and the drain of the transistor Scl are respectively connected to the Y electrode of the panel capacitor Cp. The anode of the diode D1 is connected to the first output terminal OUT1 of the DC-DC converter 410 that supplies the first voltage VscH, and the diode (S) is connected to the first input terminal 431 of the scanning circuit 430. The cathode of D1) is connected. The first end of the capacitor C1 is connected to the cathode of the diode D1, and the second end of the capacitor C1 is connected to the second input terminal 432 of the scanning circuit 430. At this time, the transistor Ysc is turned on, and the capacitor C1 is charged with the voltage (VscH-VscL). The transistor Ysc is connected between the power supply VscL and the second input terminal 432 of the scan circuit 430. In the scan circuit 430, the source of the transistor Ysc is a reference power source. That is, another voltage of the scan circuit 430 is determined based on the source voltage of the transistor Ysc.

In order to supply the control signal to the gates of the transistors Scl and Sch of the scanning circuit 430, a driving voltage for generating the control signal in a shift register (not shown) is required. The voltage charged in the capacitor C2 is used to generate the driving voltage of the scan circuit 430. In this case, the driving voltage required by the scanning circuit 430 may have a predetermined voltage range, and the regulator unit 420 maintains and transmits the driving voltage to be transmitted to the scanning circuit 430 at a predetermined voltage range. Perform. The driving voltage of the scan circuit 430 may be a bias voltage required for the scan circuit 430 to operate. The regulator unit 420 includes a regulator 421 and a buffer 422. The regulator 421 has an input terminal I1, a reference voltage terminal VR, and an output terminal OUT3, and receives the voltage VCCF2 charged in the capacitor C2 as a driving voltage of the scan circuit 430. The change is output to the buffer 422 through the output terminal OUT3. The first terminal of the capacitor C2 is connected to the input terminal IN1 of the regulator 421 and the cathode of the diode D2, and the reference voltage terminal VR of the regulator 421 is connected to the second terminal of the scan circuit 430. It is connected to the input terminal 432. In this case, since the voltage of the capacitor C2 is used to generate the voltage of the scanning circuit 430, the second end of the capacitor C2 is connected to the reference power source of the scanning circuit 430, that is, the source of the transistor Ysc. have. An anode of the diode D2 is connected to the power supply VCCF, and a cathode of the diode D2 is connected to the first end of the capacitor C2. The diode D2 is intended to form a charge path CP for charging the capacitor C2 to the VCCF voltage when the transistor Ysc is turned on, and another element capable of forming a charge path instead of the diode D2 ( For example, a transistor) may be used. At this time, the regulator unit 420 transfers the VDDF voltage which changed the VCCF voltage charged in the capacitor C2 to the scanning circuit 430 through the buffer 422. The buffer 422 transfers the VDDF voltage transferred from the regulator 421 to the scan circuit 430 according to the scan signal. Then, the scan electrode driver scan signal is transferred from the scan electrode driver 400 to the Y electrode in the address period in the address period. Although the scan electrode driver according to the exemplary embodiment of the present invention includes the regulator 420, the regulator 420 may be removed when the power supply VCCF is equal to the driving voltage VDDF.

4 is a diagram illustrating waveforms of voltages VscH and VCCF and voltage VCCF2 generated by the operation of a transistor in a scan driver according to an exemplary embodiment of the present invention.

In Fig. 4, in the conventional driving scheme, the transistor Ysc starts the switching operation from the time point T2. When the plasma display device is in an initial state in which the plasma display device is in a transient state, the switching operation of the transistor Ysc may be abnormally operated due to a malfunction. At this time, the voltage VCCF2 waveform increases to a waveform such as b. Then, at time T3 of the driving waveform generation section, the voltage VCCF2 delivered to the regulator unit 420 becomes an irregular level, and the output voltage of the regulator unit 420 has an unknown level, and the scan circuit 430 A situation arises in which it is not possible to control whether the level of the output signal of the subfield is high or low. In addition, when the switch for outputting the high level signal of the scanning circuit and the switch for outputting the low level are turned on at the same time, the element is broken.

However, in the plasma display device according to the exemplary embodiment of the present invention, the transistor Ysc starts the switching operation at T1, which is a point before the voltage VscH and VCCF waveforms reach the first level OUTH. Then, the voltage VCCF2 input to the regulator unit 420 may increase during the period A based on the start time T3 of the driving waveform generation section.

Then, even if the voltage VCCF2 rises with the same slope as b according to the transient state, the voltage VCCF2 may rise to a sufficiently high level before the time point T3 as in the waveform of the voltage VCCF2. Therefore, the voltage output from the regulator 420 is a voltage in the normal range, the scan circuit operates normally.

The waveform c of the voltage VCCF2 shows the waveform of the voltage VCCF2 in a normal situation in which startup failure does not occur during the initial driving in which the plasma display device is in a transient state.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, the present invention provides a plasma display device and a driving method thereof, which perform a switching operation in advance in order to normally generate a voltage delivered to a scan electrode. Accordingly, the present invention provides a plasma display device, a driving device thereof, and a driving method capable of preventing damage to a scan direct circuit of the plasma display device.

Claims (14)

A plurality of first electrodes, A scanning circuit connected to each of the plurality of first electrodes and selectively applying a first voltage to a corresponding first electrode of the plurality of first electrodes during an address period, and applying a second voltage to the remaining first electrodes , A first capacitor charging a third voltage, A second capacitor charging the second voltage of the scanning circuit, A first transistor having a first electrode connected to a first end of the first capacitor and a second capacitor and a second end connected to a first power source Including; And the first transistor starts a switching operation before the voltage charged in the second capacitor becomes the second voltage, and a charging path is formed, and the first capacitor is charged by the charging path. The method of claim 1, The scanning circuit, A second transistor and a third transistor, The second voltage is transferred to the first electrode of the second transistor, the first voltage is transferred to the second electrode of the third transistor, and the second electrode of the second transistor and the first electrode of the third transistor are And an intersection where the intersection points are connected to the first electrode. The method of claim 2, The charging path is, And a diode having an anode connected to the second power supply and a cathode connected to a second end of the first capacitor. The method of claim 3, wherein And the third voltage is supplied to a driving voltage of the scan circuit. The method of claim 4, wherein And a regulator unit having an input terminal connected to a second end of the first capacitor and an output terminal connected to the scan circuit. The regulator receives the third voltage, and adjusts the third voltage to a driving voltage of a normal range of the scan circuit. The method according to any one of claims 1 to 5, And the first voltage is lower than the second voltage. In the driving device of the plasma display device including a plurality of scan electrodes, First power source, A first transistor having a first electrode connected to the first power source, A first capacitor connected to a second electrode of the first transistor, the first capacitor being charged with a first voltage by a charging path generated according to a switching operation of the first transistor, A second capacitor charged with a second voltage, and A scan circuit receiving the first voltage as a driving voltage and selectively transferring the voltage of the first power source or the second voltage to a scan electrode Including; And the switching operation of the first transistor starts before the voltage charged in the second capacitor becomes the second voltage. The method of claim 7, wherein The scanning circuit, A second transistor and a third transistor, The second voltage is transferred to the first electrode of the second transistor, the third voltage is transferred to the second electrode of the third transistor, and the second electrode of the second transistor and the first electrode of the third transistor are A driving device of the plasma display device, wherein an intersection point of the meeting is connected to the scan electrode. The method of claim 8, The charging path is, And a diode having an anode connected to the second power supply and a cathode connected to a second end of the first capacitor. The method of claim 9, And a regulator unit having an input terminal connected to a second end of the first capacitor and an output terminal connected to the scan circuit. And the regulator unit receives the first voltage and adjusts the first voltage to a driving voltage in a normal range of the scan circuit. The method according to any one of claims 7 to 10, And a driving device of the plasma display device, wherein the third voltage is lower than the second voltage. A driving method of a plasma display device comprising a plurality of first electrodes and a scanning circuit connected to the plurality of first electrodes, a) charging the first capacitor to a first voltage in accordance with the switching operation of the first transistor, and b) charging a second capacitor having a first end connected to a first input end of the scanning circuit, And the step a) starts before the second capacitor reaches a second voltage in step b). The method of claim 12, Driving the scan circuit using the first voltage, and selectively transferring the second voltage or the third voltage to the scan electrode. The driving method of the plasma display device further comprising. The method of claim 13, And the third voltage is lower than the second voltage.

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