KR100739639B1 - Plasma display device and driving method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display device and a driving method thereof. In the initial driving of a plasma display device, a plurality of reset waveforms are applied to a scan electrode to prevent low discharge in an address period. In particular, the number of reset waveforms applied when the temperature of the plasma display panel is high is reduced.

Plasma Display Panel, Initial Drive, Low Discharge, Wall Charge, Discharge Cell, Discharge

Description

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

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

2 is a driving waveform diagram of a plasma display device according to a first embodiment of the present invention.

3 is a diagram illustrating an operation of a controller according to a second exemplary embodiment of the present invention.

4 is a driving waveform diagram when the temperature of the plasma display panel according to the second embodiment of the present invention is high.

The present invention relates to a method of driving a plasma display device including a plasma display panel (PDP).

A plasma display device is a flat display device that displays characters or images by using plasma generated by gas discharge. The display panel may have tens to millions or more of discharge cells (hereinafter, referred to as "cells") depending on its size. Arranged in matrix form.

In general, the plasma display device divides one frame into a plurality of subfields having respective weights, and time-division controls them to implement gray scale.

Each subfield consists of a reset period, an address period, and a sustain period. The reset period is a period for initializing the state of each cell to smoothly perform an address operation on the cell, and the address period is a period for selecting a cell to be turned on from a plurality of cells through address discharge. That is, in the address period, scan pulses are sequentially applied to the plurality of scan electrodes, and address pulses are applied to the address electrodes. At this time, address discharge occurs in a cell to which a scan pulse and an address pulse are simultaneously applied. In the sustain period, sustain discharge pulses having a high level voltage and a low level voltage are alternately applied to the scan electrode and the sustain electrode in opposite phases to generate sustain discharge in a cell to be turned on.

On the other hand, in the reset period, a voltage is sufficiently high between the electrodes to cause discharge to the cells to be initialized, but a voltage is applied to generate weak discharge in order to uniformly control the wall charge state of all cells. The reset period controls the wall charge so that no discharge occurs in the sustain period without the address period.

However, when the power is turned on after the voltage is not applied to the electrodes in the panel, or when the power is turned off and the power is turned on again when the wall charge in the cell is not well defined, the initial operation of the panel ( Low discharge may occur for several seconds at power on. That is, the address discharge is not properly performed in the address period due to the lack of priming particles between the electrodes or the wall charge structure that is not controlled in the reset period.

SUMMARY OF THE INVENTION The present invention has been made in an effort to solve such a conventional problem, and to provide an initial driving method capable of removing low discharge during initial driving of a plasma display panel.

A driving method of a plasma display device according to an aspect of the present invention for achieving the above object is a plurality of first electrodes and a plurality of second electrodes and the plurality of first electrodes and the plurality of second electrodes. The present invention provides an initial driving method applied when a power supply of a plasma display device including a plasma display panel including a plurality of third electrodes formed in a direction to be turned on. In the driving method, during the reset period, the voltages of the plurality of first electrodes are raised from the first voltage to the second voltage, and the third voltages of the plurality of first electrodes are applied while the third voltage is applied to the plurality of second electrodes. And applying at least one or more first reset waveforms for lowering a voltage from a fourth voltage to a fifth voltage, wherein the first reset when the temperature of the plasma display panel and the surrounding temperature is lower than a predetermined first temperature. The number of application of the waveform is different from the number of application of the first reset waveform when the frequency is higher than the first temperature.

According to another aspect of the present invention, a plasma display device includes a plurality of first electrodes, a plurality of second electrodes, and a plurality of third electrodes formed in a direction crossing the plurality of first electrodes and the plurality of second electrodes. A plasma display panel comprising a; A temperature sensing unit sensing a temperature of the plasma display panel; In the reset period, the voltages of the plurality of first electrodes are raised from the first voltage to the second voltage, and the voltages of the plurality of first electrodes are increased from the fourth voltage while a third voltage is applied to the plurality of second electrodes. A driving circuit for applying a first reset waveform to the fifth voltage; And in the initial driving applied when the power is turned on, when the temperature transmitted from the temperature sensing unit is higher than a predetermined first temperature, the first reset waveform is applied N times, and the temperature transmitted from the temperature sensing unit is applied. And a control unit configured to apply the first reset waveform more than N times when the temperature is lower than the first temperature.

DETAILED DESCRIPTION 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. Like parts are designated by like reference numerals throughout the specification.

In addition, the wall charge referred to in the present invention refers to a charge formed in the wall (eg, a dielectric layer) of the discharge cell close to each electrode and accumulated in the electrode. Such wall charges are not actually in contact with the electrodes themselves, but here wall charges are described as "formed", "accumulated" or "stacked" on the electrodes. In addition, wall voltage refers to the potential difference formed in the wall of a discharge cell by wall charge.

A method of driving a plasma display device according to an exemplary embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

First, a plasma display device according to an exemplary embodiment of the present invention will be described with reference to FIG. 1. 1 is a schematic conceptual diagram of 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 panel 100, a controller 200, an address electrode driver 300, a scan electrode driver 400, a sustain electrode driver 500, and the like. It includes a temperature sensor 600.

The plasma panel 100 includes a plurality of address electrodes A1 to Am arranged in the column direction, a plurality of sustain electrodes X1 to Xn arranged in the row direction, and scan electrodes Y1 to Yn.

The controller 200 receives an image signal from the outside and outputs an address electrode A driving control signal, a sustain electrode X driving control signal, and a scan electrode Y driving control signal. The controller 200 divides and drives one frame into a plurality of subfields, and each subfield is represented by a reset period, an address period, and a sustain period. At this time, the controller 200 outputs a control signal for adjusting the number of reset waveforms applied during initial driving according to the temperature of the plasma display panel 100 or the ambient temperature of the plasma display panel received from the temperature sensing unit 600. do.

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

The scan electrode driver 400 receives a scan electrode driving control signal from the controller 200 and applies a driving voltage to the scan electrode. The sustain electrode driver 500 receives the sustain electrode driving control signal from the controller 200 and applies a driving voltage to the sustain electrode.

The temperature detector 600 detects the temperature of the plasma display panel 100 or the temperature around the plasma display panel and transmits the detected temperature to the controller 200. Hereinafter, the temperature sensing unit 600 will be described as sensing the temperature of the plasma display panel for convenience. However, it is natural that the temperature sensing unit 600 can measure the temperature of not only the plasma display panel but also other parts.

2 is a driving waveform diagram of a plasma display device according to a first embodiment of the present invention.

As shown in Fig. 2, each subfield consists of a reset period, an address period, and a sustain period, and the reset period consists of a rising period and a falling period.

In the rising period of the reset period, the scan electrode Y is increased from the Vs voltage to the Vset voltage while the sustain electrode X is held at 0V. Then, a weak reset discharge occurs from the scan electrode Y to the address electrode A and the sustain electrode X, respectively, and a negative wall charge is formed on the scan electrode Y, and the address electrode A and the A positive wall charge is formed on the sustain electrode X.

In the falling period of the reset period, the scan electrode Y is reduced from the Vs voltage to the Vnf voltage while the sustain electrode X is held at the Ve voltage. Then, while the voltage of the scan electrode Y decreases, a weak reset discharge occurs between the scan electrode Y and the sustain electrode X and between the scan electrode Y and the address electrode A. The negative wall charges formed at (Y) and the positive wall charges formed at the sustain electrode X and the address electrode A are erased.

Next, in the address period, a scan pulse having a VscL voltage is sequentially applied to the scan electrode Y to select a discharge cell, and the scan electrode to which the VscL voltage is not applied is biased to the VscH voltage. At this time, the VscL voltage is called a scan voltage and the VscH voltage is also called a non-scan voltage. In addition, an address pulse having a Va voltage is applied to an address electrode A passing through a discharge cell to be selected from among a plurality of discharge cells formed by the scan electrode Y to which the VscL voltage is applied. A) biases to a reference voltage (0V in FIG. 2). Then, an address discharge occurs in the discharge cell formed by the address electrode A applied with the Va voltage and the scan electrode Y with the VscL voltage, and positive wall charges are formed on the scan electrode Y. A negative wall charge is formed in the sustain electrode X. In addition, a negative wall charge is formed on the address electrode A as well.

At this time, the address discharge should be formed at a moment of application of a short voltage of about 2 to 3 kV when the scan pulse and the address pulse are simultaneously applied. However, when the priming particles are insufficient in the cell, the discharge is not easily formed.

Therefore, there is a high possibility that low discharge occurs for a few seconds during the initial driving of the panel which is kept off for a long time. When the wall charge state becomes unpredictable at the time of power-off, even if the panel is turned on immediately, the low charge occurs because the wall charge state formed at the time of panel off cannot be initialized in the reset period. In addition, when the magnitude of the voltage applied in the reset period is small because of contrast ratio or circuit cost reduction, low discharge may occur momentarily during initial driving.

Therefore, in order to prevent such low discharge, a plurality of reset waveforms are applied to the scan electrode Y in the reset period as shown in FIG. 3.

That is, since the wall charges are accumulated between the electrodes during the initial driving of the plasma display device, a reset waveform is applied several times to generate a weak reset discharge between the electrodes several times. By a plurality of reset discharges, a sufficient amount of wall charges are accumulated between the scan electrode Y and the sustain electrode X for the addressing operation. Therefore, as the reset waveform is applied, the amount of wall charge accumulated between the electrodes increases, thereby preventing address low discharge in the address period.

Subsequently, in the sustain period, the sustain discharge pulse of the Vs voltage is sequentially applied to the scan electrode Y and the sustain electrode X. FIG. When the wall voltage is formed between the scan electrode Y and the sustain electrode X by the address discharge in the address period, the discharge occurs at the scan electrode Y and the sustain electrode X by the wall voltage and the Vs voltage. Thereafter, the process of applying the sustain discharge pulse of the Vs voltage to the scan electrode Y and the process of applying the sustain discharge pulse of the Vs voltage to the sustain electrode X are repeated the number of times corresponding to the weight indicated by the corresponding subfield. .

Meanwhile, as described with reference to FIG. 1, the magnitude of the (Vnf-Ve) voltage is set to the discharge start voltage Vfxy between the scan electrode Y and the sustain electrode X. In this case, the plasma display panel temperature changes. Accordingly, the discharge start voltage Vfxy between the scan electrode Y and the sustain electrode X also changes. This is because the conditions for forming magnesium oxide (MgO) covering the scan electrode (Y) and sustain electrode (X), which have the greatest influence in determining the discharge start voltage (Vfxy), are sensitively changed depending on the plasma display panel temperature. In general, when the plasma display panel temperature rises, the discharge start voltage Vfxy decreases, and conversely, when the temperature decreases, the discharge start voltage Vfxy increases. In addition, when the discharge start voltage Vfxy between the scan electrode Y and the sustain electrode X is low, even if a small amount of wall charges accumulate in the selected cell in the address period, sustain discharge can occur properly. Similarly, when the discharge start voltage Vfxy between the scan electrode Y and the sustain electrode X is high, discharge may occur only when a large amount of wall charges are accumulated in the cell to be selected in the address period.

Therefore, when the same number of reset waveforms as at normal temperature are applied regardless of the temperature, the discharge start voltage is lowered at high temperature, so that sustain discharge may occur in a cell not selected in the address period. That is, in the case of a cell corresponding to the scan electrode Y to which a plurality of reset waveforms are applied, since a sufficient amount of wall charges have already been accumulated to cause an address discharge, mis-discharge may occur at a high temperature.

Therefore, in the second embodiment of the present invention, the number of reset waveforms to be applied is determined according to the temperature of the plasma display panel.

Next, operations of the controller 200 in the plasma display device according to the second exemplary embodiment of the present invention will be described in detail with reference to FIGS. 3 and 4.

3 is a view showing the operation of the controller shown in FIG. 1 according to the second embodiment of the present invention, and FIG. 4 is a driving waveform diagram when the temperature of the plasma display panel according to the second embodiment of the present invention is high. to be.

As shown in FIG. 3, the controller 200 receives the temperature of the plasma display panel 100 sensed by the temperature sensor 600 and compares the temperature with a predetermined temperature (S410-S420).

In this case, when the sensed temperature is less than the predetermined temperature, that is, at room temperature, the controller 200 outputs a general control signal for applying N reset waveforms in the reset period (S430).

On the other hand, if the detected temperature is higher than the predetermined temperature, that is, the high temperature, the control unit 200 outputs a control signal for applying a number of reset waveforms less than N in the reset period (S440).

As such, the control signal output from the controller 200 is input to the scan electrode driver 400 and the sustain electrode driver 500 to control the wall voltage between the scan electrode Y and the sustain electrode X during the reset period. (S450).

Here, the predetermined temperature may be obtained through an experimental method as the temperature of the point where the erroneous discharge occurs in the address period or the sustain period, and the detailed description thereof will be omitted since it will be readily understood by those skilled in the art. Generally, the predetermined temperature is measured at about 55 ° C to 60 ° C.

That is, assuming that the reset waveform as shown in FIG. 2 is applied when the temperature of the plasma display panel is room temperature at the time of initializing driving of the plasma display device, the reset waveform is applied as shown in FIG. 4 when the temperature of the plasma display panel is high temperature. Reduce the number of

Although not mentioned in the drawings, when the temperature of the plasma display panel is low, the discharge start voltage is increased, so that a larger number of reset waveforms are applied than at normal temperature to prevent address low discharge.

Although the preferred 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 invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, according to the present invention, the address discharge can be stably generated by adjusting the number of reset waveforms applied according to the temperature at the time of initial driving of the plasma display device.

Claims (6)

A plasma display panel including a plurality of first electrodes, a plurality of second electrodes, and a plurality of third electrodes formed in a direction crossing the plurality of first electrodes and the plurality of second electrodes. In the initial driving method applied at the power-on, In the reset period, The voltages of the plurality of first electrodes are raised from a first voltage to a second voltage, and the voltages of the plurality of first electrodes are increased from a fourth voltage to a fifth voltage while a third voltage is applied to the plurality of second electrodes. Applying at least one time to the first reset waveform to be lowered to; When the number of times of applying the first reset waveform when the temperature of the plasma display panel and the surrounding temperature is lower than the predetermined first temperature is different from the number of times of applying the first reset waveform when the temperature of the plasma display panel and the surrounding temperature is higher than the first temperature, Driving method. The method of claim 1, And when the temperature of the plasma display panel and the surroundings is higher than the first temperature, the number of times of applying the first reset waveform is smaller than that of the lowering of the first temperature. The method of claim 2, And when the temperature of the plasma display panel and the surroundings is higher than the first temperature, the number of times of applying the first reset waveform decreases as the temperature of the plasma display panel and the surroundings increases. A plasma display panel including a plurality of first electrodes, a plurality of second electrodes, and a plurality of third electrodes formed in a direction crossing the plurality of first electrodes and the plurality of second electrodes; A temperature sensing unit sensing a temperature of the plasma display panel; In the reset period, the voltages of the plurality of first electrodes are raised from the first voltage to the second voltage, and the voltages of the plurality of first electrodes are increased from the fourth voltage while a third voltage is applied to the plurality of second electrodes. A driving circuit for applying a first reset waveform to the fifth voltage; And In the initial driving applied at power-on, the first reset when the number of times of applying the first reset waveform when the temperature transmitted from the temperature sensing unit is higher than a first predetermined temperature is lower than the first temperature. And a control unit configured to apply less than the number of times the waveform is applied. The method of claim 4, wherein The control unit, When the temperature transmitted from the temperature sensing unit is higher than the first temperature, the number of times of applying the first reset waveform decreases as the transmitted temperature increases. The method of claim 4, wherein And the first voltage and the fourth voltage have the same voltage level.

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