KR20090121682A - Plasma display, and driving method thereof - Google Patents

Abstract

PURPOSE: A plasma display and a driving method thereof are provided to implement a touch sensing function without increase a size of a plasma display by using a light from each discharge cell of the plasma display panel. CONSTITUTION: A plasma display and a driving method thereof are comprised of the steps: Initializing a plurality of discharge cells for a first reset period; applying a second voltage a plurality of scan electrodes successively for a first period following to the first reset period while applying a first voltage to the plural address electrodes; Initializing the plural discharge cells at a second reset period; and applying the first voltage to the plural address electrodes for a second period following to the second reset period while supplying a second voltage to the plural scan electrodes. Determining a contact position from an outside based on a light generated in the first and the second period.

Description

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

The present invention relates to a plasma display device and a driving method thereof, and more particularly, to a plasma display device having a touch sensing function and a driving method thereof.

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.

The plasma display apparatus drives by dividing one frame into a plurality of subfields having respective luminance weights. The cells are initialized through the reset discharge during the reset period of each subfield, and the light emitting cells and the non-light emitting cells are selected by the address discharge during the address period. In the sustain period, sustain discharge occurs as many times as the number corresponding to the weight of the corresponding subfield in the light emitting cell, thereby displaying an image.

The plasma display panel of the plasma display device is used as an input device that can be input by direct contact with a hand or a pen. There is a method of using infrared rays to implement a touch sensing function in a plasma display panel. As such, in order to implement a touch sensing function in the plasma display panel using infrared rays, an infrared source for emitting infrared rays and an infrared sensor for detecting infrared rays must be additionally mounted on the plasma display device.

In addition, in order to implement a stable touch sensing function in the plasma display panel, an appropriate amount of infrared rays must be uniformly emitted. In this case, in order to emit a uniform amount of infrared rays, there are a method of disposing several infrared sources or a single infrared source away from an object in the plasma display device. However, both these methods increase the volume of the plasma display device.

An object of the present invention is to provide a plasma display device and a driving method thereof capable of implementing a touch sensing function without increasing the volume of the plasma display device.

According to an embodiment of the present invention, each frame is weighted in a plasma display device including a plurality of discharge cells formed by a plurality of scan electrodes extending in a row direction and a plurality of address electrodes extending in a column direction. There is provided a method of driving divided into a plurality of subfields having. The driving method includes the steps of: initializing the plurality of discharge cells in a first reset period in a first subfield of the plurality of subfields; in a first period following the first reset period; Sequentially applying a second voltage to the plurality of scan electrodes in a state where a voltage is applied, initializing the plurality of discharge cells in a second reset period, in a second period subsequent to the second reset period, Sequentially applying the first voltage to the plurality of address electrodes in a state where the second voltage is applied to the plurality of scan electrodes, and based on light generated in the first and second periods. Determining the contact location.

According to another embodiment of the present invention, a plasma display device including a plasma display panel, a controller, and a driver is provided. The plasma display panel includes a plurality of discharge cells by a plurality of row electrodes and a plurality of column electrodes. The controller divides and drives one frame into a plurality of subfields having respective weights, and among the first period and the contact position for determining a vertical position among contact positions from outside of the plurality of subfields. A second period for determining a horizontal position is set, and the contact position from the outside is determined based on light generated during the first and second periods. The driving unit sequentially applies a second voltage to each row electrode of the first group in a state in which a first voltage is applied to the plurality of column electrodes during the first period, and the second electrode is applied to the row electrodes of the second group. And applying a third voltage higher than a voltage, applying the third voltage to the row electrodes of the first group and applying the second voltage to the row electrodes of the second group during the second period. The first voltage is sequentially applied to a column electrode.

According to another embodiment of the present invention, a plasma display in which a plurality of discharge cells are formed by a plurality of row electrodes formed in one direction and a plurality of column electrodes formed in a direction crossing the plurality of first electrodes A method of driving a frame by dividing the frame into a plurality of subfields having respective weights is provided. The driving method may include: initializing the plurality of discharge cells during a first reset period in a first subfield of the plurality of subfields, and generating a first one of the plurality of row electrodes during a first period following the first reset period. Sequentially generating an address discharge between each row electrode of the first group and the plurality of column electrodes, initializing the plurality of discharge cells during a second reset period, each during a second period subsequent to the second reset period Sequentially generating the address discharges at a column electrode and a row electrode of a second group of the plurality of row electrodes, and contacting positions from the outside based on light by the address discharges in the first and second periods. Determining.

According to an embodiment of the present invention, by using the light generated in each discharge cell of the plasma display panel, it is possible to implement a touch sensing function in the plasma display panel without increasing the volume of the plasma display device.

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.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, except to exclude other components unless specifically stated otherwise.

In addition, the wall charge referred to in the present invention refers to a charge formed close to each electrode on the wall of the cell (eg, the dielectric layer). 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. The weak discharge refers to a discharge weaker than the address discharge in the address period and the sustain discharge in the sustain period.

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

1 is a diagram schematically illustrating a plasma display device according to an exemplary embodiment of the present invention, and FIG. 2 is a diagram illustrating a subfield arrangement 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 sustain electrode driver 400, and a scan electrode driver 500. It includes.

The plasma display panel 100 includes a plurality of address electrodes (hereinafter referred to as "A electrodes") A1-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-Xn) and scan electrodes (hereinafter referred to as" Y electrodes ") (Y1-Yn). In general, the X electrodes X1 to Xn are formed corresponding to the respective 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-Yn and the X electrodes X1-Xn are arranged to be orthogonal to the A electrodes A1-Am. At this time, the discharge space at the intersection of the A electrodes A1-Am and the X and Y electrodes X1-Xn and Y1-Yn forms a discharge cell 110 (hereinafter referred to as a cell). 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 driving control signals of the A electrodes A1-Am, the X electrodes X1-Xn, and the Y electrodes Y1-Yn, and one frame is shown in FIG. 2. As described above, driving is performed by dividing into a plurality of subfields having respective luminance weights.

As shown in FIG. 2, one frame is divided into a plurality of subfields SF1-SF11 having respective luminance weights, and gray scales are expressed by a combination of weights of the respective subfields. Each subfield SF1-SF11 includes an address period and a sustain period. In this case, each subfield SF1-SF11 may further include a reset period immediately before the address period. In FIG. 2, one frame is composed of eleven subfields SF1-SF11 having weights of 1, 2, 3, 5, 8, 12, 19, 28, 40, 59, and 78, respectively, representing from 0 gray scale to 255 gray scale. This is illustrated as possible.

The control unit 200 according to an embodiment of the present invention is for determining a contact from the outside instead of an address period and a sustain period in one subfield, for example, a subfield SF1 having the smallest weight. The sensing period is set, and the contact position from the outside is determined based on the light generated during the sensing period.

The address electrode driver 300 applies a driving voltage to the A electrodes A1-Am according to the driving control signal from the controller 200.

The sustain electrode driver 400 applies a driving voltage to the X electrodes X1-Xn according to the drive control signal from the controller 200.

The scan electrode driver 500 applies a driving voltage to the Y electrodes Y1-Yn according to the driving control signal from the controller 200.

3 is a driving waveform diagram of a plasma display device according to a first embodiment of the present invention. The driving waveform of FIG. 3 may be applied to the subfields SF2-SF11. In FIG. 3, the driving waveform of FIG. 3 will be described based on a cell formed by the second subfield SF2 and one A electrode, the X electrode, and the Y electrode. .

In the main reset period of the second subfield SF2, during the rising period, the address electrode driver 300 and the sustain electrode driver 400 bias the A electrode and the X electrode to a reference voltage (0 V voltage in FIG. 3), respectively. The scan electrode driver 500 gradually increases the voltage of the Y electrode from the voltage Vs to the voltage Vset. In FIG. 3, the voltage of the Y electrode is increased 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. At this time, the Vset voltage may be set higher than the discharge start voltage between the X electrode and the Y electrode so that discharge occurs in all cells.

Subsequently, in the main reset period of the second subfield SF2, the sustain electrode driver 400 biases the X electrode to the Ve voltage during the falling period, and the scan electrode driver 500 changes the voltage of the Y electrode at the Vs voltage. Incrementally decreases to Vnf voltage. In FIG. 3, the voltage of the Y electrode is reduced in the form of a lamp. Then, a weak discharge occurs between the Y electrode and the X electrode and between the Y electrode and the A electrode while the voltage of the Y electrode decreases, and the negative wall charge formed on the Y electrode and the positive wall formed on the X electrode and the A electrode. The charge is erased. In general, the Ve voltage and the Vnf voltage are set such that the wall voltage between the Y electrode and the X electrode is nearly 0 V so that the sustain discharge does not occur in the cell that is not selected in the address period. That is, the voltage (Ve-Vnf) is set to about the discharge start voltage between the Y electrode and the X electrode.

Next, in the address period of the second subfield SF2, the sustain electrode driver 400 may select the scan electrode driver 500 and the address electrode driver to select light emitting cells while maintaining the voltage of the X electrode at a Ve voltage. 300 applies a scan pulse having a VscL voltage and an address pulse having a Va voltage to the Y electrode and the A electrode, respectively. The scan electrode driver 500 biases the Y electrode to which the VscL voltage is not applied to a VscH voltage higher than the VscL voltage, and the address electrode driver 300 applies a reference voltage to the A electrode of the non-light emitting cell. In this case, the VscL voltage may be equal to or lower than the Vnf voltage.

Specifically, in the address period, the scan electrode driver 500 and the address electrode bulb 300 apply a scan pulse to the Y electrode (Y1 in FIG. 1) in the first row and simultaneously position A in the light emitting cell in the first row. An address pulse is applied to the electrode. Then, an address discharge occurs between the Y electrode of the first row and the A electrode to which the address pulse is applied, thereby forming positive wall charges on the Y electrode and negative wall charges on the A and X electrodes, respectively. Subsequently, the scan electrode driver 500 and the address electrode driver 300 apply an address pulse to the A electrode positioned in the light emitting cell of the second row while applying a scan pulse to the Y electrode (Y2 in FIG. 1) of the second row. do. Then, address discharge occurs in the cell formed by the A electrode to which the address pulse is applied and the Y electrode of the second row, thereby forming wall charges in the cell. Similarly, the scan electrode driver 500 and the address electrode driver 300 sequentially apply scan pulses to the Y electrodes of the remaining rows, and apply address pulses to the A electrodes positioned in the light emitting cells to form wall charges.

In the sustain period of the second subfield SF2, the scan electrode driver 500 applies a sustain pulse having a high level voltage (Vs in FIG. 3) and a low level voltage (0V in FIG. 3) to the Y electrode. The number of times corresponding to the weight of the field is applied. The sustain electrode driver 400 applies a sustain pulse to the X electrode in a phase opposite to that of the sustain pulse applied to the Y electrode. That is, when the Vs voltage is applied to the Y electrode, 0 V voltage is applied to the X electrode, and when the 0 V voltage is applied to the Y electrode, Vs voltage is applied to the X electrode. In this way, the voltage difference between the Y electrode and the X electrode alternates between the Vs voltage and the -Vs voltage, whereby the sustain discharge is repeatedly generated a predetermined number of times in the light emitting cell.

Next, the third to eleventh subfields SF3-SF11 also initialize the plurality of discharge cells during the reset period in the same manner as in the second subfield SF2, and compare the light emitting cells with the light emitting cells through the address discharge during the address period. The light emitting cells are selected, and sustain discharge is performed on the light emitting cells during the sustain period. In this case, the reset period may be omitted in the second to eleventh subfields SF3-SF11, and an auxiliary reset period may be set instead of the main reset period. The main reset period initiates reset discharge in all discharge cells to initialize all discharge cells, and the auxiliary reset period generates reset discharge only in light emitting cells in which the sustain discharge has occurred in the immediately preceding subfield to reduce the background luminance, so that the sustain discharge is prevented in the immediately preceding subfield. Only the light emitting cells that have occurred are initialized.

Next, referring to FIGS. 4 and 5 for driving waveforms applied to the Y electrodes Y1-Yn, the X electrodes X1-Xn, and the A electrodes A1-Am in the subfield SF1 having the sensing period set therein. This will be described in detail.

4 and 5 are driving waveform diagrams of the plasma display device according to the second and third embodiments of the present invention, respectively.

As shown in FIG. 4, the subfield SF1 in which the sensing period is set includes a first reset period, a vertical position determination period, a second reset period, and a horizontal position determination period. At this time, the vertical position determination period and the horizontal position determination period operate as the detection period.

In the first and second reset periods of the first subfield SF1, the plurality of discharge cells may be initialized in the same manner as in the second subfield SF2 described above, and the second reset period is set as the auxiliary reset period. May be

In the vertical position determination period between the first reset period and the second reset period, the address electrode driver 300 and the sustain electrode driver 400 respectively define the A electrodes A1-Am and the X electrodes X1-Xn, respectively. The voltage is biased to the Ve voltage, and the scan electrode driver 500 sequentially applies the scan pulse of the VscL voltage to the Y electrodes Y1 to Ym. In this case, the scan electrode driver 500 biases the Y electrode to which the VscL voltage is not applied, to the VscH voltage. Then, address discharge occurs sequentially between each of the Y electrodes Y1-Yn to which the VscL voltage is applied and the A electrodes A1 to Am to which the Va voltage is applied.

In the horizontal position determination period immediately after the second reset period, the sustain electrode driver 400 and the scan electrode driver 500 set the X electrodes X1-Xn and the Y electrodes Y1-Yn to Ve voltage and VscL voltage, respectively. The address electrode driver 300 sequentially applies an address pulse of Va voltage to the A electrodes A1 to Am. Then, address discharge occurs sequentially between each of the A electrodes A1-Am to which the Va voltage is sequentially applied and the Y electrodes Y1 to Ym to which the VscL voltage is applied.

As described above, the controller (200 in FIG. 1) determines the vertical / horizontal position of the contact position from the outside by using light due to the address discharge generated in the vertical / horizontal position determination period. In this case, a light receiving element is used to sense the light by the address discharge and deliver it to the control unit 200 of FIG. 1, and a photo diode or a photo transistor may be used as the light receiving element.

That is, when the user contacts the plasma display panel 100 using the light receiving element, the light receiving element detects and transmits the light due to the address discharge generated in the vertical / horizontal position determination period to the controller 200. Then, the controller 200 may detect the vertical / horizontal position of the contact position based on the detection time point of the light.

In addition, as illustrated in FIG. 5, the Y electrode may be driven by dividing the Y electrode into first and second groups in the first subfield SF1. In FIG. 5, only one Y electrode Yodd of the Y group of the first group and one Y electrode Yeven of the Y electrode of the second group are illustrated.

Specifically, in the vertical position determination period, the address electrode driver 300 and the sustain electrode driver 400 bias the A electrodes A1-Am and the X electrodes X1-Xn with Va and Ve voltages, respectively, and scan electrodes. The driver 500 sequentially applies the scan pulse of the VscL voltage to the Y electrode Yodd of the first group. At this time, the scan electrode driver 500 biases the Y electrode to which the VscL voltage is not applied and the Y electrode Yeven of the second group to the VscH voltage among the Y electrodes Yodd of the first group. Then, address discharge occurs sequentially between each Y electrode Yodd of the first group to which the VscL voltage is applied and the A electrodes A1 to Am to which the Va voltage is applied. That is, the vertical position of the contact position can be sufficiently determined even by using the address discharge generated between the Y electrode Yodd of the first group and the A electrodes A1-Am to which the Va voltage is applied by the contact area of the light receiving element. In addition, since the scan pulse is applied only to the Y electrode Yodd of the first group, the vertical position determination period can be shortened as compared with the first embodiment.

In the horizontal position determination period, the sustain electrode driver 400 biases the Ve voltage, and the scan electrode driver 500 biases the first and second groups of Y electrodes Yodd and Yeven to the VscH and VscL voltages, respectively. . The address electrode driver 300 sequentially applies an address pulse having a Va voltage to the A electrodes A1-Am. Then, address discharge occurs between each of the A electrodes A1-Am to which the Va voltage is sequentially applied and the Y electrode Yeven of the second group to which the VscL voltage is applied. Similarly, the address discharge generated between each A electrode A1-Am to which the Va voltage is sequentially applied by the contact area of the light receiving element and each Y electrode Yeven of the second group to which the VscL voltage is applied is sufficient. The contact position from the outside can be determined.

4 and 5 illustrate that the vertical position determination period is positioned between the first and second reset periods and the horizontal position determination period is positioned after the second reset period, but is horizontal between the first and second reset periods. The position determination period may be located and the vertical position determination period may be located after the second reset period.

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.

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

2 is a diagram illustrating a subfield arrangement according to an embodiment of the present invention.

3 to 5 are driving waveform diagrams of the plasma display device according to the first to third embodiments of the present invention, respectively.

Claims (16)

In a plasma display device including a plurality of discharge cells formed by a plurality of scan electrodes extending in a row direction and a plurality of address electrodes extending in a column direction, one frame is driven by dividing one frame into a plurality of subfields having respective weights. In the way, In a first subfield of the plurality of subfields, Initializing the plurality of discharge cells in a first reset period, In the first period following the first reset period, sequentially applying a second voltage to the plurality of scan electrodes while applying a first voltage to the plurality of address electrodes; Initializing the plurality of discharge cells in a second reset period, Sequentially applying the first voltage to the plurality of address electrodes in a state in which the second voltage is applied to the plurality of scan electrodes in a second period following the second reset period, and Determining a contact position from the outside based on light generated in the first and second periods Method of driving a plasma display device comprising a. The method of claim 1, The determining step, Detecting a vertical position of the contact position from light generated in the first period, and Detecting a horizontal position of the contact position from light generated in the second period. The method of claim 2, And the first subfield is a subfield having a minimum weight. The method according to any one of claims 1 to 3, In the plurality of second subfields other than the first subfield among the plurality of subfields, Selecting a light emitting cell and a non-light emitting cell among the plurality of discharge cells in an address period, and Sustain-discharging the light-emitting cell the number of times corresponding to the weight of the second subfield in the sustain period. The driving method of the plasma display device further comprising. The method of claim 4, wherein The selecting step, Sequentially applying the second voltage to the plurality of scan electrodes, and And applying the first voltage to an address electrode of a light emitting cell among the plurality of address electrodes while the second voltage is sequentially applied to the plurality of scan electrodes. The method of claim 4, wherein In at least one second subfield of the plurality of second subfields, Initializing at least one discharge cell of the plurality of discharge cells during a third reset period immediately before the address period; The driving method of the plasma display device further comprising. A plasma display panel including a plurality of discharge cells by a plurality of row electrodes and a plurality of column electrodes, A frame is driven by dividing a frame into a plurality of subfields having respective weights, and a first period for determining a vertical position among contact positions from outside of the plurality of subfields and a horizontal position of the contact positions. A control unit for setting a second period for determining a position, and for determining the contact position from the outside based on light generated during the first and second periods; and In the state where a first voltage is applied to the plurality of column electrodes during the first period, a second voltage is sequentially applied to each row electrode of the first group and higher than the second voltage to the row electrodes of the second group. Applying a third voltage to the plurality of column electrodes while applying the third voltage to the row electrodes of the first group and applying the second voltage to the row electrodes of the second group during the second period. Driver for sequentially applying the first voltage Plasma display device comprising a. The method of claim 7, wherein And the first subfield is a subfield having a minimum weight among the plurality of subfields. The method of claim 8, And the control unit sets a reset period for initializing the plurality of discharge cells immediately before the first period and between the first period and the second period. The method according to any one of claims 7 to 9, The control unit sets reset periods, address periods, and sustain periods in a plurality of second subfields of the plurality of subfields, And the driving unit selects a light emitting cell and a non-light emitting cell among the plurality of discharge cells during the address period, and sustain discharges the light emitting cell by a number of times corresponding to a weight of the second subfield during the sustain period. The method according to any one of claims 7 to 9, The controller receives light generated in the first and second periods from a light receiving element, The light receiving element is a photodiode or phototransistor. In a plasma display device in which a plurality of discharge cells are formed by a plurality of row electrodes formed in one direction and a plurality of column electrodes formed in a direction crossing the plurality of first electrodes, a plurality of frames each having a weight In the driving method divided into subfields of In a first subfield of the plurality of subfields, Initializing the plurality of discharge cells during a first reset period, Sequentially generating an address discharge between each row electrode of the first group and the plurality of column electrodes of the plurality of row electrodes during the first period following the first reset period; Initializing the plurality of discharge cells during a second reset period, Sequentially generating the address discharge at each column electrode and a second group of row electrodes of the plurality of row electrodes during a second period following the second reset period, and Determining a contact position from the outside based on light by the address discharge in the first and second periods Method of driving a plasma display device comprising a. The method of claim 12, In the first period, further comprising sequentially generating an address discharge between each row electrode of the second group and the plurality of column electrodes of the plurality of row electrodes, In the second period, further comprising sequentially generating the address discharge at each column electrode and a row group of a first group of the plurality of row electrodes, In each of the first and second periods, the address discharge is generated alternately between each row electrode of the first group and the plurality of column electrodes and between each row electrode of the second group and the plurality of column electrodes. A method of driving a plasma display device. The method of claim 13, Generating the address discharge sequentially in the first period, Sequentially applying a second voltage to the plurality of row electrodes while applying a first voltage to the plurality of column electrodes, Generating the address discharge sequentially in the second period of time, And sequentially applying the first voltages to the plurality of column electrodes while the second voltages are applied to the plurality of row electrodes. The method of claim 12, Generating the address discharge sequentially in the first period, In the state where a first voltage is applied to the plurality of column electrodes, a second voltage is sequentially applied to each row electrode of the first group, and a third voltage higher than the second voltage is applied to the row electrodes of the second group. Including the steps of: Generating the address discharge sequentially in the second period of time, Sequentially applying the first voltage to the plurality of column electrodes while applying the third voltage to the row electrodes of the first group and applying the second voltage to the row electrodes of the second group. A method of driving a plasma display device. The method according to any one of claims 12 to 15, In each of the remaining second subfields except for the first subfield among the plurality of subfields, Selecting a light emitting cell and a non-light emitting cell among the plurality of discharge cells during an address period, and Sustaining and discharging the light emitting cells a number of times corresponding to a weight of the second subfield during the sustaining period; The driving method of the plasma display device further comprising.

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