KR100684858B1 - Plasma display and driving method thereof - Google Patents

Abstract

A plasma display device and a driving method thereof are provided to improve brightness of the plasma display device by using two electrodes with a variable distance between them for respective sub-fields with different weighted values. A plasma display device includes a PDP(Plasma Display Panel,100), a controller(200), an address electrode driver(300), a sustain electrode driver(400), a switching unit(500), and a scan electrode driver(600). During a sub-field group having sub-fields with low weighted values, the sustain electrode driver applies a sustain discharge pulse, which alternately has high and low level voltages. The sustain electrode driver applies a sustain discharge pulse with the opposite phase to the sustain discharge pulse applied to the sustain electrode driver, to the scan electrode driver. A sustain discharge is performed between two electrodes with small distance between them, so that a low gradation representing performance of the plasma display device is improved.

Description

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

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

FIG. 2 is a partial plan view of the plasma display panel of FIG. 1;

3 is a cross-sectional view taken along line III-III ′ of FIG. 2,

4 is a diagram illustrating an arrangement of subfields according to an embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display device and a driving method thereof, and more particularly, to a method for enhancing low gradation power.

The plasma display device is a device that displays characters or images using plasma generated by gas discharge. In general, a plasma display device is driven by dividing a frame into a plurality of subfields having respective luminance weights. The light emitting cells and the non-light emitting cells are selected during the address period of each subfield, and the sustain discharge is generated by the number of times corresponding to the weight of the subfield in the light emitting cells during the sustain period, thereby displaying an image.

In order to increase the luminance in such a plasma display device, a method of increasing the number of sustain discharges or increasing the luminance by one sustain discharge is required. However, since there is a limit to increasing the number of sustain discharges, a method of increasing the brightness of sustain discharges is used. In general, when the distance between the discharge electrodes (scanning electrode and sustain electrode) is wide in the plasma display device, positive column discharge is formed, thereby improving discharge efficiency. Therefore, the luminance of the sustain discharge can be increased by widening the interval between the discharge electrodes. In this case, however, the luminance of one sustain discharge is so bright that there is a problem in low gradation expression.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a plasma display device and a driving method thereof capable of increasing low gradation power while increasing luminance.

In order to solve this problem, the present invention uses at least two sustain electrodes in one discharge cell.

According to an embodiment of the present invention, a plurality of first electrodes extending in one direction, a plurality of second electrodes, a plurality of third electrodes, first and second drivers, first and second switches, and a controller are included. A plasma display device is provided. The plurality of second electrodes extends at a first interval from the plurality of first electrodes, and the plurality of third electrodes extends at a second interval narrower than the first intervals with the plurality of first electrodes. The first eastern part applies a voltage to the plurality of first electrodes, and the second driver applies a voltage to the plurality of second electrodes and the plurality of third electrodes. The first switch is connected to the plurality of second electrodes, and the second switch is connected to the plurality of third electrodes. The controller selectively connects the first switch and the second switch to an output terminal of the second driver.

In this case, the controller divides one frame into a plurality of subfields having respective luminance weights, and in the first subfield group including at least one subfield among the plurality of subfields, the second switch includes the second switch. The first switch may be connected to an output terminal of the second driver in a second subfield group including at least one subfield different from the first subfield group among the plurality of subfields. .

The luminance weight of the subfield belonging to the first subfield group may be lower than the luminance weight of the subfield belonging to the second subfield group.

According to another embodiment of the present invention, there is provided a plasma display device including a plurality of first electrodes extending in one direction, a plurality of second electrodes, a plurality of third electrodes, first and second drivers, and a controller. . The plurality of second electrodes extends at a first interval from the plurality of first electrodes, and the plurality of third electrodes extends at a second interval narrower than the first intervals with the plurality of first electrodes. The first driver applies a voltage to the plurality of first electrodes, and the second driver selectively applies a voltage to the plurality of second electrodes and the plurality of third electrodes. The controller divides one frame into a plurality of subfields having respective luminance weights, and in at least one first subfield of the plurality of subfields, between the plurality of first electrodes and the plurality of third electrodes. And discharge is formed between the plurality of first electrodes and the plurality of second electrodes in at least one second subfield of the plurality of subfields.

According to another embodiment of the present invention, a plurality of first electrodes extending in one direction, a plurality of second electrodes extending at a first interval with the plurality of first electrodes, and the plurality of first electrodes and the first electrode A driving method of a plasma display device including a plurality of third electrodes extending at a second interval narrower than one interval is provided. The driving method includes dividing a frame into a plurality of subfields having respective luminance weights, wherein the plurality of first electrodes and the plurality of third electrodes are included in at least one first subfield of the plurality of subfields. Generating sustain discharge therebetween, and generating sustain discharge between the plurality of first electrodes and the plurality of second electrodes in at least one second subfield of the plurality of subfields.

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, and like reference numerals designate like parts 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 otherwise stated.

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 schematic conceptual view of a plasma display device according to an exemplary embodiment of the present invention, a partial plan view of the plasma display panel of FIG. 1, and FIG. 3 is a cross-sectional view taken along line III-III ′ of FIG. 2. 4 is a diagram illustrating an arrangement of subfields according to an 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 switching unit 500. ) And a scan electrode driver 600.

1 and 2, the plasma display panel 100 includes a plurality of address electrodes (hereinafter referred to as “A electrodes”) A1-Am and 11 extending in the column direction, and a plurality of second electrodes extending in the row direction. 1 sustain electrode (hereinafter referred to as "first X electrode") (X11-X1n, 21), a plurality of second sustain electrodes (hereinafter referred to as "second X electrode") (X21-X2n, 22) and plural Scan electrodes (hereinafter referred to as "Y electrodes") (Y1-Yn, 23). These first and second X electrodes X11-X1n and X21-X2n are formed corresponding to the respective Y electrodes Y1-Yn. The discharge space at the intersection of the A electrodes A1-Am, the X electrodes and the Y electrodes X11-X1n, X21-X2n, and Y1-Yn forms the discharge cells 110.

2 and 3, the A electrode 11 extends in one direction (y-axis direction in FIGS. 2 and 3) on the substrate 10, and the dielectric layer 12 covers the A electrode 11. It is formed on (10). The A electrode 11 is formed to be parallel to the neighboring A electrode 11 at regular intervals, and the direction in which the A electrode 11 extends (y-axis direction) and the direction orthogonal thereto on the dielectric layer 12 (FIG. 2 and 3, the partition 13 is formed along the x-axis direction. The discharge cells 30R, 30G, 30B and 110 in FIG. 1 are partitioned by the partition wall 13 formed in the lattice shape in this way. The fluorescent layer 14 is formed on the side surface of the partition 13 and the dielectric layer 12, and the red, green, and blue fluorescent layers 14 are formed in the discharge cells 30R, 30G, and 30B, respectively. The color of the discharge cells 30R, 30G, 30B is determined. 2 and 3 illustrate the partition wall 13 in a lattice shape, the partition wall 13 may be formed in a closed structure other than a stripe shape or a lattice shape.

The first X electrode 21, the second X electrode 22, and the Y electrode 23 extend in the direction orthogonal to the A electrode 11 (the x-axis direction of FIGS. 2 and 3) on the substrate 20. The second X electrode 22 is formed closer to the Y electrode 23 than the first X electrode. A transparent dielectric layer 24 and a passivation layer 25 are formed on the substrate 20 while covering the first and second X electrodes 21 and 22 and the Y electrode 23. 2 and 3, the transparent electrodes 26 and 27 may be formed in the first X electrode 21 and the Y electrode 23 in the column direction to secure the discharge region.

In this manner, the distance between the first X electrode 21 and the Y electrode 23 may be longer than the distance between the second X electrode 22 and the Y electrode 23 in the discharge cell. That is, the discharge between the first X electrode 21 and the Y electrode 23 may be stronger than the discharge between the second X electrode 22 and the Y electrode 23.

Referring back to FIG. 1, the controller 200 divides one frame into a plurality of subfields having respective luminance weights, each subfield having an address period for selecting light emitting cells among the plurality of discharge cells 110 and a plurality of subfields. And a sustain period for sustain discharge of the light emitting cell by applying a sustain discharge pulse to the discharge cell. In FIG. 4, for example, one frame includes eight subfields SF1-SF8 having weights of 1, 2, 4, 8, 16, 32, 64, and 128, respectively. The controller 200 determines the total number of sustain discharge pulses allocated to one frame, and allocates the determined total number of sustain discharge pulses to the plurality of subfields SF1-SF8. In this case, the controller 200 may allocate the sustain discharge pulses to the plurality of subfields SF1-SF8 such that the number of sustain discharge pulses allocated to each subfield is proportional to the weight of the corresponding subfield. The control unit 200 applies a driving control signal to the A electrode, the X electrode, and the Y electrode driving units 300, 400, and 600 according to the number of the image signal and the sustain discharge pulse, and supplies the switching signal for each subfield. 500).

The switching unit 500 includes a first switch SW1 connected to the first X electrodes X11-X1n and a second switch SW2 connected to the second X electrodes X21-X2n. The first and second switches SW11 and SW12 respectively switch an output terminal of the X electrode driver 400 and a power supply (a ground terminal in FIG. 1) that supplies a reference voltage.

Specifically, as shown in FIG. 4, the control unit 200 generates a switching signal for forming a discharge to the second X electrodes X21-X2n in the subfields having low weights (for example, SF1, SF2, SF3). Output to the switching unit 500. Then, the switching unit 500 connects the second switch SW2 to the output terminal of the X electrode driver 400 and the first switch SW1 to the ground terminal. In addition, the control unit 200 outputs a switching signal to the switching unit 500 to form a discharge in the first X electrodes X11-X1n in the subfield having a high weight (eg, SF4-SF8). Then, the switching unit 500 connects the first switch SW1 to the output terminal of the X electrode driver 400 and the second switch SW2 to the ground terminal.

That is, in the subfield group including the low-weight subfields SF1-SF3, the X electrode driver 400 generates a sustain discharge pulse alternately having a high level voltage and a low level voltage at the second X electrodes X21-X2n. The Y electrode driver 500 applies a sustain discharge pulse to the Y electrodes Y1-Yn in a phase opposite to that of the sustain discharge pulse applied to the second X electrodes X21-X2n. Then, while the second X electrodes X21-X2n and the Y electrodes Y1-Yn alternately have a high level voltage and a low level voltage, sustain discharge occurs in the light emitting cell. Since the reference voltage is continuously applied to the first X electrodes X11-X1n, no sustain discharge occurs between the first X electrodes X11-X1n and the Y electrodes Y1-Yn. At this time, since the sustain discharge occurs between the two narrow electrodes, the luminance of light emitted by one sustain discharge is low, thereby increasing the low gradation power.

In the subfield group consisting of the high-weight subfields SF4-SF8, the X electrode driver 400 applies the sustain discharge pulse to the first X electrodes X11-X1n, unlike the low-weight subfields SF1-SF3. do. Then, sustain discharge occurs in the light emitting cell while the first X electrodes X21-X2n and the Y electrodes Y1-Yn alternately have a high level voltage and a low level voltage. Since the reference voltage is continuously applied to the second X electrodes X11-X1n, no sustain discharge occurs between the second X electrodes X11-X1n and the Y electrodes Y1-Yn. At this time, since the sustain discharge occurs between the two electrodes having a wide interval, the luminance by one sustain discharge is high and the light emission luminance increases.

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, according to the exemplary embodiment of the present invention, the low gray scale expressive power is increased by using two electrodes having a narrow spacing in the low weight subfield, and the light emission luminance is increased by using two electrodes having a wide spacing in the high weight subfield. Can be.

Claims (10)

A plurality of first electrodes extending in one direction, A plurality of second electrodes extending at a first distance from the plurality of first electrodes, A plurality of third electrodes extending at a second interval narrower than the first intervals with the plurality of first electrodes, A first driver which applies a voltage to the plurality of first electrodes, A second driver which applies a voltage to the plurality of second electrodes and the plurality of third electrodes, A first switch connected to the plurality of second electrodes, A second switch connected to the plurality of third electrodes, and A control unit for selectively connecting the first switch and the second switch to the output terminal of the second drive unit Plasma display device comprising a. The method of claim 1, The controller may be configured to connect the second switch to a power supply for supplying a reference voltage when the first switch is connected to an output terminal of the second driver, and to connect the second switch to an output terminal of the second driver. And a plasma display device for connecting the first switch to the power source. The method according to claim 1 or 2, The controller divides one frame into a plurality of subfields having respective luminance weights, and in the first subfield group including at least one subfield among the plurality of subfields, the second switch includes the second switch. A plasma display device connected to an output terminal and connecting the first switch to an output terminal of the second driver in a second subfield group including at least one subfield among the plurality of subfields; . The method of claim 3, And the luminance weight of a subfield belonging to the first subfield group is lower than the luminance weight of a subfield belonging to the second subfield group. A plurality of first electrodes extending in one direction, A plurality of second electrodes extending at a first distance from the plurality of first electrodes, A plurality of third electrodes extending at a second interval narrower than the first intervals with the plurality of first electrodes, A first driver which applies a voltage to the plurality of first electrodes, A second driver selectively applying voltage to the plurality of second electrodes and the plurality of third electrodes, and A frame is divided into a plurality of subfields having respective luminance weights, and discharge is formed between the plurality of first electrodes and the plurality of third electrodes in at least one first subfield of the plurality of subfields. And a controller configured to form a discharge between the plurality of first electrodes and the plurality of second electrodes in at least one second subfield of the plurality of subfields. Plasma display device comprising a. The method of claim 5, And the first subfield has a luminance weight lower than that of the second subfield. The method according to claim 5 or 6, And the second driver applies a voltage to the plurality of third electrodes in the first subfield, and the second driver applies a voltage to the plurality of second electrodes in the second subfield. A plurality of first electrodes extending in one direction, a plurality of second electrodes extending at first intervals from the plurality of first electrodes, and a plurality of first electrodes extending at a second interval narrower than the first intervals; A driving method of a plasma display device comprising a plurality of third electrodes, Dividing a frame into a plurality of subfields having respective luminance weights, Generating sustain discharge between the plurality of first electrodes and the plurality of third electrodes in at least one first subfield of the plurality of subfields, and Causing sustain discharge between the plurality of first electrodes and the plurality of second electrodes in at least one second subfield of the plurality of subfields; Driving method comprising a. The method of claim 8, The first subfield has a lower luminance weight than the second subfield. The method according to claim 8 or 9, Applying a predetermined voltage to the plurality of second electrodes in the at least one first subfield, and Applying a predetermined voltage to the plurality of third electrodes in the at least one second subfield Driving method further comprising.

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