KR20050112865A - Plasma display device and driving method thereof - Google Patents

Abstract

The present invention provides a plasma display device and a driving method thereof, wherein a weak waveform is applied by applying a ramp waveform that gradually increases a driving voltage applied to a Y electrode from a first voltage to a second voltage in a sustain period of at least one subfield. Then, the third voltage is applied to the pulse waveform, and at this time, the X electrode is floated or a bias voltage is applied to cause the discharge. Here, desired light may be obtained by adjusting the length of the floating section or the bias voltage.

Description

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

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display device, and more particularly to a method of driving a plasma display panel.

Plasma display devices are flat display devices that display characters or images using plasma generated by gas discharge, and dozens to millions or more of pixels are arranged in a matrix form according to their size. First, a structure of a general plasma display panel will be described with reference to FIGS. 1 and 2.

1 is a partial perspective view of a plasma display panel, and FIG. 2 shows an electrode arrangement diagram of the plasma display panel.

As shown in Fig. 1, the plasma display panel includes two glass substrates 1 and 6 facing each other apart. On the glass substrate 1, the scan electrode 4 and the sustain electrode 5 are formed in pairs and in parallel, and the scan electrode 4 and the sustain electrode 5 are covered with the dielectric layer 2 and the protective film 3. have. A plurality of address electrodes 8 are formed on the glass substrate 6, and the address electrodes 8 are covered with the insulator layer 7. The address electrode 8 and the partition 9 are formed on the insulator layer 7 between the address electrodes 8. In addition, the phosphor 10 is formed on the surface of the insulator layer 7 and on both sides of the partition wall 9. The glass substrates 1 and 6 are disposed to face each other with the discharge space 11 therebetween so that the scan electrode 4, the address electrode 8, the sustain electrode 5, and the address electrode 8 are orthogonal to each other. The discharge space 11 at the intersection of the address electrode 8 and the paired scan electrode 4 and the sustain electrode 5 forms a discharge cell 12.

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

In addition to forming a discharge space, the partition wall blocks light generated during discharge to prevent cross talk of neighboring pixels. A plurality of such unit structures are formed on a single substrate in a matrix form, and a fluorescent material is applied to each unit structure to form one pixel, and the pixels are gathered to form a plasma display panel. Plasma display panels, which are currently commercialized, generate a discharge in each pixel, and excite a fluorescent material coated on the inner wall of the pixel with ultraviolet rays generated by the discharge to realize a desired color.

As shown in FIG. 2, the electrode of the plasma display panel has a matrix structure of n × m. In the column direction, address electrodes A ₁ -A _m are arranged, and in the row direction, n rows of scan electrodes Y ₁ -Y _n and sustain electrodes X ₁ -X _n are arranged in pairs.

In order to achieve the performance as a color display, the plasma display device needs to implement a halftone. Currently, a halftone implementation method of dividing one TV field into a plurality of subfields and controlling the time division is used. have.

3 is a half gray scale implementation method of an AC plasma display panel that is generally applied.

FIG. 3 illustrates a 6-bit gray scale implementation method, in which one TV field is divided into six subfields, and each subfield is divided into an address period and a display discharge sustain period.

In such a plasma display panel, the minimum unit light is represented by a sum of weak reset discharge, address discharge, and sustain discharge. Here, since the reset discharge is weak, it can be said to be mainly expressed by the sum of the address discharge and the sustain discharge.

4 is a view showing a driving waveform of a conventional plasma display device.

In Fig. 4, the pulse wave is applied in the sustain period to cause the strong discharge.

FIG. 5 is a graph illustrating luminance values according to gray levels when strong discharge occurs due to application of pulse waves in a sustain period.

FIG. 6 is a diagram showing weak discharge in a ramp waveform instead of a pulse wave in the sustain period, and FIG. 7 is a graph showing a measurement of luminance at each gray scale by this method.

Referring to FIGS. 5 and 7, when the lamp waveform of FIG. 6 is applied instead of the strong discharge due to the application of the pulse wave in the sustain period, the light discharge may be less than that of the existing unit, thereby reducing the minimum unit light. Able to know.

In addition, when the ramp waveform is applied in the sustain period, the linearity is improved. However, if the luminance at gray scale 1, which is the minimum unit light, is further improved in the graph of FIG. 7, the linearity may be more improved. .

SUMMARY OF THE INVENTION The present invention has been made in an effort to solve the above-described problems of the related art, and is to further improve gray scale linearity by implementing minimum unit light in a combination of a lamp and a pulse wave in a plasma display device.

The plasma display panel according to one aspect of the present invention for solving the above problems,

A plasma display device which receives image data input from an external source and displays data therein,

A first substrate including a plurality of first and second electrodes that are formed in parallel with each other,

A second substrate having a plurality of third electrodes formed in a direction crossing the first and second electrodes,

A driving circuit for supplying a plurality of sustain waveforms including a first sustain waveform to the first electrode to discharge the discharge cells formed by the adjacent first, second and third electrodes,

The drive circuit,

A first interval gently rising from the first voltage to the second voltage,

Applying a first sustain waveform to the first electrode, the first sustain waveform including a second section maintained at a third voltage after rapidly rising from the second voltage to a third voltage,

The second electrode is floated in the second section.

In addition, the plasma display panel according to another aspect of the invention,

A plasma display device which receives image data input from an external source and displays data therein,

A first substrate including a plurality of first and second electrodes that are formed in parallel with each other,

A plurality of third electrodes formed in a direction crossing the first and second electrodes; Second substrate,

A driving circuit for supplying a plurality of sustain waveforms including a first sustain waveform to the first electrode to discharge the discharge cells formed by the adjacent first, second and third electrodes,

The drive circuit,

A first interval gently rising from the first voltage to the second voltage,

Applying a first sustain waveform to the first electrode, the first sustain waveform including a second section maintained at a third voltage after rapidly rising from the second voltage to a third voltage,

And biasing the second electrode to a fourth voltage in the second section.

The driving method of the plasma display panel according to another aspect of the present invention for solving the technical problem,

A plurality of first electrodes and second electrodes formed on the first substrate, and a plurality of third electrodes formed on the second substrate and crossing the first and second electrodes, respectively; A driving method of a plasma display device to which a plurality of sustain waveforms including one first sustain waveform are applied,

The first sustain waveform includes a first section that gently rises from a first voltage to a second voltage, and a second section that is rapidly maintained from a second voltage to a third voltage and then maintained at a third voltage. Applying to one electrode;

Maintaining the second electrode at a fourth voltage in the second section.

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.

8 is a configuration diagram of a plasma display device according to an embodiment of the present invention.

Referring to FIG. 8, 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, and a scan electrode driver (hereinafter referred to as a “Y electrode driver”). 400 and a sustain electrode driver (hereinafter referred to as an 'X electrode driver') 500.

The plasma display panel 100 includes a plurality of address electrodes A1-Am arranged in a column direction, a plurality of sustain electrodes (hereinafter referred to as 'X electrodes') (X1-Xn) and scans arranged in a row direction. Electrodes (hereinafter referred to as 'Y electrodes') Y1-Yn. The X electrodes X1-Xn are formed corresponding to the respective Y electrodes Y1-Yn, and generally have one end connected in common to each other. The plasma display panel 100 includes a glass substrate (not shown) in which the X and Y electrodes X1-Xn and Y1-Yn are arranged, and a glass substrate (not shown) in which the address electrodes A1-Am are arranged. Is done. The two glass substrates are disposed to face each other with the discharge space therebetween so that the Y electrodes Y1-Yn and the address electrodes A1-Am and the X electrodes X1-Xn and the address electrodes A1-Am are orthogonal to each other. At this time, the discharge space at the intersection of the address electrodes A1-Am and the X and Y electrodes X1-Xn and Y1-Yn forms a discharge cell. The controller 200 receives an image signal from the outside and outputs an address driving signal, an X electrode driving signal, and a Y electrode driving signal. The controller 200 divides and drives one frame into a plurality of subfields, and each subfield includes a reset period, an addressing period, and a sustain period. In particular, the control unit 200 causes a weak discharge by slowly increasing the driving voltage applied to the scan electrode from the first voltage to the second voltage in the sustain period of at least one subfield, thereby causing weak discharge. The third voltage is applied to cause strong discharge. The address electrode driver 300 receives an address electrode driving signal from the controller 200 and applies a display data signal for selecting a discharge cell to be displayed to each address electrode A1-Am. The X electrode driver 500 receives an X electrode driving signal from the controller 200 and applies a driving voltage to the X electrodes X1 to Xn. The Y electrode driver 400 receives the Y electrode driving signal from the controller 200 and applies a driving voltage to the Y electrodes Y1-Yn.

The operation of the plasma display device according to the embodiment of the present invention having such a configuration will now be described in detail.

First, the controller 200 receives an externally input image signal, corrects a gamma value according to the characteristics of the plasma display panel, generates the corrected image signal into N subfields, and generates an address electrode driving signal for each subfield. Output

The controller 200 calculates the load ratio of the gamma corrected image signal and generates and outputs an X electrode driving signal and a Y electrode driving signal with a sustain number corresponding to the current load ratio.

In this case, the Y electrode driver 400 generates the waveform shown in FIG. 9 in the sustain period in response to the Y electrode driving signal received from the controller 200.

That is, the Y electrode driver 400 applies a ramp wave having a constant slope to the Y electrode in the sustain period, and then applies a pulse wave for strong discharge.

In this case, higher luminance can be obtained than in the case where only the existing ramp waveform is applied. In addition, as shown in FIG. 9, the amount of strong discharge can be adjusted according to whether or not the width of ΔV is increased or decreased, so that the luminance can be varied.

Therefore, the minimum unit light can be adjusted according to the luminance amount of the upper gradation, so that more accurate gradation linearity can be secured.

FIG. 10 shows gray scale linearity when a minimum unit light has a luminance of about 1.8 cd / m 2 due to a driving waveform that generates a weak discharge by applying a ramp waveform to the Y electrode and then generates a strong discharge by applying a pulse waveform. Referring to FIG. 10, it can be seen that the linearity is improved when compared with the gray scale linearity that implements the minimum unit light using only the ramp waveform.

Here, the X electrode driving signal and the address electrode driving signal are applied in the same waveform as the conventional art. In the case where there are several sustain pulses, the waveform of FIG. 9 is applied to the X electrode to apply the waveform of FIG. The ground level potential or a relatively low potential may be applied. Since such matters can be easily implemented by those skilled in the art from the above description, detailed descriptions are omitted.

In particular, the waveform of the present invention is useful in generating the smallest unit light and can be applied to all sustain pulses as necessary.

In the above-described embodiment of the present invention, the weak and strong discharges are caused by the ramp waveform and the pulse waveform, but this may be modified as necessary, and the weak discharge may be gradually increased by increasing the voltage, and the strong discharge may be rapidly increased by causing the strong discharge. Various variations can be made.

Such modifications will be described as the second and third embodiments.

Since the block diagram is similar to that of FIG. 8, a description thereof will be omitted. Since only the sustain waveform output by the Y electrode driver is modified based on the control signal output from the controller 200, the waveform will be mainly described.

11 is a view showing a driving waveform of the plasma display device according to the second embodiment of the present invention.

Referring to FIG. 11, in the sustain period, a ramp waveform having a constant slope is applied to the Y electrode to generate a weak discharge, and then a pulse wave is applied. Unlike the first embodiment, the X electrode is floated so that no strong discharge occurs.

In this case, luminance lower than that of the waveform of the first embodiment can be obtained.

Further, in the second embodiment, the minimum unit light can be adjusted by adjusting the floating period.

12 is a view showing a driving waveform of the plasma display device according to the third embodiment of the present invention.

Referring to FIG. 12, in the sustain period, a ramp waveform having a constant slope is applied to the Y electrode to generate a weak discharge, and then a pulse wave is applied. Unlike the first embodiment, a bias voltage is applied to the X electrode so that a strong discharge does not occur. Is authorized. At this time, the bias voltage is such that the difference between the voltage applied to the Y electrode and the bias voltage is larger than the discharge start voltage and smaller than the voltage applied to the Y electrode.

In this case, luminance lower than that of the waveform of the first embodiment can be obtained.

Further, in the third embodiment, the minimum unit light can be adjusted by adjusting the bias voltage. If the bias power supply is Ve, it is not necessary to make a new power supply.

The unit light having the desired luminance can be obtained from the second or third embodiment of the present invention, and through a time point for applying a bias to the Y electrode, a time and slope for allocating the lamp, and a time point for biasing the X electrode, etc. A unit light having a desired luminance can be obtained, which can be variously modified.

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 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 desired amount of light can be obtained by controlling the luminance generated in the minimum unit light in the plasma display panel, and the detailed gray scale expression power can be secured.

1 is a schematic partial perspective view of a typical plasma display panel.

2 is an electrode array diagram of a general plasma display panel.

3 is a diagram illustrating a method of implementing gray scales of an AC plasma display device, which is generally applied.

4 is a view showing a driving waveform of a conventional plasma display device.

FIG. 5 is a diagram illustrating luminance according to an increase in gray scale when the pulse waveform of FIG. 4 is applied.

6 is a diagram illustrating the application of the sustain section as a ramp waveform.

FIG. 7 is a diagram illustrating luminance according to an increase in gray level when the ramp waveform of FIG. 6 is applied.

8 is a configuration diagram of a plasma display device according to an embodiment of the present invention.

FIG. 9 is a diagram illustrating applying a pulse waveform after applying a ramp waveform to a sustain period in the plasma display device according to the first exemplary embodiment of the present invention.

FIG. 10 is a diagram illustrating luminance according to gray level increase when a pulse waveform is applied after the ramp waveform is applied to FIG. 9. FIG.

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

12 illustrates driving waveforms of a plasma display device according to a third exemplary embodiment of the present invention.

Claims (9)

A plasma display device which receives image data input from an external source and displays data therein, A first substrate including a plurality of first and second electrodes that are formed in parallel with each other, A second substrate having a plurality of third electrodes formed in a direction crossing the first and second electrodes, A driving circuit for supplying a plurality of sustain waveforms including a first sustain waveform to the first electrode to discharge the discharge cells formed by the adjacent first, second and third electrodes, The drive circuit, A first interval gently rising from the first voltage to the second voltage, Applying a first sustain waveform to the first electrode, the first sustain waveform including a second section maintained at a third voltage after rapidly rising from the second voltage to a third voltage, And plasma the second electrode in the second section. The method of claim 1, And the driving circuit applies a ramp waveform that increases from a first voltage to a second voltage during the first period. The method of claim 2, And the first sustain waveform is applied to the sustain period of the lowest subfield. A plasma display device which receives image data input from an external source and displays data therein, A first substrate including a plurality of first and second electrodes that are formed in parallel with each other, A second substrate having a plurality of third electrodes formed in a direction crossing the first and second electrodes, A driving circuit for supplying a plurality of sustain waveforms including a first sustain waveform to the first electrode to discharge the discharge cells formed by the adjacent first, second and third electrodes, The drive circuit, A first interval gently rising from the first voltage to the second voltage, Applying a first sustain waveform to the first electrode, the first sustain waveform including a second section maintained at a third voltage after rapidly rising from the second voltage to a third voltage, And plasma biasing the second electrode to a fourth voltage in the second section. The method of claim 4, wherein And the driving circuit controls the size of the total light of the subfield by adjusting the length of the second section. A plurality of first electrodes and second electrodes formed on the first substrate, and a plurality of third electrodes formed on the second substrate and crossing the first and second electrodes, respectively; A driving method of a plasma display device to which a plurality of sustain waveforms including one first sustain waveform are applied, The first sustain waveform includes a first section that gently rises from a first voltage to a second voltage, and a second section that is rapidly maintained from a second voltage to a third voltage and then maintained at a third voltage. Applying to one electrode; And maintaining the second electrode at a fourth voltage in the second section. The method of claim 6, And driving the second electrode to maintain the second electrode at a fourth voltage. The method of claim 7, wherein And controlling the length of the floating section to adjust the size of the entire light of the subfield. The method of claim 6, And controlling the magnitude of the total light of the subfield by adjusting the magnitude of the fourth voltage.