KR100324265B1 - Method For Driving Plasma Display Panel Of High Frequency - Google Patents

Abstract

The present invention relates to a driving method capable of driving a high frequency plasma display panel by a subframe method.

A method of driving a high frequency plasma display panel according to the present invention includes applying a high frequency signal to a high frequency line from a high frequency generator, applying a first writing pulse to scan lines from a first writing pulse generator, and a second writing pulse. A second writing pulse having a polarity opposite to the first writing pulse and being synchronized with the first writing pulse is applied to the data line from the generator to cause a writing discharge, and is applied to the high frequency line in the discharge cells in which the writing discharge is generated. Generating a high frequency discharge by a high frequency signal, applying a first erase pulse to a scan line supplied with a first writing pulse from a first erase pulse generator, and supplying a second writing pulse from a second erase pulse generator. Second data lines having the same polarity as the first erasing pulse and synchronous with the first erasing pulse I is the pulse is characterized by including the step of maintaining comprising the steps of: erasing a high-frequency discharge, the first and second high-frequency discharge in the discharge cells of erase pulses are not applied to the next writing stage.

Description

Driving Method for High Frequency Plasma Display Panel {Method For Driving Plasma Display Panel Of High Frequency}

The present invention relates to a plasma display device, and more particularly, to a driving method of a high frequency plasma display panel capable of driving a plasma display panel using a high frequency discharge by a subframe method.

Recently, researches on plasma display panels (hereinafter referred to as PDPs), which are easy to manufacture panels as large-area flat panel displays, have been actively conducted according to the needs of large flat panel displays. The PDP uses a gas discharge phenomenon to display an image using visible light generated by vacuum ultraviolet rays generated during gas discharge by emitting phosphors.

Referring to FIG. 1, a structure of a discharge cell configured in a PDP of a three-electrode alternating current (AC) surface discharge method which is commonly used is shown.

In the discharge cell 28 of the PDP shown in FIG. 1, the upper substrate 10 and the lower substrate 12, which are display surfaces of an image, are arranged in parallel by partitions not shown, and a sustain electrode on the upper substrate 10 is provided. A pair, that is, the scan / sustain electrode 14 and the sustain electrode 16 are formed side by side with an upper dielectric layer 18 and a protective layer 20 applied thereon. The address electrode 22 is formed on the lower substrate 12 in a direction perpendicular to the sustain electrode pairs 14 and 16, and the lower dielectric layer 24 and the fluorescent layer 26 are sequentially applied thereon. The discharge gas is injected into the discharge space 21 provided by the partition wall.

The discharge cell 28 having such a configuration is selected by the address discharge between the address electrode 22 and the scan / sustain electrode 16, and then the vacuum ultraviolet rays generated by the continuous sustain discharge between the sustain electrodes 14 and 16 are discharged. The fluorescent material 26 emits visible light. In this case, by adjusting the sustain discharge period, that is, the number of sustain discharges, a gray scale necessary for displaying an image is realized. Accordingly, the number of sustain discharges is an important factor in determining the brightness and discharge efficiency of the PDP. For this sustain discharge, step pulses having a frequency of about 200 to 300 kHz, a pulse width of about 10 to 20 Hz, and a duty ratio of 1 are periodically applied to the sustain electrodes 14 and 16. In this case, the sustain discharge occurs only once at an extremely short instant per sustain pulse. Then, the charged particles generated by the sustain discharge move the discharge paths formed between the sustain electrodes 14 and 16 according to the polarity of the electrodes, so that wall charges are formed inside the discharge space 21 and the discharge space ( The discharge stops while the discharge voltage in 21) decreases. As described above, the sustain discharge by the existing sustain pulse is generated only once at a short time per pulse, and most of the other time is consumed in the preparation of the wall charge and the next discharge, so that the discharge efficiency of the PDP is inevitably low.

Recently, in order to solve the low discharge efficiency problem of the PDP, a method of using a high frequency discharge using a high frequency signal as a display discharge has recently emerged. High frequency discharge is usually generated by high frequency signals in the range of tens of MHz to hundreds of MHz. As the electron vibrates by vibrating electric field, it causes continuous ionization and excitation of discharge gas. It occurs continuously. The high frequency discharge has a physical effect such as a positive column having a very high discharge efficiency when the distance between the electrodes is long in the glow discharge. Accordingly, there is an advantage that can significantly improve the discharge efficiency of the PDP when using a high frequency discharge.

2, there is shown a perspective view showing a discharge cell configured in a high frequency PDP.

The PDP discharge cell shown in FIG. 2 includes a high frequency electrode 50 disposed on the upper substrate 40, an address electrode 44 and a scanning electrode 46 disposed on the lower substrate 42. The upper substrate 40 and the lower substrate 42 are spaced apart from each other in parallel, and the address electrode 44 in the vertical direction and the scan electrode 46 in the horizontal direction are formed on the lower substrate 42. A dielectric layer 48 is formed between the address electrode 44 and the scan electrode 46. The upper substrate 40 is formed with a high frequency electrode 50 to which a high frequency voltage is applied in the same direction as the scan electrode 46. Between the upper substrate 40 and the lower substrate 42, barrier ribs 52 for eliminating optical interference between neighboring discharge cells are formed in a closed block structure. On the surfaces of the upper substrate 40 and the partition wall 52 on which the high frequency electrode 50 is formed, a phosphor 54 for generating visible light of red, green, or blue is coated. Then, the discharge gas is filled in the discharge space therein. In the discharge cell, when the scan voltage is supplied to the scan electrode 46 and the data voltage is supplied to the address electrode 44, the charged particles are generated by address discharge by the voltage difference. Subsequently, the charged particles continuously ionize and excite the discharge gas while vibrating by the high frequency voltage supplied to the high frequency electrode 50, and emits vacuum ultraviolet rays while the excited gas atoms and molecules transition to the ground state. Visible light is emitted by emitting the phosphor 54.

FIG. 3 shows the overall electrode arrangement structure of the PDP constituting the discharge cell shown in FIG.

The PDP shown in FIG. 3 includes address electrode lines X1 to Xm arranged corresponding to each column line, and scan electrode lines Y1 arranged side by side corresponding to each row line. Yn) and high frequency electrode lines RF. The discharge cells 34 are provided at the intersections of the address electrode lines X1 to Xm, the scan electrode lines Y1 to Yn, and the high frequency electrode lines RF.

However, such a high frequency PDP has a problem that it is difficult to stop the high frequency discharge by erasing discharge when using the subframe method, which is one of the driving methods of the PDP. Hereinafter, this problem will be described in detail with reference to the accompanying drawings.

The driving method of the low frequency AC PDP can be roughly divided into a sub-field method and a sub-frame method.

The subfield driving method is a method of driving the PDP separately from the address discharge period and the sustain discharge period. In other words, the subfield driving method utilizes an address discharge period in which all discharge cells arranged in a matrix form are selectively discharged using scan voltage and data voltage, and wall charges and sustain voltages formed in the selected discharge cells are used. In a sustain discharge period to maintain a discharge. In this case, brightness is expressed according to the sustain discharge period, and a plurality of subfields having different brightnesses are combined to implement gradation for one frame. However, since the subfield driving method requires scanning the full screen for each address period of each subfield, the wall charges formed in the discharge cells are nonuniform due to the time required for the address period. As a result, the image quality is deteriorated.

On the other hand, the subframe driving method compensates for the shortcomings of the above-described subfield driving method and drives the PDP so that the address discharge and the sustain discharge coexist without separating the address discharge period and the sustain discharge period like the subfield method. Way. In other words, the subframe driving method continuously supplies a sustain voltage of a constant frequency to the entire PDP so that address discharge occurs in a plurality of scan lines for each cycle of the sustain voltage. In this case, since the long address period is not necessary as in the subfield driving method, the sustain discharge period can be increased by that amount, thereby improving luminous efficiency.

Referring to FIG. 4, the driving order of the PDP according to the subframe driving method is displayed in time for one frame (ie, 16.67 ms).

In FIG. 4, when the PDP has 480 scan lines, the time of one frame is divided by 512 and driven. In detail, 512 sustain pulses are generated in a period of 32 ms during a frame time based on the time axis, and are commonly supplied to scan / sustain electrode lines and sustain electrode lines of the PDP. In addition, eight scan / sustain electrode lines having intervals of T, T / 2, T / 4, T / 8, T / 16, T / 32, T / 64, and T / 128 in one sustain pulse period are selected. Scan pulses for writing data are applied and data pulses are applied to the address electrode lines in synchronization with the scan pulses. Then, in the sustain pulse period, eight scan lines increased by one line are selected from the eight scan lines in which the data is written, and data is written, and in the eight scan lines in which the data is written, the sustain pulses are used. Maintenance discharge will occur. For example, the 128th, 192th, 224th, 240th, 248th, 252th, 254th, and 255th scanning lines are selected in an arbitrary sustain pulse period, and data is sequentially written, followed by 129, 193 in the second sustain pulse period. , 225, 241, 249, 253, 255, and 256th scan lines are selected to sequentially write data. In this manner, eight scanning lines in which data is written for each sustain pulse period are sustained by the sustain pulse until the next data is written.

Referring to FIG. 5, the driving pulses supplied to the sustain electrode lines Z of the scan / sustain electrode lines Y1 to Y480 when shown in the selective erasing method in the subframe driving method are illustrated.

In Fig. 5, scan / sustain electrode lines Y1 to Y480 and sustain electrode lines Z are basically supplied with sustain pulses S having polarities opposite to each other and having a frequency equal to 32 kHz of the video signal. Able to know. Then, a writing pulse W for selecting eight scan lines in one sustain pulse and a scan pulse for writing data sequentially to the scan lines, that is, an erase pulse E, are added to the scan / sustain electrode line. Fields Y128, Y192, ... are supplied. In detail, the writing pulse W is simultaneously supplied to the scan / hold electrode lines Y128, Y192, ... of the eight scan lines to which data is to be written first, so that writing discharge occurs in all the discharge cells of the scan lines. Done. In this case, the writing pulse W is supplied in the form added to the holding pulse S. Subsequently, the erase pulse E added to the next sustain pulse S supplied in a state opposite to the previous one is sequentially supplied to the eight scan electrode lines Y128, Y192, ..., and the data pulses to the address electrode lines. (Not shown) is applied to cause selective erasure discharge. In this case, the discharge cells to which the data pulse corresponding to '0' is applied are turned off by erasing discharge and remain off until the next writing discharge occurs. In addition, the discharge cells to which the data pulse corresponding to '1' is applied maintain the light emitting state by generating a sustain discharge and maintain the light emitting state by the sustain discharge until the next writing discharge occurs. As described above, in the subframe driving method applied to the low-frequency AC type PDP, when the selective erasing method is applied, high voltage writing pulses are simultaneously applied to eight scan lines per sustain pulse period, thereby turning on all the cells of the scan line. Thereafter, only cells without display data selectively cause an erase discharge and cells with display data display an image by maintaining the discharge.

FIG. 6 illustrates driving waveforms applied to the electrode lines shown in FIG. 3 when the above-described subframe driving method of the selective erasure address method is applied to the high frequency PDP as it is.

In FIG. 6, a high frequency voltage is commonly supplied to the high frequency electrode lines RF, and basic pulses having opposite polarities are supplied to the address electrode lines X1 to Xm and the scan electrode lines Y1 to Yn. In addition, the address electrode lines X1 to Xm and the eight scan electrode lines Y128, Y192, Y224, Y240, Y248, Y252, Y254, and Y255 to be selected in any one period of the basic pulse have polarities opposite to each other. The writing pulse W is added to the sustain pulse B and supplied at the same time so that the writing discharge occurs in all the discharge cells of the scan lines. In this case, the high frequency discharge is generated by the high frequency voltage supplied to the high frequency electrode lines RF in the discharge cells in which the writing discharge is generated. Subsequently, positive erase pulses E are sequentially supplied to the eight scan electrode lines Y128, Y192, Y224, Y240, Y248, Y252, Y254, and Y255, and address electrode lines X1 are provided. A selective erase discharge is caused by applying a negative data pulse (D) to ˜Xm). However, since this erase discharge makes it impossible to erase the high frequency discharge, it is impossible to selectively erase according to the data. In other words, in order to erase the high frequency discharge, a voltage capable of attracting and extinguishing electrons is required. When the erase voltage and the data voltage are applied, only the discharge occurs, and the high frequency discharge cannot be erased. Accordingly, there is a difficulty in applying the subframe driving method to the high frequency PDP.

Accordingly, an object of the present invention is to provide a high frequency PDP driving method which can apply a subframe driving method to a high frequency PDP.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing a discharge cell formed in a conventional three-electrode alternating current surface discharge plasma display panel.

2 is a perspective view showing a discharge cell formed in a typical high frequency plasma display panel.

FIG. 3 is an overall electrode layout view of a plasma display panel including the discharge cells shown in FIG. 2.

4 is a diagram illustrating an operation period in chronological order according to a subframe driving method;

5 is a driving waveform diagram for driving a conventional AC plasma display panel by a subframe driving method using a selective erasure address method;

6 is a conventional driving waveform diagram for driving a high frequency plasma display panel by a subframe driving method using a selective erasure address method;

7 is a driving waveform diagram applied to a high frequency plasma display panel driving method according to the present invention;

FIG. 8 is a view showing details of a driving waveform during one period in which data is written to any of eight scan lines in FIG. 7; FIG.

9 is a view illustrating an erase principle applied to a method of driving a high frequency plasma display panel according to the present invention;

<Brief description of symbols for the main parts of the drawings>

10, 40: upper substrate 12, 42: lower substrate

14, 46: scanning electrode 16: sustaining electrode

18, 48, 54: dielectric layer 20, 56: protective layer

22, 44: address electrodes 26, 54: phosphor

21: discharge space 28, 34: discharge cell

50: high frequency electrode 52: partition wall

In order to achieve the above object, the high frequency PDP driving method according to the present invention comprises the steps of applying a high frequency signal from the high frequency generator to the high frequency line, the first writing pulse from the first writing pulse generator to the scanning lines, A second writing pulse having a polarity opposite to the first writing pulse and being synchronized with the first writing pulse from the second writing pulse generator to the data line is applied to cause a writing discharge, and a high frequency in the discharge cells in which the writing discharge is generated. Generating a high frequency discharge by a high frequency signal applied to the line, applying a first erasing pulse to a scan line supplied with a first writing pulse from the first erasing pulse generator, and a second from the second erasing pulse generator The writing pulses have the same polarity as the first erasing pulse and are synchronized with the first erasing pulse. A second erase pulse is applied to is characterized in that it comprises the step of maintaining comprising the steps of: erasing a high-frequency discharge, first and second high-frequency discharge in discharge cells that are not applied with the second erase pulse to the next writing stage.

Other objects and advantages of the present invention in addition to the above object will be apparent from the description of the preferred embodiments of the present invention with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 7 to 9.

FIG. 7 illustrates a driving waveform applied to a high frequency PDP driving method according to an embodiment of the present invention. In the case of driving the high frequency PDP shown in FIG. The drive waveform supplied is shown.

In FIG. 7, high frequency voltages are commonly supplied to the high frequency electrode lines RF, and first and second basic pulses B1 and B2 having arbitrary periods are provided to the scan electrode lines Y1 to Yn. Supplied. Then, while the first basic pulse B1 is applied (A), a writing pulse W for selecting eight scan lines is supplied. Subsequently, while the second basic pulse B2 is applied (C), scan pulses for writing data sequentially to the eight scan lines, that is, erase pulses E, are supplied to the eight scan electrode lines. In detail, while the first basic pulse B1 is applied (A), the writing pulses W having opposite polarities are simultaneously supplied to the address electrode lines X1 to Xm and the eight scan electrode lines to be selected. Writing discharge occurs in all the discharge cells of the scan lines. In this case, the writing pulses W supplied to the eight scan electrode lines are supplied in the form of being added to the first basic pulse B1. The discharge cells in which the writing discharge is generated generate high frequency discharge by a high frequency voltage supplied to the high frequency electrode lines RF. Subsequently, while the second basic pulse B2 is applied (C), the positive erase pulse E is sequentially supplied to the eight scan electrode lines, and the address electrode lines X1 to Xm are provided. By applying the same positive data pulse (D) to, the selective discharge erasing is performed. In this case, the space electrons involved in the high frequency discharge in the discharge cell to which the positive polarity (+) erase voltage and the data voltage are applied are attracted to the scan electrode to be extinguished so that the high frequency discharge is erased. Accordingly, in the discharge cells to which the data voltage corresponding to '0' is applied, the high frequency discharge is erased and turned off, and is maintained until the next writing discharge occurs. In addition, in the discharge cells to which the data voltage corresponding to '1' is applied, high frequency discharge is generated to maintain the light emitting state, and the light emitting state is maintained by high frequency discharge until the next writing discharge occurs. Then, the corresponding data is written in the same manner as above in eight scan lines increased by one line from the eight scan lines while the first and second basic pulses B1 and B2 of the next period are applied. As described above, according to the driving method of the high frequency PDP of the present invention, after the first and second basic pulses B1 and B2 are applied, eight scanning lines are selected to start high frequency discharge, and then only discharge cells having no display data. Optionally, the high frequency discharge is canceled and the cells with the display data display the image by maintaining the high frequency discharge.

FIG. 8 illustrates in detail the driving waveform during one period in which data is written to any of eight scan lines in FIG. 7.

In FIG. 8, a high frequency voltage is commonly supplied to the high frequency electrode lines RF, and scan electrode lines Y128, Y192, Y224, Y240, Y248, Y252, Y254, and Y255 of eight scan lines to be selected. The first and second basic pulses B1 and B2 are supplied to the. While the first basic pulse B1 is applied, the positive writing pulse W is applied to the eight scan electrode lines Y128, Y192, Y224, Y240, Y248, Y252, Y254, and Y255. The addition and supply at the same time and the negative (-) writing pulse (W) is applied to the address electrode lines (X1 ~ Xm), the writing discharge occurs in all the discharge cells of the eight scan lines. In this case, the voltage supplied to the scan electrode lines Y128, Y192, Y224, Y240, Y248, Y252, Y254, and Y255 at the writing time set to Tw is the sum of the first base voltage B1 and the writing voltage W. It is set to about 300V or more, and the voltage supplied to the address electrode lines X1 to Xm is set to about -100V. As a result, writing discharge occurs instantaneously in all the discharge cells of the eight scan lines. Subsequently, the space electrons generated by the writing discharge are subjected to the high frequency discharge by the high frequency voltage supplied to the high frequency electrode lines RF. Next, a positive erase pulse E is applied to the eight scan electrode lines Y128, Y192, Y224, Y240, Y248, Y252, Y254, and Y255 while the second basic pulse B2 is applied. Is sequentially supplied, and the same positive data pulse D is applied to the address electrode lines X1 to Xm to selectively discharge the discharge. Accordingly, the high frequency discharge of the discharge cells having no display data in the eight scan lines is erased, and only the cells having the display data are maintained at the high frequency discharge. In this case, it is preferable that the width Te of the erase pulse E supplied to one scan electrode line is usually set to 1 m or less, and the voltage is set smaller than the voltage of the writing pulse W. As described above, when the high frequency PDP is driven by the subframe method using the selective erasure address method, data is written using an erase pulse having a relatively small width, thereby reducing the time for writing the data, that is, the address time. It is possible to improve the luminous efficiency by increasing the discharge time.

9 shows the principle of high frequency discharge erasing in any discharge cell.

As shown in FIG. 9, a positive data voltage and an erase voltage are applied to a scan electrode 46 and an address electrode (not shown) disposed on a lower plate in an arbitrary discharge cell in which a high frequency discharge is generated. In this case, the space electrons involved in the discharge in the discharge space are attracted to the scan electrode 46. The electrons attracted toward the scan electrode 46 are neutralized and dissipated by the dielectric polarization charge generated in the dielectric layer 58 by the positive polarity of the scan electrode 46. In this case, when the erase voltage is continuously applied, that is, when the width of the erase pulse is large, electrons may be generated that may be caused by the high frequency voltage again due to the influence between the wall charge and the erase voltage, the wall charge and the data voltage. do. Therefore, the width of the erase pulse must be short.

As described above, according to the high frequency PDP driving method according to the present invention, the high frequency PDP can be driven by the subframe method using the selective erasure address method. Accordingly, according to the high frequency PDP driving method according to the present invention, since the data is written using an erase pulse having a relatively small width, the data writing time, that is, the address time is reduced, thereby increasing the high frequency discharge time. The efficiency can be improved.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (6)

A plasma display panel driving method comprising a plurality of high frequency lines, a scanning line, and a data line, and sequentially scanning n (n is an integer of 1 or more) in order of a binary operation, Applying a high frequency signal from the high frequency generator to the high frequency line; Applying a first writing pulse to the scan lines from a first writing pulse generator; Applying a second writing pulse from the second writing pulse generator to the data line, the second writing pulse having a polarity opposite to the first writing pulse and causing writing discharge; Generating a high frequency discharge by the high frequency signal applied to the high frequency line in the discharge cells in which the writing discharge is generated; Applying a first erase pulse to the scan line supplied with the first writing pulse from a first erase pulse generator; The second erase pulse having the same polarity as the first erase pulse and a second erase pulse synchronized with the first erase pulse are applied to the data lines supplied with the second writing pulse from the second erase pulse generator to erase the high frequency discharge. To do that, And maintaining the high frequency discharge until the next writing step in the discharge cells to which the first and second erase pulses are not applied. The method of claim 1, And a first writing pulse supplied to the scan line in a form added to a basic pulse having a predetermined level. The method of claim 1, And a first erasing pulse supplied to the scan line in a form added to a basic pulse having a predetermined level. delete delete delete