KR100577158B1 - Method Of Driving Plasma Display Panel Using High Frequency And Apparatus Thereof - Google Patents

Abstract

The present invention relates to a method and apparatus for driving a plasma display panel using a high frequency that can prevent the occurrence of contour noise.

A plasma display panel driving method using a high frequency of the present invention is characterized in that the scanning lines of the panel are scanned in units of horizontal periods, and during the horizontal periods, a data triggering signal having a time difference and initiating a high frequency discharge is provided during the horizontal periods. It is done.

According to the present invention, since gray scales are displayed while scanning the scan lines sequentially, contour noise does not occur, and the circuit configuration is simplified since only the analog signals are sampled and only a driving signal corresponding to the level of the sampled image signal is supplied. do.

Description

Method and apparatus for driving plasma display panel using high frequency {Method Of Driving Plasma Display Panel Using High Frequency And Apparatus Thereof}             

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 configured in a conventional plasma display panel using a high frequency wave.

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

4 is a block diagram showing a conventional plasma display panel driving apparatus using a high frequency wave.

5 is a view showing a plasma display panel driving method using a high frequency according to the present invention.

FIG. 6 is a waveform diagram showing details of a driving signal supplied during one horizontal scanning period in FIG. 5; FIG.

7 is a driving waveform diagram illustrating a method of driving a plasma display panel using high frequency according to an embodiment of the present invention.

8 is a block diagram illustrating a plasma display panel driving apparatus using high frequency according to an embodiment of 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: dielectric layer 20: protective layer

22, 44: address electrodes 26, 54: phosphor

21: discharge space 28, 34: discharge cell

50: high frequency electrode 52: partition wall

60, 72: A-D converter 62: multiplexer

64: frame memory 65: memory controller

66: demultiplexer 68, 78: data driver

70, 80: PDP 74: Line memory

76: controller

The present invention relates to a plasma display device, and more particularly, to a method and apparatus for driving a plasma display panel using a high frequency that can prevent the occurrence of contour noise.

Recently, research on plasma display panels (hereinafter referred to as PDPs), which are easy to manufacture panels as large-area flat panel displays, has been actively conducted according to the needs of large flat panel displays. The PDP generally uses a gas discharge phenomenon to display an image using visible light generated by vacuum ultraviolet rays generated during gas discharge to emit 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, an upper substrate 10 and a 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. The charged particles generated by the sustain discharge move the discharge paths formed between the sustain electrodes according to the polarities of the electrodes, so that wall charges are formed in the discharge space of the cell, and the discharge voltage in the discharge space decreases due to the wall charges. Will stop. 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 is possible to cause continuous discharge. 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 PDP using a high frequency.

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 50 is provided 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 for eliminating optical interference between adjacent discharge cells are formed in a block-shaped structure. On the surface of the upper plate 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 phosphors.

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.

The high frequency PDP is usually driven by an ADS (Address and Display Separation) driving method. The ADS driving method is a method of driving a PDP by separating an address period and a display period, that is, a high frequency discharge period. In this case, one frame is divided into eight subfields corresponding to each bit of 8-bit video data, and each subfield is further divided into an address period and a display period. Here, the address period of each subfield is the same and 1: 2: 4: 8:... The gray scale is represented by a combination of display periods by giving a weight of: 128 ratio. The display order of the subfield periods corresponding to each bit is also in the order of SF1, SF2, SF3, SF4, SF5, SF6, SF7, SF8. As such, since the PDP displays an image by superimposing light emitted by the discharge time modulation method, there is a problem in that contour noise is generated due to a mismatch between the integration direction of the light assumed in the driving method and the visual characteristics recognized by the human eye. . Contour noise is usually observed between white and black bands between frames, and occurs when levels with very different periods between emission patterns are displayed continuously, for example, between levels 127-128, 63-64, 31-32. It is becoming. Here, when the frame displaying 127 and the frame displaying 128 are adjacent to each other, the frame displaying 127 emits light during the second to seventh subfields. Subsequently, in the next frame displaying 128, it is turned off during the first to seventh subfield periods, and then emits light only in the eighth subfield corresponding to 128. In this way, black bands are observed between the two frames as the light emission patterns become longer due to the first to seventh subfield periods that are turned off even though the brightness level difference between the frames is not large. In addition, bright bands are observed between the two frames varying from 128 to 127 due to the same cause. Such contour noise usually occurs most frequently when the chromosome moves. In particular, when displaying a color image, the contour noise may cause a problem in that the image is deteriorated due to unbalanced colors.

For this reason, the contour noise is minimized by rearranging the display order of the subfields so as not to be large between the light emission patterns or by rearranging the eighth subfield period corresponding to 128 by two-half 64-64. However, since this requires a rearrangement process using a complicated memory circuit, the configuration of the data driving circuit is complicated.

FIG. 4 is a block diagram showing a conventional PDP data driving device. The data driving device of FIG. 4 is an analog-to-digital converter (hereinafter referred to as 'A-D') converter 60 for sampling an input analog video signal. ), A multiplexer 62 for converting the sampling signal input from the AD converter 60 into 8-bit video data, a frame memory 64 for temporarily storing the video data input from the multiplexer 62, and a frame memory. From the memory controller 65 for rearranging and outputting the image data of 64, the demultiplexer 66 for separating and outputting the image data output from the memory controller 65 by the same bit, and from the demultiplexer 66. And a data driver 68 for outputting a driving pulse according to the input image data to the PDP 70.

In the high frequency PDP data driving apparatus shown in FIG. 4, the A-D converter 60 samples and outputs an input analog video signal. The multiplexer 62 converts the sampling signal input from the A-D converter 60 into 8-bit image data and outputs it. The frame memory 64 temporarily stores image data input from the multiplexer 62. In this case, the frame memory 64 has a capacity for storing video data of one frame. The memory controller 65 rearranges and outputs image data output from the frame memory 64. When the subfields need to be divided and rearranged to minimize the contour noise, a memory controller 65 having a complicated circuit configuration is required. The demultiplexer 66 separates and outputs image data input from the memory controller 65 for each bit. In this case, the image data output from the memory controller 65 is continuous with single bits corresponding to the same subfield. For example, when the PDP 70 is driven during the lowest subfield period having the smallest weight, the video signal supplied to the data driver 68 is continuous with pixel data of least significant bit (LSB). The data driver 68 drives the address electrode lines on the PDP 70 by the pixel data input from the demultiplexer 66.

As described above, the conventional PDP data driving circuit has a complicated configuration.

Accordingly, an object of the present invention is to provide a method and apparatus for driving PDP using high frequency which can eliminate the contour noise problem by removing the cause of contour noise in advance by displaying gray scales while sequentially scanning.

Another object of the present invention is to provide a PDP driving method and apparatus using a high frequency that can simplify the configuration of the data driving circuit.

In order to achieve the above objects, the PDP driving method using the high frequency according to the present invention scans the scanning lines of the panel in the horizontal period unit, and during the horizontal period has a time difference according to the brightness level of the image signal and triggers the high-frequency discharge It is characterized by supplying a signal.

A PDP driving apparatus using a high frequency according to the present invention includes a sampling means for sampling an input analog video signal, a storage means for temporarily storing the sampled video signal in scan line units, and a stored sampling video signal at a luminance level. And control means for generating drive signals rearranged according to the luminance level and having a time difference according to the luminance level, and data driving means for supplying data triggering signals according to the drive signals to the data electrode lines of the panel.

Other objects and advantages of the present invention in addition to the above object will become apparent from the description of the preferred embodiment 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. 5 to 8.

5 shows a high frequency PDP driving method according to the present invention.

5, the high frequency PDP driving method according to the present invention implements gradation by a sequential scanning method in the same manner as the conventional cathode ray tube (CRT) driving method. In other words, the scan lines are sequentially selected and corresponding gray levels are implemented within the selected time. This is possible because the high frequency PDP has a significantly higher discharge efficiency than the existing low frequency AC PDP. In detail, the scan signals SS1 to SSn are sequentially supplied to the n scan electrode lines Y1 to Yn as shown in FIG. 3 and the image is in one horizontal period 1H in which any one scan signal is supplied. According to the luminance level of the signal, a data triggering signal DTS for starting high frequency discharge is supplied to m address electrode lines X1 to Xm at different supply points. In this case, the high frequency signal RF is supplied to the high frequency electrode lines RF. Accordingly, gray scales can be expressed by adjusting the high frequency discharge time by varying the supply timing of the data triggering signal DTS according to the luminance level.

Referring to FIG. 6, a driving waveform supplied to display 256 gray scales during a period in which a scanning signal of one horizontal period 1H is supplied to the i-th scan electrode line is shown.

In FIG. 6, it can be seen that 256 data triggering signals DTS255 to DTS0 are required to display all 256 gray levels during one horizontal period. In the case of displaying the brightest 255 level, a data triggering signal DTS255 is applied, which can start high frequency discharge at the start of one horizontal period 1H. In the discharge cells to which the data triggering signal DTS255 is supplied, a discharge occurs due to a voltage difference between the data triggering signal DTS255 and the scan signal SSi, and the charged particles generated by the discharge generate a high frequency signal RFS. This causes high frequency discharge for almost one horizontal period (1H), whereby 255 luminance levels can be displayed. In addition, when displaying 254 levels, the data triggering signal DTS254 shifted by one step is applied to the data triggering signal DTS255 for displaying the 255 level, and when the luminance level 0 is displayed, the data triggering signal DTS is applied. The data triggering signal DTS0 is applied at the end of one horizontal period 1H that is not supplied. As such, the data triggering signals DTS255 to DTS0 are supplied according to the luminance level to be displayed during one horizontal period 1H in which the corresponding scan electrode line is selected, thereby adjusting the high frequency discharge period to display gray scales. In this case, the high frequency signal RFS, which is commonly supplied to the high frequency electrode lines RF, should be a power below a threshold that does not generate high frequency discharge with its own power. Therefore, high frequency discharge can be started only with the help of the wall charges accumulated by the data triggering signals DTS255 to DTS0 for gray scale implementation. The high frequency signal RFS is continuously supplied, and an erase signal is applied to the scan electrode lines Y1 to Yn every one horizontal period 1H, thereby stopping the high frequency discharge. In addition, it is possible to stop the high frequency discharge by turning on the high frequency signal RFS at the start point of the scan signal SS of one horizontal period 1H and turning off the high frequency signal RFS at the end point. As a result, in the high frequency PDP driving method of the present invention, the gradation can be realized by supplying the high frequency signal RFS only during one horizontal period 1H.

7 illustrates a driving waveform applied to a high frequency PDP driving method according to an embodiment of the present invention.

First, the scan signal SS1 is supplied to the first scan electrode line Y1, and the luminance is applied to the m address electrode lines X1 to Xm during one horizontal period 1H to which the scan signal SS1 is supplied. Depending on the level, the data triggering signals DTS255 to DTS0 along the driving time point are supplied. When the data triggering signals DTS255 to DTS0 are applied, a discharge is generated, and a high frequency discharge is performed using the high frequency signal RFS supplied to the charged particles generated at the discharge and the high frequency electrode lines RF. After the one horizontal period 1H ends, the erase signal ES is supplied to the first scan electrode line Y1 to stop the high frequency discharge. In this manner, the scan signals SS2, SS3, ... shifted by one horizontal period are supplied to the remaining scan electrode lines Y2, Y3, ..., and the data triggering signals DTS255 to DTS0 according to the luminance level are supplied. Therefore, by adjusting the high frequency discharge period, it is possible to realize gradation while performing sequential scanning. Accordingly, in the high frequency PDP driving method of the present invention, since gray scale display is performed while scanning lines sequentially, the contour noise generated in the conventional PDP driving method is not generated. In addition, since the high frequency discharge starts immediately by the data triggering signal according to the luminance level without the need of a separate address time, the discharge efficiency can be increased by increasing the high frequency discharge time by an unnecessary address time. In this case, the scan signal is supplied from the scan driver of the PDP driver, the high frequency signal is supplied from the high frequency driver, and the data triggering signal is supplied from the data driver.

FIG. 8 is a block diagram illustrating a high frequency PDP data driving apparatus according to an embodiment of the present invention. The data driving apparatus of FIG. 8 is an analog-to-digital converter (hereinafter, referred to as 'A-D') converter for sampling an input analog video signal. 72, the line memory 74 for temporarily storing the sampling video signal input from the AD converter 72 in scanning line units, and the sampling video signal stored in the line memory 74 are rearranged in accordance with the brightness level to obtain a luminance level. Controller 76 for generating a drive signal having a time difference, and a data driver 78 for supplying a data triggering signal according to a drive signal input from the controller 76 to address electrode lines on the PDP 80. It is provided.

In the high frequency PDP data driving circuit shown in FIG. 8, the A-D converter 72 samples and outputs an input analog video signal. The line memory 74 temporarily stores the sampling video signal input from the A-D converter 72. In this case, the line memory 74 has a capacity for storing video signals for one scan line. The controller 76 rearranges the image signals of one scan line stored in the line memory 74 in the order of the luminance levels, and generates a drive signal having a time difference in accordance with the luminance levels. In this case, the drive signals output from the controller 76 are output in the order of the drive signals of the discharge cells having the high luminance level from the drive signals of the discharge cells having the low luminance level. The data driver 78 generates the data triggering signal DTS according to the driving signal input from the controller 76 to drive the address electrode lines on the PDP 80.

As a result, the conventional high frequency PDP driving device requires a complicated memory design to reduce the contour noise and a circuit for converting an image signal into an 8-bit subfield signal, whereas the PDP driving device according to the present invention merely converts an analog signal. The circuit configuration can be simplified because only the driving signal corresponding to the sampled and sampled video signal level is supplied.

As described above, according to the PDP driving method using the high frequency according to the present invention, the gray scales are displayed while scanning the scanning lines sequentially so that the contour noise generated in the conventional PDP driving method is not generated. In addition, according to the PDP driving method using the high frequency according to the present invention, since the high frequency discharge starts immediately by the data triggering signal according to the luminance level without the need of a separate address time, the high efficiency discharge time is increased by the unnecessary address time to increase the discharge efficiency. You can do it. In addition, the high-frequency PDP driving apparatus according to the present invention simply samples the analog signal and supplies only the driving signal according to the level of the sampled video signal, in contrast to the conventional complicated circuit configuration. The cost can be reduced because it can be reduced.

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 (7)

In a driving method of a plasma display panel using a high frequency discharge, The plasma display panel is scanned on the scanning lines of the panel in units of horizontal periods, and has a time difference according to the luminance level of the image signal during the horizontal periods, and supplies a data triggering signal for initiating high frequency discharge. Driving method. The method of claim 1, And the data triggering signal is supplied in a form shifted from the higher to the lower luminance level. The method of claim 1, And a high frequency signal is continuously supplied to the high frequency electrode lines of the panel and the erase signal is simultaneously applied to the scan lines to stop the high frequency discharge. The method of claim 1, And a high frequency signal is turned on at the start point of the horizontal period and supplied to the high frequency electrode lines of the panel, and the high frequency discharge is stopped at the end point. In the driving device of the plasma display panel using a high frequency discharge, Sampling means for sampling an input analog video signal, Storage means for temporarily storing the sampled video signal in units of scan lines; Control means for reading out the stored sampling video signal and rearranging the stored sampling video signal with a luminance level and having a time difference according to the luminance level; And a data driving means for supplying a data triggering signal according to the driving signal to the data electrode lines of the panel. The method of claim 5, wherein Scan driving means for supplying a scan signal to the scan electrode lines of the panel in units of horizontal periods; And a high frequency driving means for supplying a high frequency signal to the high frequency electrode lines of the panel. The method of claim 6, And the control means supplies the drive signal in a form shifted from the higher to the lower luminance level.

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