KR20040074895A - A method for displaying pictures on plasma display panel and an apparatus thereof - Google Patents

Abstract

PURPOSE: A method and an apparatus for displaying an image on a plasma display panel are provided to reduce a flicker by periodically maintaining a center of luminous between sub-field groups. CONSTITUTION: An image processing unit(100) generates digital image data by converting an input image signal from analog to digital. A vertical frequency detector(200) determines whether the digital image data is an NTSC(National Television System Committee) signal or PAL(Phase Alternation by Line system) signal to output resultant value together with the digital image data. A gamma compensating and error-diffusion unit(300) performs a gamma compensation and an error-diffusion operation on the digital image data from the vertical frequency detector. A memory controller(400) generates a sub-field data corresponding to the vertical frequency data inputted from the gamma compensating and error-diffusion unit. An address driver(500) generates address data corresponding to the sub-field data from the memory controller to supply the address data to address electrodes of a PDP(Plasma Display Panel)(1000). An APC(Automatic Power Control) unit(600) detects a load factor, calculates an APC level according to the load factor detected, and outputs the number of sustain pulse corresponding to the APC level. A sub-field variable range determining unit(700) determines a variable range of each sub-field according to the load factor. A sustain-scan pulse driving controller(800) generates a sub-field arrangement structure. A sustain-scan pulse driver(900) generates a sustain pulse and a scan pulse to supply them to scan electrodes and sustain electrodes of the PDP.

Description

Image display method of plasma display panel and apparatus therefor {A METHOD FOR DISPLAYING PICTURES ON PLASMA DISPLAY PANEL AND AN APPARATUS THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display method and a device of a plasma display panel (hereinafter referred to as a PDP). In particular, a flicker generated when a PAL (Phase Alternating by Line) image signal of 50 Hz is input to implement an image. And a PDP image display method and apparatus for reducing pseudo contours.

A PDP is a type of display element that recovers image data input as an electric signal by arranging a plurality of discharge cells in a matrix and selectively emitting them.

In order to show performance as a color display element in such a PDP, gray scale display should be possible. As a method of implementing the gray scale display, a gray scale implementation method of dividing one field into a plurality of subfields and controlling the time division is used.

On the other hand, flicker is closely related to human visual characteristics. Generally, the larger the screen or the lower the frequency, the better the flicker is perceived by the eye.

When the image of the PAL video signal is implemented in the PDP, the above two conditions are satisfied to generate a large amount of flicker.

Therefore, a large amount of flicker occurs when the PDP is driven at a vertical frequency of 50 Hz by using the minimum increment array or the minimum decrease array, which is a conventional subfield array used in the PDP.

Since the screen size cannot be adjusted among the two conditions in which flicker occurs as described above, flicker can be reduced by using a method of adjusting the remaining frequencies.

As such, there is a Korean Patent Application Publication No. 2000-16955 as a conventional method for reducing the flicker by adjusting the frequency. In this patent, in order to reduce a large screen flicker generated when a PDP is driven by inputting a 50 Hz video signal, as shown in FIG. 1, subfields in one frame are divided into two groups G1 and G2. The group is set such that the remaining subfield arrays except the LSB (Least Significant Bit) subfield have the same structure or similarly distribute the luminance weight to the subfields of each group. This method is very effective in reducing flicker, compared with a subfield arrangement such as a conventional minimum incremental arrangement or minimal reduction array.

Referring to FIG. 1, the duration of one frame is 20 ms in total, and the duration of each group G1 and G2 is fixed to 10 ms. There are two idle periods, one located at the end of the frame period, that is, at the end of the second group G2, and the other between the two groups G1, G2, that is, at the end of the first group G1. Located.

2 is a diagram illustrating an example of implementing some low gray levels using a conventional subfield arrangement.

As shown in FIG. 2, when a low gray scale, for example, a low gray scale of 0 to 11, is represented using a conventional subfield arrangement, a time difference between subfields corresponding to LSB and LSB + 1 becomes several ms. .

For example, in the case of low gray level 3, the lowest subfield SF1 of the first group G1 is turned on and the lowest subfield SF1 of the second group G2 is turned on. In this case, the subfield of the first group G1 becomes a subfield of the LSB, and the subfield of the second group G2 becomes a subfield of LSB + 1, and the time difference between these subfields is 10 ms, which is very large.

When the low gray scale is expressed by using the subfield arrangement of the patent application and error diffusion is applied, the time difference between subfields corresponding to LSB and LSB + 1 is about several ms, and the light emission duration time of light emission having such a time difference is Because of this shortness, there is a problem that severe pseudo contours occur at the boundary between gray scales and gray scales when the image is shifted due to human vision. FIG. 3 is a conceptual diagram of pseudo contour generation generated when an image moves when adjacent grayscales are 4 and 3 in the published patent. As shown in FIG. 3, in the disclosed patent, when the adjacent grayscales are 4 and 3, respectively, pseudo contours are generated at five points when the image moves, and the highest grayscale 4 and the distorted grayscale among the original grayscales. The difference between and is 2, 1, 3, 2, 1.5 depending on the occurrence point. This difference indicates the intensity of occurrence of the pseudo contour. This distorted gradation appears as a distortion of the color during image movement, and as a distortion of the color having the shape of an outline to the human eye.

On the other hand, in the PDP, the power consumption is high due to its driving characteristics, and thus, an automatic power control (APC) technique that controls power consumption according to the load ratio (average signal level or load ratio) of a frame to be displayed is used. This APC method is a method of varying the APC level according to the load ratio of the input image data, limiting the power consumption to a certain level or less while varying the number of sustain pulses for each APC level.

According to this APC technique, the number of sustain pulses applied to each subfield changes according to the load ratio. That is, the total number of sustain pulses applied in each group (G1, G2) is changed according to the load ratio, so each subfield has the number of sustain pulses corresponding to the luminance specific gravity value of the subfield. The number of sustain pulses applied to the subfield is changed.

FIG. 4 is a diagram showing the subfield position of each APC and the center position of light emission in the subfield structure of the conventional PDP, (a) when APC is minimum, (b) when APC is maximum, and (c) The time when the first group G1 is larger than the second group G2 is shown.

As shown in (a) and (b) of FIG. 4, when the APC is the minimum and the maximum, the time intervals (TIME G1G2 and TIME G2G1) between the emission center positions of each group G1 and G2 are all the same, so that the APC is the same. The emission center positions of the first group G1 and the second group G2 according to the change of the level have periodicity in various gradation regions. Therefore, the amount of flicker is small in the subfield structure of the conventional PDP.

However, as shown in FIG. 4C, the subfield occupancy time of the first group G1 is smaller than the subfield occupancy time of the second group G2 in forming some gray scales regardless of the APC level. If large, the positions of the most significant subfield of the first group G1 and the most significant subfield of the second group G2 are different. Referring to FIG. 4C, the time interval TIME G1G2 between the emission center of the first group G1 and the emission center of the second group G2 is determined by the emission center of the second group G2 and the next frame. There is a problem in that flicker occurs because the emission centers of the groups G1 and G2 read periodicity as compared with the time interval TIME G2G1 between the emission centers of the first group G1.

Accordingly, an object of the present invention is to solve the above-described problems, and the light emission center between the subfield groups is changed by varying the start position of the subfield according to the load ratio of the video frame during driving by the 50Hz PAL video signal subfield arrangement. By maintaining it periodically, it is possible to reduce flicker generation and to place subfields corresponding to LSB and LSB + 1 used to form low gradation adjacent to the second group G2 to reduce the time difference between subfields. Disclosed is a PDP image display method and apparatus for minimizing pseudo contours generated during movement.

1 is a diagram illustrating a conventional subfield arrangement.

2 is a diagram illustrating an example of implementing some low gray levels using a conventional subfield arrangement.

3 is a conceptual diagram of pseudo contour generation generated when an image moves when adjacent grayscales are 4 and 3 in a conventional subfield arrangement.

FIG. 4 is a diagram showing the subfield position of each APC and the center position of light emission in the subfield structure of the conventional PDP, (a) when APC is minimum, (b) when APC is maximum, and (c) The time when the first group G1 is larger than the second group G2 is shown.

5 is a diagram illustrating a subfield structure according to the first embodiment of the present invention.

FIG. 6 is a diagram illustrating an example of implementing some low gray levels using an arrangement according to the first embodiment of the present invention.

7 is a conceptual diagram of pseudo contour generation generated when an image moves when adjacent grayscales are 4 and 3 in the subfield structure according to the first embodiment of the present invention.

FIG. 8 is a diagram illustrating sub-field positions for each APC and a center position of light emission in the subfield structure shown in FIG. 5, (a) shows when APC is minimum, and (b) shows when APC is maximum. Drawing.

9 is a diagram illustrating a subfield structure according to a second embodiment of the present invention, where (a) is the minimum APC, (b) is the intermediate APC, and (c) is the maximum APC. If it is.

FIG. 10 is a diagram illustrating a subfield position for each APC and a center position of light emission in the subfield structure shown in FIG. 9, (a) shows when APC is minimum, and (b) shows when APC is maximum. Drawing.

11 is a diagram showing a relationship between an APC level and a subfield period (occupancy time), in which (a) is a case of a subfield structure according to the first embodiment of the present invention, and (b) is a first embodiment of the present invention. This is the case of the subfield structure of the PDP according to the second embodiment.

12 is a block diagram of an image display device of a PDP according to an embodiment of the present invention.

In order to achieve the above object, the image display method of the PDP according to the characteristics of the present invention,

A PDP image display method of dividing an image of each frame displayed on a PDP in correspondence with an input video signal into a plurality of subfields, and displaying gray levels by combining luminance specific values of the subfields.

The plurality of subfields are composed of two consecutive subfield groups, and the number of subfields included in the subfield group located second in time among the two consecutive subfield groups is the two consecutive subfields. More than the number of subfields included in the first subfield group in time among the subfield groups, and the subfields used to form the low grayscale are included in the second subfield group, and the input is performed. The start time of the subfield group located second in time among the two consecutive subfield groups is varied according to the load ratio of the video signal.

PDP image display method according to another aspect of the present invention,

A PDP image display method of dividing an image of each frame displayed on a PDP in correspondence with an input video signal into a plurality of subfields, and displaying gray levels by combining luminance specific values of the subfields.

a) determining whether the input video signal is a PAL signal; b) if it is determined that the input video signal is a PAL signal, subfield data and address data corresponding to the input video signal are generated, and the number of sustain pulses and the start position of each subfield according to the load ratio of the input video signal; Generating a control signal related to a subfield arrangement structure based on the control; And c) applying the generated subfield data, address data, and a control signal related to the subfield arrangement structure to the PDP, wherein the subfield data is composed of two consecutive subfield groups. Corresponding to the number of subfields included in the second subfield group in time is greater than the number of subfields included in the first subfield group in time and used to form a low gray scale. The subfield is formed to be included in the second subfield group.

Here, it is preferable that the luminance specific gravity values of the subfields used to form the low gray scale correspond to LSB (Least Significant Bit) and LSB + 1 among the luminance specific gravity values of the plurality of subfields.

In addition, the subfield used to form the low gradation is preferably located at the start of the second subfield group.

In addition, it is preferable that the start time of the second subfield group when the load ratio is large is earlier than the start time of the second subfield group when the load ratio is small.

In addition, the occupancy time of the first subfield group is included in the occupancy time of the first subfield group, and the occupancy time of the first subfield group is variable according to the load ratio.

In addition, it is preferable that the occupancy time of the first subfield group decreases as the load factor increases.

PDP image display method according to another aspect of the present invention,

A PDP image display method of dividing an image of each frame displayed on a PDP in correspondence with an input video signal into a plurality of subfields, and displaying gray levels by combining luminance specific values of the subfields.

The plurality of subfields are composed of two consecutive subfield groups, and the number of subfields included in the subfield group located second in time among the two consecutive subfield groups is the two consecutive subfields. More than the number of subfields included in the first subfield group in time among the subfield groups, and the subfields used to form the low grayscale are included in the second subfield group, and the input is performed. Irrespective of the variation in the load ratio of the video signal, light emission centers are formed periodically between subfield groups formed in the frame.

Here, the periodic formation of the emission centers between the subfield groups may include a time interval of the emission centers between the first subfield group and the second subfield group formed in the same frame, and the second subfield group formed in a different frame. It is preferable that the time intervals of the emission centers between the first subfield groups are the same.

According to another aspect of the present invention, an image display apparatus of a PDP is provided.

A PDP image display apparatus for dividing an image of each frame displayed on a PDP in correspondence with an input video signal into a plurality of subfields, and displaying a gray level by combining luminance specific values of the subfields.

A video signal processor for digitizing the input video signal to generate digital video data; A vertical frequency detector which analyzes the digital image data output from the image signal processor to detect whether the input image data is an NTSC signal or a PAL signal, and outputs the result along with the digital image data as a data switch value ; The digital image data and the data switch value generated by the vertical frequency detector are input, and the subfield data corresponding to the NTSC image signal or the PAL image signal according to the data switch value, wherein the subfield data are two consecutive subfield groups. The number of subfields included in the subfield group that is second in time corresponds to the subfields that are configured to be greater than the number of subfields included in the first subfield group in time. A subfield used to form grayscales to be included in the second subfield group; and a memory controller for generating address data and applying the same to the PDP; And an APC unit for detecting a load ratio of the digital image data output from the vertical frequency detector, calculating an APC (Automatic Power Control) level according to the detected load ratio, and calculating and outputting a number of sustain pulses corresponding to the calculated APC level. ; A subfield variable range determination unit determining a variable range of each subfield according to a load ratio output from the APC unit, and determining a start position of each subfield within the determined variable range; And a number of sustain pulses output from the subfield variable range determination unit, an address pulse width of each subfield, a start position of each subfield, and a data switch value, and an NTSC video signal according to the data switch value and a PAL. And a sustain / scan pulse driver for generating a subfield array structure separately from each other in the case of an image signal, and generating and applying a control signal based on the generated subfield array to the PDP.

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.

First, an image display method of a PDP according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

5 is a diagram illustrating a subfield structure according to the first embodiment of the present invention.

As shown in FIG. 5, the frame according to the first embodiment of the present invention is composed of two separate subfield groups G1 and G2. In addition, there are two rest periods (pause period 3 and pause period 4), which are located at the end of each group G1 and G2.

The first group G1 is composed of six subfields, and each luminance specific value is set to 4, 8, 16, 24, 32, and 40 from the lower subfield, but may be changed by those skilled in the art according to a usage form. The second group G2 is composed of eight subfields, and each luminance specific value is set to 1, 2, 4, 8, 16, 24, 32, and 40 from the lower subfield, but is set in the first group G1. It may be set differently by those skilled in the art according to the luminance specific gravity. In this case, the subfield arrangement of the second group G2 is further added such that the LSB and LSB + 1 subfields having luminance specific values of 1 and 2 are adjacent to the subfield arrangement of the first group G1.

Here, the first group G1 starts at the start position of the frame, that is, 0 ms, and the total period A including the idle period (pause period 3) when the APC is not operated because the load factor is minimum is smaller than 10 ms. Is set. Therefore, the second group G2 is set such that the total period including the rest period (pause period 4) is greater than 10 ms.

FIG. 6 is a diagram illustrating an example of implementing some low gray levels using an arrangement according to the first embodiment of the present invention.

As shown in Fig. 6, when a low gray scale, for example, a low gray scale of 0 to 11, is expressed using a subfield arrangement according to the first embodiment of the present invention, luminance specific gravity 1 and 2, that is, LSB and LSB The time difference between subfields corresponding to +1 becomes negligibly small.

For example, in the case of low gray level 3, the lowest subfields SF1 and SF2 of the second group G2 are turned on. In this case, since the subfields SF1 and SF2 to be turned on are all in the second group G2, there is almost no time difference between these subfields.

As such, when the subfields corresponding to the LSB and LSB + 1 used to form the low gray are disposed adjacent to the start position of the second group G2, the time difference between the subfields corresponding to the LSB and LSB + 1 is almost eliminated. Therefore, when the image is moved by being perceived by human vision, pseudo contours generated at the grayscale and grayscale boundary can be greatly reduced.

7 is a conceptual diagram of pseudo contour generation generated when an image moves when adjacent grayscales are 4 and 3 in the subfield structure according to the first embodiment of the present invention.

As shown in FIG. 7, in the subfield structure according to the first exemplary embodiment of the present invention, when the adjacent grayscales are 4 and 3, respectively, three points of pseudo contours are generated when the image moves. The difference between the highest gradation 4 and the distorted gradation is 2, 0.5, and 2.5, respectively, depending on the point of occurrence. This can be seen that the number of pseudo contours generated in comparison with the conventional PDP subfield structure described with reference to FIG. 3 is reduced, and the difference between the distorted gradation value and the original gradation is reduced to half.

Therefore, in the subfield structure according to the first embodiment of the present invention, pseudo contour generation is greatly reduced as compared with the case of the conventional PDP subfield structure.

On the other hand, the subfield position and the emission center when APC is performed in the subfield structure according to the first embodiment of the present invention will be described.

FIG. 8 is a diagram illustrating a subfield position for each APC and a center position of light emission in the subfield structure shown in FIG. 5, (a) shows when APC is minimum, and (b) shows when APC is maximum. Drawing.

Referring to FIG. 8, when the APC is the minimum, an interval between the emission center positions of the first group G1 and the emission center positions of the second group G2 in the same frame is 11 ms, for example, and the second group G2. The interval between the light emitting center positions of and the light emitting center positions of the first group G1 of the next frame is, for example, 9 ms, which is slightly smaller than the above-described intervals (11 ms).

Referring to FIG. 8B, the distance between the emission center positions of the first group G1 and the emission center positions of the second group G2 when the APC is operated or maximized compared to when the APC is minimum is shown in FIG. The same as when the APC shown in (a) of FIG. 8 is minimum, and the interval between the emission center positions of the second group G2 and the emission center positions of the first group G1 of the next frame is also shown in FIG. Same as when APC shown in FIG.

As described above, when the APC is operated or maximized as compared to when the APC is minimum, the respective subfield periods of the first group G1 and the second group G2 are decreased, and conversely, the rest period (pause period 3, pause). Although the period 4) is increased, the start time of the second group G2 is the same so that the distance between the emission center position of the first group G1 and the emission center position of the second group G2 in the same frame is farther apart, Since the distance between the light emission center positions of the two groups G2 and the light emission center positions of the first group G1 of the other frames is up to, as a result, each light emission center position interval becomes the same as the minimum APC regardless of the APC level.

Therefore, the start position of the subfield is fixed regardless of the change in the APC level, that is, the start time of the second group G2 is fixed regardless of the APC level, so that the emission centers of the groups G1 and G2 are fixed. Since it is formed aperiodically, there is a problem that flicker occurs.

The subfield structure according to the second embodiment of the present invention for solving this problem will be described in detail.

9 is a diagram illustrating a subfield structure according to a second embodiment of the present invention, where (a) is the minimum APC, (b) is the intermediate APC, and (c) is the maximum APC. If it is.

As shown in FIG. 9A, when the APC is the minimum, the subfield structure according to the second embodiment of the present invention is the same as the subfield structure in the first embodiment of the present invention described with reference to FIG. 5. Therefore, detailed description is omitted here.

On the other hand, as shown in (b) of FIG. 9, in the load factor at which the APC operates, unlike the subfield structure in the first embodiment of the present invention described with reference to FIG. 5, the period of the first group G1 ( B) is smaller than the period A when the APC is not operated (i.e., B < A), and thus the start position of the second group G2 is also when the APC is not operated, i.e., FIG. Compared to the subfield structure shown in FIG. At this time, the rest period (pause period 5) is fixed to the same or slightly larger than the rest period (pause period 3) when the APC is not operating, and the rest period (pause period 6) is the same as the rest period (pause period 5). It is increased, including the increase part, and is much larger than the rest period (pause period 4) when the APC is not operating.

In addition, as shown in (c) of FIG. 5, when APC is maximum at the maximum load rate, the period C of the first group G1 is also reduced to the maximum so that the period A in FIG. And (B) in Fig. 5B. That is, C <B <A. However, the rest period (pause period 7) is fixed to the same or slightly larger than the rest period (pause period 3, rest period 5) in FIGS. 5A and 5B, and the rest period (pause period 8) It is larger than the rest period (pause period 4, rest period 6).

FIG. 10 is a diagram illustrating a subfield position for each APC and a center of light emission in the subfield structure shown in FIG. 9, (a) shows when APC is minimum, and (b) shows when APC is maximum. Drawing.

As shown in (a) and (b) of FIG. 10, the subfield periods of the first group G1 and the second group G2 are reduced when the APC is maximum compared to when the APC is minimum, and vice versa. The period is increased.

At this time, since the start time of the second group G2 varies toward the first group G1 according to the level of the APC, the emission center position of the first group G1 and the light emission of the second group G2 in the same frame. The interval between the center positions is, for example, 10 ms, which is closer to that of the conventional art. On the contrary, the distance between the center of emission positions of the second group G2 and the center of emission positions of the first group G1 of the next frame is 10 ms, for example. Farther away.

In this way, by varying the light emission center positions within the same frame or between different frames to make each time interval the same (for example, 10 ms), the distance between the light emission center positions between the subfield groups G1 and G2 becomes periodic, thereby causing flicker. Occurrence can be reduced.

Therefore, the start position variable of the second group G2 should be varied within a range in which the distance between the light emission center positions of the first group G1 and the light emission center positions of the second group G2 becomes the same or similar.

11 is a diagram showing a relationship between an APC level and a subfield period (occupancy time), in which (a) is a case of a subfield structure according to the first embodiment of the present invention, and (b) is a first embodiment of the present invention. This is the case of the subfield structure of the PDP according to the second embodiment.

As shown in (a) and (b) of FIG. 11, the subfield according to the second embodiment of the present invention is compared with the subfield period according to the APC level in the subfield structure according to the first embodiment of the present invention. Since the subfield period in accordance with the APC level in the structure is formed such that the interval is smaller for each of the groups G1 and G2 due to the change in the starting position of the second group G2, the flicker occurrence is reduced.

12 is a block diagram of an image display device of a PDP according to an embodiment of the present invention.

As shown in FIG. 12, an image display apparatus of a PDP according to an exemplary embodiment of the present invention includes an image signal processor 100, a vertical frequency detector 200, a gamma correction and error diffusion unit 300, and a memory controller 400. And an address driver 500, an APC unit 600, a subfield variable range determination unit 700, a sustain / scan pulse drive control unit 800, and a sustain / scan pulse driver 900.

The image signal processing unit 100 digitizes an image signal input from the outside to generate digital image data.

The vertical frequency detector 200 analyzes the digital image data output from the image signal processor 100 to determine whether the input image data is an NTSC signal of 60 Hz or a PAL signal of 50 Hz, and sets the result as a data switch value. Output with digital image data.

The gamma correction and error diffusion unit 300 receives digital image data output from the vertical frequency detector 200, corrects the gamma value according to the characteristics of the PDP, and performs a diffusion process on the surrounding pixels to output the display error. At this time, the data switch value indicating whether the video signal output from the vertical frequency detector 200 is 50Hz or 60Hz is output to the memory controller 400 and the APC unit 600 as it is.

The memory controller 400 receives the digital image data and the data switch value output from the gamma correction and error diffusion unit 300, and separates the case of the 50 Hz image signal and the 60 Hz image signal according to the data switch value. Subfield data corresponding to the digital image data is generated.

When the data switch value represents a 60 Hz video signal, the subfield data corresponding to the digital video data is generated by generating subfield data as one subfield group.

However, when the data switch value represents a video signal of 50 Hz, as shown in Figs. 5 and 9 (a), it is divided into two subfield groups G1 and G2, and in the first group G1, There are six subfields, and the subfield data is generated such that eight subfields exist in the second group G2. The subfield data generated as described above is subjected to memory input / output processing and output to the address driver 500.

The address driver 500 generates address data corresponding to the subfield data output from the memory controller 400 and applies the address data to the address address electrodes A1, A2,... Am of the PDP 1000.

Meanwhile, the APC unit 600 detects a load ratio using the image data output from the gamma correction and error diffusion unit 300, calculates an APC level according to the detected load ratio, and maintains and discharges corresponding to the calculated APC level. The number of pulses is calculated and output.

The subfield variable range determination unit 700 determines the variable range of each subfield according to the load ratio output from the APC unit 800, and determines the start position of each subfield within the determined variable range.

The sustain / scan pulse driving control unit 800 receives the number of sustain pulses output from the subfield variable range determination unit 700, the start position of each subfield, and the data switch value, and is a 50 Hz image signal according to the data switch value. The subfield array structure is separately generated and output to the sustain / scan pulse driver 900.

The sustain / scan pulse driver 900 generates sustain pulses and scan pulses based on the subfield array structure output from the sustain / scan pulse drive control unit 800 to generate the scan electrodes X1, X2,... Xn) and sustain electrodes Y1, Y2, ..., Yn.

Although the present invention has been described with reference to the most practical and preferred embodiments, the present invention is not limited to the above disclosed embodiments, but also includes various modifications and equivalents within the scope of the following claims.

According to the present invention, the occurrence of pseudo contours for the low gradation region is significantly reduced by arranging the subfields used to form the low gradation adjacent to the second group G2 to reduce the time difference between the subfields.

In addition, flickering is significantly reduced by periodically maintaining the emission center between the subfield groups.

Claims (12)

An image display method of a plasma display panel in which an image of each frame displayed on a plasma display panel in response to an input video signal is divided into a plurality of subfields, and a gray level is displayed by combining luminance specific gravity values of the subfields. The plurality of subfields are composed of two consecutive subfield groups, The number of subfields included in the subfield group located second in time among the two consecutive subfield groups is included in the subfield group located first in time in the two consecutive subfield groups. More than the number of subfields Subfields used to form a low grayscale are included in the second subfield group, The start time of the subfield group located second in time among the two consecutive subfield groups is changed according to the load ratio of the input video signal. An image display method of a plasma display panel. An image display method of a plasma display panel in which an image of each frame displayed on a plasma display panel in response to an input video signal is divided into a plurality of subfields, and a gray level is displayed by combining luminance specific gravity values of the subfields. a) determining whether the input video signal is a PAL signal; b) if it is determined that the input video signal is a PAL signal, subfield data and address data corresponding to the input video signal are generated, and the number of sustain pulses and the start position of each subfield according to the load ratio of the input video signal; Generating a control signal related to a subfield arrangement structure based on the control; And c) applying the generated subfield data, address data, and a control signal related to the subfield arrangement structure to the plasma display panel; Including; The subfield data, Subfields corresponding to subfields composed of two consecutive subfield groups, and the number of subfields included in the subfield group located second in time is the subfield included in the first subfield group located in time. More than the number of fields, the subfields used to form the low gradation are formed to be included in the second subfield group An image display method of a plasma display panel. The method according to claim 1 or 2, And a luminance specific gravity value of a subfield used to form the low gray level corresponds to a LSB (Least Significant Bit) and LSB + 1 among the luminance specific gravity values of the plurality of subfields. The method of claim 3, And the subfield used to form the low gradation is located at a start point of the second subfield group. The method according to claim 1 or 2, And the start time of the second subfield group when the load ratio is large is earlier than the start time of the second subfield group when the load ratio is small. The method according to claim 1 or 2, The occupancy time of the first subfield group includes the idle period of the first subfield group, Occupancy time of the first subfield group is variable according to the load ratio An image display method of a plasma display panel. The method of claim 6, The occupancy time of the first subfield group is reduced as the load factor is increased. An image display method of a plasma display panel in which an image of each frame displayed on a plasma display panel in response to an input video signal is divided into a plurality of subfields, and a gray level is displayed by combining luminance specific gravity values of the subfields. The plurality of subfields are composed of two consecutive subfield groups, The number of subfields included in the subfield group located second in time among the two consecutive subfield groups is included in the subfield group located first in time in the two consecutive subfield groups. More than the number of subfields Subfields used to form a low grayscale are included in the second subfield group, Irrespective of the variation in the load ratio of the input video signal, light emission centers are formed periodically between subfield groups respectively formed in a frame. An image display method of a plasma display panel. The method of claim 8, Periodic formation of the emission center between the subfield groups, The time interval of the emission center between the first subfield group and the second subfield group formed in the same frame and the time interval of the emission center between the second subfield group and the first subfield group formed in the different frame are the same. The image display method of the plasma display panel characterized by the above-mentioned. An image display apparatus of a plasma display panel in which an image of each frame displayed on a plasma display panel in response to an input video signal is divided into a plurality of subfields, and a gray level is displayed by combining luminance specific gravity values of the subfields. A video signal processor for digitizing the input video signal to generate digital video data; A vertical frequency detector which analyzes the digital image data output from the image signal processor to detect whether the input image data is an NTSC signal or a PAL signal, and outputs the result along with the digital image data as a data switch value ; The digital image data and the data switch value generated by the vertical frequency detector are input, and the subfield data corresponding to the NTSC image signal or the PAL image signal according to the data switch value, wherein the subfield data are two consecutive subfield groups. The number of subfields included in the subfield group that is second in time corresponds to the subfields that are configured to be greater than the number of subfields included in the first subfield group in time. A subfield used to form grayscales to be included in the second subfield group; and a memory controller configured to generate address data and apply the same to a plasma display panel; And An APC unit for detecting a load ratio of the digital image data output from the vertical frequency detector, calculating an APC (Automatic Power Control) level according to the detected load ratio, and calculating and outputting a number of sustain pulses corresponding to the calculated APC level; A subfield variable range determination unit determining a variable range of each subfield according to a load ratio output from the APC unit, and determining a start position of each subfield within the determined variable range; And The number of sustain pulses output from the subfield variable range determination unit, the address pulse width of each subfield, the start position of each subfield, and a data switch value are input. A sustain / scan pulse driver for generating a subfield array structure by separately separating the signal cases, and generating and applying a control signal based on the generated subfield array to the plasma display panel. An image display device of a plasma display panel comprising a. The method of claim 10, The subfield variable range determination unit is configured such that the start time of the second subfield group when the load ratio is large is earlier than the start time of the second subfield group when the load ratio is small. Image display device. An image display method of a plasma display panel in which an image of each frame displayed on a plasma display panel in response to an input video signal is divided into a plurality of subfields, and gray levels are displayed by combining luminance specific values of the subfields. a) determining whether the input video signal is a PAL signal; b) if it is determined that the input video signal is a PAL signal, subfield data corresponding to the input video signal, wherein the subfield data corresponds to a subfield consisting of two consecutive subfield groups, and in time; The number of subfields included in the second subfield group is greater than the number of subfields included in the first subfield group in time, and the second subfield is used to form a low gray level. And generating address data, and generating control signals related to the subfield array structure based on the number of sustain pulses according to the load ratio of the input video signal and the start position of each subfield. ; And c) a function of applying the generated subfield data, address data, and a control signal related to the subfield arrangement structure to the plasma display panel; Record medium that stores the program to implement.