KR100560489B1 - Method and apparatus to prevent afterimage for plasma panel and a plasma display panel having that apparatus - Google Patents

Abstract

The present invention relates to a method and an apparatus for preventing afterimage of a plasma panel and a plasma display panel having the apparatus. In the present invention, the still image determination unit receives an external image signal to determine whether the still image, and the still image area determination unit determines the area of the still image input from the still image determination unit. The luminance controller controls the luminance of the image data to be lowered when the entire screen is a still image. The still image part extractor extracts a still image part when a part of the screen is a still image. The still image part converting unit converts the image data of the still image part extracted by the still image part extracting unit so as to move a certain distance for a predetermined time. By doing in this way, the afterimage which arises in a plasma panel can be prevented.

Plasma, PDP, fixed pattern, phase, shift, luminance

Description

Method and apparatus for preventing afterimage of plasma panel, plasma display panel having the device {Method and apparatus to prevent afterimage for plasma panel and a plasma display panel having that apparatus}

1 is a partial perspective view of an AC plasma display panel.

2 shows a three-electrode surface discharge structure of the plasma display panel.

3 is a configuration diagram of a plasma display panel according to an embodiment of the present invention.

4 is a block diagram of the afterimage prevention unit according to the first embodiment of the present invention.

5 is an operation flowchart of a method for preventing an afterimage of a plasma panel according to the first embodiment of the present invention.

6 is a diagram illustrating a moving path of a partial still image.

7 is a diagram illustrating luminance control of all still images.

8 is a configuration diagram of an afterimage prevention unit according to a second exemplary embodiment of the present invention.

9 is an operation flowchart of a method of preventing an afterimage of a plasma panel according to a second exemplary embodiment of the present invention.

10 is a diagram illustrating extraction of a boundary portion.

Fig. 11 is a diagram illustrating converting a boundary portion.

12 and 13 are diagrams showing examples of the brightness at the converted boundary portion.

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

Recently, flat display devices such as liquid crystal displays (LCDs), field emission displays (FEDs), and PDPs have been actively developed. Among these flat panel display devices, PDPs have advantages of higher luminance and luminous efficiency and wider viewing angles than other flat panel display devices. Therefore, the PDP is in the spotlight as a display device to replace the conventional cathode ray tube (CRT) in a large display device of 40 inches or more.

PDPs are flat display devices that display characters or images using plasma generated by gas discharge, and dozens to millions or more of pixels are arranged in a matrix according to their size. Such PDPs are classified into a direct current type (DC type) and an alternating current type (AC type) according to the shape of the driving voltage waveform applied and the structure of the discharge cell.

In the DC-type PDP, since the electrode is exposed to the discharge space as it is, the current flows in the discharge space while voltage is applied, and there is a disadvantage in that a resistance for current limitation must be made for this purpose. On the other hand, in the AC type PDP, the electrode covers the dielectric layer, so the current is limited by the formation of a natural capacitance component, and the electrode is protected from the impact of ions during discharge.

1 is a partial perspective view of an AC plasma display panel.

As shown in FIG. 1, the scan electrode 4 and the sustain electrode 5 covered with the dielectric layer 2 and the protective film 3 are arranged in parallel on the first substrate 1. A plurality of address electrodes 8 covered with the insulator layer 7 are provided on the second substrate 6. A partition 9 is formed on the insulator layer 7 between the address electrodes 8 in parallel with the address electrode 8. In addition, the phosphor 10 is formed on the surface of the insulator layer 7 and on both side surfaces of the partition wall 9. The first substrate 1 and the second substrate 6 may be arranged with the discharge space 11 therebetween so that the scan electrode 4 and the address electrode 8 and the sustain electrode 5 and the address electrode 8 are orthogonal to each other. It is arranged toward. The discharge space at the intersection of the address electrode 8 and the pair of the scanning electrode 4 and the sustain electrode 5 forms a discharge cell 12.

2 shows a three-electrode surface discharge structure of the plasma display panel.

Referring to FIG. 2, an address electrode is disposed to face the scan electrode and the sustain electrode which are formed in parallel in the discharge space formed by the partition wall. In this structure, a discharge is generated to generate wall charges to select a pixel between the address electrode and the scan electrode, and then a discharge for displaying an image between the scan electrode and the sustain electrode is repeated for a predetermined time.

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

The plasma display panel displays a still image for a long time as needed. In this case, an afterimage occurs due to a difference in display material.

The technical problem to be achieved by the present invention is to solve such a conventional problem, by reducing the brightness of the screen by detecting a still picture or by moving the still picture little by little after a certain time to minimize material changes in a specific area A method and apparatus for preventing afterimages and a plasma display panel having the apparatus are provided.

Method for preventing the afterimage of the plasma panel according to an aspect of the present invention for achieving the above object,

A method of preventing an afterimage of a plasma panel including a plurality of address electrodes and a plurality of scan electrodes and sustain electrodes,

A first step of receiving an image signal and determining whether the image is a still image or a moving image;

A second step of determining whether the full screen is a still image if it is a still image;

If the entire screen is a still image, reducing the luminance of the video signal;

If the specific portion is a still image, a fourth step of outputting data of the still image portion by moving a predetermined distance for a predetermined time.

Method for preventing the afterimage of the plasma panel according to an aspect of the present invention for achieving the above object,

A method of preventing an afterimage of a plasma panel including a plurality of address electrodes and a plurality of scan electrodes and sustain electrodes,

A first step of receiving an image signal and determining whether the image is a still image or a moving image;

A second step of determining whether the full screen is a still image if it is a still image;

If the entire screen is a still image, reducing the luminance of the video signal;

If the specific portion is a still image, extracting a boundary portion of the still image;

And a fifth step of periodically adding or subtracting the extracted image data of the boundary portion and outputting the converted image data.

The afterimage prevention device of the plasma panel according to another feature of the present invention for achieving the above object,

A still image determination unit which receives an external image signal and determines whether the image is a still image;

A still image region determination unit which determines an area of a still image input by the still image determination unit;

A luminance controller which controls to lower the luminance of the image data when the entire screen is a still image;

A still image part extracting unit extracting a still image part when a part of the screen is a still image;

And a still image part converting unit converting and outputting the image data of the still image part extracted by the still image part extracting unit to move a predetermined distance for a predetermined time.

The afterimage prevention device of the plasma panel according to another aspect of the present invention for achieving the above object,

A still image determination unit which receives an external image signal and determines whether the image is a still image;

A still image region determination unit which determines an area of a still image input by the still image determination unit;

A luminance controller which controls to lower the luminance of the image data when the entire screen is a still image;

A boundary portion extractor for extracting a boundary portion of the still image when a portion of the screen is a still image;

And a boundary portion converter for periodically subtracting and converting image data of the boundary portion of the still image extracted by the boundary portion extractor.

According to another aspect of the present invention for achieving the above object,

A plasma panel including a plurality of address electrodes, a plurality of scan electrodes, and a sustain electrode;

A residual image prevention unit for determining whether the image is a still image by receiving an image signal, controlling the luminance to be lowered to a predetermined luminance when the entire screen is a still image, and converting and outputting data of the still image portion when the portion is a still image;

A controller for controlling luminance according to the luminance control signal output from the afterimage prevention unit, and generating and outputting a sustain electrode driving signal, a scan electrode driving signal, and an address electrode driving signal by receiving an image signal of the afterimage preventing unit;

An address electrode driver for applying a voltage to the address electrode of the plasma panel according to an address driving signal output from the controller;

A sustain electrode driver for applying a sustain voltage to the sustain electrode according to a sustain electrode driving signal of the controller;

And a sustain electrode driver configured to apply a scan voltage to the scan electrode according to the scan electrode driving signal of the controller.

Next, the present invention will be described with reference to the accompanying drawings so that the present invention may be easily implemented by those skilled in the art as follows.

3 is a configuration diagram of a plasma display panel according to an embodiment of the present invention.

Referring to FIG. 3, a plasma display panel according to an exemplary embodiment of the present invention includes a plasma panel 100, a controller 200, an address electrode driver 300, and a scan electrode driver (hereinafter referred to as a “Y electrode driver”) ( 400, a sustain electrode driver (hereinafter referred to as an “X electrode driver”) 500, and an afterimage prevention part 600.

The plasma panel 100 includes a plurality of address electrodes A1-Am arranged in the column direction, a plurality of sustain electrodes (hereinafter referred to as 'X electrodes') (X1-Xn) and scan electrodes arranged in the row direction. (Hereinafter referred to as 'Y electrode') (Y1-Yn). The X electrodes X1-Xn are formed corresponding to the respective Y electrodes Y1-Yn, and generally have one end connected in common to each other. The plasma panel 100 includes a glass substrate (not shown) on which the X and Y electrodes X1-Xn and Y1-Yn are arranged, and a glass substrate (not shown) on which the address electrodes A1-Am are arranged. . The two glass substrates are disposed to face each other with the discharge space therebetween so that the Y electrodes Y1-Yn and the address electrodes A1-Am and the X electrodes X1-Xn and the address electrodes A1-Am are orthogonal to each other. At this time, the discharge space at the intersection of the address electrodes A1-Am and the X and Y electrodes X1-Xn and Y1-Yn forms a discharge cell.

The afterimage prevention unit 600 receives an image signal from the outside to determine whether the image is a still image, and outputs a luminance control signal to lower the luminance to a predetermined luminance when the entire screen is a still image, and when the portion is a still image, the still image. Convert and output the data of the part.

The controller 200 controls the luminance according to the luminance control signal output from the afterimage prevention unit, and receives an image signal of the afterimage prevention unit to output an address driving signal, an X electrode driving signal, and a Y electrode driving signal. The controller 200 divides and drives one frame into a plurality of subfields, and each subfield includes a reset period, an addressing period, and a sustain period.

The address electrode driver 300 receives an address electrode driving signal from the controller 200 and applies a display data signal for selecting a discharge cell to be displayed to each address electrode A1-Am.

The X electrode driver 500 receives an X electrode driving signal from the controller 200 and applies a driving voltage to the X electrodes X1 to Xn.

The Y electrode driver 400 receives the Y electrode driving signal from the controller 200 and applies a driving voltage to the Y electrodes Y1-Yn.

4 is a configuration diagram of an afterimage prevention unit according to the first embodiment.

Referring to FIG. 4, the afterimage prevention unit 600 according to the first embodiment includes a still image determination unit 610, a luminance control unit 620, a still image area determination unit 630, and a still image partial extraction unit 640. ), And a still image partial converter 650.

A still image determination unit which receives an external image signal and determines whether the image is a still image;

A still image region determination unit which determines an area of a still image input by the still image determination unit;

A luminance controller which controls to lower the luminance of the image data when the entire screen is a still image;

A still image part extracting unit extracting a still image part when a part of the screen is a still image;

And a still image part converting unit converting and outputting the image data of the still image part extracted by the still image part extracting unit to move a predetermined distance for a predetermined time.

Next, a method and apparatus for preventing afterimages of a plasma panel according to an exemplary embodiment of the present invention having such a configuration and an operation of a plasma display panel having the apparatus will be described in detail.

5 is an operation flowchart of a method for preventing an afterimage of a plasma panel according to the first embodiment of the present invention.

Referring to FIG. 5, first, an image signal is externally input to the still image determination unit 610 of the afterimage prevention unit 600 (S500).

Then, the still image determination unit 610 determines whether the received image signal is a still image (S510). At this time, the method of determining the still image is detected by comparing the change of the N-th field (or FRAME) and the N + 1st field (or FRAME) constituting the screen. And calculate the RGB value of each field or frame. Then, it is determined that the case where the difference between the previous field and the current field is less than 1 when the constant field continues for a predetermined field or more.

That is, K <| Fn (RGB) n -1-Fn (RGB) n |

In the case where K is smaller than 1, the image is judged to be a still picture, where N is available for each CELL (PIXEL), LINE, BLOCK, FIELD, and FRAME.

If it is determined that the input image signal is a still image, the still image determination unit 610 outputs an image signal to the still image area determination unit 630, and otherwise, directly outputs it to the control unit 200.

Then, the still image area determiner 630 determines the still image part by calculating a difference from the previous field for each pixel. Here, if necessary, the still image determining unit 610 may also determine the still image part at the time of determining the still image by comparing the previous field for each pixel (S520).

If a portion of the screen is a still image, the still image area determiner 630 outputs an image signal to the still image portion extractor 640.

Then, the still image part extractor 640 extracts and outputs a still image part of the image signal (S530).

Then, the still image part converting unit 650 converts the image data of the still image part into data shifted by a predetermined amount of movement for a predetermined time and outputs the converted data (S540 and S550). At this time, an example of moving the still image portion is shown in FIG.

Referring to FIG. 6, each pixel of the still image continues to move to the positions of a, b, c, d, and e at a predetermined time, and then comes to the position of a again. Such a movement path may be variously modified as necessary. have.

On the other hand, if the entire screen is a still image, the still image area determination unit 630 outputs an image signal to the luminance controller 620.

Then, the luminance controller 620 outputs the luminance control signal to the controller 200 to lower the luminance of the image signal to a predetermined luminance (S560), and also outputs the image signal to the controller 200.

Then, the controller 200 displays the data by lowering the luminance of the input image signal according to the luminance control signal. In this case, the luminance may be lowered by the controller 200 reducing the number of sustains in the automatic power control.

At this time, control of luminance is shown in FIG.

Referring to FIG. 7, the luminance is lowered to a certain luminance (40 IRE) in the entire still image section (B), and when it is a video, the luminance is returned to the original luminance again.

Meanwhile, the controller 200 corrects the gamma value according to the characteristics of the plasma display panel, generates the corrected image signal into N subfields, and controls the X electrode driving signal and the Y electrode driving for each subfield. Signal and address electrode drive signal are output.

Then, the address driver 300 receives an address electrode driving signal and applies a display data signal for selecting a discharge cell to be displayed to each address electrode A1-Am.

The X electrode driver 500 receives the X electrode driving signal to apply a driving voltage to the X electrodes X1 to Xn, and the Y electrode driving unit 400 receives the Y electrode driving signal to receive the Y electrode Y1 to Yn. Is applied to the driving voltage.

Then, in the plasma panel 100, the luminance is lowered at the time of the full screen still image, and the image data is displayed while the data is moved by a certain amount of movement in the partial still image so that there is no afterimage.

In the first embodiment, the method of removing the afterimage of the partial still image may be variously modified, and the image data of the warp portion may be deformed without moving to eliminate the afterimage.

This content is explained as a 2nd Example as follows.

8 is a configuration diagram of the afterimage prevention unit 601 of the plasma panel according to the second embodiment of the present invention.

Referring to Figure 8, afterimage prevention unit 601 according to a second embodiment of the present invention,

A still image determining unit 610 which receives an external image signal and determines whether the image is a still image;

A still image region determination unit 630 which determines an area of a still image input by the still image determination unit;

A luminance controller 620 for controlling the luminance of the image data to be lowered when the entire screen is a still image;

A boundary portion extractor 640 for extracting a boundary portion of the still image when a portion of the screen is a still image;

And a boundary portion converter 650 for periodically adding or subtracting and converting image data of the boundary portion of the still image extracted by the boundary portion extractor.

In the second exemplary embodiment, the boundary image extracting unit 641 and the boundary portion converting unit 651 replace the still image portion extracting unit 640 and the still image portion converting unit 650 of the first embodiment. To prevent afterimages.

The operation of the afterimage prevention unit 601 according to the second embodiment having such a configuration will be described in detail as follows.

9 is an operation flowchart of a method of preventing an afterimage of a plasma panel according to a second exemplary embodiment of the present invention.

Referring to FIG. 9, an image signal is received from the outside by the still image determining unit 610 of the afterimage prevention unit 601 (S500), and whether or not a still image is determined (S510). In operation S520, it is determined whether the image is a partial still image or a whole still image.

In the case of the whole still image, the luminance is controlled as in the first embodiment (S560). In the case of the partial still image, the input image signal is transmitted to the edge detector 641.

Then, the boundary portion extractor 641 extracts a boundary portion of the still image of the image signal recognized as the partial still image (S531). At this time, the extracted boundary portion is shown in FIG.

Referring to FIG. 10, a portion extracted as a boundary portion of an image signal has a certain shape of one line.

The extracted image data and the image signal of the boundary portion are transmitted to the boundary portion converter 651. When the image data of the boundary portion is transmitted, the boundary portion converter 651 makes a diagonal shape by using a method of periodically adding or subtracting the image data input to the image data of the next line of the boundary portion. In addition, in the next line, the phase is added or subtracted at a period of 180 degrees (S541). The results of using this method are shown in FIGS. 11 and 12.

Fig. 11 is a diagram showing an example of data conversion of the boundary portion, in which an image (n line) of the boundary portion is converted into n + 1 line and n + 2 line.

12 is a diagram illustrating brightness of converted data.

As shown in Fig. 12, the light and dark portions are repeated repeatedly, so that only the boundary portion is blurred. Therefore, when the pattern having such a border portion is switched to another pattern, the afterimage is improved by the blurred border portion.

Such boundary part transformation may be variously modified, and may be modified in the order of bright, dark, dark, light, bright, ....., etc., as shown in FIG. You can do this by dimming. In addition, the converted line may increase the number of lines in various ways, such as three or four, instead of two lines, or may be converted into one line, and the next line (n + 1) and the next line (n +). It is also possible to convert to the previous line n-1 and the previous line n-2 instead of 2).

Then, the boundary part converter 651 applies the thus converted boundary part to the image signal and outputs it (S550).

Then, the controller 200 generates and outputs an X electrode driving signal, a Y electrode driving control signal, and an address electrode driving signal from the input image signal.

Then, the address driver 300 receives the address electrode driving signal and applies a display data signal for selecting the discharge cells to be displayed to each address electrode A1-Am, and the X electrode driver 500 drives the X electrode. The signal is received and a driving voltage is applied to the X electrodes X1 to Xn, and the Y electrode driving unit 400 receives a Y electrode driving signal to apply a driving voltage to the Y electrodes Y1 to Yn.

As a result, data without an afterimage is displayed on the plasma panel 100.

The present invention is not limited to the above embodiments, but may be modified and improved by those skilled in the art within the spirit and scope of the invention as defined in the claims.

As described above, in the embodiment of the present invention, when the entire still image is input, the luminance is lowered, and when the partial still image is input, the afterimage may be prevented by moving the partial still image or faintly converting the boundary portions. A method and an apparatus for preventing an afterimage of a plasma panel which is present, and a plasma display panel having the apparatus can be provided.

Claims (20)

delete delete delete delete A still image determination unit which receives an external image signal and determines whether the image is a still image; A still image region determination unit which determines an area of a still image input by the still image determination unit; A luminance controller which controls to lower the luminance of the image data when the entire screen is a still image; A boundary portion extractor for extracting a boundary portion of the still image when a portion of the screen is a still image; And a boundary portion converter configured to periodically add or subtract and convert image data of the boundary portion of the still image extracted by the boundary portion extractor. The method of claim 5, The boundary portion extracting unit extracts the boundary portion in a single line shape. The method of claim 6, And the boundary portion converting unit generates image data of the next line of the boundary portion line by periodically adding or subtracting image data of the boundary portion. The method of claim 7, wherein And the boundary portion conversion unit generates and subtracts the image data of the next line of the boundary portion line at intervals of 180 degrees out of phase with the next line of the boundary portion line. A plasma panel including a plurality of address electrodes, a plurality of scan electrodes, and a sustain electrode; A residual image prevention unit for determining whether the image is a still image by receiving an image signal, controlling the luminance to be lowered to a predetermined luminance when the entire screen is a still image, and converting and outputting data of the still image portion when the portion is a still image; A controller for controlling luminance according to the luminance control signal output from the afterimage prevention unit, and generating and outputting a sustain electrode driving signal, a scan electrode driving signal, and an address electrode driving signal by receiving an image signal of the afterimage preventing unit; An address electrode driver for applying a voltage to the address electrode of the plasma panel according to an address driving signal output from the controller; A sustain electrode driver for applying a sustain voltage to the sustain electrode according to a sustain electrode driving signal of the controller; A sustain electrode driver configured to apply a scan voltage to the scan electrode according to the scan electrode driving signal of the controller; The afterimage prevention unit, A still image determination unit which receives an external image signal and determines whether the image is a still image; A still image region determination unit which determines an area of a still image input by the still image determination unit; A luminance controller which controls to lower the luminance of the image data when the entire screen is a still image; A boundary portion extractor for extracting a boundary portion of the still image when a portion of the screen is a still image; And a boundary portion converter for periodically adding or subtracting and converting image data of the boundary portion of the still image extracted by the boundary portion extractor. delete delete The method of claim 9, The still image determination unit, And determining that the difference between the previous field and the current field is less than or equal to a predetermined value when the difference is greater than or equal to the predetermined field. The method of claim 12, The boundary portion converting unit generates image data of the next line of the boundary portion line by periodically adding or subtracting image data of the boundary portion, and generates image data of the next line of the boundary portion line with the next line of the boundary portion line. And a plasma display panel, the plasma display panel being generated at intervals of varying road phases. delete delete delete A method of preventing an afterimage of a plasma panel including a plurality of address electrodes and a plurality of scan electrodes and sustain electrodes, A first step of receiving an image signal and determining whether the image is a still image or a moving image; A second step of determining whether the full screen is a still image if it is a still image; If the entire screen is a still image, reducing the luminance of the video signal; If the specific portion is a still image, extracting a boundary portion of the still image; And a fifth step of periodically adding or subtracting the extracted image data of the boundary portion, and outputting the converted image data. The method of claim 17, In the fourth step, the afterimage boundary method of the partial still image is extracted in the form of a single line. The method of claim 18, The fifth step is a method for preventing afterimages in a plasma panel, characterized in that the boundary area of the partial still image is converted to become blurred when viewed with the naked eye. The method of claim 18, In the fifth step, the image data of the next line of the boundary portion line is generated by periodically adding or subtracting the image data of the boundary portion, and the image data of the next line of the boundary portion line and the next line of the boundary portion line. An afterimage prevention method of a plasma panel, characterized in that the generation by adding or subtracting at a period of 180 degrees phase change.

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