KR20060098458A - Method of preventing permanent image sticking in plasma display panel - Google Patents

Abstract

The present invention relates to a method for preventing permanent afterimage generation of a plasma display panel, and more particularly, a still image sensing step of detecting whether an input image to be displayed on a screen is a still image; And a permanent afterimage generation prevention step of preventing permanent afterimages by repeatedly moving the displayed image when the input image is a still image. According to the present invention, the permanent display of the edge portion of the panel that can be deepened when the image of the aspect ratio of 4: 3 is displayed on the plasma display panel having the aspect ratio of 16: 9 in the long term is effectively prevented. It can be prevented.

Description

Method of preventing permanent image sticking in plasma display panel

1 is a perspective view showing an internal structure of a conventional three-electrode surface discharge plasma display panel.

FIG. 2 is a cross-sectional view illustrating a configuration of a unit display cell of the panel of FIG. 1.

3 is a graph schematically illustrating a method for preventing permanent image retention in a conventional plasma display panel.

4A is a schematic plan view of a plasma display panel having a typical horizontal and vertical ratio of 16: 9.

FIG. 4B is a schematic plan view illustrating generation of black regions on both sides of the panel by displaying a 4: 3 image on the 16: 9 plasma display panel of FIG. 4A.

FIG. 4C is a schematic plan view illustrating that afterimages are again displayed on the plasma display panel of FIG. 4B to increase permanent persistence due to an edge effect.

5A to 5D are flowcharts schematically illustrating a screen moving algorithm for a method of preventing permanent afterimage generation of a plasma display panel according to an exemplary embodiment of the present invention.

The present invention relates to a method for preventing permanent image retention of a plasma display panel. More particularly, the present invention relates to a plasma display panel having a aspect ratio of 16: 9. The present invention relates to a method for preventing permanent afterimage generation of a plasma display panel that can effectively prevent the generation of permanent afterimages at the edges of a panel which may be deepened when displayed for a long time.

1 is an internal perspective view illustrating a structure of a conventional three-electrode surface discharge plasma display panel, and FIG. 2 is a cross-sectional view illustrating a unit display cell of the panel of FIG. 1.

Referring to the drawings, between the front and rear glass substrates 10, 13 of the conventional surface discharge plasma display panel 1, the address electrode lines A _R1 , A _G1 , ..., A _Gm , A _Bm ), Dielectric layers 11 and 15, Y electrode lines (Y ₁ , ..., Y _n ), X electrode lines (X ₁ , ..., X _n ), fluorescent layer 16, partition wall 17 ) And a magnesium monoxide (MgO) layer 12 as a protective layer.

The address electrode lines A _R1 , A _G1 ,..., A _Gm , A _Bm are formed in a predetermined pattern on the front side of the rear glass substrate 13. The lower dielectric layer 15 is applied entirely in front of the address electrode lines A _R1 , A _G1 ,..., A _Gm , A _Bm . In front of the lower dielectric layer 15, barrier ribs 17 are formed in a direction parallel to the address electrode lines A _R1 , A _G1 ,..., A _Gm , A _Bm . These partitions 17 function to partition the discharge area of each discharge cell and prevent optical cross talk between each discharge cell. The fluorescent layer 16 is formed between the partition walls 17.

The X electrode lines (X ₁ , ..., X _n ) and the Y electrode lines (Y ₁ , ..., Y _n ) are the address electrode lines (A _R1 , A _G1 , ..., A _Gm , A _Bm ) is formed in a constant pattern on the back of the front glass substrate 10 to be orthogonal to each other. Each intersection sets a corresponding discharge cell. Each X electrode line (X ₁ , ..., X _n ) and each Y electrode line (Y ₁ , ..., Y _n ) are connected to a transparent electrode line and conductivity of a transparent conductive material such as ITO (Indium Tin Oxide). Metal electrode lines for heightening are formed in combination. The front dielectric layer 11 is formed by applying the entire surface to the back of the X electrode lines (X ₁ , ..., X _n ) and the Y electrode lines (Y ₁ , ..., Y _n ). A protective layer 12 for protecting the panel 1 from a strong electric field, for example a magnesium monoxide (MgO) layer, is formed by applying the entire surface to the rear of the front dielectric layer 11. The gas for plasma formation is sealed in the discharge space 14.

As a driving method of the plasma display panel 1 having the above-described structure, an address-display separation driving method mainly used is disclosed in US Pat.

When the input image signal of the plasma display panel is input as the same signal for a long time, permanent image sticking may occur due to damage of the phosphor and the protective layer (MgO). In order to prevent this, an afterimage preventing method of the plasma display panel may be used.

3 is a graph schematically illustrating a method for preventing afterimage generation of a conventional plasma display panel.

Referring to the drawings, in the conventional method of preventing afterimage generation of a plasma display panel, it is determined whether a received image input signal is a still image, and in the case of a still image, the number of sustain pulses is gradually reduced. In this case, the number of sustain pulses may be expressed as luminance as shown in the figure, and the graph shows a luminance reduction algorithm by decreasing the number of sustain pulses at the time of inputting a still image. In this case, it is based on the 1% window.

That is, when the same still picture is detected for a predetermined time t ₀ , the received video input signal is determined to be a still picture, and the number of sustain pulses is reduced step by step. At this time, when the number of the sustaining pulses is reduced in stages to reach a predetermined time t ₁ , the number of the sustaining pulses that are decreased is saturated.

However, in the conventional method of preventing afterimage generation, the number of sustaining pulses is unilaterally reduced, and thus the luminance is reduced, so that the change in brightness of the screen can be easily detected with the naked eye. That is, in this case, although there is an effect of reducing the permanent afterimage in the still image, there is a problem that the luminance of the screen to be displayed is not sufficiently expressed.

This is the main purpose of the display such as the display of an image or a character when the same video signal is prolonged for a long time to deliver the brightness, which results in sacrificing the display of the target brightness by the down rate shown.

In particular, most commercially available plasma display panels are manufactured in a ratio of 16: 9 in aspect ratio (Fig. 4A), but a ratio of 4: 3 may be preferred for certain fields and consumers. When a 4: 3 image is displayed on such a 16: 9 panel, black regions exist at both sides of the panel (FIG. 4B), and thus, these black regions are relatively less deteriorated. As a result, displaying a 16: 9 image later on such a 16: 9 panel causes a deeper afterimage due to a border effect (FIG. 4C).

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and prevents the occurrence of permanent image sticking, which may occur when a still image is continued for a long time, and at the same time, displays a plasma display capable of sufficiently displaying the luminance of a screen to be displayed. An object of the present invention is to provide a method for preventing the occurrence of afterimages on a panel.

In particular, the present invention effectively prevents the occurrence of permanent afterimages at the edges of the panel, which may be deepened when a long-term display of 4: 3 aspect ratio is 4: 3 on a plasma display panel having a 16: 9 aspect ratio. An object of the present invention is to provide a method of preventing permanent image retention of a plasma display panel.

The present invention in order to achieve the above technical problem, in one embodiment,

A method for preventing permanent afterimage generation of a plasma display panel,

A still image detecting step of detecting whether an input image to be displayed on the screen is a still image; And

When the input image is a still image, permanent afterimage prevention step of preventing permanent afterimage by repeatedly moving the displayed image

It provides a method for preventing permanent afterimage generation of the plasma display panel comprising a.

In the permanent afterimage generation prevention step, if the input image is determined to be a still image by the detection in the still image detection step, the permanent afterimage generation prevention step is performed, and when it is determined that the input image is not a still image, It is preferable not to perform the permanent afterimage prevention step.

Preferably, the step of preventing permanent image retention includes a first step, a second step, a third step, and a fourth step which are repeatedly performed. In the first step, the displayed image is moved in one direction from the center of the plasma display panel. In the second step, the displayed image is moved back to the center of the plasma display panel. In a step opposite to one side direction in the step, the fourth step moves the displayed image back to the center of the plasma display panel.

In the method according to the present invention, the displayed image is preferably moved at a time interval of 1 minute to 10 hours. This is because when the time interval is too short to be less than the range, there is a problem of increasing the possibility of detecting the screen movement, and when the time interval is too long to exceed the range, it is not preferable because there is a problem of permanent permanent image generation.

The method of preventing permanent afterimage generation according to the present invention may be usefully applied to various plasma display panels, but preferably may be applied to a plasma display panel having a horizontal and vertical ratio of 16: 9. It is preferable that the aspect ratio is 4: 3.

According to the present invention, it is possible to faithfully display the luminance of the screen to be expressed while preventing the occurrence of permanent afterimages that may occur when a still image is continued for a long time. It is possible to effectively prevent the occurrence of permanent afterimages at the edges of the panel, which may be deepened when displaying an image having a 4: 3 aspect ratio in a long term.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 5 is a flowchart schematically illustrating a screen shift algorithm for a permanent afterimage prevention step in the method of preventing permanent afterimage generation of a plasma display panel according to an exemplary embodiment of the present invention.

In the still image detection step, the 4: 3 image determined as the still image is displayed at the center of the 16: 9 plasma display panel (FIG. 5A), and the image displayed at the center of the panel is 10 minutes after the start of display. , 1 to 5 pixels to the left side of the panel (pixel means a white composition unit, it is not desirable because the moving distance is greater than 5 pixels, there is a problem that the detectability of the screen movement is sharply increased). (FIG. 5B).

Then, the still image, which has been moved to the left of the panel, is moved back to the center of the panel after 10 minutes have elapsed (Fig. 5C). Finally, the still image, which has been moved to the center of the panel, is moved to the right side of the panel (FIG. 5D), and the permanent afterimage prevention step according to the present invention is performed by repeating the above steps 5a to 5d.

According to the present invention, there is provided a method of preventing afterimage generation of a plasma display panel capable of sufficiently displaying the luminance of a screen to be displayed while preventing the occurrence of permanent image sticking that may occur when a still image continues for a long time. In particular, a permanent display of the edges of the panel may be generated when a long-term display of a 4: 3 aspect ratio is displayed on a plasma display panel having a 16: 9 aspect ratio. A method of preventing permanent afterimage generation of a plasma display panel that can be effectively prevented can be provided.

Claims (5)

A method for preventing permanent afterimage generation of a plasma display panel, A still image detecting step of detecting whether an input image to be displayed on the screen is a still image; And When the input image is a still image, permanent afterimage prevention step of preventing permanent afterimage by repeatedly moving the displayed image Permanent afterimage generation of the plasma display panel comprising a. The method of claim 1, In the permanent afterimage generation prevention step, if the input image is determined to be a still image by the detection in the still image detection step, the permanent afterimage generation prevention step is performed, and when it is determined that the input image is not a still image, A permanent afterimage prevention method of a plasma display panel, characterized in that the step of preventing permanent afterimage generation is not performed. The method of claim 1, The permanent afterimage prevention step, A first step of moving the displayed image in one direction from a center of the plasma display panel; A second step of moving the displayed image back to the center of the plasma display panel; A third step of moving the displayed image in a direction opposite to one side direction in the first step; And A fourth step of moving the displayed image back to the center of the plasma display panel Method of preventing permanent afterimage generation of the plasma display panel, characterized in that for repeatedly performing. The method of claim 1, And the displayed image is moved at a time interval of 1 minute to 10 hours. The method of claim 1, The plasma display panel is a plasma display panel having a ratio of 16: 9 in width and length, and the displayed image is an image having a ratio of 4: 3 in width and length. .

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