KR20040063567A - Method for preventing image sticking on a image display device using pdp module - Google Patents

Abstract

PURPOSE: A method for preventing an afterimage of an image display device using a PDP module is provided to prevent afterimages on a screen by dividing the screen into blocks and changing each contrast ratio of the divided blocks. CONSTITUTION: A method for preventing an afterimage of an image display device using a PDP module includes a division process, a detection process, and a reduction process. The division process is performed to divide a full screen into a plurality of blocks(110). The detection process is performed to detect a displaying state of a still picture and a displaying state of a motion picture from the divided blocks(120). The reduction process is performed to reduce a contrast ratio of the blocks corresponding to the still pictures(130). In addition, the reduction process is performed to reduce the contrast ratio of the full screen when the number of the blocks corresponding to the still pictures is more than a predetermined number(140,150).

Description

How to prevent after-image of video display device using PD module {METHOD FOR PREVENTING IMAGE STICKING ON A IMAGE DISPLAY DEVICE USING PDP MODULE}

The present invention relates to a method for preventing afterimages in a PDP, and more specifically, blocks the entire screen of the PDP panel, detects whether the image is a still image or a moving image in units of blocks, and thus prevents the occurrence of afterimages in units of blocks. It relates to a method of preventing afterimages.

In the image display device using the PDP module, when a still image is displayed for a long time, an image sticking phenomenon occurs in which the phosphor of the partition wall of the inner cell of the PDP module is worn and an afterimage occurs between the bright part and the dark part. This phenomenon greatly affects the image quality of the video display device.

In order to prevent an afterimage as described above, a conventional image display device using the PDP module uses a method of gradually darkening the brightness of an image when a still image is displayed for a long time. However, this conventional method reduces the degree of the afterimage on the screen, but does not completely prevent the afterimage from occurring.

In another conventional method proposed to prevent afterimages from occurring, when a still image is displayed on the PDP module for a long time, several horizontal and vertical pixel lines move up, down, left, and right to reduce the level of the still image. There is a method of preventing the afterimage from occurring. However, according to the conventional method, it is difficult for a viewer to detect when moving one pixel line, but in this case, there is no significant effect on preventing afterimage, and when moving at least three pixel lines up, down, left, and right Although there is an afterimage preventing effect, there is a problem that the viewer detects movement.

In order to solve the above problems, an object of the present invention is to provide a method for blocking an entire screen and preventing after-images on a block basis in a video display device using a PDP module.

1 is a flowchart sequentially illustrating a method of preventing an afterimage in a video display device using a PDP module according to the present invention.

2 is a diagram illustrating a screen divided into 16 blocks by an afterimage preventing method according to an exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

200: screen

210: block with reduced contrast ratio

According to an aspect of the present invention, there is provided a method of preventing an afterimage in a video display device using a PDP module, the method comprising: (a) dividing an entire screen into a predetermined number of blocks; and (b) dividing each block. Regarding, the method may further include detecting whether the still image or the moving image is displayed, and (c) the block on which the still image is displayed comprises reducing the contrast ratio.

In this case, the method may further include determining the number of blocks on which the still image is displayed and reducing the contrast ratio of the entire screen when the number of blocks on which the still image is displayed is greater than or equal to a predetermined number.

In the step (b), when the number of discharges of a specific block is the same as the number of sustain discharges previously stored in the memory, it is preferable to determine that the still image is displayed on the block.

According to the present invention, a screen of an image display device using a PDP module is classified into a predetermined number of blocks, and it is determined that each of the classified blocks and the pixels constituting the blocks are still images, and the contrast ratio of the corresponding blocks is changed. By preventing the afterimage on the screen, it is possible to obtain an improved afterimage prevention effect while not being detected by the viewer.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention. First, in adding reference numerals to the components of each drawing, it should be noted that the same components are denoted by the same reference numerals as much as possible even if they are displayed on different drawings.

Hereinafter, a method of preventing afterimages in a video display device using a PDP module according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a flowchart sequentially showing a method of preventing an afterimage according to the present invention. Referring to FIG. 1, first, information about each pixel of a full screen is stored in a memory (step 100). In this case, the information on the pixels stored in the memory is data obtained by counting the number of discharges for each pixel.

Next, the entire screen is divided into a predetermined number of blocks (step 110). FIG. 2 exemplarily shows that the entire screen (200 of FIG. 2) is divided into 16 blocks. For example, in the case of the PDP module having 852 × 480 pixels in width × length, if the block is divided into 16 blocks, each block is composed of 213 × 120 pixels, which can be represented by start coordinates and end coordinates. .

Next, it is determined whether a still image or a moving image is displayed for each divided block (step 120). In general, since the brightness of the PDP module consists of sustain discharge, the brightness and contrast ratio are determined by the number of discharges. Therefore, in order to determine whether the image displayed in each block is a still image, data on the number of sustain discharges is read out of information on the corresponding pixels of each block previously stored in the memory, and the read data and the present By comparing the number of discharges for the corresponding pixels of, it is determined that the number of discharges of the pixels in the block is the same as the stored data.

If the block is determined to be a still image through this process, the contrast ratio of the block is reduced to such an extent that the quality of the block is not affected (step 130).

Next, if the number of blocks determined to be the still image is more than a certain number (step 140), the contrast ratio for the entire screen is adjusted to be the same as the block in which the still image is displayed and the contrast ratio is lowered (step 150). As shown in FIG. 2, when the entire screen is divided into 16 blocks, if the still image is displayed in four or more blocks, it may be desirable to constantly lower the contrast ratio for the entire screen.

On the other hand, when the size of one block is large, since there is too much information on the pixels per block, one block may be divided into four small blocks to use pixel information on the small blocks.

Next, the number of discharges for each pixel constituting each block is detected again, and the number of detected discharges is compared with the previously stored data, and when it is determined that they are different from each other and a video is displayed in a predetermined number or more blocks, the total The image on the screen is restored to its original contrast ratio and displayed normally. For example, when the entire screen is divided into 16 blocks, if it is determined that 13 or more blocks are displayed, it may be desirable to restore the contrast ratio of the entire screen normally.

Hereinafter, the operation of each component of the video display device including the PDP module operated according to the above-described afterimage prevention method will be described.

The video display device includes a microcontroller for managing and controlling all operations, a memory unit for storing predetermined data under control of the microcontroller, a scaler, and the like.

The memory unit stores information about each block, information on data of the number of sustain discharges for pixels of each block, and the like.

The microcontroller determines whether an image displayed in each block is a still image or a moving image using data stored in the memory unit. If the image displayed in a particular block is a still image, the microcontroller controls the scaler to reduce the contrast ratio of the block to prevent afterimages from occurring. In addition, if the number of blocks on which the still image is displayed is a certain number, the microcontroller adjusts the contrast ratio of the entire screen to be equal to the contrast ratio of the already reduced blocks.

As described above, in the detailed description of the present invention, specific embodiments have been described, but various modifications can be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims below, but also by those equivalent to the claims.

According to the present invention, a screen of an image display device using a PDP module is classified into a predetermined number of blocks, and it is determined that each of the classified blocks and the pixels constituting the blocks are still images, and the contrast ratio of the corresponding blocks is changed. By preventing the afterimage on the screen, it is possible to obtain an improved afterimage prevention effect while not being detected by the viewer.

Claims (3)

In the afterimage prevention method in a video display device using a PDP module, (a) dividing the entire screen into a predetermined number of blocks; (b) detecting, for each divided block, whether a still image or a moving image is displayed; (c) reducing the contrast ratio in the block in which the still image is displayed. Afterimage prevention method comprising the. The afterimage of claim 1, further comprising: determining the number of blocks on which the still image is displayed, and reducing the contrast ratio of the entire screen when the number of blocks on which the still image is displayed is greater than or equal to a predetermined number. Prevention method. The afterimage prevention of claim 1, wherein the step (b) determines that the still image is displayed when the specific block has the same number of discharges as the number of sustain discharges stored in the memory. Way.