KR20040079138A - Apparatus for driving plasa display panel - Google Patents

Abstract

PURPOSE: An apparatus for driving a plasma display panel is provided to improve the quality of image by minimizing the false contour noise with compensating the difference obtained by comparing the subfield mapped on the previous image data with the subfield mapped on the current image data. CONSTITUTION: An apparatus for driving a plasma display panel includes an inverse gamma correction unit(110), a gain controller(120), an error diffusion unit(130), a subfield mapping(140), a subfield frame storage and correction unit(160) and a data arranger(170). The inverse gamma correction unit(110) performs the inverse gamma correction of the image data. The gain controller(120) expands the data by multiplying the inverse gamma corrected image data by the gain. The error diffusion unit(130) diffuses the error into the adjacent pixels by using the error components existed in the pixels. The subfield mapping(140) maps so as to drive the error diffused image data by each of the subfield. The subfield frame storage and correction unit(160) stores the mapped previous subfield frame on the image data and compensates the mapped subfield to the current image data as the stored previous subfield frame. And, the data arranger(170) transmits the image data mapped as the subfield compensated at the subfield frame storage and correction unit(160) to the data driver of the plasma display panel(PDP) by being adaptively arranged in the format of PDP data driver.

Description

Apparatus for driving plasa display panel

The present invention relates to a driving device of a plasma display panel, and more particularly, to a difference between a subfield mapped to previous image data and a subfield mapped to current image data. The present invention relates to a driving apparatus of a plasma display panel which can improve image quality by minimizing moving image pseudo contour noise by comparing and compensating for.

In general, a plasma display panel (hereinafter referred to as a 'PDP') is an image including characters or graphics by emitting phosphors by 147 nm ultraviolet rays generated when discharged from He + Xe or Ne + Xe inert mixed gas. Will be displayed.

Such a PDP is not only thin and easy to enlarge, but also greatly improved in quality due to recent technology development.

In particular, the three-electrode AC surface discharge type PDP accumulates wall charges on the surface during discharge and protects the electrodes from sputtering caused by the discharge, and thus has advantages of low voltage driving and long life.

FIG. 1 is a diagram illustrating gradations during one frame of a typical plasma display panel. In order to realize gray levels of an image, the PDP may display various subfields SF1, SF2, SF3, SF4 having different number of emission times. , SF5, SF6, SF7, SF8).

Each subfield SF1, SF2, SF3, SF4, SF5, SF6, SF7, SF8 is again grayed out according to a reset period for causing discharge uniformly, an address period for selecting a discharge cell, and the number of discharges. It is divided into sustain periods to implement.

For example, in a case where the image is to be displayed with 256 gray levels, a frame period (16.67 ms) corresponding to 1/60 second is divided into eight subfields.

In addition, each of the eight subfields is divided into an address period and a sustain period.

FIG. 2 is a block diagram schematically illustrating a driving apparatus of a plasma display panel according to the related art, in which an inverse gamma correction unit 10 receives image data and performs inverse gamma correction, and gains the inverse gamma corrected image data. The controller 20 multiplies and multiplies the gain, and fine-tunes the luminance value by spreading the expanded image data to adjacent pixels using the error component in the pixels of the image.

The error-proliferated image data is mapped to be driven by each subfield mapping in the subfield mapping unit 40, and the mapped image data is PDP in the data arranger 50. When the data driver is arranged in accordance with the format of the data driver, the screen is generated on the PDP panel.

As described above, the PDP uses a method of adjusting the number of discharges by time division, which shows a very excellent characteristic when displaying still images by this driving method, but displays when the viewpoint of the observer moves. The phenomenon that the image to be distorted appears.

This is called a pseudo-animation contour, which is dependent on the product of the emission time of the pixel and the moving speed of the viewpoint and the temporal asynchronousness of the emission, which is represented by a distortion of gradation or a distortion of color.

And, the pseudo pseudo contour noise is observed between the frames, and when the levels in which the light emission patterns differ greatly are continuously displayed, for example, between the levels of 127-128 and 63-64.

This phenomenon occurs a lot in the moving object, which has a problem that the PDP quality is significantly reduced.

Accordingly, the present invention has been made to solve the above problems, and the difference between the subfields mapped to the previous image data and the subfields mapped to the previous image data is a pseudo pseudo contour noise that must be generated by subfield driving. The present invention aims to provide a driving device of a plasma display panel that can improve image quality by minimizing moving image pseudo contour noise by comparing and compensating.

A preferred aspect for achieving the above object of the present invention includes an inverse gamma correction unit that receives image data and performs inverse gamma correction;

A gain control unit for expanding the inverse gamma corrected image data by the inverse gamma correction unit by multiplying a gain;

An error diffusion unit that spreads the error of the image data expanded by the gain control unit to adjacent pixels using error components in the pixels of the image;

A subfield mapping unit for mapping the image data having an error spread by the error diffusion unit to be driven for each subfield;

A subfield frame storage and compensation unit for storing a previous subfield frame mapped to image data in the subfield mapping unit and compensating for a subfield mapped to current image data with the stored previous subfield frame;

And a data arranger for arranging the image data mapped to the subfields compensated by the subfield frame storing and compensating unit according to the format of the data driver of the PDP and transferring the image data to the data driver of the PDP panel. There is provided a driving device of the plasma display panel.

1 is a diagram illustrating gradations during one frame of a typical plasma display panel.

2 is a block diagram schematically illustrating a driving apparatus of a plasma display panel according to the related art.

3 is a block diagram of a driving device of a plasma display panel capable of removing pseudo pseudo contour noise according to the present invention.

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

110: reverse gamma correction unit 120: gain control unit

130: error diffusion unit 140: subfield mapping unit

151: subfield frame storage unit 152: subfield compensation unit

160: subfield frame storage and compensation unit 170: data alignment unit

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

3 is a block diagram of a driving apparatus of a plasma display panel capable of removing moving image pseudo contour noise, according to an embodiment of the present invention, comprising: an inverse gamma correction unit 110 that receives image data and performs inverse gamma correction; A gain controller (120) for expanding the inverse gamma corrected image data by the inverse gamma correction unit (110) by multiplying a gain; An error diffusion unit (130) for diffusing the image data expanded by the gain control unit (120) to an adjacent pixel using error components in the pixels of the image; A subfield mapping unit 140 for mapping the image data having an error spread by the error diffusion unit 130 to drive each subfield; A subfield frame storage and compensation unit 160 for storing a previous subfield frame mapped to image data in the subfield mapping unit 140 and compensating for a subfield mapped to current image data with the stored previous subfield frame; ; A data arranger for arranging the image data mapped to the subfields compensated by the subfield frame storage and compensator 160 in accordance with the format of the data driver of the PDP and transferring the image data to the data driver of the PDP panel. (170).

The moving picture pseudo contour noise removing device of the present invention configured as described above receives the image data in the inverse gamma correction unit 110 and performs inverse gamma correction, and the inverse gamma corrected image data is multiplied by the gain in the gain control unit 120 to expand it. Then, the error diffusion unit 130 diffuses the error to the adjacent pixels by using the error component in the pixel of the image, thereby finely adjusting the luminance value.

Here, the inverse gamma correction unit 110 inversely gamma corrects the gamma corrected video signal so as to be a signal suitable for the PDP and linearly converts the luminance value according to the gray value of the image signal.

Subsequently, the subfield mapping unit 140 maps the image data having spread with the error so as to be driven for each subfield mapping.

At this time, the present invention is characterized in that it further comprises a sub-field frame storage and compensation unit 160 compared to the prior art.

Therefore, the subfield frame storing and compensating unit 160 may include a subfield storage unit 151 for storing a previous subfield frame mapped to the image data in the subfield mapping unit 140, and the subfield frame storage unit. The subfield compensator 152 is provided with the previous subfield frame stored in 151 to compensate for the subfield mapped to the current image data, so that the pseudo pseudo contour noise is generated between the previous frame and the current frame. The subfield mapped to the image data can be compensated with the subfield frame mapped to the image data.

In more detail, the operation of the subfield frame compensator 152 is compared with the data values 1 through 128 of the previously mapped subfield and the data values 1 through 128 of the currently mapped subfield, and the previous mapping is performed. Compensates the data values of the currently mapped subfield frame to match the subfield frame.

As another compensation method, the subfield frame compensator 152 generates a moving picture pseudo contour noise mainly at 15, 16, 31, 32, 63, 64, 127, and 128. The amount of change of the most significant bit (MSB) and the least significant bit (LSB) of the subfield may be measured and compensated if it is changed.

In this case, the compensation may compensate only the most significant bit of the currently mapped subfield frame, or may only compensate the least significant bit.

For example, to compensate for 128, the most significant bit, change the value of '10000000' to '10000001' in binary representation.

The present invention compares and compensates the difference between the subfields mapped to the previous image data and the subfields mapped to the current image data by compensating for the moving image pseudo contour noise, which must be generated by the subfields, thereby minimizing the moving image pseudo contour noise. To improve the effect occurs.

Although the invention has been described in detail only with respect to specific examples, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.

Claims (4)

An inverse gamma correction unit which receives image data and performs inverse gamma correction; A gain control unit for expanding the inverse gamma corrected image data by the inverse gamma correction unit by multiplying a gain; An error diffusion unit that spreads the error of the image data expanded by the gain control unit to adjacent pixels using error components in the pixels of the image; A subfield mapping unit for mapping the image data having an error spread by the error diffusion unit to be driven for each subfield; A subfield frame storage and compensation unit for storing a previous subfield frame mapped to image data in the subfield mapping unit and compensating for a subfield mapped to current image data with the stored previous subfield frame; And a data arranger for arranging the image data mapped to the subfields compensated by the subfield frame storing and compensating unit according to the format of the data driver of the PDP and transferring the image data to the data driver of the PDP panel. And a driving device of the plasma display panel. The method of claim 1, The subfield frame storage and compensation unit, A subfield storage unit for storing a previous subfield frame mapped to image data in the subfield mapping unit; And a subfield compensator for receiving a previous subfield frame stored in the subfield frame storage to compensate for a subfield mapped to current image data. The method of claim 2, The subfield compensation unit, And compare data values of the previously mapped subfield with data values of the currently mapped subfield to compensate data values of the currently mapped subfield frame to match the previously mapped subfield frame. Drive. The method of claim 2, The subfield compensation unit, A device for driving a plasma display panel configured to measure and compensate changes in most significant bit (MSB) and least significant bit (LSB) of each previously mapped subfield and each currently mapped subfield. .