KR20050038912A - Driving apparatus of plasma display panel and method for displaying pictures on plasma display panel - Google Patents

Abstract

The present invention relates to an apparatus for driving a plasma display panel and an image display method for a plasma display panel for increasing a subfield without installing hardware. The present invention detects whether subfields having the same luminance weight are simultaneously turned on or off in the first and second subfield groups when the input image signals are arranged in successive first and second subfield groups. In this case, when subfields having the same luminance weight are simultaneously turned on or off, the same luminance belonging to the first subfield group without storing address data of the subfield having the same luminance weight belonging to the second subfield group when the memory is stored. Only address data of weighted subfields is stored in the memory. Here, when the address data of the subfields of the second subfield group having the same luminance weight is read from the memory, the address data of the subfields of the first subfield group having the same luminance weight is replaced and read from the memory. Through this, the subfield can be increased without increasing hardware and the storage memory capacity can be reduced.

Description

The driving device of the plasma display panel and the image display method of the plasma display panel {DRIVING APPARATUS OF PLASMA DISPLAY PANEL AND METHOD FOR DISPLAYING PICTURES ON PLASMA DISPLAY PANEL}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving apparatus for a plasma display panel (PDP) and an image display method for a plasma display panel, and more particularly to a plasma display panel driving apparatus and a plasma display panel for increasing a subfield without installing hardware. It relates to an image display method.

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

A plasma display panel is a flat panel display device that displays characters or images using plasma generated by gas discharge, and tens to millions or more of pixels are arranged in a matrix form according to their size. The plasma display panel is classified into a direct current type and an alternating current type according to a shape of a driving voltage waveform applied and a structure of a discharge cell.

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

On the other hand, in the plasma display panel, flicker occurs in expressing gray scale, which is closely related to human visual characteristics. Generally, the larger the screen or the lower the frequency, the better the flicker is perceived to the eye. When the image of the PAL image signal is implemented in the plasma display panel, the two conditions are satisfied to generate a large amount of flicker.

Therefore, a large amount of flicker is generated when the plasma display panel 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 plasma display panel.

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

Korean Patent Laid-Open Publication No. 2000-16955 is a conventional method for reducing such flicker by adjusting such frequencies. As disclosed in FIG. 1, in order to reduce a large screen flicker generated when a plasma display panel is driven using a 50 Hz image signal, the disclosed patent includes subfields in one frame into two groups G1 and G2. Each subfield is set to have the same structure except for the LSB (Least Significant Bit) subfield, or the luminance weight is similarly distributed 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.

In this case, when the subfields are arranged in two groups as shown in FIG. 1, subfields having the same subfield luminance weights exist, and even when subfields having the same luminance weight are simultaneously turned on. Subfield generation and address data are generated and applied to the plasma display panel. However, when the subfields are arranged in two groups in order to reduce flicker in the above manner, the number of subfields is large, resulting in an increase in the operation clock and storage memory capacity when storing address data. .

The technical problem to be solved by the present invention is to solve the above-mentioned problems of the prior art, and the image of the plasma display panel which reduces the increase of the subfield generated when driving the input image signal of one frame divided into two subfield groups. It is for providing a display method.

A driving apparatus of a plasma display panel according to a feature of the present invention for achieving the above object is

When the input video signal is a PAL signal, subfield data including two consecutive first and second subfield groups is generated, and subfields having the same luminance weight in the first and second subfield groups are simultaneously. A subfield generator for detecting whether it is on or off;

The subfield data is divided into respective subfields, and address data is stored in a frame memory to output address data for each subfield, and the subfield generator detects that subfields having the same luminance weight are simultaneously turned on and off. A memory controller for storing only address data of subfields belonging to a first subfield group among subfields having the same luminance weight in a frame memory; And

And an address driver for generating and outputting a control signal corresponding to the address data output from the memory controller. Here, when the address control unit reads address data corresponding to a subfield belonging to a second subfield group among the subfields having the same luminance weight from the frame memory, the memory controller controls the first subfield group among the subfields having the same luminance weight. The address data corresponding to the subfield belonging to is replaced by the frame memory.

The gray scale display method of the plasma display panel according to another aspect of the present invention

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 weights of the plurality of subfields.

(a) dividing the plurality of subfields into successive first and second subfield groups to form subfields to form subfield data;

(b) detecting whether subfields having the same luminance weight in the first and second subfield groups are turned on or off at the same time; And

(c) when detecting that the subfields having the same luminance weight are simultaneously turned on and off in step (b), only the address data of the subfields belonging to the first subfield group among the subfields having the same luminance weight are frame memory Including the step of storing in. Here, when outputting the address data stored in the step (c), the address data of the subfield belonging to the second subfield group among the subfields having the same luminance weight is the address data of the subfield belonging to the first subfield group. It further includes the step of outputting.

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.

A driving apparatus of a plasma display panel and an image display method of the plasma display panel according to an exemplary embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

2 is a schematic plan view of a plasma display panel according to an embodiment of the present invention.

As shown in FIG. 2, the plasma display panel according to the exemplary embodiment of the present invention includes a plasma panel 100, an address driver 200, a scan / sustain driver 300, and a controller 400.

The plasma panel 100 includes a plurality of address electrodes A1-Am arranged in the column direction, and a plurality of scan electrodes Y1-Yn and sustain electrodes X1-Xn arranged in a zigzag pattern in the row direction. . The address driver 200 receives an address drive control signal from the controller 400 and applies a display data signal for selecting a discharge cell to be displayed to each address electrode A1-Am. The scan / hold driver 300 receives a control signal from the controller 400 and alternately inputs a sustain voltage to the scan electrodes Y1-Yn and the sustain electrodes X1-Xn to perform sustain discharge for the selected discharge cell. .

The controller 400 receives R, G, and B image signals and a synchronization signal from the outside, divides one frame into several subfields, and divides each subfield into a reset period, an address period, and a sustain discharge period to drive the plasma display panel. do. At this time, the controller 400 adjusts the number of sustain pulses in each sustain period of the subfield in one frame and supplies the necessary control signals to the address driver 200 and the scan sustain driver 300.

Hereinafter, the controller 400 according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 3 and 4.

3 is a schematic block diagram of a controller 400 of a plasma display panel according to an exemplary embodiment of the present invention. FIG. 4 is a diagram illustrating a case in which the luminance weights are simultaneously turned on in the same subfield 7 in the subfield array when the subfield array is divided into two groups and the subfield array according to the input image signal data.

As shown in FIG. 3, the control unit 400 of the plasma display panel includes an image signal processor 410, a vertical frequency detector 420, a gamma correction and error diffusion unit 430, a subfield generator 440, and a memory controller. 450, an address driver 460, a frame memory unit 470, a sustain / scan pulse drive control unit 480, and a sustain / scan pulse driver 490.

The image signal processor 410 digitizes an image signal input from the outside to generate digital image data.

The vertical frequency detector 420 analyzes the digital image data output from the image signal processor 410 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 430 receives digital image data output from the vertical frequency detection unit 420, 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 420 is 50Hz or 60Hz is output to the subfield generator 440 and the sustain / scan pulse drive controller 480 as it is.

The subfield generator 440 receives the digital image data and the data switch value output from the gamma correction and error diffusion unit 430, 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 input 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 an image signal of 50 Hz, as shown in FIG. 4, the data switch value is divided into two subfield groups G1 and G2, and the first and second groups G1 and G2 are divided into two groups. Subfield data is generated so that there are seven subfields each. The subfield data generated as described above is output to the memory controller 450. At this time, the number of subfields and the luminance weight of each subfield can be changed by those skilled in the art.

At this time, the subfield generation unit 440 generates the subfield data whether or not the subfields having the same subfield luminance weight are simultaneously turned on in the digital image data (one pixel means data) of one frame. Judge. That is, as illustrated in FIG. 4, it is determined whether subfield 7, which is a subfield having the same luminance weight, is turned on or off among digital image data of one frame. For example, when the gray level value of the digital image data is 80, the subfield 7 (luminance weight 40) of the first group G1 and the second group G2 is turned ON in the subfield arrangement as shown in FIG. The subfield generator 440 generates the digital image data to have the subfield arrangement as shown in FIG. 4 and detects that the subfield 7 having the same luminance weight is turned on. As described above, in the case of a 50 Hz input video signal, the subfield generator 440 generates two groups of subfield arrays (meaning the subfield array as shown in FIG. 4), and equal luminance weights in each subfield belonging to the two groups. It also detects whether or not the subfield having ON is ON or OFF at the same time. The subfield generation unit 440 also outputs the state information for which the same weight is simultaneously turned on or off together with the subfield data to the memory controller 450.

The memory controller 450 separates the subfield data transmitted from the subfield generator 440 for each subfield for all subfields of one frame, and for each subfield (that is, the subfield data for all pixels of one frame). Information is separated for each subfield and stored according to the subfield) and stored in the frame memory unit 470. At this time, the memory controller 450 also receives the state information from the subfield generator 440 that the same weight described above is ON or OFF at the same time. OFF)), the memory controller 450 stores the address data corresponding to the same weight in the frame memory unit 470 only once (that is, the address data of the subfield having the same weight is stored in the first group G1). ) Is stored only in the subframe of frame memory). In addition, the memory controller 450 reads address data for each subfield from the frame memory unit 470 and transmits the address data to the address driver 460. In this case, the same weights are simultaneously turned on or off when each subfield address data is read from the frame memory unit 470 using information that is simultaneously turned on or off. For the same weight subfield of the two groups, the address data of the same weight subfield of the first group is read. That is, only one time is stored for the subfields (meaning when the same weighted subfields are ON or OFF at the same time) when they are stored in the frame memory unit 470 and the frame memory unit 470 is stored once. When reading, the stored address data is replaced.

For example, the case where the digital image data is gradation 80 as shown in FIG. 4 will be described. When the digital image data is 80, the subfield 7 having the luminance weight 40 is turned on at the same time (that is, the subfield 7 of the first group G1 and the subfield 7 of the second group G2). This information is detected by the subfield generator 440 and transmitted to the memory controller 450. The memory controller 450 divides the subfield data for each subfield and stores the address data for the subfield 7 of the second group G2 (that is, the subgroup of the second group G2 in the predetermined pixel) when the subfield data is stored in the memory storage unit. Information on whether the field 7 is ON or not) is stored in the frame memory unit 470 without storing the address data for the subfield 7 of the first group G2 in the frame memory unit 470. . This method is performed simultaneously on the gradations for all the pixels. In addition, the memory controller 450 may read the address data of the subfield 7 of the first group G1 with respect to the address data of the subfield 7 of the second group G2 even when reading address data from the frame memory unit 470. Read in place.

 The address driver 460 applies the address data A1, A2, ... Am of the plasma panel 100 to correspond to the address data output from the memory controller 450.

On the other hand, the sustain / scan pulse drive control unit 480 uses the number of sustain pulses corresponding to the subfield arrangement (this is determined according to the load ratio detected by the APC unit although not shown in FIG. 3) and the data switch values. By subdividing the case of the 50 Hz video signal and the case of the 60 Hz video signal according to the switch value, a subfield array structure is generated and output to the sustain / scan pulse driver 490, respectively.

The sustain / scan pulse driver 490 generates sustain pulses and scan pulses based on the subfield array structure output from the sustain / scan pulse drive controller 480 to scan electrodes X1, X2,. Xn) and sustain electrodes Y1, Y2, ..., Yn.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

As described above, according to the present invention, when the subfield array is divided into two groups, when the subfields having the same luminance weight are ON or OFF at the same time, they are stored only once when storing the address data. When loading and loading, you can increase the subfields without increasing hardware by loading them redundantly. This can also reduce the capacity of the storage memory.

1 is a diagram illustrating a conventional subfield arrangement.

2 is a schematic plan view of a plasma display panel according to an embodiment of the present invention.

3 is a schematic block diagram of a controller of a plasma display panel according to an exemplary embodiment of the present invention.

FIG. 4 is a diagram illustrating a case in which the luminance weights are simultaneously turned on in the same subfield 7 in the subfield array when the subfield array is divided into two groups and the subfield array according to the input image signal data.

Claims (7)

When the input video signal is a PAL signal, subfield data including two consecutive first and second subfield groups is generated, and subfields having the same luminance weight in the first and second subfield groups are simultaneously. A subfield generator for detecting whether it is on or off; The subfield data is divided into respective subfields, and address data is stored in a frame memory to output address data for each subfield, and the subfield generator detects that subfields having the same luminance weight are simultaneously turned on and off. A memory controller for storing only address data of subfields belonging to a first subfield group among subfields having the same luminance weight in a frame memory; And And an address driver for generating and outputting a control signal corresponding to the address data output from the memory controller. The method of claim 1, The memory controller, when reading address data corresponding to a subfield belonging to a second subfield group among the subfields having the same luminance weight, from the frame memory, belongs to the first subfield group among the subfields having the same luminance weight. And the address data corresponding to the subfield is retrieved from the frame memory. The method according to claim 1 or 2, And a vertical frequency detector for detecting whether an input video signal is a PAL signal and outputting the result as a data switch value to the subfield generator. 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 weights of the plurality of subfields. (a) dividing the plurality of subfields into successive first and second subfield groups to form subfields to form subfield data; (b) detecting whether subfields having the same luminance weight in the first and second subfield groups are turned on or off at the same time; And (c) when detecting that the subfields having the same luminance weight are simultaneously turned on and off in step (b), only the address data of the subfields belonging to the first subfield group among the subfields having the same luminance weight are frame memory And storing the data in the plasma display panel. The method of claim 4, wherein When outputting the stored address data in step (c), address data of a subfield belonging to a second subfield group among subfields having the same luminance weight replaces address data of a subfield belonging to the first subfield group. And outputting the same. The method of claim 5, And generating a control signal corresponding to the output address data and applying the control signal to the plasma display panel. The method of claim 4, wherein Detecting before the step (a) whether the input video signal is a PAL signal and outputting the result as a data switch value.