KR100517861B1 - Driving Method of Flat Panel Display - Google Patents

Abstract

The present invention divides one frame into a plurality of subframes, sets different sustain pulses to each subframe, selects the same number of display lines as the divided subframes, and allocates the divided subframes. After the front discharge and scanning in the sustain pulse period, display of each subframe is progressed, and then continuously moving by one or two lines until the display of each subframe divided for all display lines is completed. In the driving method, while the last display lines are selected and the display of the most significant bit subframe is performed, an erase pulse is applied to the display lines that have completed the display of all the subframes, and the display is stopped. After that is completed, the next frame display is started.

According to the present invention, the display of adjacent frames is prevented from overlapping, whereby two frames can be prevented from appearing in an overlapped state in the eyes of an observer at the time of moving picture representation.

Description

Driving Method of Flat Panel Display

The present invention relates to a method of driving a flat panel display, and more particularly, in a display device using an alternating-current plasma display panel, two frames are applied to an observer's eye when displaying a video by multi-scan frame division multiplexing in a single holding pulse. A driving method is adapted to prevent an image from appearing in an overlapped state.

Recently, the plasma display panel has advantages over other flat panel devices, such as being larger than 40 inches and easy to color, and having a wide viewing angle. Being potent.

In general, a plasma display panel is a device that displays characters or graphics by using light emitted from a plasma generated during gas discharge. The plasma display panel is a direct current (DC) type depending on the type of driving voltage applied externally to make a plasma. -Type) or AC-Type.

In addition, the plasma display panel is divided into a two-electrode type for performing selective discharge (address discharge) and sustain discharge by two electrodes and a three-electrode type for performing selective discharge (address discharge) and sustain discharge using three electrodes. do.

1 is a cross-sectional view schematically showing a discharge cell of a conventional plasma display panel, and FIG. 2 is a plan view showing a conventional three-electrode plasma display panel.

As shown in FIG. 1, the three-electrode plasma display panel 1 includes two glass substrates 12 and 13 arranged in parallel to each other and a first glass substrate 13 facing the second glass substrate 12. The first electrode 14 (X electrode) and the second electrode 15 (Y electrode), which are disposed in parallel with each other on the surface of the C, and cover the sustain electrodes 14 and 15. In order to protect the dielectric layer 18, the MgO layer 21 covered thereon is provided with the sustain electrodes 14 and 15 on the surface of the second glass substrate 12 facing the first glass substrate 13. A third electrode 16 arranged to be substantially orthogonal to each other and used as address electrodes, a partition 17 formed in a lattice or stripe shape between the two glass substrates to define each discharge cell, and the It is comprised by the fluorescent substance 19 arrange | positioned at the surface in which the address electrode 16 on the 2nd glass substrate 12 is formed.

As shown in Fig. 2, in the plasma display device, a plurality of X electrodes and Y electrodes are arranged in pairs in parallel with each other, and the Y electrodes are individual Y scan driving circuits (connected to the Y electrode holding driver circuit 3). 4-1 to 4-n are independently driven, and the X electrodes are connected in common and driven by a single X electrode driving circuit 5. The address electrodes 16-1 to 16-n are disposed orthogonal to the X electrodes and the Y electrodes, and the address electrodes are formed to be driven by the address driving circuit 6. Further, the individual Y scan driving circuits 4-1 to 4-n are connected to the Y electrode holding driving circuit 3, respectively, so that the scan pulses are connected to the Y scan driving circuits 4-1 to 4-n. And the sustain discharge pulses are generated by the Y electrode sustain drive circuit 3 to pass through the Y electrodes 15-1 to 15-n via the individual Y scan drive circuits 4-1 to 4-n. Is applied to. The common X electrode driving circuit 5 generates sustain pulses, which are applied in parallel to each X electrode. The drive circuits 3, 5, 6 are controlled by a control circuit (not shown), which is sequentially controlled by a synchronization signal and a display data signal applied from the outside of the apparatus. In FIG. 2, 1 represents a PDP panel, and 10 represents a cell constituting the PDP panel 10.

There are various driving methods for the multi-gradation display of the plasma display device. For example, a frame of one screen is divided into a plurality of subframes, each subframe is divided into an addressing period and a sustaining period, and the entire screen is displayed. There is an ADS driving method of Fujitsu (see US Pat. No. 54,36,633) of a driving method which maintains common after addressing sequentially.

Figure 3 shows a frame configuration for explaining a conventional ADS driving method. In the ADS driving method, when a frame of one screen is divided into eight subfields when the number of scan lines is 480, the time required for the addressing operation in the frame of one screen is approximately 11 to 12 msec. Since the display time (holding time) for viewing the screen remains only about 5 to 6 msec, the display period (holding period) actually contributing to the brightness of the screen is only about 30%, which reduces the brightness of the screen. In this case, the frequency of the sustain pulse is increased to compensate for the decrease in luminance of the screen, which leads to an increase in power consumption and relatively low driving stability.

The present applicant has proposed a new driving method to solve the problem of the ADS driving method (application number PCT / KR98 / 00204). The basic feature of this new driving method is to divide one frame into a plurality of subframes, and sequentially apply scan pulses corresponding to the total number of the divided subframes within one sustain pulse applied to the Y scan-hold electrodes. Select a display line and assign each subframe to the selected display lines to display the subframe. Subsequently, the display moves downward by one line, selects display lines corresponding to the total number of the divided subframes within one sustain pulse applied to the Y scan-hold electrodes, and performs subframe display. Subsequently, one frame display is completed by repeating the subframe display for the display line while moving the display line until each subframe is displayed for all the display lines. As such, the characteristic of this driving method is that scanning of another display line is possible while the other display lines are held. To realize this, the total number of sustain pulses of one frame and the number of display lines must be set equal, and the positions of the first selected display lines must be considered in the number of sustain pulses allocated to each subframe. As a result, subframes to be displayed on the selected display lines are allocated according to positions of the display lines that are initially selected.

4 and 5, the characteristics of the driving method will be described in detail as follows. For convenience of explanation, for example, one frame is divided into three subframes SF1, SF2, and SF3, and a display line is assumed to be seven lines. Therefore, it is possible to set the sustain periods to 1, 2, and 4 in each subframe SF1, SF2, SF3, respectively, and the position of the first selected display line for each subframe SF1, SF2, SF3. The display lines D1, D3, and D7 can be selected in consideration of the set sustain period. 4 shows a subframe selection and display state for each display line of the new driving method. As shown in the figure, the display lines D1, D3, and D7 are first selected to display respective subframes SF1, SF2, and SF3, and then the display lines are moved to below one display line. Fields D2, D4 and D1 are selected to display respective subframes SF1, SF2 and SF3, and then display lines D3, D5 and D2 are selected to display respective subframes SF1. , SF2, SF3 display, and then display lines D4, D6, D3 are selected to display respective subframes SF1, SF2, SF3, and then display lines D5, Select D7, D4 to proceed to display the respective subframes SF1, SF2, SF3, and then select display lines D6, D1, D5 to select the respective subframes SF1, SF2, SF3. ), And finally, the display lines D7, D2, and D6 are selected to display the respective subframes SF1, SF2, and SF3, thereby completing the display of one frame. Subsequently, the display returns to the beginning and the display lines D1, D3, and D7 are selected to display the respective subframes SF1, SF2, and SF3 of the next frame. At this time, in the display of each subframe of the next frame, the state of progressing the display of the subframe of the previous frame is overlapped. In FIG. 4, while the display lines D2, D4, D5, and D6 display subframes SF2, SF3, SF3, and SF3 of the previous frame, subframe display of the next frame is performed.

FIG. 5 is a pulse waveform diagram applied to each electrode for displaying a frame shown in FIG. 4, showing driving by a selective erasing method. First, display lines D1, D3, and D7 having the same number as the divided subframes are selected, and each divided subframe SF1, SF2, SF3 is assigned to each display line. In other words, a negative voltage pulse having a constant voltage is applied to the Y electrodes Y1, Y3, and Y7 constituting the selected display lines D1, D3, and D7, and at the same time, a positive (+) voltage is applied to the common X electrode. After performing the front discharge by applying a voltage pulse, within one holding period of the sustain pulse applied by the common Y electrode driving circuit, the scan pulses generated in the Y scan driving circuit are applied to the selected Y electrodes, The address pulses generated in the address driving circuit are applied to the address electrodes in accordance with the image data to be displayed. The above-described state explains the discharge principle. As a result of the front discharge, positive wall charges are accumulated on the dielectric layer covering the Y electrode and negative wall charges are accumulated on the dielectric covering the common X electrode. Subsequently, when the scan pulse and the address pulse are applied, the accumulated wall charges are erased. Therefore, the wall charge is erased on the display line to which the address pulse is applied, and no sustain discharge is performed even if a positive sustain pulse is applied to the common X electrodes next, and the display line to which the address pulse is not applied is the wall charge. The sustain discharge is performed because is formed.

Subsequently, within the next Y electrode applying sustain period, the Y electrodes Y2, which move down one line from the selected Y electrodes Y1, Y3, Y7 and constitute display lines D2, D4, D1, A constant negative voltage pulse is applied to Y4 and Y1, and a positive voltage pulse is applied to the common X electrode to perform front discharge of the selected display line, and scan pulses generated in the Y scan driving circuit are applied. Simultaneously with the selected Y electrodes, an address pulse generated by the address driving circuit is applied to the address electrodes in accordance with the image data to be displayed. In this case, the display line D1 of the display lines D1, D3, and D7 selected and held in the previous Y electrode applying sustain period is affected by the scan pulse applied to the selected Y electrodes in the next Y electrode applying sustain period. Therefore, the sustain discharge ends. As such, allocating each subframe to each of the selected display lines is determined in advance by the position of the first selected display lines.

Subsequently, the display of one frame is completed by moving each line by one line until the respective subframes are displayed for all Y electrodes. Similarly, the display lines that have completed the display of all subframes of the previous frame end their discharge by the scan pulse for the display of the subframe of the next frame. Therefore, this driving method can be displayed with efficiency almost 100% in theory because there is no rest period in one frame period.

However, as shown in Figs. 4 and 5, in the conventional driving method, the next frame is simultaneously displayed for at least a certain period during one frame display period. As a result, the display division between adjacent frames is not clear, and as a result, the image of one frame that is still stopped is not displayed correctly, and the problem is that two frames appear overlapped with the viewer's eyes when displaying a moving image. Occurs.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to clearly distinguish display divisions between adjacent frames in a multi-scan frame division multiplexing method in a single sustaining pulse, so that two frames of images are superimposed on the eyes of an observer during moving picture representation. It is to provide a driving method for preventing the appearance.

The driving method of the present invention for achieving the above object, a pair of substrates spaced apart from each other, a plurality of common X electrodes and Y electrodes arranged in parallel on the one substrate, the one A plurality of display lines consisting of a Y electrode and one or more common X electrodes, a dielectric layer covering the X electrodes and the Y electrodes, and crossing the plurality of display lines on another substrate. A plurality of arranged address electrodes, a plurality of pixels formed at intersections of the display lines and the address electrodes, barrier ribs forming a discharge space between the pair of substrates to partition the plurality of pixels, and the discharge space In the method of driving a plasma display panel comprising a gas filled in

Dividing one image frame into n subframes, each of which is pre-assigned a specific number of sustain pulses;

First, the number of display lines equal to the total number of the divided subframes is selected, and the positions of the selected display lines are set in consideration of the sustain pulses pre-assigned to each subframe. Assign to display lines;

In addition to applying scan pulses having different phases to the Y electrodes constituting the selected display lines, address pulses are applied to the address electrode to designate pixels to be displayed, and a specific number of the assigned subframes. Applying a sustain pulse to the X electrode commonly connected to the selected Y electrode to perform display of each subframe allocated to the selected display lines;

Subsequently, each allocation sub for each selected display line is moved by one display line or two or more display lines until each subframe is displayed for all display lines, with each of the first selected display lines as a starting point. Display line which proceeds with frame display, but after addressing for display of the last selected display lines until the subframe display of the most significant bit of the last selected display lines is completed. The subframe of the next frame is not started.

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

6 shows subframe display timings between two adjacent frames in the driving method of the present invention. For convenience of description in FIG. 6, for example, one frame is divided into three subframes SF1, SF2, and SF3, and each subframe SF1, SF2, SF3 has a sustain period of 1, 2, It was set to 4 and the display line was assumed to be 7 lines. However, in actual AC-PDP products, one frame is divided into six, eight or more subframes, and the maintenance period of each subframe can be set in various ways according to the user. It can consist of lines.

Referring to Figure 6 will be described in detail the features of the driving method of the present invention. Since the retention periods allocated to the respective subframes SF1, SF2, and SF3 are set to 1, 2, and 4, respectively, the position of the first selected display line is determined for each of the subframes SF1, SF2, SF3. The display lines D1, D3, and D7 may be selected in consideration of the set sustain period. As shown in the figure, the display lines D1, D3, and D7 are first selected to display the respective subframes SF1, SF2, and SF3, and then the display lines are moved below one display line. Fields D2, D4 and D1 are selected to display respective subframes SF1, SF2 and SF3, and then display lines D3, D5 and D2 are selected to display respective subframes SF1. , SF2, SF3 display, and then display lines D4, D6, D3 are selected to display respective subframes SF1, SF2, SF3, and then display lines D5, Select D7, D4 to proceed to display the respective subframes SF1, SF2, SF3, and then select display lines D6, D1, D5 to select the respective subframes SF1, SF2, SF3. ), And finally, the display lines D7, D2, and D6 are selected to display the respective subframes SF1, SF2, and SF3, thereby completing the display of one frame. After the selection of the last display lines, the selection for the next frame display is stopped for the display lines that are already selected and have completed the display of the respective subframes SF1, SF2, SF3, and among the last selected display lines. The display of the next frame is started after completion of the display of the most significant bit, for example, the subframe SF3. As a result, after completion of one frame display for every display line, the idle period H is provided for at least the most significant bit subframe holding period.

FIG. 7 is a pulse waveform diagram applied to each electrode for displaying the frame shown in FIG. 6, showing driving by a selective erasing method. First, display lines D1, D3, and D7 having the same number as the divided subframes are selected, and each divided subframe SF1, SF2, SF3 is assigned to each display line. In other words, a negative voltage pulse having a constant voltage is applied to the Y electrodes Y1, Y3, and Y7 constituting the selected display lines D1, D3, and D7, and at the same time, a positive (+) voltage is applied to the common X electrode. After performing the front discharge by applying a voltage pulse, within one holding period of the sustain pulse applied by the common Y electrode driving circuit, the scan pulses generated in the Y scan driving circuit are applied to the selected Y electrodes, The address pulses generated in the address driving circuit are applied to the address electrodes in accordance with the image data to be displayed.

Subsequently, within the next Y electrode applying sustain period, the Y electrodes Y2, which move down one line from the selected Y electrodes Y1, Y3, Y7 and constitute display lines D2, D4, D1, A constant negative voltage pulse is applied to Y4 and Y1, and a positive voltage pulse is applied to the common X electrode to perform front discharge of the selected display line, and scan pulses generated in the Y scan driving circuit are applied. Simultaneously with the selected Y electrodes, an address pulse generated by the address driving circuit is applied to the address electrodes in accordance with the image data to be displayed. In this case, the display line D1 of the display lines D1, D3, and D7 selected and held in the previous Y electrode applying sustain period affects the scan pulse applied to the selected Y electrodes in the next Y electrode applying sustain period. The discharge is terminated because of the As such, allocating each subframe to each of the selected display lines is determined in advance by the position of the first selected display lines.

Subsequently, the display of one frame is completed by displaying each subframe while moving one line until all the subframes are displayed for all display lines. In this case, erase pulses P _e are applied to the Y electrode constituting the display lines displaying each subframe, that is, one frame, by the Y electrode scan driving circuit, and the image data of the next frame is applied to the address electrode. Not authorized The timing of applying the erase pulse _Pe of the Y electrode scan driving circuit to the display lines that have been completed is calculated from the Y electrode applying sustain pulse to which the first scan pulse is applied for displaying the frames of the corresponding display lines. A pulse, for example seven sustain pulses, may be applied and then applied. Next, after displaying the subframe SF3 of the most significant bit of the last selection display lines and applying the erase pulse _Pe to the most significant bit display line, the next frame is displayed. As shown in FIG. 7, the erase pulse _Pe may be applied to the Y electrode or the sustain pulse period, and as shown in FIG. 8, the erase pulse _Pe may be applied between the X electrode or the sustain pulse and the Y electrode or the sustain pulse. have.

As described so far, according to the present invention, after the display of one frame is completed for all the display lines, the display of the next frame is started so that the display between the frames does not overlap, and the eyes of the observer are displayed during the moving picture representation. Two frames can be prevented from appearing in an image overlapped state.

On the other hand, the present invention is not limited only to the above-described embodiments, but may be modified and modified without departing from the scope of the present invention. For example, the present invention has been described with reference to a three-electrode surface discharge alternating current plasma display device, but the two-electrode opposing alternating current plasma display device, a four-electrode surface discharge alternating current plasma display device, and a DC-type alternating current plasma display device are also described. It is possible to apply. In addition, although the driving method of the present invention has been described by the selective erasing method, it is also possible to apply to the selective writing method.

1 is a cross-sectional view schematically showing a discharge cell of a typical plasma display panel;

2 is a plan view showing a typical three-electrode plasma display panel;

3 is a frame diagram illustrating a conventional ADS driving method;

4 is a timing diagram of image frame division by subframes employed in a conventional driving method;

5 is a pulse waveform diagram applied to each electrode for a conventional frame display;

6 is a subframe display timing diagram between two adjacent frames illustrating one embodiment of the present invention;

7 is a pulse waveform diagram applied to each electrode according to an embodiment of the present invention,

8 is a pulse waveform diagram applied to each electrode according to the second embodiment of the present invention.

<Description of reference numerals for main parts of the drawings>

1: display panel 3: Y electrode holding driving circuit

5 X electrode driving circuit 6 address driving circuit

10: cell 12, 13: glass substrate

14: X electrode 15: Y electrode

16 address electrode 17 partition wall

Claims (5)

A plurality of displays comprising a pair of substrates spaced apart from each other, a plurality of X electrodes and Y electrodes arranged in parallel on the one substrate, and one or more X electrodes Lines, a plurality of address electrodes arranged in a direction traversing the plurality of display lines on another substrate, a plurality of pixels formed at intersections of the display lines and the address electrodes, between the pair of substrates In the driving method of the flat panel display comprising a partition wall forming a discharge space to partition the plurality of pixels, and the gas filled in the discharge space, Dividing one image frame into n subframes, and a predetermined number of sustain pulses are pre-assigned to each subframe; First, the number of display lines equal to the total number of the divided subframes is selected, and the positions of the selected display lines are set in consideration of the sustain pulses pre-assigned to each subframe. Assign to display lines; In addition to applying scan pulses having different phases to the Y electrodes constituting the selected display lines, specifying the pixels to be displayed by applying address pulses to the address electrode, and specifying a specific number of the allocated subframes. Applying a sustain pulse of to the selected Y and X electrodes to perform display of each subframe allocated for the selected display lines; Subsequently, each subframe for the selected display lines is moved by one display line or two or more display lines until each subframe is displayed for all display lines, with each of the first selected display lines as a starting point. The display lines which have already been selected and have completed all the subframes are displayed, after the addressing for the display of the last selected display lines until the subframe display of the most significant bit of the last selected display lines is completed. And a rest period during which the subframe of the next frame is not displayed. The method of claim 1, And the erasing period is started by applying an erase pulse to display lines that have already been selected and have completed all subframe display after addressing for display of the display lines to be selected last. The method of claim 2, And an erase pulse is applied to each of the display lines after the total sustain pulses of one frame are applied after the addressing for the first subframe display. The method of claim 2 or 3, And applying the plurality of erase pulses to the plurality of display lines in different phases within one sustain pulse. The method according to claim 1 or 3, And applying the erase pulse between the X electrode sustain pulse and the Y electrode apply sustain pulse.