JP2008197293A - Driving method of plasma display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma display device which prevents a decrease in contrast characteristics by preventing image retention and an erroneous discharge generated during driving. <P>SOLUTION: A driving method includes: a step of applying a first reset pulse including an up ramp pulse and a down ramp pulse to a scan electrode in a reset period of a first sub-field among a plurality of sub-fields of the plasma display device; a step of applying a second reset pulse including an up ramp pulse and a down ramp pulse to the scan electrode in a reset period of a sub-field turned on right after a turned-off subfield among other sub-fields other than the first sub-field; and a step of applying a third reset pulse including only a down ramp pulse to the scan electrode in reset periods of other sub-fields except the sub-fields wherein the first reset pulse and second reset pulse are applied. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a display device, and more particularly to a driving method of a plasma display device.

  Generally, among display devices, the plasma display device includes a plasma display panel and a driving unit for driving the plasma display panel.

  Generally, in a plasma display panel, a barrier rib formed between a front panel and a rear panel forms one discharge cell, and each discharge cell includes neon (Ne), helium (He) or neon and A main discharge gas such as a mixed gas of helium (Ne + He) and an inert gas containing a small amount of xenon (Xe) are filled.

  A plurality of such discharge cells gather to form one pixel. For example, red (Red, R) discharge cells, green (Green, G) discharge cells, and blue (Blue, B) discharge cells gather to form one pixel.

  When the plasma display panel is discharged by a high-frequency voltage, the inert gas generates vacuum ultraviolet rays, and the phosphor formed between the barrier ribs emits light to realize an image. The Such a plasma display panel is in the spotlight as a next-generation display device because it can be configured to be lightweight and thin.

  On the other hand, in the case of the up ramp pulse supplied to the scan electrode during the reset period, the amount of light generated by the discharge generated by the up ramp pulse as a high voltage pulse is relatively large.

  Therefore, the luminance in a state where all the discharge cells of the plasma display panel are turned off, that is, the black luminance is relatively increased, the contrast characteristic is deteriorated, and an afterimage is generated. There was a problem.

  In order to prevent such a problem, a method of supplying an up-ramp pulse only in one subfield of one frame has been presented to improve a certain part of the contrast characteristics. The problem that electric discharge occurs will occur.

  An object of the present invention is to prevent afterimages and erroneous discharges that occur during driving of a plasma display device and prevent deterioration of contrast characteristics.

  A driving method of a plasma display apparatus according to an embodiment of the present invention applies a first reset pulse including an up-ramp pulse and a down-ramp pulse to a scan electrode during a reset period of a first sub-field among a plurality of sub-fields. And a second reset pulse including an up-ramp pulse and a down-ramp pulse in a reset period of a turned-on subfield next to a turned-off subfield among other subfields excluding the first subfield. Applying a scan electrode to the scan electrode; and a third reset pulse including only a down-ramp pulse in a reset period of another subfield excluding the subfield to which the first reset pulse and the second reset pulse are applied. Applying to.

  Applying a first pre-reset pulse to the scan electrode before a reset period of the first subfield, and applying a second pre-reset pulse having a reverse polarity corresponding to the first pre-reset pulse to the sustain electrode; Further, it can be included.

  The first subfield may be a subfield having the lowest gradation weight value.

  The subfield to which the second reset pulse is applied may be after the fifth subfield in order from the lowest to the highest grayscale weight value.

  The peak voltage of the rising ramp pulse of the second reset pulse may be lower than the peak voltage of the rising ramp pulse of the first reset pulse.

  The first pre-reset pulse may be negative.

  The first pre-reset pulse may be a descending ramp pulse that gradually decreases.

  The down-ramp pulse of the third reset pulse can fall from a constant bias voltage.

  The constant bias voltage may be substantially the same as the sustain voltage.

  A driving method of a plasma display apparatus according to another embodiment of the present invention applies a first reset pulse including an ascending ramp pulse and a descending ramp pulse to a scan electrode during a reset period of a first frame among a plurality of frames. And applying a second reset pulse including only a down-ramp pulse to the scan electrodes in all reset periods of a second frame that is continuous with the first frame.

  The down-ramp pulse of the second reset pulse can fall from a constant bias voltage.

  The constant bias voltage may be substantially the same as the sustain voltage.

  The method may further include applying a third reset pulse and a fourth reset pulse to the scan electrode in a reset period of a first subfield of a third frame that is continuous with the second frame.

  The third reset pulse and the fourth reset pulse may include an up ramp pulse.

  The peak voltage of the third reset pulse may be greater than the peak voltage of the fourth reset pulse.

  The difference between the peak voltage of the third reset pulse and the peak voltage of the fourth reset pulse may be 100V or less.

  The third reset pulse may include a rectangular wave, and the fourth reset pulse may include an up ramp pulse.

  The period in which the rectangular wave of the third reset pulse is applied can be shorter than the period in which the up-ramp pulse of the fourth reset pulse is applied.

  A driving method of a plasma display apparatus according to another embodiment of the present invention applies a first reset pulse including an up ramp pulse and a down ramp pulse to a scan electrode during a reset period of a first frame among a plurality of frames. And applying a second reset pulse including at least two ascending ramp pulses to the scan electrode in all reset periods of a second frame that is continuous with the first frame, and Of the reset pulses, the period during which one up-ramp pulse is applied may be shorter than the period during which the up-ramp pulse of the first reset pulse is applied.

  The number of up-ramp pulses of the second reset pulse may be 2 to 3 for each subfield.

  The method may further include applying a third reset pulse and a fourth reset pulse to the scan electrode in a reset period of a first subfield of a third frame that is continuous with the second frame.

  The third reset pulse and the fourth reset pulse may include an up ramp pulse.

  The peak voltage of the third reset pulse may be greater than the peak voltage of the fourth reset pulse.

  The difference between the peak voltage of the third reset pulse and the peak voltage of the fourth reset pulse may be 100V or less.

  The third reset pulse may include a rectangular wave, and the fourth reset pulse may include an up ramp pulse.

  The period in which the rectangular wave of the third reset pulse is applied can be shorter than the period in which the up-ramp pulse of the fourth reset pulse is applied.

  A driving method of a plasma display apparatus according to another embodiment of the present invention applies a first reset pulse including an up ramp pulse and a down ramp pulse to a scan electrode during a reset period of a first frame among a plurality of frames. And a second reset pulse including only a down-ramp pulse instead of the first reset pulse in a reset period of at least one subfield of a second frame that is continuous with the first frame. Applying the scan electrode to the scan electrode, and the number of the second reset pulses may be increased every frame change.

  The number of the second reset pulses may be increased by 1 every frame change.

  The second reset pulse may be applied to the scan electrode from a subfield having the highest gradation weight value.

  The number of subfields to which the first reset pulse is applied in one frame may be one or more.

  The down-ramp pulse of the second reset pulse can fall from a constant bias voltage.

  The constant bias voltage may be substantially the same as the sustain voltage.

  According to the present invention, it is possible to obtain a plasma display device with improved contrast characteristics by preventing afterimages and erroneous discharges that occur during driving.

  Hereinafter, a specific embodiment according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a view showing a plasma display panel according to an embodiment of the present invention.

  Referring to FIG. 1, the plasma display panel includes a front substrate 101, which is a display surface on which an image is displayed, and a front substrate 101 in which a plurality of sustain electrode pairs each having a scan electrode 102 and a sustain electrode 103 formed in pairs are arranged. The panel 100 and the rear panel 110 in which the plurality of address electrodes 113 are arranged on the rear substrate 111 on the back so as to cross the plurality of sustain electrode pairs described above are coupled so as to be parallel to each other with a certain distance. Is done.

  The front panel 100 is composed of a scan electrode 102 and a sustain electrode 103 for causing mutual discharge in one discharge cell and maintaining light emission of the cell, that is, a transparent electrode (a) formed of a transparent ITO material and a metal material. A scan electrode 102 and a sustain electrode 103 provided in the fabricated bus electrode (b) are included in a pair.

  The scan electrode 102 and the sustain electrode 103 are covered with one or more upper dielectric layers 104 that limit the discharge current and insulate between the electrode pairs. Therefore, a protective layer 105 is formed by depositing magnesium oxide (MgO).

  In the rear panel 110, a plurality of discharge spaces, that is, stripe type (or well type) barrier ribs 112 for forming discharge cells are arranged in parallel. In addition, a large number of address electrodes 113 that perform address discharge and cause the inert gas in the discharge cell to generate vacuum ultraviolet rays are arranged in parallel to the barrier ribs 112.

  Red (R), green (G), and blue (B) phosphors 114 that emit visible light for image display during a sustain discharge are applied to the upper surface of the rear panel 110. A lower dielectric layer 115 for protecting the address electrode 113 is formed between the address electrode 113 and the phosphor 114.

  In the plasma display panel having such a structure, a plurality of discharge cells are formed in a matrix structure, and a driving unit including a driving circuit for supplying a predetermined pulse to the discharge cells is attached and driven. .

  A method of expressing the image gradation of the conventional plasma display panel having such a structure will be described with reference to FIG.

  FIG. 2 is a diagram illustrating a method for expressing image gradation of a plasma display apparatus according to an embodiment of the present invention.

  Referring to FIG. 2, the image gradation of the plasma display panel is driven by dividing one frame into a number of subfields having different numbers of light emission. Each subfield is divided into a reset period for generating a discharge uniformly, an address period for selecting a discharge cell, and a sustain period for realizing a gray level according to the number of discharges.

  For example, when an image is to be displayed with 256 gradations, a frame section (16.67 ms) corresponding to 1/60 seconds is divided into eight subfields. In addition, each of the eight subfields is divided into a reset period, an address period, and a sustain period.

Here, the reset period and address period of each subfield are the same for each subfield, while the sustain period is 2 ⁿ (n = 0, 1, 2, 3, 4, 5, 6, 7 in each subfield). ). Here, one frame section is divided into eight subfields. However, the present invention is not limited to this, and one frame section can be divided into 10 to 12 subfields.

  A driving apparatus for driving such a plasma display panel will be described as follows.

  FIG. 3 is a view showing a plasma display apparatus according to an embodiment of the present invention.

  Referring to FIG. 3, a plasma display apparatus according to an embodiment of the present invention includes a panel 300 including scan electrodes, a timing controller 301, a data driver 302, a scan driver 303, a sustain driver 304, and a subfield mapping. Part 305.

  The timing controller 301 receives the vertical and horizontal synchronization signals and a predetermined clock signal, generates timing control signals (CTRX, CTRY, CTRZ) for controlling the driving units 302, 303, 304, and controls the timing. Signals (CTRX, CTRY, CTRZ) are supplied to the corresponding driving units 302, 303, 304.

  By doing in this way, operation | movement of each drive part 302,303,304 is controlled. In addition, the timing controller 931 controls the scan driving unit 303 to supply a reset pulse including only a down-ramp pulse in some of the subfields to the scan electrodes. By operating in this way, it is possible to prevent erroneous discharge due to unstable discharge, which will be described in detail later.

  The data driver 302 samples and latches the data pulse in response to the timing control signal (CTRX) from the timing controller 301 described above, and then supplies the data pulse to the address electrodes (X1 to Xm).

  The scan driver 303 adjusts the reset pulse applied to the scan electrodes (Y1 to Yn) during the reset period under the control of the timing controller 301.

  Further, the scan pulse (Sp) of the scan voltage (−Vy) is sequentially supplied to the scan electrodes (Y1 to Yn) during the address period under the control of the timing controller 301.

  The sustain driver 304 supplies a bias voltage of the sustain voltage (Vs) to the sustain electrode (Z) during the set-down period and the address period of the reset period under the control of the timing controller 301, and the scan driver 303 and the sustain driver 304 during the sustain period. By operating alternately, the sustain pulse (SUS) is supplied to the sustain electrode (Z).

  In addition, when the last sustain discharge is finished in one subfield, the sustain driver 304 supplies the erase ramp waveform (V (ramp-ers)) to the sustain electrode (Z).

  The subfield mapping unit 305 maps and outputs the video data processed through a predetermined video processing process to the subfield.

  For example, video data input from an external predetermined signal processing means (not shown), for example, a VSC (Video Signal Controller) chip (not shown) is processed by motion (Motion) processing, APL (Average Power Level) processing, half After video processing is performed through a process such as tone (Half Tone) correction processing, mapping is performed for each subfield to generate subfield mapping data, and such subfield mapping data is output.

  FIG. 4 is a diagram illustrating a driving method of the plasma display apparatus according to the first embodiment of the present invention.

  Referring to FIG. 4, the driving method of the plasma display apparatus according to the first embodiment of the present invention represents an image in a number of frames, and each frame is divided into a number of subfields having different numbers of light emission. . For example, each frame may be composed of 10 or 12 subfields with different numbers of light emission.

  In addition, the driving method of the plasma display apparatus includes a reset period for initializing the entire screen, an address period for selecting a cell to be discharged, a sustain period for maintaining the discharge of the selected cell, and a discharge period. It is driven by being divided into erase intervals for erasing the wall charges in the cell.

  Here, in the driving method of the plasma display apparatus according to the first embodiment of the present invention, the up-ramp pulse and the down-ramp are set in the reset period of the subfield having the lowest gradation weight, for example, the first subfield (SF1). A first reset pulse (RP1) including a pulse is applied to the scan electrode, and a third reset pulse (RP3) including only a down-ramp pulse is applied to the other subfields excluding the first subfield (SF1).

  Here, the down-ramp pulse of the third reset pulse (RP3) is a pulse that falls after maintaining a sustain voltage (Vs) that is a constant bias voltage. Thus, the contrast characteristics can be improved by reducing the number of up-ramp pulses, which are high voltage pulses.

  In addition, when the up-ramp pulse supplied in one frame is supplied once, in order to improve the problem that erroneous discharge can occur at a specific gradation, the next turn-on subfield is turned on. In addition, a second reset pulse (RP2) including an up-ramp pulse and a down-ramp pulse can be applied to the scan electrode during the reset period of the subfield to prevent erroneous discharge at a specific gradation.

  For example, if all the subfields in the frame are turned on, even if the subfield (SF3) turned on in the subfield having a relatively low gradation weight is unstable, Since all the subfields are turned on, the discharge can be stabilized by the discharge of many sustain pulses.

  However, as shown in FIG. 4, among the subfields (SF1 to SF5) having a low gradation weight, three subfields (SF1, SF2, SF3) are turned on, and then the fifth subfield ( If SF5) is turned on, the number of sustain pulses after the third subfield (SF3) that is turned on is not sufficient, so that the discharge cannot be stabilized, and an error occurs in the fifth subfield (SF5) that is turned on. Discharging will occur.

  In order to solve such a problem, the second reset pulse (RP2) including the up-ramp pulse is applied to the turned-on subfield (SF5) immediately after the subfield (SF3) where the discharge is unstable. This prevents the occurrence of erroneous discharge.

  In FIG. 4, the first, second, third, and fifth subfields (SF1, SF2, SF3, and SF5) are turned on. However, this is an example for explaining the present invention, and the present invention is not limited thereto.

  That is, assuming that the first subfield (SF1) is turned on and then turned on again in the fifth subfield (SF5), the second, third, and fourth subfields (SF2, SF3, SF4). ), The third reset pulse (RP3) including only the down-ramp pulse is applied in the reset period, so that the probability of erroneous discharge occurring in the fifth subfield (SF5) increases.

  Therefore, the fifth subfield (SF5) includes an up-ramp pulse different from the third reset pulse (RP3) applied in the reset period of the second, third, and fourth subfields (SF2, SF3, SF4). By applying the second reset pulse (RP2), occurrence of erroneous discharge can be prevented.

  In addition, the subfield to which the third reset pulse (RP3) is applied may be a low-gradation subfield, and the low-gradation subfield is the fifth from the lowest to the highest weighting value. Preferably it is within the subfield.

  Also, the subfield to which the second reset pulse (RP3) is applied is preferably the fifth subfield and thereafter (SF5 to SF12) in order from the lowest to the highest grayscale weight value.

  This is because the first reset pulse (RP1) including the up-ramp pulse is applied only to the subfield (SF1) having the lowest gradation weight value, and within the fifth subfield in order from the lowest gradation weight value to the highest ( If the third reset pulse (RP3) including only the down-ramp pulse is applied to SF1 to SF5), the probability of erroneous discharge occurring due to the unstable discharge due to this increases, so in order to avoid this erroneous discharge, The second reset pulse (RP2) is applied after the fifth subfield (SF5 to SF12) from the lowest to the highest weighting value.

  In this way, the number of up-ramp pulses supplied in one frame can be considerably reduced, and erroneous discharge at a specific gradation can be prevented while improving contrast characteristics.

  FIG. 5 is a diagram illustrating a driving method of the plasma display apparatus according to the second embodiment of the present invention.

  As shown in FIG. 5, in the present embodiment, the second reset applied in the reset period of the subfield (SF5) that is continuously turned on after the subfield (SF4) that is turned off among the plurality of subfields. The peak voltage (Vpeak2) of the rising ramp pulse in the pulse (RP2) is the peak voltage (Vpeak2) of the rising ramp pulse in the first reset pulse (RP1) applied in the reset period of the subfield (SF1) having the lowest gradation weight value ( Vpeak 1).

  In order to prevent erroneous discharge, the up-ramp pulse in the first reset pulse (RP1) applied in the reset period of the subfield (SF1) having the lowest gradation weight value in FIG. 4 (first embodiment). An up-ramp pulse having the same peak voltage (Vpeak1) was applied during the reset period of the fifth subfield (SF5). On the other hand, in FIG. 5 (second embodiment), the second reset pulse is set to be lower than the peak voltage (Vpeak1) of the up-ramp pulse applied in the reset period of the subfield (SF1) having the lowest gradation weight. The peak voltage (Vpeak2) of the up-ramp pulse in (RP2) is applied to the subfield (SF5) that is turned on continuously after the subfield (SF4) that is turned off. This aims to prevent flicker induction.

  FIG. 6 is a diagram for comparing and explaining the regions A and B in FIG. 5 in more detail. As shown in FIG. 6, the peak voltage (Vpeak1) of the up-ramp pulse (A) applied in the reset period of the subfield (SF1) having the lowest gradation weight is continued after the turned-off subfield. It is higher than the peak voltage (Vpeak2) of the up-ramp pulse (B) applied during the reset period of the turned-on subfield (SF5).

  FIG. 7 is a view for explaining the first subfield in more detail in the driving method of the plasma display apparatus according to the third embodiment of the present invention.

  As shown in FIG. 7, before applying the first reset pulse (RP1) including the rising ramp pulse and the falling ramp pulse to the scan electrode in the reset period of the first subfield (SF1) described with reference to FIGS. In addition, a first pre-reset pulse (PRP1) is applied to the scan electrode, and a second pre-reset pulse (PRP2) having a reverse polarity corresponding to the first pre-reset pulse (PRP1) is applied to the sustain electrode.

  Here, the first pre-reset pulse (PRP1) has a negative polarity, and is a down-ramp pulse that gradually decreases from a predetermined voltage, for example, the base voltage (GND). The second pre-reset pulse (PRP2) is a positive voltage and is a rectangular wave.

  Thus, by applying the first and second pre-reset pulses (PRP1, PRP2) before the reset period of the first subfield (SF1), the up-ramp pulse of the first reset pulse applied to the reset period. Since the peak voltage (Vpeak1) can be reduced, the black luminance in the reset process can be reduced.

  FIG. 8 is a diagram illustrating a driving method of the plasma display apparatus according to the fourth embodiment of the present invention.

  As shown in FIG. 8, in the driving method of the plasma display apparatus according to the fourth embodiment of the present invention, an image is expressed by a plurality of frames, and each frame is divided into a number of subfields having different numbers of times of light emission. For example, each frame is composed of 10 or 12 subfields with different numbers of light emission.

  Further, the plasma display apparatus includes a reset period for initializing the entire screen, an address period for selecting a cell to be discharged, a sustain period for maintaining the discharge of the selected cell, and a discharge cell. It is driven by being divided into erasing sections for erasing wall charges.

  Here, in the driving method of the plasma display apparatus according to the fourth embodiment of the present invention, the first reset pulse includes an up-ramp pulse and a down-ramp pulse in the reset period of each subfield (SF1 to SF12) of the first frame. (RP1) is applied.

  Next, when the second frame continuous to the first frame is turned off, the reset period of all subfields (SF1 to SF12) of the second frame includes only the down-ramp pulse. A second reset pulse (RP2) is applied to the scan electrode.

  For example, a first frame (not shown) corresponding to a part of a panel display surface (not shown) is turned on, and a first reset pulse (RP1) is applied to 12 subfields. When the second frame, which is the next frame, is turned off in the entire panel (not shown), the window pattern displayed on a part of the panel display surface (not shown) appears as an afterimage pattern.

  From the viewpoint of reducing this afterimage, only the down-ramp pulse applied to all subfields of the second frame at the time of switching from the first frame that is an On cell to the second frame that is an Off cell. It is preferable to apply a second reset pulse (RP2) including

  FIG. 9 is a diagram for explaining the region A in FIG. 8 in more detail. As shown in FIG. 9, the second reset pulse applied in all the subfields of the second frame includes only the down-ramp pulse.

  Such a down-ramp pulse is a pulse that gradually decreases after maintaining the sustain voltage (Vs) that is a bias voltage.

As described above, the luminance of the second reset pulse (RP2) including only the down-ramp pulse applied to the second frame is about 0 cd / m ² per pulse, and thus the luminance is about 0.1 cd / m ² or more per pulse. Compared to the first reset pulse (RP1), there is an effect that the level of the afterimage generated at the time of switching to the off cell can be lowered, and the contrast characteristics can be improved.

  FIG. 10 is a diagram illustrating a driving method of the plasma display apparatus according to the fifth embodiment of the present invention, and FIG. 11 is a diagram for explaining the region B of FIG. 8 in more detail.

  As shown in FIG. 10, in the present embodiment, the first reset pulse (RP1) including the up-ramp pulse and the down-ramp pulse is applied to the reset period of each subfield (SF1 to SF12) of the first frame.

  Next, when the second frame continuous to the first frame is turned off, the up-ramp pulse is included in the reset period of all the subfields (SF1 to SF12) in the second frame. A second reset pulse (RP2) including at least two is applied.

  Here, during the second reset pulse (RP2) applied to all the subfields in the second frame, the period (A) in which one up-ramp pulse is applied is applied to the subfields of the first frame. The first reset pulse (RP1) is preferably shorter than the period (B) during which the up-ramp pulse is applied.

  In addition, the number of up-ramp pulses applied to all subfields in the second frame is preferably 1 to 3 for each subfield in the second frame.

Here, since the luminance of the up-ramp pulse applied to the subfield of the first frame is approximately 0.1 cd / m ² per pulse, the on cell and the off cell are alternately switched. The flicker may occur due to the luminance deviation, and the contrast characteristics may be deteriorated.

Therefore, it is preferable to apply the second reset pulse (RP2) including two to three up-ramp pulses having a luminance of about 0.04 cd / m ² per pulse. Thereby, by generating a weak discharge many times, the level of dark afterimage can be lowered by generating a large discharge at once, and flicker due to luminance deviation can be prevented.

  FIG. 12 is a diagram illustrating a driving method of the plasma display apparatus according to the sixth embodiment of the present invention.

  FIG. 12A shows a conventional reset pulse in the last subfield of the second frame shown in FIGS. 8 and 10 and the first subfield portion of the third frame which is the next frame. is there.

  As shown in FIG. 12A, after the second reset pulse (RP2) illustrated in FIGS. 8 and 10 is applied to the second frame, the first frame of the third frame continuous to the second frame is applied. When only one reset pulse is applied in the reset period of the subfield, it is necessary to start from a complete off cell, so that it is difficult to perform discharge switching when switching to an on cell.

  FIG. 12B is a diagram showing reset pulses in the last subfield and the first subfield portion of the next frame according to the sixth embodiment of the present invention. In order to solve the problem in the case of FIG. 12A described above, as shown in FIG. 12B, the third reset pulse is applied to the first subfield of the third frame continuous to the second frame. It is preferable to apply (RP3) and the fourth reset pulse (RP4).

  Here, it is preferable that the third reset pulse (RP3) and the fourth reset pulse (RP4) applied to the first subfield of the third frame all include an up-ramp pulse.

  Further, the first peak voltage (Vpeak1) of the third reset pulse (RP3) is preferably larger than the second peak voltage (Vpeak2) of the fourth reset pulse (RP4).

  Further, the difference (Vpeak1-Vpeak2) between the first peak voltage (Vpeak1) and the second peak voltage (Vpeak2) is preferably 100 V or less.

  As described above, the third reset pulse (RP3) higher than the fourth reset pulse (RP4) by 100V (Vpeak1-Vpeak2) or less is applied to the first subfield of the third frame, thereby completely turning off (Off ) Discharge instability can be eliminated when switching from cell to on cell.

  Apart from this, the case where the third reset pulse (RP3) is applied will be described with reference to FIG.

  As shown in FIG. 12C, the third reset pulse applied to the first subfield of the third frame includes a rectangular wave.

  The voltage value of the rectangular wave is the same as the second peak voltage value (Vpeak2) of the fourth reset pulse (RP4). The period (C) in which the rectangular wave of the third reset pulse (RP3) is applied is preferably shorter than the period (D) in which the up-ramp pulse of the fourth reset pulse (RP4) is applied.

  In this way, the third reset pulse (RP3) shorter than the period (D) during which the fourth reset pulse (RP4) is applied is applied to the first subfield of the third frame together, thereby completely turning off (Off ) Discharge instability can be eliminated when switching from cell to on cell.

  FIG. 13 is a view showing a driving method of the plasma display apparatus according to the seventh embodiment of the present invention, and FIG. 14 is a view for explaining the region A of FIG. 13 in more detail.

  As shown in FIG. 13, in the driving method of the plasma display apparatus according to the seventh embodiment of the present invention, an image is expressed by a plurality of frames, and each frame is divided into a number of subfields having different numbers of times of light emission. For example, each frame is composed of 10 or 12 subfields with different numbers of light emission.

  Further, the plasma display apparatus includes a reset period for initializing the entire screen, an address period for selecting a cell to be discharged, a sustain period for maintaining the discharge of the selected cell, and a discharge cell. It is driven by being divided into erasing sections for erasing wall charges.

  Here, in the driving method of the plasma display apparatus according to the seventh embodiment of the present invention, the first reset pulse including the up ramp pulse and the down ramp pulse is included in the reset period of each subfield (SF1 to SF12) of the first frame. (RP1) is applied.

  Next, when the second frame continuous to the first frame is turned off (Off) cell, an up-ramp pulse and a down-link are included in the reset period of at least one subfield (SF12) of the second frame. Instead of the first reset pulse (RP1) including the ramp pulse, a second reset pulse (RP2) including only the downward ramp pulse is applied to the scan electrode.

  For example, when the first frame is an on cell, 12 first reset pulses (RP1) are applied to 12 subfields, and the second frame, which is the next frame, is an off cell. As a result, an afterimage pattern is generated.

  Therefore, in order to reduce an afterimage, a second reset pulse is generated from the last subfield (SF12) of the second frame when switching from the first frame that is an On cell to the second frame that is an Off cell. Start applying (RP2).

  Accordingly, assuming that the number of subfields in the second frame is 12, the first reset pulse (RP1) is applied in 11 subfields of the second frame, and the second subfield is in the second frame. A reset pulse (RP2) is applied.

  Next, when the third frame continued to the second frame is also an off cell, the first reset pulse (RP1) is applied to 10 subfields of the third frame, and 2 In the subfield, the second reset pulse (RP2) is applied.

  As described above, when the off cell is continuously maintained, the number of the second reset pulse (RP2) increases from the previous frame every time the frame is changed. Here, the number of second reset pulses (RP2) increases by one for each frame change.

  As shown in FIG. 14, the second reset pulse (RP2) applied in place of the first reset pulse (RP1) in at least one subfield of the second frame according to the seventh embodiment of the present invention. Contains only down-ramp pulses.

  Such a down-ramp pulse is a pulse that gradually decreases after maintaining the sustain voltage (Vs) that is a bias voltage.

Since the second reset pulse (RP2) including only the down-ramp pulse has a luminance difference of about 0 cd / m ² per pulse, the up-ramp pulse has a luminance difference of about 0.1 cd / m ² or more per pulse. As compared with the first reset pulse (RP1) including the above, there is an effect that the level of the afterimage generated at the time of switching to the off cell can be reduced.

  FIG. 15 is a diagram for explaining in more detail driving waveforms according to the driving method of the plasma display apparatus according to the seventh embodiment of the present invention.

  As shown in FIG. 15A, the second reset pulse (RP2) applied in at least one subfield of the second frame is applied according to the reverse order of the subfield having the highest gradation weight value.

  For example, if the subfield of one frame is composed of 12 subfields, and the next frame of the first frame that is an On cell is changed to an Off cell, the last subfield of the next frame is changed. The second reset pulse (RP2) is applied during the reset period of the field (SF12).

  Next, if the next frame of the frame that is an off cell is also an off cell, the second reset pulse is transferred to the reset period of the two subfields (SF11) from the last subfield (SF12). (RP2) is applied. Accordingly, the number of second reset pulses (RP2) increases according to the reverse order of the subfields by the number of times the frame that is an off cell is repeated.

  On the other hand, if the next frame of the frame that is an off cell is switched to an on cell, the first reset pulse RP1 is applied to all the subfields.

  However, when a frame that is an off cell is continuously repeated and the number of first reset pulses (RP1) is decreased and the number of second reset pulses (RP2) is increased at each frame change time. However, it is preferable that the number of first reset pulses (RP1) is one or more in one frame.

  For example, after the first frame that is an On cell, after the second frame to the 15th frame, the sub-field of the 11th frame includes the first frame in the first frame. A reset pulse (RP1) is applied, and a second reset pulse (RP2) is applied to the 11 subfields.

  Next, when the twelfth frame continuous with the eleventh frame is also an off cell, the second reset pulse (RP2) is not applied to all subfields of the twelfth frame. Thus, in the twelfth subfield, the first reset pulse (RP1) is applied to one subfield, and the second reset pulse (RP2) is applied to the eleventh subfield.

  In this way, if the second reset pulse (RP2) is applied in the reverse order of the subfield having the highest gradation weight value, the occurrence of erroneous discharge can be prevented and the level of the dark afterimage can be removed quickly according to a certain time. become.

  Unlike this, the second reset pulse (RP2) can be applied, which will be described with reference to FIG. 15B.

  As shown in FIG. 15A, the second reset pulse (RP2) applied in at least one of the subfields of the second frame is increased by one at every frame change regardless of the order of the subfields. Is done.

  For example, if the subfield of one frame is composed of 12 subfields, and the next frame of the first frame that is an On cell is switched to an Off cell, the last field of the next frame The second reset pulse (RP2) may be applied during the reset period of the subfield (SF12), and the second reset pulse (RP2) may be applied during the reset period of the tenth subfield (SF10). .

  Next, if the next frame of the frame that is an off cell is also an off cell, the second reset pulse (RP2) is applied to the reset period of the third subfield (SF3). Accordingly, the number of second reset pulses (RP2) increases according to the reverse order of the subfields by the number of times the frame that is an off cell is repeated.

  On the other hand, if the next frame of the frame that is an off cell is switched to an on cell, the first reset pulse RP1 is applied to all the subfields.

  In this way, by applying the second reset pulse (RP2) in the reverse order of the subfield having the highest gradation weight value, the occurrence of erroneous discharge can be prevented and the level of the dark afterimage can be removed quickly according to a certain time. Become.

  The detailed objects, features, and advantages of the present invention will become more apparent through the following detailed description in conjunction with the accompanying drawings. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Throughout the specification, identical reference numbers indicate identical components. Further, when it is determined that a specific description of a known function or configuration related to the present invention can obscure the gist of the present invention, a detailed description thereof will be omitted.

It is a figure which shows the plasma display panel which concerns on one Embodiment of this invention. It is a figure which shows the method of expressing the image gradation of the plasma display apparatus which concerns on one Embodiment of this invention. It is a figure which shows the plasma display apparatus which concerns on one Embodiment of this invention. It is a figure which shows the drive method of the plasma display apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the drive method of the plasma display apparatus which concerns on 2nd Embodiment of this invention. FIG. 6 is a diagram for comparing and explaining regions A and B in FIG. 5 in more detail. It is a figure for demonstrating in detail the 1st subfield among the drive methods of the plasma display apparatus which concerns on 3rd Embodiment of this invention. It is a figure which shows the drive method of the plasma display apparatus which concerns on 4th Embodiment of this invention. It is a figure for demonstrating the area | region A of FIG. 8 in detail. It is a figure which shows the drive method of the plasma display apparatus which concerns on 5th Embodiment of this invention. It is a figure for demonstrating the area | region B of FIG. 8 in detail. It is a figure which shows the drive method of the plasma display apparatus which concerns on 6th Embodiment of this invention. It is a figure which shows the drive method of the plasma display apparatus which concerns on 7th Embodiment of this invention. It is a figure for demonstrating the area | region A of FIG. 13 in detail. It is a figure for demonstrating in detail the drive waveform by the drive method of the plasma display apparatus which concerns on 7th Embodiment of this invention. It is a figure for demonstrating in detail the drive waveform by the drive method of the plasma display apparatus which concerns on 7th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Front panel 101 Front substrate 102 Scan electrode 103 Sustain electrode 104 Upper dielectric layer 111 Rear substrate 113 Address electrode 115 Lower dielectric layer 300 Panel 301 Timing controller 302 Data drive unit 303 Scan drive unit 304 Sustain drive unit 305 Subfield mapping unit

Claims (32)

A driving method of a plasma display apparatus for displaying an image by time-dividing one frame into a plurality of subfields,
Applying a first reset pulse including an up-ramp pulse and a down-ramp pulse to the scan electrode during the reset period of the first sub-field among the plurality of sub-fields;
Among the other subfields excluding the first subfield, a second reset pulse including an up-ramp pulse and a down-ramp pulse is applied to the scan electrode during the reset period of the turned-on subfield after the turned-off subfield. Applying, and
Applying a third reset pulse including only a down-ramp pulse to the scan electrode during a reset period of another subfield excluding the subfield to which the first reset pulse and the second reset pulse are applied;
A method of driving a plasma display apparatus including:   Applying a first pre-reset pulse to the scan electrode before a reset period of the first subfield, and applying a second pre-reset pulse having a reverse polarity corresponding to the first pre-reset pulse to the sustain electrode; The method of driving a plasma display device according to claim 1, further comprising:   3. The method as claimed in claim 2, wherein the first subfield is a subfield having the lowest gradation weight value.   3. The method of claim 2, wherein the subfield to which the second reset pulse is applied is after the fifth subfield in order from the lowest gradation weight value to the highest.   3. The method of claim 2, wherein a peak voltage of the rising ramp pulse of the second reset pulse is lower than a peak voltage of the rising ramp pulse of the first reset pulse.   3. The method of claim 2, wherein the first pre-reset pulse has a negative polarity.   7. The method of claim 6, wherein the first pre-reset pulse is a descending ramp pulse that gradually falls.   The method of claim 2, wherein the down-ramp pulse of the third reset pulse drops from a constant bias voltage.   The method of claim 8, wherein the constant bias voltage is substantially the same as a sustain voltage. A method of driving a plasma display apparatus in which a plurality of frames display images,
Applying a first reset pulse including an up-ramp pulse and a down-ramp pulse to a scan electrode during a reset period of the first frame among the plurality of frames;
Applying a second reset pulse including only a down-ramp pulse to all the reset periods of the second frame that is continuous with the first frame, to the scan electrode;
A method for driving a plasma display device, comprising:   The method of claim 10, wherein the down-ramp pulse of the second reset pulse falls from a constant bias voltage.   The method of claim 11, wherein the constant bias voltage is substantially the same as a sustain voltage.   The method of claim 10, further comprising: applying a third reset pulse and a fourth reset pulse to the scan electrode in a reset period of a first subfield of a third frame that is continuous with the second frame. Driving method of plasma display apparatus.   The method of claim 13, wherein the third reset pulse and the fourth reset pulse include an up-ramp pulse.   The method of claim 14, wherein a peak voltage of the third reset pulse is larger than a peak voltage of the fourth reset pulse.   The method of claim 15, wherein a difference between a peak voltage of the third reset pulse and a peak voltage of the fourth reset pulse is 100V or less.   The method of claim 13, wherein the third reset pulse includes a rectangular wave, and the fourth reset pulse includes an ascending ramp pulse.   The method of claim 17, wherein a period during which the rectangular wave of the third reset pulse is applied is shorter than a period during which the up-ramp pulse of the fourth reset pulse is applied. A method of driving a plasma display apparatus in which a plurality of frames display images,
Applying a first reset pulse including an up-ramp pulse and a down-ramp pulse to a scan electrode during a reset period of the first frame among the plurality of frames;
Applying a second reset pulse including at least two ascending ramp pulses to all of the reset periods of the second frame that is continuous with the first frame, to the scan electrode,
The method of driving a plasma display apparatus, wherein a period during which one up-ramp pulse of the second reset pulse is applied is shorter than a period during which the up-ramp pulse of the first reset pulse is applied.   The method as claimed in claim 19, wherein the number of up-ramp pulses of the second reset pulse is 2 to 3 for each subfield.   20. The method of claim 19, further comprising applying a third reset pulse and a fourth reset pulse to the scan electrode in a reset period of a first subfield of a third frame that is continuous with the second frame. Driving method of plasma display apparatus.   The method of claim 21, wherein the third reset pulse and the fourth reset pulse include an up-ramp pulse.   23. The method of claim 22, wherein a peak voltage of the third reset pulse is greater than a peak voltage of the fourth reset pulse.   24. The method of claim 23, wherein a difference between a peak voltage of the third reset pulse and a peak voltage of the fourth reset pulse is 100V or less.   The method of claim 21, wherein the third reset pulse includes a rectangular wave, and the fourth reset pulse includes an ascending ramp pulse.   26. The driving method of the plasma display apparatus according to claim 25, wherein a period during which the rectangular wave of the third reset pulse is applied is shorter than a period during which the up-ramp pulse of the fourth reset pulse is applied. A method of driving a plasma display apparatus in which a plurality of frames display images,
Applying a first reset pulse including an up-ramp pulse and a down-ramp pulse to a scan electrode during a reset period of the first frame among the plurality of frames;
A second reset pulse including only a down-ramp pulse is applied to the scan electrode instead of the first reset pulse during a reset period of at least one subfield of a second frame that is continuous with the first frame. Including the steps of:
The method of driving a plasma display apparatus, wherein the number of the second reset pulses increases every frame change.   28. The method as claimed in claim 27, wherein the number of the second reset pulses increases by one for each frame change.   29. The method of claim 28, wherein the second reset pulse is applied to the scan electrode from a subfield having the highest gradation weight value.   30. The method of claim 29, wherein the number of subfields to which the first reset pulse is applied in one frame is one or more.   28. The method of claim 27, wherein the down-ramp pulse of the second reset pulse falls from a constant bias voltage.   32. The method of claim 31, wherein the constant bias voltage is substantially the same as a sustain voltage.