KR20070094093A - Method for driving discharge display panel wherein discharge-sustain pulse includes electrical floating area - Google Patents

Abstract

A method for driving a discharge display panel wherein discharge-sustain pulse includes electrical floating area is provided to enhance display quality effectively by making a brightness difference between adjacent gray scales uniform. In a method for driving a discharge display panel, wherein a unit frame is divided into a plurality of sub fields each having predetermined gray scale weight for time-division gray scale display, and each of the sub fields includes an addressing period and a sustain period, at least one sustain pulse includes electrical floating area in the sustain period of the sub field having the smallest gray scale weight among the sub fields.

Description

Method for driving discharge display panel wherein discharge-sustain pulse includes electrical floating area}

1 is an internal perspective view showing the structure of a three-electrode surface discharge plasma display panel as a discharge display panel according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating an example of one display cell of the plasma display panel of FIG. 1.

3 is a block diagram illustrating a driving apparatus of the plasma display panel of FIG. 1.

4 is a timing diagram illustrating a method of driving the plasma display panel of FIG. 1.

FIG. 5 is a waveform diagram illustrating driving signals used in a first subfield having the lowest gray scale weight value among the subfields of FIG. 4.

6 is a cross-sectional view showing the wall charge distribution of any of the display cells at the time point t ₆ of Fig.

FIG. 7 is a cross-sectional view illustrating wall charge distribution of any one display cell at time t ₈ of FIG. 5.

<Explanation of symbols for main parts of the drawings>

1 ... discharge display panel, 10 ... front glass substrate,

11, 15 dielectric layer, 12 protective layer,

13 ... back glass substrate, 14 ... discharge space,

16 fluorescent layers, 17 bulkheads,

X ₁ , ..., Xn ... X electrode line, Y ₁ , ..., Yn ... Y electrode line,

A _R1 , ..., A _Bm ... address electrode line, X _na , Y _na ... transparent electrode line,

X _nb , Y _nb ... metal electrode line, SF ₁ , ... SF ₈ ... subfield,

S _Y ... Y drive control signal, V _G ... ground potential,

S _X ... X drive control signal, S _A ... address drive control signal,

31 image processing unit, 32 control unit,

33 ... address drive, 34 ... X drive,

65 ... Y drive unit, 66 ... image processing unit.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of driving a discharge display panel, and more particularly, having a front substrate and a rear substrate opposed to each other, wherein the sustain electrode lines and the scan electrode lines are alternately and side by side. And a method of driving a discharge display panel in which address electrode lines are formed to cross the sustain and scan electrode lines.

In a typical discharge display device, for example, the plasma display device of US Pat. No. 5,541,618, a unit frame is divided into a plurality of subfields for time division gray scale display, and each of the subfields is a reset period, an addressing period, and a sustain period. It includes. Each of the subfields has a unique gray scale weight value, and a sustain period, that is, the number of sustain pulses is set in proportion to the gray scale weight value.

In the conventional discharge display apparatus as described above, in the display cells that realize the gray level '0' in the unit frame, no discharge occurs in all the subfields of the unit frame. In addition, in a display cell that realizes gradation '1' in a unit frame, discharge occurs only in the sustain period of the subfield having the smallest gradation weight value, for example, the first subfield.

In the subfield having the least gray scale weight value, for example, in the sustain period of the first subfield, only one sustain pulse can be set, but in relation to the reset discharge of the next subfield, for example, the second subfield. It is desirable that a pair of sustain pulses be set. For example, in the sustain period of the subfield with the lowest gray scale weight value, after the first sustain pulse is applied to the scan electrode lines, the second sustain pulse is applied to the sustain electrode lines.

On the other hand, when sustain pulses of the same potential are applied successively, the first sustain discharge is stronger than each of the subsequent discharges.

For the above reason, in a typical discharge display apparatus, the luminance difference between the adjacent grayscales '0' and '1' is greater than the other adjacent grayscales, and the luminance difference between the adjacent grayscales '1' and '2'. Is less than other adjacent gradations. Accordingly, there is a problem in that display reproducibility is deteriorated due to a decrease in luminance linearity in a low gray scale region.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for efficiently increasing display reproducibility by efficiently increasing luminance linearity in a low gray scale region in a method of driving a discharge display panel.

In the method of driving the discharge display panel of the present invention, a unit frame is divided into a plurality of subfields each having a set gray scale weight value for time division gray scale display, and each of the subfields includes an addressing period and a sustaining period. In the sustain period of the subfield having the lowest gray scale weight value among the plurality of subfields, at least one sustain pulse includes an area of electrical floating.

According to the method of driving the discharge display panel of the present invention, since at least one sustain pulse includes the area of electrical floating in the sustain period of the subfield with the lowest gray scale weight value, the amount of discharge current in the area of the electrical floating. This decreases. Accordingly, the luminance difference between the adjacent grayscales '0' and '1' is not larger than other adjacent grayscales, and the luminance difference between the adjacent grayscales '1' and '2' is not less than that of the other grayscales. . Therefore, display reproducibility can be efficiently increased because luminance linearity in the low gradation region is efficiently increased.

Hereinafter, preferred embodiments according to the present invention will be described in detail.

1 shows a structure of a plasma display panel 1 of a three-electrode surface discharge method as a discharge display panel according to an embodiment of the present invention. FIG. 2 shows an example of one display cell of the plasma display panel 1 of FIG. 1.

1 and 2, between the front and rear glass substrates 10 and 13 of the three-electrode surface discharge plasma display panel 1 according to an embodiment of the present invention, the address electrode lines A _R1,. ..., A _Bm ), dielectric layers 11 and 15, X electrode lines X ₁ , ..., X _n as sustain electrode lines, Y electrode lines Y ₁ as scan electrode lines. ..., Y _n ), phosphor 16, partition 17, and magnesium monoxide (MgO) layer 12 as a protective layer are provided.

The address electrode lines A _R1 ,..., A _Bm are formed in a predetermined pattern on the front side of the rear glass substrate 13. The lower dielectric layer 15 is applied to the entire surface in front of the address electrode lines A _R1 ,..., A _Bm . In front of the lower dielectric layer 15, barrier ribs 17 are formed in a direction parallel to the address electrode lines A _R1 ,..., And A _Bm . These partitions 17 function to partition the discharge area of each display cell and to prevent optical cross talk between each display cell. The fluorescent layer 16 is applied between the partition walls 17.

The X electrode lines X ₁ ,..., X _n as sustain electrode lines and the Y electrode lines Y ₁ , ..., Y _n as scan electrode lines are formed of address electrode lines A _R1,. ..., A _Bm ) are formed alternately and side by side at the rear of the front glass substrate 10 in a direction intersecting with. Each intersection sets a corresponding display cell. Each X electrode line (X ₁ , ..., Xn) and each Y electrode line (Y ₁ , ..., Y _n ) is a transparent electrode line of a transparent conductive material such as indium tin oxide (ITO) or the like (see FIG. 2). X _na , Y _na ) and a metal electrode line (X _nb , Y _nb of FIG. 2) for increasing conductivity are formed. The front dielectric layer 11 is formed by applying the entire surface to the rear of the X electrode lines X ₁ ,..., X _n and the Y electrode lines Y ₁ ,..., Y _n . A protective layer 12 for protecting the panel 1 from a strong electric field, for example, a magnesium monoxide (MgO) layer, is formed by applying the entire surface to the back of the front dielectric layer 11. The plasma forming gas is sealed in the discharge space 14.

In the driving method applied to such a discharge display panel, reset, addressing, and discharge-sustaining cycles are sequentially performed in the unit subfield. In the reset period, the charge states of all display cells are uniform. In the addressing period, a predetermined wall potential is generated in the selected display cells. In the sustain period, a predetermined alternating voltage is applied to all the XY electrode line pairs so that the display cells in which the wall potential is formed in the addressing period cause sustain discharge. In this sustain period, plasma is formed in the discharge space 14 of the selected display cells, that is, the gas layer, which causes the sustain discharge, and the fluorescent layer 16 is excited by the ultraviolet radiation to generate light.

Referring to FIG. 3, the driving apparatus of the plasma display panel 1 of FIG. 1 includes an image processor 31, a controller 32, an address driver 33, an X driver 34, and a Y driver 35. do.

The image processing unit 31 converts an external analog image signal into a digital signal to convert an internal image signal, for example, 8 bits of red (R), green (G), and blue (B) image data, a clock signal, vertical and horizontal, respectively. Generate sync signals.

The controller 32 generates driving control signals S _A , S _Y , and S _X according to an internal image signal from the image processor 31. A related driving method will be described in detail with reference to FIGS. 4 to 7.

The address driver 33 generates display data signals according to the address signals S _A among the driving control signals S _A , S _Y , and S _X from the controller 32, and generates the generated display data signals. It is applied to the address electrode lines (A _R1 , ..., A _Bm in FIG. 1). X driver 34 to the driving control signal from the control unit (32) (S _A, S _Y, S _X) among the X electrode lines as a sustain electrode line according to the X driving control signal (S _X) (Fig. 1 Drive X ₁ , ..., X _n ). The Y driving unit 35 is Y electrode lines as scan electrode lines according to the Y driving control signals S _Y among the driving control signals S _A , S _Y , and S _X from the control unit 32 (FIG. 1). Drive Y ₁ , ..., Y _n ).

4 illustrates a method of driving the plasma display panel 1 of FIG. 1.

Referring to FIG. 4, each of the unit frames is divided into _eight subfields SF ₁ ,..., SF ₈ to realize time division gray scale display. In addition, each subfield SF ₁ , ..., SF ₈ has a reset period R ₁ , ..., R ₈ , an addressing period A ₁ , ..., A ₈ , and a sustain period S ₁ , ..., S ₈ ).

The discharge conditions of all the display cells are made uniform in each reset period R ₁ , ..., R ₈ and at the same time are adapted to the addressing to be performed in the next period.

In each addressing period A ₁ ,..., And A ₈ , display data signals are applied to the address electrode lines A _R1 , ..., A _{Bm in} FIG. 1, and at the same time, each Y electrode line Y ₁ ,. ..., Y _n ), the scanning pulses are sequentially applied. Accordingly, when a high level display data signal is applied while the scan pulse is applied, the wall potential above the set potential is formed by the addressing discharge in the corresponding discharge cell, and the wall potential above the set potential is not formed in the discharge cell that is not.

In each sustain period S ₁ , ..., S ₈ , all Y electrode lines Y ₁ , ..., Y _n and all X electrode lines X ₁ , ..., X _n A sustain pulse is applied alternately, causing sustain discharge in discharge cells in which wall potentials above a set potential are formed in corresponding addressing periods A ₁ , ..., A ₈ . Therefore, the brightness of the discharge display panel is proportional to the length of the sustain periods S ₁ ,..., S ₈ occupied in the unit frame, that is, the number of sustain pulses. The length of the sustain periods S ₁ ,..., S ₈ occupied in the unit frame is 255T (T is a unit period). Therefore, it can be displayed in 256 gray scales, even if it is not displayed once in a unit frame.

Here, the first sub sustain period (S _1), the period (1T) which corresponds to ²⁰ of the field (SF ₁₎ is, the second sustain period of the sub-fields (SF ₂₎ (S ₂₎ is equivalent to ²¹ The period 2T corresponds to the period 4T corresponding to 2 ² in the sustain period S ₃ of the third subfield SF ₃ , and the period 2T corresponds to ² in the sustain period S ₄ of the fourth subfield SF ₄ . ^The period 8T corresponding to ³ includes the period 16T corresponding to 2 ⁴ in the sustain period S ₅ of the fifth subfield SF ₅ , and the sustain period S of the sixth subfield SF ₆ . ₆ ) has a period 32T corresponding to 2 ⁵ , a holding period S ₇ of the seventh subfield SF ₇ has a period 64T corresponding to 2 ⁶ , and an eighth subfield SF ₈ . The period 128T corresponding to 2 ⁷ is set in the sustain period S _{8 of} .

Accordingly, if a subfield to be displayed among the eight subfields is appropriately selected, 256 gray levels may be displayed including all zero (zero) grays not displayed in any subfields.

In each of the sustain periods S ₁ , ..., S _{8 of the} subfields SF ₁ , ..., SF ₈ , a number of sustain pulses set in proportion to the gray scale weight as described above are used as the sustain electrode lines. Are alternately applied to the X electrode lines (X ₁ , ... X _{n in} FIG. 1) and the Y electrode lines (Y ₁ , ... Y _{n in} FIG. 1) as scan electrode lines.

FIG. 5 shows driving signals used in the first subfield SF ₁ having the least gray weight among the subfields of FIG. 4. In FIG. 5, reference numeral S _{AR1 .. ABm} denotes driving signals applied to each address electrode line (A _R1 , A _G1 ,..., A _Gm , A _Bm of FIG. 1), and S _{X1 ..Xn} denotes an X electrode. Driving signals applied to the lines (X ₁ , ... X _{n in} FIG. 1), and S _Y1 , ..., S _Yn are the respective Y electrode lines (Y ₁ , ... Y _{n in} FIG. 1). Indicates driving signals applied to the. 6 shows a wall charge distribution of any of the display cells at the time point t ₆ of Fig. FIG. 7 illustrates a wall charge distribution of one display cell at time t ₈ of FIG. 5.

5, the sustain period of the first subfield (SF ₁₎ with small gray scale weight value (S ₁₎ from the, all Y electrode lines (Y _1, ... Y _n) it is first applied at the same time The sustain pulse includes the areas t11 to t12 of electrical floating. Similarly, the second sustain pulse applied simultaneously to all X electrode lines X ₁ ,... X _n includes the areas t13 to t14 of electrical floating.

The amount of discharge current decreases in the areas t11 to t12 and t13 to t14 of the electrically floating in the sustain period S ₁ of the first subfield SF ₁ . Accordingly, the luminance difference between the adjacent grayscales '0' and '1' is not larger than other adjacent grayscales, and the luminance difference between the adjacent grayscales '1' and '2' is not less than that of the other grayscales. . Therefore, display reproducibility can be efficiently increased because luminance linearity in the low gradation region is efficiently increased.

The reset period R ₁ and the addressing period A ₁ , which will be described below, are divided into different subfields SF _2. Reset cycles R _{2 of} s SF ₈ ) The same applies to R ₈ ) and the addressing periods A ₂ to A ₈ .

)보다 제6 전위(V_SET)만큼 더 높은 최고 전위로서의 정극성의 제1 전위(

) 예를 들어, 355 볼트(V)까지 상승된다. 정극성의 제3 전위(

)는 부극성의 제2 전위(V_SCL)와 부극성의 제4 전위(V_SCH)의 차이에 의하여 발생된다. Referring to FIG. 5, in the potential rising period t1 to t6 of the reset period R ₁ , the Y electrode-lines Y _1. To Y _n ), the potential applied from the ground potential V _G to the third potential (

The first potential of positive polarity as the highest potential higher by the sixth potential V _SET than

For example, it is raised to 355 volts (V). Positive third potential (

) Is generated by the difference between the second negative potential V _SCL and the fourth negative potential V _SCH .

X electrode-lines (X ₁ To X _n ) and address electrode-lines A _R1 To A _Bm ), the ground potential V _G is applied.

Accordingly, Y electrode-lines Y ₁ To Y _n ) and the X electrode-lines (X ₁₎ To X _n ), while discharge occurs between Y electrode-lines Y _1. To Y _n ) and address electrode-lines A _R1 To A _Bm ). Accordingly, all Y electrode-lines Y ₁ To Y _n ), negative wall charges are formed and all X electrode-lines (X ₁ ) are formed. To X _n ), positive wall charges are formed, and all address electrode-lines A _R1. To A _Bm ), positive wall charges are formed (see FIG. 6).

)로부터 부극성의 제7 전위(V_NF)까지 하강된다. 여기에서, 어드레스 전극-라인들(A_R1 내지 A_Bm)에는 접지 전위(V_G)가 인가된다. 이에 따라, X 전극-라인들(X₁ 내지 X_n)과 Y 전극-라인들(Y₁ 내지 Y_n) 사이의 방전으로 인하여, Y 전극-라인들(Y₁ 내지 Y_n) 주위의 부극성의 벽전하들의 일부가 X 전극-라인들(X₁ 내지 X_n) 주위로 적절히 이동한다(도 7 참조). 또한, 어드레스 전극-라인들(A_R1 내지 A_Bm)에는 접지 전위(V_G)가 인가되므로, 어드레스 전극-라인들(A_R1 내지 A_Bm) 주위의 정극성의 벽전하들이 적절히 감소한다(도 7 참조). Next, in the potential drop period t6 to t8 of the reset period R ₁ , the X electrode-lines X _1. To Y _n , the Y electrode-lines Y ₁ in the state where the potential applied to the fifth potential V _E is maintained at the fifth potential V _E. To Y _n ), the potential applied to the first potential (

) To the negative seventh potential V _NF . Here, address electrode-lines A _R1 To A _Bm ), the ground potential V _G is applied. Accordingly, X electrode-lines X ₁ To X _n ) and the Y electrode-lines Y ₁ To due to the discharge between the Y _n), Y electrode lines (Y ₁ To Y _n , some of the negative wall charges around the X electrode-lines (X _1). To X _n ), as appropriate (see FIG. 7). In addition, address electrode-lines A _R1 To A _Bm ), since the ground potential V _G is applied, the positive wall charges around the address electrode-lines A _R1 to A _Bm are appropriately reduced (see FIG. 7).

Thus, in the following addressing period A ₁ , the address electrode-lines A _R1 To A _Bm ), the display data signal is applied to the Y electrode-lines Y ₁ biased to the negative fourth potential V _SCH . To Y _n ), as the scan pulses of the negative second potential V _SCL are sequentially applied, smooth addressing may be performed. In the display data signal applied to each of the address electrode lines A _R1 to A _Bm , the positive address potential V _A is applied when the display cell is selected, and the ground potential V _G is applied when the display cell is not selected. Accordingly, when the display data signal of the positive address potential V _A is applied while the scan pulse of the second negative potential V _SCL is applied, wall charges are formed by the address discharge in the corresponding display cell. In other display cells, wall charges are not formed. Here, the positive fifth potential V _E is applied to the X electrode-lines X ₁ ,... X _{n for} more accurate and efficient address discharge.

The sustain period of the first subfield (SF ₁₎ has the lowest gray scale weight value (S ₁₎ in, after which the first sustain pulse applied to all the Y electrode lines (Y _1, ... Y _n), all of X is applied to the second sustain pulse to the electrode lines _{(X 1, ... X n)} . This causes sustain discharge in the display cells in which the set wall potential has been formed in the addressing period A. FIG.

As described above, the first sub-field (SF ₁₎ in the sustain period (S _1), all the Y electrode lines (Y _1, ... Y _n) to be applied simultaneously to the first holding with the lowest gray scale weight value The pulses comprise the areas t11-t12 of electrical floating. Similarly, the second sustain pulse applied simultaneously to all X electrode lines X ₁ ,... X _n includes the areas t13 to t14 of electrical floating.

Of course, any one of the first and second sustain pulses may not have the area of the floating according to the characteristics of the discharge display device.

As described above, according to the driving method of the discharge display panel according to the present invention, since at least one sustain pulse includes an area of electrical floating in the sustain period of the subfield having the smallest gray scale weighting value, The amount of discharge current in the region is reduced. Accordingly, the luminance difference between the adjacent grayscales '0' and '1' is not larger than other adjacent grayscales, and the luminance difference between the adjacent grayscales '1' and '2' is not less than that of the other grayscales. . Therefore, display reproducibility can be efficiently increased because luminance linearity in the low gradation region is efficiently increased.

The present invention is not limited to the above embodiments, but may be modified and improved by those skilled in the art within the spirit and scope of the invention as defined in the claims.

Claims (9)

A method of driving a discharge display panel in which a unit frame is divided into a plurality of subfields each having set gray scale weight values for time division gray scale display, and each of the subfields includes an addressing period and a sustaining period. And at least one sustain pulse includes an area of electrical floating in a sustain period of a subfield having the least gray scale weight value among the plurality of subfields. A front substrate and a rear substrate spaced apart from each other, wherein the sustain electrode lines and the scan electrode lines are alternately and side-by-side formed between the substrates, and the address electrode lines are crossed with respect to the sustain and scan electrode lines. In the method of driving a discharge display panel, Dividing the unit frame into a plurality of subfields for time division gray scale display; And Dividing each of the subfields into a reset period, an addressing period, and a sustain period; And at least one sustain pulse includes an area of electrical floating in a sustain period of a subfield having the least gray scale weight value among the plurality of subfields. The method of claim 2, wherein in each of the sustain periods of the plurality of subfields, And a number of sustain pulses set in proportion to the gray scale weight value are alternately applied to the sustain electrode lines and the scan electrode lines. 4. The method of claim 3, wherein in the sustain period of the subfield having the least gray scale weight value, Applying a first sustain pulse to the scan electrode lines, and And applying a second sustain pulse to the sustain electrode lines. The method according to claim 4, wherein in the sustain period of the subfield having the least gray scale weight value, And each of the first and second sustain pulses comprises an area of electrical floating. The method of claim 1, The reset period of at least one subfield among the plurality of subfields is A potential raising period for raising a potential applied to the scan electrode lines to a first positive potential; And And a potential drop period for dropping the potentials applied to the scan electrode lines to a second negative potential. The method of claim 6, wherein in the potential drop period, And a bias potential is applied to the sustain electrode lines, and a ground potential is applied to the address electrode lines. The method of claim 7, wherein And a bias potential applied to the sustain electrode lines in the potential drop period is continuously applied to the sustain electrode lines even in the addressing period. The method of claim 6, wherein in the potential rising period, And a ground potential is applied to the address electrode lines and the sustain electrode lines.

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