KR20050040385A - Driving method and apparatus of plasma display panel - Google Patents

Abstract

The present invention relates to a plasma display panel driving method capable of performing automatic power control (APC) at the time of displaying an OSD signal, thereby reducing stress on a driver and reducing power consumption. In the method of driving a plasma display panel according to the present invention, there are a plurality of sub-fields for time division gray scale display for each frame as a display period, each sub-field having a reset period, an address period, and a sustain discharge period. In the sustain discharge period, alternating sustain pulses are applied to all discharge cells to cause sustain discharge in the discharge cells selected in the address cycle, and when the load ratio, which is the ratio of the number of discharge cells to be displayed among all the discharge cells, is greater than or equal to the reference load rate. Automatic power control is performed according to an automatic power control level in which the number of sustain pulses in each unit frame is inversely proportional to the load factor, and a warning message stored in advance in the absence of an image signal input from the outside is displayed on the screen. In the method of driving a plasma display panel to display, a) generating no input signal when there is no video signal input from the outside; And (b) performing automatic power control according to the no input signal.

Description

Plasma display panel driving method and apparatus {Driving method and apparatus of plasma display panel}

The present invention relates to a method for driving a plasma display panel, and more particularly, to perform automatic power control (APC) when displaying an On Screen Display (OSD) signal, thereby reducing stress on a driver and reducing power consumption. The present invention relates to a plasma display panel driving method.

1 is a perspective view showing an internal structure of a conventional three-electrode surface discharge plasma display panel. FIG. 2 is a cross-sectional view illustrating a configuration of a unit display cell of the panel of FIG. 1.

Referring to the drawings, between the front and rear glass substrates 10 and 13 of the conventional surface discharge plasma display panel 1, the address electrode lines A _R1 , A _G1 , ..., A _Gm , A _Bm ), Dielectric layers 11 and 15, Y electrode lines (Y ₁ , ..., Y _n ), X electrode lines (X ₁ , ..., X _n ), fluorescent layer 16, partition wall 17 ) And a magnesium monoxide (MgO) layer 12 as a protective layer.

The address electrode lines A _R1 , A _G1 ,..., A _Gm , A _Bm are formed in a predetermined pattern on the front side of the rear glass substrate 13. The lower dielectric layer 15 is entirely applied in front of the address electrode lines A _R1 , A _G1 ,..., A _Gm , 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 , A _G1 ,..., A _Gm , A _Bm . These partitions 17 function to partition the discharge area of each discharge cell and to prevent optical cross talk between each discharge cell. The fluorescent layer 16 is formed between the partition walls 17.

The X electrode lines (X ₁ , ..., X _n ) and the Y electrode lines (Y ₁ , ..., Y _n ) are the address electrode lines (A _R1 , A _G1 , ..., A _Gm , A _Bm ) is formed in a predetermined pattern on the back of the front glass substrate 10 to be orthogonal to each other. Each intersection sets a corresponding discharge cell. Each X electrode line (X ₁ , ..., X _n ) and each Y electrode line (Y ₁ , ..., Y _n ) have a conductivity and a transparent electrode line made of a transparent conductive material such as indium tin oxide (ITO). Metal electrode lines for heightening are formed in combination. 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.

As a driving method of the plasma display panel 1 having the structure described above, an address-display separation driving method which is mainly used is disclosed in US Pat.

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

A typical driving device 2 of the plasma display panel 1 includes an image processor 26, a logic controller 22, an address driver 23, an X driver 24, and a Y driver 25. The image processing unit 26 converts an external analog image signal into a digital signal, for example, an internal image signal, for example, 8-bit red (R), green (G), and blue (B) image data, a clock signal, vertical and horizontal, respectively. Generate synchronization signals. The logic controller 22 generates driving control signals S _A , S _Y , and S _X according to an internal image signal from the image processor 26.

In this case, the driving unit such as the address driver 23, the X driver 24, and the Y driver 25 receives input from the driving control signals S _A , S _Y , and S _X , and generates respective driving signals. The applied driving signal to each of the electrode lines.

That is, the address driver 23 processes the address signal S _A among the drive control signals S _A , S _Y , and S _X from the logic controller 22 to generate a display data signal, and generates the displayed display. The data signal is applied to the address electrode lines. The X driver 24 processes the X driving control signal S _X among the driving control signals S _A , S _Y , and S _X from the logic controller 22 and applies the X driving control signal S _X to the X electrode lines. The Y driver 25 processes the Y driving control signal S _Y among the driving control signals S _A , S _Y , and S _X from the logic controller 22 and applies the Y driving control signal S _Y to the Y electrode lines.

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

Referring to the drawing, a unit frame is divided into eight subfields SF1, ..., SF8 to realize time division gray scale display. Each subfield SF1, ..., SF8 is divided into a reset period (not shown), an address period A1, ..., A8, and a sustain discharge period S1, ..., S8. do.

The luminance of the plasma display panel is proportional to the length of the sustain discharge cycles S1, ..., S8 occupied in the unit frame. The lengths of the sustain discharge cycles S1, ..., S8 occupy a unit frame are 255T (T is the unit time). At this time, a time corresponding to 2n is set in the sustain discharge period Sn of the nth subfield SFn. Accordingly, when the subfield to be displayed among the eight subfields is appropriately selected, it can be seen that display of 256 gray levels can be performed including all zero (zero) gray levels that are not displayed in any of the subfields.

FIG. 5 is a timing diagram illustrating driving signals applied to electrode lines of the plasma display panel of FIG. 1 in a unit sub-field of FIG. 4.

In FIG. 5, reference numeral S _{AR1 ..ABm} denotes a driving signal applied to each address electrode line (A _R1 , A _G1 ,..., A _Gm , A _{Bm in} FIG. 1), and S _{X1 .. Xn} denotes an X electrode. Drive signal applied to the lines (X ₁ , ..., X _n of FIG. 1), and S _{Y1 ..Yn} is applied to each Y electrode line (Y ₁ , ..., Y _n of FIG. 1). Indicates a driving signal.

Referring to the drawing, in the reset period PR of the unit sub-field SF, first, the voltage applied to the X electrode lines X ₁ ,..., X _n is set from the ground voltage V _G to the second. for the voltage (V _S) for example, then continue to rise to 155 volts (V). Here, the ground voltage V _G is applied to the Y electrode lines Y ₁ ,..., Y _n and the address electrode lines A _R1 , A _G1 ,..., A _Gm , A _Bm .

Next, the voltage applied to the Y electrode lines Y ₁ ,..., Y _n is third from the second voltage V _S , for example, from 155 volts V to a second voltage than the second voltage V _S. The highest voltage V _SET + V _{S that} is as high as the voltage V _SET is continuously raised to, for example, 355 volts (V). Here, the ground voltage V _G is applied to the X electrode lines X ₁ ,..., X _n and the address electrode lines A _R1 , A _G1 ,..., A _Gm , A _Bm .

Next, in the state where the voltage applied to the X electrode lines X ₁ ,..., X _n is maintained at the second voltage V _S , the Y electrode lines Y ₁ ,..., Y _n The voltage applied to) is continuously lowered from the second voltage V _S to the ground voltage V _G. Here, the ground voltage V _G is applied to the address electrode lines A _R1 , A _G1 ,..., A _Gm , and A _Bm .

Accordingly, in the address period (PA), leading address is applied to a display data signal to the electrode lines, the the second voltage (V _S) lower fourth voltage (V _SCAN) to bias the Y-electrode line than the (Y ₁ As a scan signal of the ground voltage V _G is sequentially applied to the ..., Y _n ), smooth addressing may be performed. The display data signal applied to each of the address electrode lines A _R1 , A _G1 , ..., A _Gm , A _Bm has a positive address voltage V _A when the discharge cell is selected, and a ground voltage when the discharge cell is not. (V _G ) is applied. Accordingly, when the display data signal of the positive address voltage V _A is applied while the scan pulse of the ground voltage V _G is applied, wall charges are formed by the address discharge in the corresponding discharge cell. Wall charges do not form. Here, for more accurate and efficient address discharge, the second voltage V _S is applied to the X electrode lines X ₁ ,..., X _n .

In the sustain discharge period PS that follows, the second voltage V _S is applied to all of the Y electrode lines Y ₁ , ..., Y _n and the X electrode lines X ₁ , ..., X _n . The display sustain pulse is alternately applied, causing a discharge for display retention in the discharge cells in which wall charges are formed in the corresponding address period PA.

6 is a graph schematically illustrating the principle of automatic power control in a conventional plasma display panel.

Referring to the drawings, in general, according to Automatic Power Control (APC), the ratio of the discharge cells that are turned on (ON) of the discharge cells of the entire screen, the sustain electrode in the sustain discharge period in one frame according to the load ratio Control the number of sustain pulses applied to the line pairs. At this time, the number of sustain pulses in the unit frame is inversely related to the load ratio. In other words, if the load ratio is small, the number of sustain pulses in the unit frame is increased to increase the brightness of the displayed image. If the load ratio is large, power consumption can be reduced by reducing the number of sustain pulses in the unit frame.

In this case, in the automatic power control of the conventional plasma display panel driving method, the automatic power control mode is activated when the load ratio reaches a certain level. Therefore, if the load level does not reach a certain level, the automatic power control mode does not operate even when the power consumption is large.

If there is no video signal in the plasma display panel, the set is notified to the user through a warning message. To this end, a white caption is typically displayed on a black screen, where the white caption is fixed at a specific position on the screen or moved on the screen. The message output on the screen is called an OSD (On Screen Display).

At this time, since the discharge cells that are turned on out of all the discharge cells on the screen are only white-captioned portions, the automatic power control mode does not operate as in the case of La on the drawing because the load factor is small. However, the display of the fixed or moving white subtitles on the screen is very large, but the automatic power control mode is not activated, which causes a large stress on the driving circuit unit and the panel.

The present invention is to solve the above problems, by performing an automatic power control (APC) during the display of the OSD (On Screen Display) signal, it is possible to reduce the stress of the drive unit and reduce power consumption An object of the present invention is to provide a plasma display panel driving method.

In the method of driving a plasma display panel according to the present invention for achieving the above object, there are a plurality of sub-fields for time division gray scale display for each frame as a display period, and each sub-field has a reset period and an address period. And sustain discharge cycles, in which sustain pulses are alternately applied to all discharge cells to generate sustain discharge in the discharge cells selected in the address period, and the number of discharge cells to be displayed among the total discharge cells. In the case where the ratio of the load is equal to or greater than the reference load ratio, automatic power control is performed according to the automatic power control level in which the number of sustain pulses in each unit frame is inversely proportional to the load ratio, and when there is no image signal input from the outside. Plasma display that displays pre-stored warning messages on the screen In the driving method of ray panel, (a) generating a non-input signal in the absence of a video signal inputted from the outside; And (b) performing automatic power control according to the no input signal.

In the step (a), (a1) detecting the video signal input from the outside to determine whether the video signal is input from the outside, and (a2) the image input from the outside by the determination of the step (a1) If no signal is detected, it is desirable to have a step of generating an inputless signal.

The step (b) includes (b1) determining whether the automatic power control is currently performed, and (b2) determining the automatic power control when the automatic power control is not currently performed according to the determination of the (b1) step. It is desirable to have a step to perform.

In this case, it is preferable to perform the automatic power control to lower the automatic power control level.

Further, it is desirable to lower the automatic power control level to a level having the number of sustain pulses in the smallest number of unit frames.

In the apparatus for driving a plasma display panel according to another aspect of the present invention, there are a plurality of sub-fields for time division gray scale display for each frame as a display period, and each sub-field has a reset period, an address period, and a sustain discharge period. And sustain pulses alternately applied to all the discharge cells in the sustain discharge cycle to generate sustain discharge in the discharge cells selected in the address cycle, wherein the load ratio, which is the ratio of the number of discharge cells to be displayed among the total discharge cells, is a reference. When the load ratio is higher than or equal to the automatic power control level in which the number of sustain pulses in each unit frame is inversely proportional to the load ratio, automatic power control is performed. Driving field of the plasma display panel displayed on the screen In, for generating a non-input signal in the absence of a video signal inputted from the outside to the external image sensing unit; And an automatic power control unit for performing automatic power control according to the no input signal.

The external image sensing unit detects an image signal input from the outside to determine whether an image signal is input from the outside, and an image signal input determination unit, and generates an input signal if the image signal input from the outside is not detected. It is preferable to have an input-free signal generator.

The automatic power control unit performs automatic power control whether the automatic power control is performed or not when the automatic power control is not performed. It is preferable to have an automatic power control performer.

According to the present invention, the automatic power control (APC) is performed when the OSD (On Screen Display) signal is displayed on the screen, thereby reducing the stress of the driving unit and reducing power consumption.

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

7 is a flowchart schematically illustrating a method of driving a plasma display panel according to an exemplary embodiment of the present invention. FIG. 8 is a graph schematically illustrating automatic power control level adjustment by the method of driving the plasma display panel of FIG. 7. FIG. 9 is a block diagram schematically illustrating a plasma display panel driving apparatus for implementing the method of driving the plasma display panel of FIG. 7.

Referring to the drawing, the method 100 for driving a plasma display panel includes a plurality of sub-fields (SFs of FIGS. 4 and 5) for time division gray scale display for each frame as a display period, and each sub-field ( SF has a reset period (PR in FIG. 5), an address period (PA in FIG. 5), and a sustain discharge period (PS in FIG. 5), and in the sustain discharge period PS, sustain alternates with all discharge cells. The pulses are applied to cause sustain discharge in the selected discharge cells in the address period PA. When the load ratio, which is the number of discharge cells to be displayed among the total discharge cells, is equal to or greater than the reference load ratio, the number of sustain pulses in each frame is determined. Plasma to perform automatic power control to inversely proportional to the load rate and to display a warning message (OSD, On Screen Display) previously stored on the screen when there is no video signal input from the outside A method of driving a display panel, the method comprising the steps (a) and (b).

In step (a), if there is no video signal input from the outside, no input signal is generated (S101 and S102). In step (b), automatic power control is performed according to the non-input signal (S103, S104).

In this case, step (a) includes step (a1) (S101) and step (a2) (S102). In the step (a1), it is detected whether an image signal is input from the outside by detecting an image signal input from the outside (S101). In the step (a2), if the video signal input from the outside is not detected by the determination in the step (a1), an input signal is generated (S102).

Step (b) includes step (b1) (S103) and step (b2) (S104). In step (b1), it is determined whether automatic power control is currently performed (S103). In the step (b2), by the determination of the step (b1), if the automatic power control is not currently performed to perform the automatic power control (S104).

In this case, it is preferable to perform the automatic power control to lower the automatic power control level, and more preferably, to lower the automatic power control level to a level having the number of sustain pulses in the smallest number of unit frames.

In the driving method 100 of the plasma display panel, there are a plurality of sub-fields SF for time division gray scale display for each frame as a display period. In addition, each sub-field SF has a reset period PR, an address period PA, and a sustain discharge period PS.

In the present embodiment, in the reset period PR, a rising ramp pulse is applied to the Y electrode lines while maintaining the address voltage applied to the address electrode lines as the reference voltage V _G as shown in FIG. 5. And discharge ramp pulses are sequentially applied to initialize all discharge cells.

As the scan signal of the ground voltage V _G is sequentially applied to the Y electrode lines Y ₁ ,..., Y _n biased with the scan voltage V _{SCAN in} the address period PA, respectively. The display data signal is applied to each of the address electrode lines of the discharge cells to be displayed with respect to the scan signal of and the address discharge is generated only in the discharge cells to be displayed to form wall charges in the discharge cells to be displayed.

In the sustain discharge period PS that follows, the second voltage V _S is applied to all of the Y electrode lines Y ₁ , ..., Y _n and the X electrode lines X ₁ , ..., X _n . The display sustain pulse is alternately applied, causing a discharge for display retention in the discharge cells in which wall charges are formed in the corresponding address period PA.

In this case, the luminance of the plasma display panel is proportional to the length of the sustain discharge period (S1, ..., S8 in FIG. 4), that is, the number of sustain pulses occupied in the unit frame. In addition, in the present embodiment, the power consumption is controlled by an automatic power control (APC). Automatic power control (APC) controls the number of sustain pulses in each frame to be inversely proportional to the load rate, where the load rate is the ratio of the number of discharge cells to be displayed among the total discharge cells. However, as in the normal case, automatic power control (APC) in the present invention is performed only when the load rate is more than the reference load rate (Lc of FIG. 6).

In addition, the image board 36 detects an image signal input from the outside, and when there is no image signal input from the outside, a warning message (OSD, On Screen Display) previously stored in the memory is stored in the micom of the image board 36. Display on the screen. At this time, in the case of controlling the driving of the panel by the normal automatic power control (APC), the portion displayed on the entire screen is small and the load factor is small. Therefore, automatic power control is often not performed.

In this case, in the present invention, when a warning message (OSD, On Screen Display) is to be displayed on the screen, the warning message (OSD) is displayed on the screen from the microcomputer of the image board 36 to the logic board 32. When the load ratio is less than the reference load ratio Lc by giving a signal, the automatic power control can be performed in the logic board 32 that does not perform the automatic power control. Accordingly, even in the case of an OSD signal having a load ratio of less than or equal to the reference load ratio Lc, automatic power control can be performed to reduce driving stress and reduce power consumption.

To this end, the method 100 for driving a plasma display panel according to the present invention includes (a) steps (S101 and S102) and (b) steps (S103 and S104). If there is no video signal, a non-input signal is generated (S101, S102), and in step (b), automatic power control is performed according to the non-input signal (S103, S104).

In this case, step (a) includes step (a1) (S101) and step (a2) (S102), and step (b) includes step (b1) (S103) and step (b2) (S104). do.

In the step (a1), it is detected whether an image signal is input from the outside by detecting an image signal input from the outside (S101). In the present embodiment, the external image sensor 371 may detect an image signal input from the outside, and determine whether the image signal is input from the outside. In this case, the external image sensing unit 371 may perform a function of the image sensing unit 371 in the microcomputer in the image processing unit 36 of the driving apparatus of the plasma display panel.

In the step (a2), the video signal input from the outside is detected by the determination in the step (a1), and if there is no video signal input from the outside, a no input signal is generated (S102).

In step (b1), it is determined whether automatic power control is currently performed (S103). This is to check whether the automatic power control (APC) mode is used to determine the number of sustain pulses in the unit frame to be applied to the Y electrode lines in the logic controller 32 to display the image to be displayed at present. will be. At this time, the automatic power control (APC) determines that the number of sustain pulses in the unit frame is inversely proportional to the load rate, and is activated only when the load rate is greater than or equal to the reference load rate Lc.

In the step (b2), by the determination of the step (b1), if the automatic power control is not currently performed to perform the automatic power control (S104). That is, when the OSD signal is to be displayed on the screen, the load ratio is too small and the automatic power control (APC) mode is not performed. Therefore, the driver stress and power consumption are maintained by the number of sustain pulses in the maximum unit frame. In order to reduce the number of sustain pulses, an automatic power control mode may be performed.

In this case, as shown in FIG. 8, it is preferable to perform the automatic power control to lower the automatic power control level, and in particular, the number of sustain pulses within the smallest number of unit frames for the automatic power control level. It is more preferable to lower the level to.

Here, the driving device of the plasma display panel shown in FIG. 9 is for implementing the driving method of the plasma display panel shown in FIG. 7 and the same components as the driving device of the plasma display panel shown in FIG. 3 are specifically mentioned. Except for one matter, the same functions as shown in FIG. 3 are used, and similar reference numerals are used for them, and detailed description thereof will be omitted.

FIG. 10 is a block diagram schematically illustrating a logic controller of the plasma display panel driver of FIG. 9.

Referring to the drawings, the driving controller 42 according to the present invention includes a clock buffer 45, a synchronization controller 426, a gamma correction unit 41, an error diffusion unit 412, and first-in first-out. ) Memory 411, Subfield Generator 421, Subfield Matrix 422, Matrix Buffer 423, Memory Controller 424, Frame-Memorys RFM1, ..., BFM3, Cultivation Thermal section 425, average signal level detection section 43a, power control section 43, EPIROM 44a, I ² C serial communication interface 44b, timing-signal generator 44c, and XY control section 44 ).

The clock buffer 45 converts the 26-megahertz (MHz) clock signal CLK26 from the image processor (36 in FIG. 8) into a 40-megahertz (MHz) clock signal CLK40 and outputs the converted signal. The synchronization adjusting unit 426 includes a clock signal CLK40 of 40 mega-hertz (MHz) from the clock buffer 45, an initialization signal RS from the outside, and a horizontal synchronization signal from the image processing unit (36 in FIG. 8). (H _SYNC ) and the vertical sync signal V _SYNC are input. The synchronization adjusting unit 426 outputs the horizontal synchronization signals H _SYNC1 , H _SYNC2 , and H _SYNC3 to which the input horizontal synchronization signal H _SYNC is delayed by a predetermined number of clocks, respectively. V _SYNC ) outputs vertical synchronization signals V _SYNC2 and V _SYNC3 delayed by a predetermined number of clocks, respectively.

The image data R, G, and B input to the gamma correction unit 41 have reverse nonlinear input / output characteristics in order to correct the nonlinear input / output characteristics of the cathode ray tube. Therefore, the gamma correction unit 41 processes the image data R, G, and B of the reverse nonlinear input and output characteristics to have a linear input and output characteristic. The error diffusion unit 412 reduces the data transmission error by using the first-in first-out memory 411 to move the position of the maximum sign bit, which is the boundary bit of the image data R, G, and B. FIG.

The subfield generator 421 converts the 8-bit image data R, G, and B into image data R, G, and B of the bit number corresponding to the number of subfields, respectively. For example, when grayscale driving is performed with 14 subfields in a unit frame, after converting 8-bit image data R, G, and B into 14-bit image data R, G and B, respectively, In order to reduce a data transmission error, 16 bits of image data R, G, and B are output by adding invalid data '0' of a maximum value bit (MSB) and a minimum value bit (Least Significant Bit).

The subfield matrix unit 422 rearranges 16-bit video data R, G, and B into which data of different subfields is simultaneously input, so that data of the same subfield is simultaneously output. The matrix buffer unit 423 processes the 16-bit image data (R, G, B) from the subfield matrix unit 422 and outputs it as 32-bit image data (R, G, B).

The memory controller 424 may include a red memory controller for controlling three red frame R memories (RFM1, RFM2, and RFM3), three green (G) frame memory memories (GFM1, GFM2, A green memory control unit for controlling GFM3) and a blue memory control unit for controlling the three blue frame B memories (BFM1, BFM2, BFM3). The frame data from the memory controller 424 is continuously output in units of frames and input to the rearrangement unit 425. In the drawing, reference numeral EN denotes an enable signal generated from the XY controller 44 and input to the memory controller 424 to control the data output of the memory controller 424. In addition, the reference numeral S _SYNC is generated from the XY control unit 44 to control data input / output in units of 32-bit slots in the memory control unit 424 and the rearrangement unit 425. The slot synchronization signal input to 425 is indicated. The rearrangement unit 425 rearranges and outputs 32-bit image data R, G, and B from the memory control unit 424 in accordance with the input format of the address driver (33 in FIG. 8).

On the other hand, the average signal level detector 43a detects the average signal-level ASL in units of frames from the 8-bit image data R, G, and B from the error diffusion unit 412, respectively, so that the power controller 43 To enter. The power control section 43 generates the number of discharge control data APC corresponding to the average signal-level ASL input from the average signal level detection section 43a, thereby making automatic power consumption constant in each frame. Perform the function of control. Here, the load rate means the average load rate of the load rates of each subfield of the frame. The load ratio of each subfield means a ratio of the number of cells to be displayed to the number of all cells of the plasma display panel 1. In the present embodiment, the power control unit 43 performs the automatic power control function when the load ratio of the frame exceeds 30%. In the YEPROM 44a, the X electrode lines (X ₁ , ..., X _n of FIG. 1) and the Y electrode lines (Y ₁ , ..., Y _{n of} FIG. Timing control data is stored. The discharge recovery control data APC from the power control unit 43 and the timing control data from EPIROM 44a are input to the timing-signal generator 44c through the I ² C serial communication interface 44b. The timing-signal generator 44c operates according to the input discharge count control data APC and the timing control data to generate a timing-signal. The XY control unit 44 operates in accordance with the timing-signal from the timing-signal generator 44c to output the X drive control signal S _X and the Y drive control signal S _Y.

At this time, in the case where an input signal is generated in the step S102 of generating the no input signal, the input signal is input to the power control unit 43, and whether the automatic power control is performed in the automatic power control unit 43 is performed. In operation S103, when the OSD signal is to be displayed even when the load ratio is low and automatic power control is not performed, the automatic power control is forcibly performed (S104).

11 is a block diagram schematically illustrating an apparatus for driving a plasma display panel according to another embodiment of the present invention.

Referring to the drawings, the driving apparatus of the plasma display panel includes a plurality of sub-fields (SFs of FIGS. 4 and 5) for time-division gray scale display for each frame as a display period, and each sub-field SF is provided. A reset cycle (PR in FIG. 5), an address cycle (PA in FIG. 5), and a sustain discharge cycle (PS in FIG. 5) are provided, and alternating sustain pulses are applied to all discharge cells in the sustain discharge cycle PS. To cause sustain discharge in the selected discharge cells in the address period PA. In the case where the load rate, which is the number of discharge cells to be displayed among the total discharge cells, is higher than the reference load rate, the number of sustain pulses in each frame is inversely proportional to the load rate. Plasma Dee performs an automatic power control to control the display and displays a pre-stored warning message (OSD, On Screen Display) when there is no video signal input from the outside. In the driving device of the play panel, outside the image detection unit (571); And an automatic power control unit 574.

The external image sensor 571 generates an input signal when there is no video signal input from the outside. The automatic power control unit 574 performs automatic power control according to the no input signal.

In this case, the external image detection unit 571 detects an image signal input from the outside to determine whether the image signal is input from the external image input determination unit 572 and the image signal input from the outside If not, it is preferable to include an input-free signal generator 573 for generating an input-free signal.

When the automatic power control unit 574 determines that the automatic power control is currently performed, the automatic power control whether to perform the automatic power control determination unit 575 and the automatic power control whether to determine whether to perform the automatic power control is not currently performed. It is preferable to have an automatic power control performing unit 576 for performing automatic power control.

The driving apparatus of the plasma display panel according to the present embodiment is a driving apparatus for implementing the driving method of the plasma display panel of FIG. 7, and performs the same function by performing the same function as the driving apparatus shown in FIGS. 8 and 9. Like reference numerals refer to like elements, and detailed descriptions thereof are omitted.

The image processor 56 includes an external image signal processor 561, a scaler 562, and an interface 563. The external video signal processor 561 receives an external video signal and converts the external video signal into a signal suitable for display on the plasma display panel. In this case, the external video signal may be a TV / video input signal, a PC input signal, a digital TV signal, or a digital versatile disc (DVD) input signal. The external image signal processor 561 may be configured to convert various input signals as described above to be displayed on the plasma display panel.

When a TV / video input signal is input, the video signal is processed through a video decoder, a deinterlacer, or the like. When a PC input signal is input, an analog to digital converter is used. Through the video signal can be processed. In addition, when a digital TV signal is input, the video signal may be processed through a video processor or the like, and when a DVD input signal is input, the video signal may be processed through a TMDS receiver (Time Modulation Differential Signal Receiver).

The scaler 562 scales the image signal processed by the external image signal processor 561 to data having a size appropriate to be displayed on the plasma display panel. In this case, the luminance information for each of red, green, and blue is reflected for each pixel of the panel to be displayed in the scaler 562 during data processing.

The interface 563 is to interface with the panel 1 so that the image signal processed in the image processing unit 56 can be displayed on the panel 1. As the interface 563 method, a method based on low voltage differential signaling (LVDS) or TMDS may be used.

In this case, the external image sensor 571 may be included in the image processor 56, and may be performed by a microcomputer that is connected to the external image signal processor or the external image signal processor in the image processor 56.

According to the plasma display panel driving method according to the present invention, by performing an automatic power control (APC) when the screen of the OSD (On Screen Display) signal is displayed, it is possible to reduce the stress of the driving unit and to reduce the power consumption .

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, it is merely an example, and those skilled in the art may realize various modifications and equivalent other embodiments therefrom. I can understand. Accordingly, the true scope of protection of the invention should be defined only by the appended claims.

1 is a perspective view showing an internal structure of a conventional three-electrode surface discharge plasma display panel.

FIG. 2 is a cross-sectional view illustrating a configuration of a unit display cell of the panel of FIG. 1.

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

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

FIG. 5 is a timing diagram illustrating driving signals applied to electrode lines of the plasma display panel of FIG. 1 in a unit sub-field of FIG. 4.

6 is a graph schematically illustrating the principle of automatic power control in a conventional plasma display panel.

7 is a flowchart schematically illustrating a method of driving a plasma display panel according to an exemplary embodiment of the present invention.

FIG. 8 is a graph schematically illustrating automatic power control level adjustment by the method of driving the plasma display panel of FIG. 7.

FIG. 9 is a block diagram schematically illustrating a plasma display panel driving apparatus for implementing the method of driving the plasma display panel of FIG. 7.

FIG. 10 is a block diagram schematically illustrating a logic controller of the plasma display panel driver of FIG. 9.

11 is a block diagram schematically illustrating an apparatus for driving a plasma display panel according to another embodiment of the present invention.

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

22, 32, 52: logic controller 26, 36, 56: image processor

371 and 571: external image detection unit 572: image signal input determination unit

573: input signal generating unit 574: automatic power control unit

575: Automatic power control execution determination unit 576: Automatic power control execution unit

Claims (10)

There are a plurality of sub-fields for time division gradation display per frame as a display period, each sub-field having a reset period, an address period, and a sustain discharge period, wherein the sustain discharge period is applied to all discharge cells. Alternating sustain pulses are applied to cause sustain discharge in the selected discharge cells in the address period, and when the load ratio, which is the ratio of the number of discharge cells to be displayed among the total discharge cells, is greater than or equal to the reference load ratio, A method of driving a plasma display panel which performs automatic power control according to an automatic power control level inversely proportional to the load ratio, and displays a pre-stored warning message on the screen when there is no image signal input from the outside. In (a) generating a no input signal when there is no video signal input from the outside; And and (b) performing the automatic power control according to the no input signal. The method of claim 1, Step (a) (a1) detecting a video signal input from the outside and determining whether a video signal is input from the outside; and (a2) generating the non-input signal if the image signal input from the outside is not detected by the determination in the step (a1). The method of claim 1, Step (b) (b1) determining whether the automatic power control is currently performed; and (b2) performing the automatic power control when the automatic power control is not currently performed according to the determination of the step (b1). The method of claim 3, And driving the automatic power control to lower the automatic power control level. The method of claim 4, wherein And driving the automatic power control level down to a level having the number of sustain pulses in the smallest number of unit frames. There are a plurality of sub-fields for time division gradation display per frame as a display period, each sub-field having a reset period, an address period, and a sustain discharge period, wherein the sustain discharge period is applied to all discharge cells. Alternating sustain pulses are applied to cause sustain discharge in the selected discharge cells in the address period, and when the load ratio, which is the ratio of the number of discharge cells to be displayed among the total discharge cells, is greater than or equal to the reference load ratio, Automatic power control is performed according to the automatic power control level in inverse proportion to the number of sustain pulses, and a pre-stored warning message is displayed on the screen when there is no image signal input from the outside. In An external image sensor for generating a no input signal when no image signal is input from the outside; And And an automatic power controller configured to perform the automatic power control in response to the no input signal. The method of claim 6, The external image detection unit, A video signal input determination unit for detecting a video signal input from the outside and determining whether a video signal is input from the outside; and generating a non-input signal for generating the no input signal if the video signal input from the outside is not detected. An apparatus for driving a plasma display panel having a portion. The method of claim 6, The automatic power control unit, Determining whether to perform the automatic power control whether the automatic power control is currently performed, and if the automatic power control is not performed as a result of the determination of the automatic power control whether to perform the automatic power control An apparatus for driving a plasma display panel having an automatic power control unit. The method of claim 8, And driving the automatic power control to lower the automatic power control level. The method of claim 9, And the automatic power control level is lowered to a level having the number of sustain pulses in the smallest number of unit frames.