KR20090043305A - Organic electro-luminescence apparatus - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent device, by adjusting the length of a light emission period in consideration of a line load, thereby compensating for luminance deviation of an image, thereby improving image quality.

The organic electroluminescent device according to the first embodiment of the present invention includes a plurality of scan lines and data lines that cross each other, and a plurality of erase lines parallel to the scan line. And an organic electroluminescent panel including a plurality of subpixels disposed at intersections of lines, erase lines, and data lines, and a driver supplying scan signals to scan lines, data signals to data lines, and erase signals to erase lines. The plurality of scan lines may include a first scan line and a second scan line having different order of supply of scan signals, and the plurality of erase lines may include a first erase line and a second scan line corresponding to the first scan line. A second erasing line corresponding to, and for the same image data, an end point of a scan signal supplied to the first scan line and an erase scene supplied to the first erase line; The time difference between the time of supply of the call is different from the time difference between the end of the scan signal supplied to the second scan line and the time of supply of the erase signal supplied to the second erase line.

Description

Organic Electroluminescence Apparatus

The present invention relates to an organic electroluminescent device.

The organic electroluminescent device includes an organic electroluminescent panel and a driver.

The organic electroluminescent panel includes an organic cell that generates predetermined light by recombination of electrons and holes.

The driver supplies a driving signal to the organic cell of the organic electroluminescent panel. Then, the organic cell may emit light by the driving signal supplied by the driving unit, thereby realizing the image.

One aspect of the present invention is to provide an organic electroluminescent device that compensates for luminance deviation of an image by adjusting the length of the light emission period in consideration of a line load.

The organic electroluminescent device according to the first embodiment of the present invention includes a plurality of scan lines and data lines that cross each other, and a plurality of erase lines parallel to the scan line. And an organic electroluminescent panel including a plurality of subpixels disposed at intersections of lines, erase lines, and data lines, and a driver supplying scan signals to scan lines, data signals to data lines, and erase signals to erase lines. The plurality of scan lines may include a first scan line and a second scan line having different order of supply of scan signals, and the plurality of erase lines may include a first erase line and a second scan line corresponding to the first scan line. A second erasing line corresponding to, and for the same image data, an end point of a scan signal supplied to the first scan line and an erase scene supplied to the first erase line; The time difference between the time of supply of the call is different from the time difference between the end of the scan signal supplied to the second scan line and the time of supply of the erase signal supplied to the second erase line.

Further, the first scan line is disposed before the second scan line in the supply direction of the data signal among the first scan line and the second scan line, and the end of the scan signal supplied to the second scan line for the same image data. The time difference between the time point and the supply point of the erase signal supplied to the second erase line is greater than the time difference between the end point of the scan signal supplied to the first scan line and the supply point of the erase signal supplied to the first erase line. Can be.

In addition, the pulse width of the scan signal supplied to the first scan line and the pulse width of the scan signal supplied to the second scan line may be the same.

Also, the pulse width of the scan signal supplied to the first scan line may be greater than the pulse width of the scan signal supplied to the second scan line.

In addition, the organic electroluminescent device according to the second embodiment of the present invention includes a plurality of scan lines and data lines that cross each other, and is disposed at a point where the scan lines and the data lines cross. An organic electroluminescent panel including a plurality of sub-pixels, and a driving unit for supplying a scan signal to a scan line and a data signal corresponding to the scan signal to a data line, within the same frame for the same image data The pulse widths of the scan signals supplied to any two scan lines of the plurality of scan lines may be different.

The plurality of scan lines may include a first scan line and a second scan line having different order of supply of scan signals, and the first scan line may include a first scan line in a supply direction of a data signal among the first scan line and the second scan line. The pulse width of the scan signal disposed before two scan lines and supplied to the first scan line within one frame may be greater than the pulse width of the scan signal supplied to the second scan line.

Also, for the same video data. The pulse width of the data signal supplied to the data line corresponding to the first scan line and the pulse width of the data signal supplied to the data line corresponding to the second scan line may be the same.

In addition, the organic electroluminescent device according to the third embodiment of the present invention includes a plurality of scan lines and data lines that cross each other, and is disposed at a point where the scan lines and the data lines cross. An organic electroluminescent panel including a plurality of subpixels, and a driver for supplying a scan signal to a scan line and a data signal corresponding to the scan signal to a data line, wherein the scan signal supplied to the scan line corresponds thereto A first portion overlapping with a data signal supplied to a data line to be supplied, and a second portion not overlapping with a data signal, and for any of the same image data, any two scan lines of a plurality of scan lines in one frame The lengths of the second portions of the scan signals supplied to the may be different.

The plurality of scan lines may include a first scan line and a second scan line having different order of supply of scan signals, and the first scan line may include a first scan line in a supply direction of a data signal among the first scan line and the second scan line. The length of the second portion of the scan signal, which is disposed before two scan lines and supplied to the first scan line within one frame, is greater than the length of the second portion of the scan signal supplied to the second scan line, for the same image data. It can be long.

In addition, for the same image data, pulse widths of scan signals supplied to any two scan lines of the plurality of scan lines in one frame may be different from each other.

In addition, the organic electroluminescent device according to the fourth embodiment of the present invention includes a plurality of scan lines, data lines, and a plurality of erase lines parallel to the scan lines. And an organic electroluminescent panel including a plurality of subpixels disposed at intersections of the scan line and the erase line with the data line, and a driver for supplying the scan signal to the scan line, the data signal to the data line, and the erase signal to the erase line. The pulse widths of the erase signals supplied to any two erase lines of the plurality of erase lines in one frame may be different with respect to the same image data.

The plurality of erase lines may include a first erase line and a second erase line having different order of supply of the erase signals, and the first erase line may include a first erase line in a supply direction of the data signal among the first erase line and the second erase line. The pulse width of the erase signal, which is disposed before the two erase lines and is supplied to the first erase line in one frame, may be greater than the pulse width of the erase signal supplied to the second erase line for the same image data.

Also, for the same video data. The pulse width of the scan signal supplied to the scan line corresponding to the first erase line and the pulse width of the scan signal supplied to the scan line corresponding to the second erase line may be the same.

The organic electroluminescent device according to an embodiment of the present invention has the effect of improving the image quality of the image by compensating for the luminance deviation of the image.

Hereinafter, an organic electroluminescent device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1A to 1B are views for explaining an example of an organic electroluminescent device according to an embodiment of the present invention.

First, referring to FIG. 1A, an organic electroluminescent device 100 according to an embodiment of the present invention includes an organic electroluminescent panel 110 and a driver 120.

The driver 120 may generate and control a driving signal for displaying an image on the organic electroluminescent panel 110. For example, data signals supplied to the data lines D1 to Dn and scan signals supplied to the scan lines S1 to Sm may be generated and controlled. Alternatively, the erase signal supplied to the erase lines EI ˜Em may be generated and controlled.

Here, in FIG. 1A, although the driving unit 120 is illustrated as one module, the driving unit 120 may be separated into at least two module types. For example, the driver 120 may be divided into a data driver (not shown) for generating and controlling a driving signal supplied to a data line and a scan driver (not shown) for generating and controlling a driving signal supplied to a scan line. It is.

The organic electroluminescent panel 110 may include scan lines and data lines that cross each other, and sub pixels P may be disposed at positions where the scan lines and the data lines cross.

The scan line can supply a scan signal to a subpixel. Preferably, the scan line may provide a path for supplying the scan signal generated by the driver 120.

The data line may supply a data signal to a subpixel. Preferably, the data line may provide a supply path for the data signal generated by the driver 120.

In addition, the organic electroluminescent panel 110 may further include erase lines E1 to Em that supply an erase signal to the subpixel and intersect the data line.

Such an erase line can be used to supply an erase signal to a subpixel, and if the erase signal is not used, the erase line can also be omitted.

It is also possible that the erase line is omitted even when the erase signal is used. In this case, the erase signal can be supplied to another line. For example, although not illustrated, when the organic electroluminescent panel 110 further includes a power supply line for supplying a power supply voltage VDD, the erase signal may be supplied through the power supply line.

Next, referring to FIG. 1B, an example of a structure of a subpixel is illustrated.

The subpixel may include an organic cell OLED. In addition, the subpixel may further include a first transistor Tr1, a second transistor Tr2, a third transistor Tr3, and a capacitor unit C.

When the scan signal is supplied to the scan line Scan, the first transistor Tr1 is turned on, and when the data signal is supplied to the data line Data, power is supplied to both ends of the capacitor unit C. A voltage equal to the difference between the voltage VDD and the voltage Vd of the data signal is applied, so that the voltage of (VDD-Vd) may be stored in the capacitor unit C.

Then, the voltage of the VDD-Vd is applied to the gate terminal of the third transistor Tr3, so that the third transistor Tr3 is turned on and thus stored in the capacitor unit C (VDD- A current corresponding to the voltage of Vd) is supplied to the organic cell OLED to emit light.

Meanwhile, when the erase signal is supplied to the erase line Erase, the second transistor Tr2 may be turned on. Then, since both ends of the capacitor portion C are shorted, all of the voltages charged in the capacitor portion C may be discharged, and accordingly, the third transistor Tr3 may be turned off. Can be. Then, light emission of the organic cell OLED may be stopped.

2 is a view for explaining the light emission principle of the organic cell.

Referring to FIG. 2, the organic cell includes an electron injection layer 210, an electron transport layer 220, an emission layer 230, a hole transport layer 240, and a hole injection layer 250 between the cathode 200 and the anode 260. It may include.

When voltage is applied to the cathode 200 and the anode 260, a gradation current is supplied, and thus electrons generated from the cathode 200 are transferred to the emission layer 230 through the electron injection layer 210 and the electron transport layer 220. Go to.

In addition, holes generated from the anode 260 move to the emission layer 230 through the hole injection layer 250 and the hole transport layer 240.

In this case, in the emission layer 230, electrons supplied from the electron injection layer 210 and the electron transport layer 220 collide with each other and holes supplied from the hole injection layer 250 and the hole transport layer 240 collide with each other. Light is generated in the emission layer 230 by the collision of electrons and holes.

The brightness of the light generated in the light emitting layer 230 may be proportional to the magnitude of the gradation current supplied to the anode 260.

Here, FIG. 2 illustrates an example of the structure and emission principle of the organic cell, and the present invention is not limited to FIG. 2. For example, at least one of the electron injection layer 210, the electron transport layer 220, the hole transport layer 240, and the hole injection layer 250 may be omitted in the organic cell.

3 is a view for explaining an example of the operation of the organic electroluminescent device. In FIG. 3, the case of the structure of the subpixel described above with reference to FIG. 1B will be described as an example.

Referring to FIG. 3, the driver may supply a scan signal to a scan line in an address period and a data signal to a data line.

Then, the first transistor Tr1 is turned on. Then, as described above in detail, the voltage of (VDD-Vd) may be stored in the capacitor unit C.

In the light emitting period after the address period, the driver no longer supplies the scan signal to the scan line. Then, the voltage of the VDD-Vd stored in the capacitor portion C is applied to the gate terminal of the third transistor Tr3, so that the third transistor Tr3 is turned on, and thus the capacitor portion C is turned on. A current corresponding to the stored (VDD-Vd) voltage is supplied to the organic cell OLED, so that the organic cell OLED emits light.

In the erase period after the emission period, the driver may supply an erase signal to the erase line Erase. As a result, the second transistor Tr2 is turned on, and thus, the capacitor C is discharged to stop light emission of the organic cell OLED.

Although FIG. 3 illustrates a case in which an address period, an emission period, and an erasing period are included in one subfield, the erasing period may be omitted.

4 is a view for explaining an example of the digital driving method.

Referring to FIG. 4, in the digital driving method, a gray scale of an image may be implemented by a frame in which a plurality of sub-fields are collected. Here, the subfield may include the address period and the light emission period described above with reference to FIG. 3, and may further include an erase period.

For example, when the image is to be displayed in 32 gradations, the frame may be divided into five subfields SF1 to SF5 as shown in FIG. 4, and each of the five subfields SF1 to SF5 may be divided into two frames. It can be divided into an address period, a light emission period, and an erase period.

The weight of the corresponding subfield may be set by adjusting the length of the light emission period. That is, for example, the weight of each subfield is 2 ⁿ by setting the weight of the first subfield to 2 ⁰ and the weight of the second subfield to 2 ¹ (where n = 0, 1, The weight of each subfield may be determined to increase at a ratio of 2, 3, and 4).

Then, the frame of such a structure may implement a total of 32 (2 ⁰ + 2 ¹ + ² 2 + ^{2 3} + 2 ⁴ ) gray levels. For example, when a 32-gradation image is implemented, all of the first subfield SF1 to the fifth subfield SF5 may be turned on. In other words. The organic cell can be made to emit light in the light emitting period after the address period by supplying the data signal to the data line in the address period of the first subfield SF1 to the fifth subfield SF5. In contrast, in the case of implementing 10 gray levels, the second subfield SF2 having the weight of 2 (2 ¹ ) and the fourth subfield SF4 having the weight of 8 (2 ³ ) may be turned on.

These frames may be used in a plurality of seconds, and in the case of using a total of 60 frames in one second, the length (T) of the frame may be 1/60 seconds, that is, approximately 16.67 ms, and the total in one second. In the case of using 50 frames, the length T of the frame may be approximately 20 ms.

In FIG. 4, only one frame is composed of five subfields. However, the number of subfields forming one frame may be changed in various ways. For example, one frame may be configured with 12 subfields from the first subfield to the twelfth subfield, or one frame may be configured with 10 subfields.

In addition, in FIG. 4, subfields are arranged in an order of increasing weight in one frame. Alternatively, subfields may be arranged in an order of decreasing weight, or subfields may be arranged regardless of weight. It is.

5A to 5B are diagrams for explaining an example of a method of adjusting the length of the light emission period in accordance with the arrangement order of the scan lines.

First, referring to FIG. 5A, data lines D1 to Dn and scan lines S1 to Sm that cross each other may be disposed in the organic EL panel 500.

In addition, a data driver 510 may be provided to supply a data signal to a data line of the organic light emitting panel 500, and a scan driver 520 may be provided to supply a scan signal to a scan line.

The supply direction of the data signal supplied from the data driver 510 may be a direction from the S1 scan line to the Sm scan line, as indicated by the arrows in the figure.

For example, if the scan driver 520 sequentially supplies scan signals from the S1 scan line to the Sm scan line, the data driver 510 may start from Sm to the subpixels disposed on the S1 scan line in the order of supply of the scan signals. Data signals may be sequentially supplied to subpixels disposed on the scan line.

Alternatively, when the scan driver 520 sequentially supplies the scan signals to the odd-numbered scan lines from the S1 scan line to the Sm scan lines, and then sequentially supplies the scan signals to the even-numbered scan lines, the data driver 510. ) Is sequentially supplied to the subpixels arranged on the even-numbered scan lines after the data signals are sequentially supplied to the subpixels arranged on the odd-numbered scan lines from the S1 scan line to the Sm scan line according to the scan signal supply order. The data signal can be supplied sequentially.

The supply direction of the data signal may be a direction from the S1 scan line to the Sm scan line irrespective of the supply order of the scan signal or the data signal.

Here, unlike FIG. 5A, when the data driver 510 is disposed under the organic electroluminescent panel 500, that is, the electrical distance between the data driver 510 and the Sm scan line is different between the data driver 510 and the S1 scan line. When smaller than the electrical distance, the supply direction of the data signal is the direction from the Sm scan line to the S1 scan line.

Next, referring to FIG. 5B, the lengths of light emission periods in the subpixels disposed on the Sa scan line and the subpixels disposed on the Sb scan line are different for the same image data. Preferably, assuming that the Sa scan line is disposed before the Sb scan line in the supply direction of the data signal among the Sa scan line and the Sb scan line, the sub disposed on the Sb scan line of (b) for the same image data. The length of the light emission period in the pixel is longer than the length of the light emission period in the sub pixel disposed on the Sa scan line of (a).

6A to 6D are diagrams for explaining the reason for adjusting the length of the light emission period.

First, referring to FIG. 6A, subpixels P1 to Pm may be disposed at points where the data lines D1 and the scan lines S1 to Sm cross each other.

Here, the subpixel is supplied with a data signal through a data line, which may be ideal if the electrical resistance of the data line is 0 ohms, but may not be realistic and has a certain electrical resistance value. For example, a resistor of R1 is equivalently disposed in a path through which a data signal is supplied to a P1 subpixel from a data driver (not shown), and an equivalent of R1 + R2 is equivalent to a path in which a data signal is supplied to a P2 subpixel. A resistor is disposed, and equivalently a resistor of R1 + R2 + R3 + ... + Rm is disposed in the path through which the data signal is supplied to the Pm subpixel. That is, the line loads of the data signals of each subpixel may be different.

Next, with respect to the same image data as shown in Fig. 6B, when the lengths of the light emission periods of the subpixels arranged on each scan line are the same regardless of the line load, the subpixels arranged on the S1 scan line The voltage of the data signal supplied can be kept sufficiently high, while being excessively lowered by the relatively large line load of the voltage of the data signal supplied to the subpixels disposed on the Sm scan line. Then, luminance deviation may occur in the image to be implemented.

For example, as shown in FIG. 6C, the screen area of the panel is disposed in the third area A3 having a relatively large line load, and the second area A2 arranged in the order that the data signal is supplied rather than the third area A3. And a first area A1 disposed before the second area A2 in the order in which the data signal is supplied. In addition, it is assumed that image data corresponding to the first area A1, the second area A2, and the third area A3 are all the same.

In this case, if the lengths of the light emission periods of each sub-pixel are the same as in the case of FIG. 6B, in the third region A3 where the line load is relatively large, the voltage drop of the data signal according to the in-load is realized. The brightness of the image may be relatively low.

On the other hand, in the second area A2, the line load may be smaller than that of the third area A3, so that the luminance of the image implemented in the second area A2 is implemented in the third area A3. It may be higher than the brightness of the image.

In addition, the brightness of the image implemented in the first area A1 may be higher than the brightness of the image implemented in the second area A2 and the third area A3 for the same reason as above.

As such, when the lengths of the light emission periods are the same regardless of the line load, the luminance corresponding to the same image data is different for each region, whereby a luminance step may occur, thereby degrading the image quality of the image.

On the other hand, when the length of the light emission period is adjusted according to the line load as shown in FIG. 5B, for example, as shown in FIG. 6D, the length of the light emission period in the first area A1 is determined as the light emission in the second area A2. If the length of the light emission period of the second area A2 is shorter than the length of the period, and the length of the light emission period of the second area A3 is shorter than the length of the light emission period of the third area A3, the amount of light emission in the first area A1 is changed to the second area A2. It can be made smaller than the light emission amount of, and the occurrence of the luminance step can be prevented by making the light emission amount of the second area A2 smaller than the light emission amount of the third area A3.

7 is a view for explaining an example of a method of adjusting the length of the light emission period by using the time difference between the scan signal and the erase time.

Referring to FIG. 7, assuming a Sa scan line and an Sb scan line having different scan signal supply orders, the end time t1 of the scan signal supplied to the Sa scan line of (a) and the same image data may be different from each other. The time difference t2-t1 of the time t2 of the erase signal supplied to the Ea erase line corresponding to the Sa scan line is equal to the end time t4 of the scan signal supplied to the Sb scan line of (b). This is different from the time difference t5-t4 between the time t5 of the supply of the erase signal supplied to the Eb erase line corresponding to the Sb scan line. That is, the luminance step of the image is improved by adjusting the length of the light emission period by adjusting the time difference between the end point of the scan signal and the time of supply of the erase signal according to the line load.

Preferably, assuming that the Sa scan line is disposed before the Sb scan line in the supply direction of the data signal among the Sa scan line and the Sb scan line, (t5-t4) in (b) is ( is greater than (t2-t1) in a).

As such, by adjusting the time difference between the end of the scan signal and the time of supply of the erase signal, the length of the light emission period can be adjusted, thereby preventing the luminance step of the image due to the line load.

Here, the pulse width t1-t0 of the scan signal supplied to the Sa scan electrode can be substantially the same as the pulse width t4-t3 of the scan signal supplied to the Sb scan electrode.

8A to 8D are diagrams for describing other examples of a method of adjusting a time difference between a scan signal and an erase time.

First, referring to FIG. 8A, the time difference Δt between the end point of the scan signal and the end point of the erase signal from the direction in which the data signal is supplied may gradually increase from a to b.

Alternatively, as shown in FIG. 8B, the time difference Δt between the end point of the scan signal and the end point of the erase signal is gradually increased from c to d until the P1 scan line in the direction in which the data signal is supplied, and the P1 + 1 scan From the line, the time difference DELTA t between the end time of the scan signal and the time of supply of the erase signal can be kept substantially constant at d.

Alternatively, as shown in FIG. 8C, the time difference Δt between the end point of the scan signal and the end point of the erase signal is substantially maintained at e until the P2 scan line in the direction in which the data signal is supplied, and the P2 + 1 scan From the line, the time difference Δt between the end point of the scan signal and the time point of supply of the erase signal may be gradually increased from e to f.

Alternatively, as shown in FIG. 8D, the panel includes a fourth region A4, a third region A3 disposed before the fourth region A4 in the supply direction of the data signal, and a third region A3 in the supply direction of the data signal. It is assumed that a second region A2 disposed earlier and a first region A1 disposed earlier than the second region A2 in the supply direction of the data signal are included.

Here, the time difference Δt between the end point of the scan signal and the time of supply of the erase signal in the first area A1 is g, and the end point of the end of the scan signal and the time of supply of the erase signal in the second area A2. The time difference Δt is h greater than g, and the time difference Δt between the end point of the scan signal and the time of supply of the erase signal in the third area A3 is i greater than g and h, and the fourth area. In (A4), the time difference Δt between the end time of the scan signal and the time of supply of the erase signal may be j greater than g, h, and i. In this manner, it is possible to adjust the time difference Δt between the end point of the scan signal and the time point of supply of the erase signal for each predetermined region.

9 is a view for explaining an example of a method of adjusting the length of the light emission period by adjusting the pulse width of the scan signal.

Referring to FIG. 9, assuming Sa scan lines and Sb scan lines having different scan signal supply orders, the pulse width Wa of the scan signal supplied to the Sa scan line of (a) is the same for the same image data. It may be different from the pulse width (Wb) of the scan signal supplied to the Sb scan line of b). That is, the length of the light emission period is adjusted by adjusting the pulse width of the scan signal according to the line load.

Preferably, assuming that the Sa scan line is disposed before the Sb scan line in the supply direction of the data signal among the Sa scan line and the Sb scan line, the scan supplied to the Sa scan line of (a) for the same image data. The pulse width Wa of the signal may be greater than the pulse width Wb of the scan signal supplied to the Sb scan line of (b). Here, it may be desirable to adjust the length of the light emission period by adjusting the pulse width of the scan signal in a fixed state at the time of supplying the scan signal.

As such, by adjusting the pulse width of the scan signal according to the line load, the length T1 of the light emission period in the Sa scan line can be shorter than the length T1 + Wa-Wb of the light emission period in the Sb scan line. . As a result, the luminance step problem of the image may be improved.

10 is a view for explaining another method of adjusting the length of the light emission period.

Referring to FIG. 10, a scan signal supplied to scan lines Sa and Sb includes a first portion W1 overlapping a data signal supplied to a data line D corresponding thereto, and a second portion not overlapping a data signal. It may include a portion (W2).

Here, assuming that the Sa scan line and the Sb scan line having different scan signal supply orders are different, for the same image data, the length of the second portion W2 of the scan signal supplied to the Sa scan line of (a) is ( The length of the second portion W2 of the scan signal supplied to the Sb scan line of b) may be different. That is, the length of the light emission period may be adjusted by adjusting the length of the second portion of the scan signal according to the line load.

Preferably, assuming that the Sa scan line is disposed before the Sb scan line in the supply direction of the data signal among the Sa scan line and the Sb scan line, the scan supplied to the Sa scan line of (a) for the same image data. The length of the second portion W2 of the signal may be greater than the length of the second portion W2 of the scan signal supplied to the Sb scan line of (b).

As such, when the length of the second portion W2 that does not overlap with the data signal of the scan signal is adjusted according to the line load, the length T2 of the light emission period in the Sa scan line is changed to the length of the light emission period in the Sb scan line ( Shorter than T3). As a result, the luminance step problem of the image may be improved.

In the case of FIG. 10, the pulse width of the scan signal may be changed according to the scan line. For example, the pulse width of the scan signal supplied to the Sa scan line is greater than the pulse width of the scan signal supplied to the Sb scan line, and thus the length of the second portion W2 of the scan signal supplied to the Sa scan line. May be longer than the length of the second portion W2 of the scan signal supplied to the Sb scan line.

FIG. 11 is a diagram for describing a method of controlling a length of a light emission period by adjusting a pulse width of an erase signal.

Referring to FIG. 11, assuming that Ea erasing lines and Eb erasing lines having different order of erasing signals are supplied, the pulse width W10 of the erasing signal supplied to the Ea erasing line of (a) is the same for the same image data. It may differ from the pulse width W20 of the erase signal supplied to the Eb erase line of b). That is, the length of the light emission period is adjusted by adjusting the pulse width of the erase signal in accordance with the line load.

Preferably, assuming that the Ea erasing line is disposed before the Eb erasing line in the supply direction of the data signal among the Ea erasing line and the Eb erasing line, the erase which is supplied to the Ea erasing line of (a) for the same image data. The pulse width W10 of the signal may be greater than the pulse width W20 of the erase signal supplied to the Eb erase line of (b). Here, the end point of the erasing signal may be adjusted by adjusting the pulse width of the erasing signal in a fixed state, thereby adjusting the length of the light emission period.

As such, by adjusting the pulse width of the erase signal according to the line load, the length W30 of the light emission period in the Ea erase line can be shorter than the length W40 of the light emission period in the Eb erase line. As a result, the luminance step problem of the image may be improved.

As such, the technical configuration of the present invention described above can be understood by those skilled in the art that the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention.

Therefore, the exemplary embodiments described above are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the appended claims rather than the foregoing detailed description, and the meaning and scope of the claims are as follows. And all changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

1A to 1B are views for explaining an example of an organic electroluminescent device according to an embodiment of the present invention.

2 is a diagram for explaining a light emission principle of a subpixel;

3 is a diagram for explaining an example of the operation of the organic electroluminescent device.

4 is a diagram for explaining an example of a digital driving method.

5A to 5B are views for explaining an example of a method of adjusting the length of the light emission period in accordance with the arrangement order of the scan lines.

6A to 6D are diagrams for explaining the reason for adjusting the length of the light emission period.

FIG. 7 is a diagram for explaining an example of a method of adjusting the length of a light emission period using a time difference between a scan signal and an erase signal. FIG.

8A to 8D are diagrams for explaining other examples of a method of adjusting a time difference between a scan signal and an erase time.

9 is a view for explaining an example of a method of adjusting the length of the light emission period by adjusting the pulse width of the scan signal.

10 is a diagram for explaining another method of adjusting the length of a light emission period.

FIG. 11 is a diagram for explaining a method of adjusting the length of a light emission period by adjusting a pulse width of an erase signal. FIG.

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

100 organic EL panel 110 driving unit

101: main power line D1 ~ Da: data line

S1 ~ Sm: Scan Line E1 ~ Ea: Auxiliary Power Line

Claims (13)

A plurality of scan lines and data lines intersecting each other, and a plurality of erase lines parallel to the scan lines, wherein the scan lines and erase lines intersect the data lines. An organic electroluminescent panel comprising a plurality of subpixels disposed in the; A driver supplying a scan signal to the scan line, a data signal to the data line, and an erase signal to the erase line Including, The plurality of scan lines may include a first scan line and a second scan line having different supply orders of the scan signals. The plurality of erase lines may include a first erase line corresponding to the first scan line and a second erase line corresponding to the second scan line. For the same image data, the time difference between the end time of the scan signal supplied to the first scan line and the time of supply of the erase signal supplied to the first erase line is the end of the scan signal supplied to the second scan line. And a time difference between a time point and a time point at which an erase signal supplied to the second erase line is supplied. The method of claim 1, The first scan line is disposed before the second scan line in the supply direction of the data signal among the first scan line and the second scan line, For the same image data, the time difference between the end time of the scan signal supplied to the second scan line and the time of supply of the erase signal supplied to the second erase line is the end of the scan signal supplied to the first scan line. And a time difference between a time point and a time point at which an erase signal supplied to the first erase line is supplied. The method of claim 2, The pulse width of the scan signal supplied to the first scan line and the pulse width of the scan signal supplied to the second scan line are the same. The method of claim 2, And a pulse width of the scan signal supplied to the first scan line is greater than a pulse width of the scan signal supplied to the second scan line. An organic electroluminescent panel including a plurality of scan lines and data lines that cross each other, and a plurality of subpixels disposed at intersections of the scan lines and the data lines; A driver supplying a scan signal to the scan line and a data signal corresponding to the scan signal to the data line Including, And the pulse width of the scan signal supplied to any two scan lines of the plurality of scan lines in one frame with respect to the same image data. The method of claim 5, wherein The plurality of scan lines may include a first scan line and a second scan line having different supply orders of the scan signals. The first scan line is disposed before the second scan line in the supply direction of the data signal among the first scan line and the second scan line, And the same pulse width of the scan signal supplied to the first scan line within one frame is larger than the pulse width of the scan signal supplied to the second scan line. The method of claim 6, For the same video data. And a pulse width of the data signal supplied to the data line corresponding to the first scan line and a pulse width of the data signal supplied to the data line corresponding to the second scan line. An organic electroluminescent panel including a plurality of scan lines and data lines that cross each other, and a plurality of subpixels disposed at intersections of the scan lines and the data lines; A driver supplying a scan signal to the scan line and a data signal corresponding to the scan signal to the data line Including, The scan signal supplied to the scan line includes a first portion overlapping the data signal supplied to a corresponding data line, and a second portion not overlapping the data signal, And the same length of the second portion of the scan signal supplied to any two scan lines of the plurality of scan lines in a frame are different for the same image data. The method of claim 8, The plurality of scan lines may include a first scan line and a second scan line having different supply orders of the scan signals. The first scan line is disposed before the second scan line in the supply direction of the data signal among the first scan line and the second scan line, For the same image data, the length of the second portion of the scan signal supplied to the first scan line in one frame is longer than the length of the second portion of the scan signal supplied to the second scan line. Device. The method of claim 8, And the pulse width of the scan signal supplied to any two scan lines of the plurality of scan lines in one frame with respect to the same image data. A plurality of scan lines and data lines intersecting each other, and a plurality of erase lines parallel to the scan lines, wherein the scan lines and erase lines intersect the data lines. An organic electroluminescent panel comprising a plurality of subpixels disposed in the; A driver supplying a scan signal to the scan line, a data signal to the data line, and an erase signal to the erase line Including, And the same pulse width of the erase signal supplied to any two erase lines of the plurality of erase lines in a frame is different for the same image data. The method of claim 11, The plurality of erase lines may include a first erase line and a second erase line having different supply orders of the erase signals. The first erase line is disposed before the second erase line in the supply direction of the data signal among the first erase line and the second erase line, And for the same image data, the pulse width of the erase signal supplied to the first erase line in one frame is larger than the pulse width of the erase signal supplied to the second erase line. The method of claim 12, For the same video data. And a pulse width of the scan signal supplied to the scan line corresponding to the first erase line and a pulse width of the scan signal supplied to the scan line corresponding to the second erase line.

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