KR101889784B1 - Apparatus and method for driving of organic light emitting display device - Google Patents

Abstract

The present invention relates to an organic electroluminescence (EL) display device capable of improving image quality by preventing image quality degradation and flicker-type image quality degradation due to a luminance response characteristic according to a luminance response rate of a panel when adjusting brightness by adjusting brightness according to a change in a video scene A driving device for a display device includes a plurality of red, green, and blue sub-pixels formed in a region defined by a plurality of data lines and a plurality of gate lines, panel; And a panel driver for displaying the image corresponding to the red, green, and blue input data on the display panel and adjusting the brightness of the display panel according to whether the image is changed in a frame unit or not. do.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic light emitting diode (OLED) display device,

[0001] The present invention relates to an organic light emitting diode (OLED) display, and more particularly, to an organic light emitting diode (OLED) display, The present invention relates to a driving apparatus and a driving method of an organic light emitting display device.

In recent years, the importance of flat panel displays (LCDs) has increased with the development of multimedia. Various flat panel displays such as a liquid crystal display, a plasma display panel, a field emission display, and an organic light emitting display have been put to practical use have. Of these flat panel displays, the organic light emitting display has a response speed of less than 1 ms, has a high response speed, low power consumption, self-luminescence, and thus has no problem in viewing angle, and has been attracting attention as a next generation flat panel display.

The organic light emitting display using the thin film transistor (TFT) is a device that can be used for a display device, such as a display panel due to temperature change, a current change of a thin film transistor due to external light, and a voltage drop (IR- There is a problem that a change in luminance or the like occurs. In order to prevent such a problem, a conventional organic light emitting display device feedbacks a current (OLED current) of a current organic light emitting display panel in real time, and adjusts a luminance of the organic light emitting display panel based on a feedback current .

However, in the conventional organic light emitting display device, when the luminance of the adjacent previous frame, the current frame, and the image scene is switched, the luminance response of the panel due to the luminance adjustment becomes faster or slower so that the image quality is distorted or the image quality of flicker The image quality is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and it is an object of the present invention to provide an image display device and a method of controlling the brightness of a display device, And an object of the present invention is to provide a driving apparatus and a driving method of an organic light emitting display device capable of improving image quality.

According to an aspect of the present invention, there is provided an apparatus for driving an organic light emitting display, including a plurality of data lines and a plurality of red, green, and blue subpixels formed in a region defined by a plurality of gate lines, panel; And a panel driver for displaying the image corresponding to the red, green, and blue input data on the display panel and adjusting the brightness of the display panel according to whether the image is changed in a frame unit or not. do.

The panel driver adjusts the luminance of the display panel for each blanking interval between frames or controls the luminance of the display panel at least once during one frame according to whether the image is changed or not.

And the luminance of the display panel is adjusted in units of the plurality of red subpixels, the plurality of green pixels, and the plurality of blue subpixels.

Wherein the panel driving unit determines whether the scene change is performed using the histogram of each of the input data of the current frame and the previous frame, generates a scene change signal of the first logical state when it is determined that the scene of the image is not changed, And a scene change detector for generating a scene change signal of a second logic state when it is determined that the scene of the video is changed.

Wherein the panel driving unit comprises: a panel current detector for generating current detection data corresponding to a current flowing in each of the sub pixels on a frame basis; A current predicting unit for generating predicted current data corresponding to the input data; A first luminance control signal for each blanking interval in accordance with the scene change signal of the first logic state or a luminance control signal for generating a second luminance control signal at least once during one frame in accordance with the scene change signal of the second logic state, An adjustment control section; A luminance controller for comparing the current detection data with the predictive current data each time the first luminance adjustment signal or the second luminance adjustment signal is supplied from the luminance adjustment controller to generate a gamma drive power supply corresponding to a comparison result; A gamma reference voltage generator for generating a plurality of different gamma reference voltages using the gamma driving power supplied from the brightness controller; A timing controller for generating red, green, and blue alignment data by arranging the red, green, and blue input data to be suitable for driving the display panel; A gate driver for supplying a gate signal to the gate line under the control of the timing controller; And a data driver for converting each of the red, green, and blue alignment data into a data signal using the plurality of gamma reference voltages under control of the timing controller, and supplying the data signal to the corresponding data line so as to be synchronized with the gate signal .

The timing control unit may include at least one of the brightness adjusting unit, the brightness adjusting controlling unit, and the scene change detecting unit.

According to an aspect of the present invention, there is provided a method of driving an organic light emitting display device including a plurality of data lines and a plurality of red, green and blue sub-pixels formed in a region defined by a plurality of gate lines, A method of driving an organic light emitting display having a panel, the method comprising: displaying an image corresponding to red, green, and blue input data on the display panel; Determining whether a scene change of the image is performed on a frame-by-frame basis; And adjusting the brightness of the display panel according to the determination result.

Wherein the step of determining whether or not the image is to be switched generates a scene change signal of a first logic state when it is determined that the scene of the image has not been switched based on the histogram of each of the input data of the current frame and the previous frame, The scene change signal of the second logic state is generated.

Wherein the step of adjusting the brightness of the display panel comprises: generating current detection data corresponding to a current flowing in each of the sub pixels on a frame basis; Generating predicted current data corresponding to the input data; Generating a first luminance adjustment signal for each blanking interval in accordance with the scene change signal of the first logic state or generating at least one second luminance adjustment signal for one frame in accordance with the scene change signal of the second logic state ; Comparing the current detection data with the predictive current data for each of the first luminance adjustment signal and the second luminance adjustment signal to generate a gamma drive power supply corresponding to a comparison result; Generating a plurality of different gamma reference voltages using the gamma driving power; Arranging the red, green, and blue input data to be suitable for driving the display panel to generate red, green, and blue alignment data; Supplying a gate signal to the gate line; And converting each of the red, green, and blue alignment data into a data signal using the plurality of gamma reference voltages, and supplying the data signal to the corresponding data line to be synchronized with the gate signal.

Wherein the step of controlling the brightness of the display panel includes generating red, green, and blue current detection data corresponding to the currents flowing through the red, green, and blue subpixels, respectively, on a frame-by-frame basis; Separately generating red, green, and blue current prediction data corresponding to the red, green, and blue input data, respectively; Generating a first luminance adjustment signal for each blanking interval in accordance with the scene change signal of the first logic state or generating at least one second luminance adjustment signal for one frame in accordance with the scene change signal of the second logic state ; Green, and blue current detection data and the red, green, and blue current prediction data corresponding to the red, green, and blue current detection data for each of the first luminance adjustment signal and the second luminance adjustment signal, , And a blue gamma driving power source; Separately generating a plurality of different red, green, and blue gamma reference voltages using each of the red, green, and blue gamma driving power supplies; Arranging the red, green, and blue input data to be suitable for driving the display panel to generate red, green, and blue alignment data; Supplying a gate signal to the gate line; And converting each of the red, green, and blue alignment data into a data signal using the plurality of different red, green, and blue gamma reference voltages, and supplying the data signal to the corresponding data line in synchronization with the gate signal .

As described above, the driving apparatus and the driving method of the organic light emitting display according to the present invention detect whether or not the scene change is performed from the images of the current frame and the previous frame, adjust the brightness of the display panel for each blanking interval The brightness of the display panel in the frame is adjusted at least once to prevent image quality degradation due to the luminance response characteristic of the brightness response rate of the panel and the flicker-type image quality degradation in adjusting the brightness, thereby improving the image quality.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic diagram of a driving apparatus for an organic light emitting diode display according to an embodiment of the present invention; FIG.
FIG. 2 is a view schematically showing the panel current detector shown in FIG. 1. FIG.
3 is a diagram schematically showing the current predicting unit shown in FIG.
4 is a view schematically showing the timing control unit shown in Fig.
5 is a view schematically showing the scene change detection unit shown in FIG.
FIG. 6 is a diagram schematically showing a histogram of a frame unit generated by the histogram generating unit shown in FIG. 5. FIG.
FIG. 7 is a view schematically showing the brightness adjustment control unit shown in FIG.
FIG. 8 is a diagram schematically illustrating a luminance adjustment signal generated according to whether a scene is switched or not in the luminance adjustment control unit shown in FIG. 7. Referring to FIG.
FIG. 9 is a view schematically showing the luminance controller shown in FIG. 1. FIG.
FIG. 10 is a diagram for schematically explaining a process of calculating frame current predictive data calculated by the predictive current calculator shown in FIG. 9; FIG.

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

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic diagram of a driving apparatus for an organic light emitting diode display according to an embodiment of the present invention; FIG.

1, a driving apparatus for an OLED display according to an exemplary embodiment of the present invention includes a display panel 10 for displaying an image using an organic light emitting diode (OLED), input data Ri, Gi, Bi, And a panel driving unit 20 for displaying an image corresponding to the display panel 10 on the display panel 10 and adjusting the luminance of the display panel 10 according to whether the image is switched on a frame-by-frame basis.

The display panel 10 includes a red sub-pixel formed in a pixel region defined by a plurality of data lines DL, a plurality of gate lines GL, a plurality of driving power lines VDDL, and a plurality of base power lines VSSL. And a plurality of unit pixels composed of a pixel Pr, a green subpixel Pg, and a blue subpixel Pb.

The plurality of data lines DL are formed at regular intervals along the longitudinal direction of the display panel 10 and the plurality of gate lines GL are formed to intersect the plurality of data lines DL. And are formed to have a constant spacing along the lateral direction.

A plurality of driving power supply lines (VDDL) are formed so as to be adjacent to each of the plurality of data lines (DL).

A plurality of base power supply lines (VSSL) are formed adjacent to each of the plurality of gate lines (DL). The plurality of base power supply lines VSSL includes a red base power supply line commonly connected to the red subpixel Pr, a green base power supply line commonly connected to the green subpixel Pg, and a blue subpixel Pb, And a blue base power supply line commonly connected to the power supply line.

Each of the red subpixel Pr, the green subpixel Pg and the blue subpixel Pb comprises a pixel driving circuit and an organic light emitting diode OLED.

The pixel driving circuit supplies a data current corresponding to a data signal supplied to the data line DL to the organic light emitting diode OLED in response to a gate signal supplied to the gate line GL. To this end, the pixel driver circuit according to one embodiment includes a switching transistor ST, a driving transistor DT, and a capacitor C.

The switching transistor ST is switched according to a gate signal supplied to the gate line GL to supply a data signal to the data line DL to the driving transistor DT.

The driving transistor DT is switched according to a data signal supplied from the switching transistor ST to control a current flowing from the driving power supply line VDDL to the organic light emitting diode OLED.

The capacitor C is connected between the gate terminal of the driving transistor DT and the base power line VSSL and stores a voltage corresponding to the data signal supplied to the gate terminal of the driving transistor DT, And maintains the turn-on state of the signal DT constant for one frame.

The pixel driver circuit described above may further include at least one compensation transistor (not shown) and at least one compensation capacitor (not shown) for compensating a threshold voltage of the driving transistor DT, And an emission transistor (not shown) for selectively supplying a current supplied from the organic light emitting diode OL to the organic light emitting diode OL.

The organic light emitting element OLED is electrically connected between the source terminal of the driving transistor DT and the base power supply VSSL and emits light by a current corresponding to the data signal supplied from the driving transistor DT. The organic light emitting device OLED includes an anode electrode (or a pixel electrode) connected to a source terminal of the driving transistor DT, an organic layer (not shown) formed on the pixel electrode, a cathode electrode ). Here, the organic layer may include a hole injection layer / a hole transporting layer / a light emitting layer / an electron transporting layer / an electron injection layer. The light emitting layer of the organic light emitting device OLED includes a red organic light emitting material, a green organic light emitting material, and a blue organic light emitting material so as to correspond to each of the sub pixels Pr / Pg / Pb.

The red subpixel Pr, the green subpixel Pg and the blue subpixel Pb constitute one unit pixel so that the driving power supply line VDDL To control the magnitude of the current flowing from the organic light emitting diode OLED to the organic light emitting diode OLED to emit the light emitting layer of the organic light emitting diode OLED.

The panel driving unit 20 includes a panel current detecting unit 200, a current predicting unit 300, a timing control unit 400, a luminance adjusting unit 500, a gamma reference voltage supplying unit 600, a data driving unit 700, (800).

The panel current detector 200 generates current detection data CDD corresponding to the panel current flowing in the display panel 10 and provides the current detection data CDD to the fuzzy controller 500. 2, the panel current detector 200 according to the first embodiment includes a sensing resistor Rs, an amplifier circuit 210, and a digital-to-analog converter 220 .

The sensing resistor Rs is connected to the base power line VSSL formed on the display panel 10 and senses a voltage corresponding to the current flowing from the base power line VSSL to the ground. At this time, since the voltage applied to the driving power supply line VDDL and the base power supply line VSSL of the display panel 10 is changed when the resistance value is large, the sensing resistance Rs has a very low resistance value of about 10 m? . The sensing resistance Rs senses the total amount of current supplied to the organic light emitting diode OLED of all the sub-pixels Pr / Pg / Pb formed on the display panel 10.

The amplifying circuit 210 comprises an operational amplifier OP and first to third resistors R1, R2 and R3.

The operational amplifier OP amplifies the voltage sensed by the sensing resistor Rs. At this time, the first to third resistors R1, R2, and R3 set the voltage amplification ratio of the operational amplifier OP. The resistance ratio according to the resistance values of the first to third resistors R1, R2, and R3 may be variously set by a designer.

The analog-to-digital converter 220 converts the sensing voltage amplified by the operational amplifier OP into a digital signal to generate current detection data CDD and supplies the generated current detection data CDD to the luminance controller 500. [ .

The panel current detector 200 according to the first embodiment senses and amplifies a voltage corresponding to the total amount of current flowing through the organic light emitting diode OLED of the display panel 10, And generates current detection data CDD, and supplies the generated current detection data CDD to the luminance adjustment unit 500. [

On the other hand, the panel current detection unit 200 may be connected to the driving power supply line VDDL instead of the above-described base power supply line VSSL to generate the above-described current detection data CDD.

The panel current detection unit 200 according to the second embodiment connects the sensing resistor Rs and the deposition circuit 210 to the red base power line, the green base power line, and the blue base power line, respectively, The amount of red current flowing in all the red subpixels Pr, the amount of green current flowing in all the green subpixels Pg and the amount of green current flowing in all the blue subpixels Pr are determined in accordance with the sequential driving of the digital- And the detected red, green, and blue current detection data CDD_R, CDD_G, and CDD_B may be supplied to the luminance controller 500. FIG.

1, the current predicting unit 300 predicts the current based on the red, green, and blue input data Ri, Gi, Bi input from an external system body (not shown) or a graphics card (not shown) (CED) in units of frames corresponding to the amount of current to be supplied to the luminance controller (10). 3, the current predicting unit 300 according to the first embodiment includes a red lookup table 310, a green lookup table 320, a blue lookup table 330, and a summation unit 340).

First, the current flowing in the organic light emitting diode OLED can be predicted using information obtained through image analysis and transistor information obtained through a preliminary experiment. In an ideal organic light emitting diode OLED, image data and a TFT design factor The current flowing through the display panel 10 can be predicted for each frame inputted through the current characteristic of the transistor TFT since the current flows by an amount determined by the factor. Accordingly, the predicted current value is calculated in advance through a preliminary experiment based on the transistor design factor, and the calculated predicted current value is stored in the form of a look-up table.

The red lookup table 310 includes red predicted current data mapped according to data (gradation) values of red data through a preliminary experiment as described above. The red lookup table 310 selects the red predicted current data CED_R corresponding to the input red input data Ri and supplies the red predicted current data CED_R to the adder 340.

The green look-up table 320 includes green predictive current data mapped according to data (gradation) values of green data through a preliminary experiment as described above. The green lookup table 320 selects the green predicted current data CED_G corresponding to the green input data Gi and supplies the green predicted current data CED_G to the summation unit 340.

The blue look-up table 320 includes blue predictive current data mapped according to data (gradation) values of blue data through a preliminary experiment as described above. The blue lookup table 320 selects the blue predictive current data CED_B corresponding to the input blue input data B i and supplies the blue predictive current data CED_B to the adder 340.

The adder 340 adds the red predicted current data CED_R, the green predicted current data CED_G, and the blue predicted current data CED_R supplied from the red lookup table 310, the green lookup table 320, and the blue lookup table 330, Current data CED_B in units of one horizontal line and supplies the summed predicted current data CED of one horizontal line to the luminance adjusting unit 500 and stores the sum in the memory unit 350. [

The current predicting unit 300 may further include a scale converting unit (not shown) for converting the scale of the predicted current data CED supplied from the summing unit 340 to the luminance adjusting unit 500 . That is, the scale converter converts the predicted current data CED (CED) and the predicted current data (CED) by a shift operation so that the digital bit number of the predictive current data CED is equal to the digital bit number of the current detection data CDD ) Of the digital signal.

The current predicting unit 300 according to the second embodiment includes only the red lookup table 310, the green lookup table 320, and the blue lookup table 330 described above. Accordingly, the current predicting unit 300 according to the second embodiment calculates the red predicted current data CED_R, the green predicted current data CED_R, the green predicted current data CED_R, The predictive current data CED_G and the blue predictive current data CED_B to the luminance controller 500 and stores them in the memory unit 350. [

1, the timing controller 400 includes a data processor 410, a control signal generator 420, a scene change detector 430, and a brightness controller 440, as shown in FIG. .

The data processing unit 410 arranges the red, green, and blue input data Ri, Gi, and Bi input from the external system body or the graphics card so as to be suitable for driving the display panel 10, Supply.

The control signal generator 420 generates data and gate control signals for controlling the driving timings of the data driver 700 and the gate driver 800 according to a timing synchronization signal TSS input from an external system body or a graphics card DCS, GCS).

The timing synchronization signal TSS may be a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable DE, a clock DCLK, or the like.

The data control signal DCS may be configured to include a source start pulse, a source sampling clock, a source output enable, and a polarity control signal POL .

The gate control signal GCS may include a gate start pulse (SGate Start Pulse), a plurality of gate clock signals (Gate Clock Signal), and the like.

The scene change detection unit 430 compares the current frame with the previous frame and the red, green, and blue input data Ri, Gi, and Bi input from the external system body or the graphics card, , Generates a scene change detection signal STDS according to the determination result, and supplies the scene change detection signal STDS to the brightness adjustment control unit 440. 5, the scene change detection unit 430 includes a histogram generation unit 432, a histogram operation unit 434, and a scene change determination unit 436. [

The histogram generator 432 according to the first embodiment accumulates the frequency values of each gray level (data value) using the red, green, and blue input data Ri, Gi, and Bi of the current frame, Green, and blue histograms to the histogram computation unit 434, and stores the histograms in the memory unit 350.

The histogram generator 432 according to the second embodiment selects any one of the red, green and blue input data Ri, Gi and Bi of the input current frame (for example, red input data) Accumulates the frequency of each gradation (data value) by using the selected data to generate a histogram for each gradation, supplies the histogram to the histogram computing unit 434, and stores the histogram in the memory unit 350.

The histogram generation unit 432 according to the third embodiment generates red, green, and blue input data Ri, Gi, and Bi to be supplied to the unit pixels in the red, green, and blue input data Ri, Gi, Bi) or the average gradation, and supplies the generated histogram to the histogram computing unit 434 and stores the histogram in the memory unit 350. In addition,

The histogram computation unit 434 computes the histogram of the histogram of the current frame supplied from the histogram generation unit 432 and the histogram of the histogram of the previous frame supplied from the memory unit 350, To generate a histogram computation value (HCV).

HIS _Fn represents a histogram of the current frame, and HIS _{Fn -1} represents a histogram of the input data. In the equation (1), HCV represents a histogram calculation value, i represents a number of bits of input data, Indicates the histogram of the frame.

The scene change determination unit 436 compares the histogram operation value HCV supplied from the histogram operation unit 434 with the set reference value RV and generates the scene change detection signal STDS according to the comparison result. Here, the reference value RV can be set by the user. That is, the frame-by-frame histograms may have a similar distribution diagram as shown in FIG. 6 or may have different distribution charts. If the histogram has a similar distribution such as the n-2th frame and the n-1th frame (Fn-2, Fn-1), it can be determined that the image sequence is continuous without being changed. However, And the n-th frame (Fn-1, Fn) are different from each other, it can be judged that the video scene is switched. Accordingly, the reference value RV may be set to the number of pixels for determining that the image scene is switched. Therefore, the scene change determination unit 436 generates the scene change detection signal STDS of the first logic state when the histogram computation value HCV is equal to or smaller than the reference value RV, and outputs the histogram computation value HCV as the reference value RV RV), a scene change detection signal STDS of the second logic state is generated. 6, the scene change determining unit 436 determines the last gate line GL (n) of the n-th frame Fn by comparing the histograms of the n-1th frame Fn-1 and the nth frame Fn, , It is determined that the video scene has been switched and the scene change detection signal STDS of the second logic state is generated. Then, the scene change determination unit 436 compares the histograms of the n-th frame Fn and the (n + 1) -th frame Fn + 1, It is determined that the video scene has not been switched at the driving timing of the first logic state GL and the scene change detection signal STDS of the first logic state is generated.

4, the luminance adjustment control unit 440 controls the luminance of the display panel 10 for each blanking interval based on the scene change detection signal STDS supplied from the scene change detection unit 430 And generates a first luminance control signal LCS1 or a second luminance control signal LCS2 for adjusting the luminance of the display panel 10 at least once within one frame. To this end, the luminance adjustment control unit 440 includes a counter setting unit 442 and a counter 444 as shown in Fig.

The counter setting unit 442 sets the first and second counter set values CSV1 and CSV2 according to the logical state of the scene change detection signal STDS supplied from the scene change detection unit 430 and supplies the counter 444 with the counter setting values CSV1 and CSV2 do. That is, the counter setting unit 442 sets the first counter setting value CSV1 in accordance with the scene change detection signal STDS of the first logic state, and sets the first counter setting value CSV1 in accordance with the scene change detection signal STDS of the second logic state 2 Set the counter setting value (CSV2). At this time, the first counter setting value CSV1 may be set to k, and the second counter setting value CSV2 may be set to j. Here, k represents the total number of gate lines GL formed on the display panel 10. [ The above-mentioned j may be set to k / 3, but it is not limited thereto and may be variously set by the user.

The counter 444 counts a horizontal synchronizing signal Hsync or a data output enable (SOE) signal and outputs a first luminance control signal (" 1 ") for each first counter set value CSV1 supplied from the counter setting unit 442 And supplies the second luminance control signal LCS2 to the luminance controller 500. The second luminance control signal LCS2 is supplied to the luminance controller 500 for each second counter set value CSV2.

8, when the scene changeover detection signal STDS is in the first logic state, the brightness control unit 440 controls the brightness of the first luminance control And supplies the generated signal LCS1 to the luminance controller 500. When the scene changeover detection signal STDS is in the second logic state, every time the j gate lines GL are driven, And supplies the control signal LCS2 to the luminance controller 500. [

1, the luminance controller 500 uses the current detection data CDD supplied from the panel current detector 200 and the predictive current data CED supplied from the current predicting unit 300, (VDD_GAM) according to the first or second luminance control signals LCS1 and LCS2 supplied from the gamma correction circuit 400 and supplies the generated gamma driving voltage VDD_GAM to the gamma reference voltage supplier 600. [ 9, the luminance controller 500 includes a predicted current calculator 510, a luminance adjustment data generator 520, and a gamma driving power generator 530 .

The predictive current calculator 510 according to the first embodiment sums the predictive current data CED supplied in units of one horizontal unit from the current predictor 300 according to the first embodiment, And supplies the predicted current data FCED to the luminance adjustment data generation section 520. The luminance adjustment data generation section 520 supplies the luminance adjustment data generation section 520 with the frame prediction current data FCED calculated according to the first or second luminance control signals LCS1 and LCS2. At this time, the predictive current calculator 510 updates the frame predictive current data FCED in units of one horizontal unit.

Hereinafter, a method of calculating the frame predicted current data FCED according to the first or second luminance control signals LCS1 and LCS2 will be described with reference to FIG. 10 as follows.

First, the predictive current calculator 510 according to the first exemplary embodiment calculates cumulative frame predicted current data FCED, which is updated in units of one horizontal unit, by cumulatively adding predictive current data CED supplied in units of one horizontal unit And supplies different frame predictive current data FCED to the luminance adjustment data generation unit 520 according to the first or second luminance control signals LCS1 and LCS2. That is, the frame predicted current data FCED according to the first luminance control signal LCS1 is calculated as the frame Fn-1, Fn while the frame predicted current data FCED according to the second luminance control signal LCS2 is is calculated including the predicted current data CED of the current frame Fn and the previous frame Fn-1 since it is generated every time the j gate lines GL are driven.

For example, when the current frame Fn is changed over in the previous frame Fn-1, the predictive current calculator 510 calculates the predicted current Ip in the current frame Fn by driving the first through the j- The updated frame predicted current data FCED up to the predicted current data CED corresponding to the a1 region of the display panel 10 according to the second luminance control signal LCS2 generated at the first scan completion time T1 according to the first scan completion timing T1, To the luminance adjustment data generation unit 520. [ At this time, the frame predicted current data FCED is obtained by summing the predicted current data CED of the b2 and b3 regions of the previous frame Fn-1 and the predicted current data CED of the a1 region of the current frame Fn, do.

Similarly, the predictive current calculator 510 outputs the second luminance control signal LCS2 generated at the second scan completion time T2 according to the driving of the (j + 1) th to (2j) th gate lines GL The frame predictive current data FCED calculated by summing the predictive current data CED of the b3 region of the previous frame Fn-1 and the predictive current data CED of the a1 and a2 regions of the current frame Fn And supplies it to the luminance adjustment data generation unit 520.

Similarly, the predictive current calculator 510 calculates the predicted current Ia1 of the current frame Fn based on the second luminance control signal LCS2 generated at the frame completion time Tend according to driving of the last gate line GL, and supplies the frame predictive current data FCED calculated by summing the predictive current data CED of the a2 region and the a3 region to the luminance adjustment data generation section 520. [

The predictive current calculator 510 according to the second embodiment calculates the predicted currents CED_R, CED_G and CED_B of the red, green and blue predictive currents CED_R, CED_G and CED_B supplied from the panel current detector 200 according to the second embodiment Green, and blue, respectively, as described above, and supplies the frame predictive current data to the luminance adjustment data generation unit 520. The luminance adjustment data generation unit 520 may generate the frame prediction current data.

9, the luminance adjustment data generator 520 according to the first embodiment compares the frame predicted current data FCED supplied from the predicted current calculator 510 according to the first embodiment with the first The current detection data CDD supplied from the panel current detector 200 according to the embodiment is compared each time the first or second luminance control signals LCS1 and LCS2 are supplied and the luminance adjustment data LAD And supplies the generated gamma driving power to the gamma driving power generator 530. That is, when the current detection data CDD is larger than the frame prediction current data FCED as a result of comparison between the current detection data CDD and the frame prediction current data FCED, The luminance adjustment data LAD for lowering the level of the gamma drive power supply VDD_GAM so that the CDD becomes equal to the frame predicted current data FCED. On the other hand, when the current detection data CDD is smaller than the frame prediction current data FCED as a result of the comparison between the current detection data CDD and the frame prediction current data FCED, The luminance adjustment data LAD for raising the level of the gamma drive power supply VDD_GAM so that the CDD becomes equal to the frame predicted current data FCED.

On the other hand, the luminance adjustment data generation unit 520 according to the second embodiment supplies the red, green, and blue predicted current data CED_R, CED_G, and CED_B supplied from the panel current detection unit 200 according to the second embodiment, And the frame predictive current data for each of the red, green, and blue supplied from the predictive current calculator 510 according to the above-described second embodiment are supplied to the first or second luminance control signal LCS1 and LCS2 are supplied, and generates red, green, and blue luminance adjustment data according to the comparison result, and supplies the generated data to the gamma driving power generator 530. [

The gamma driving power supply generating unit 530 according to the first embodiment supplies the gamma driving power supply VDD_GAM corresponding to the luminance adjusting data LAD supplied from the luminance adjusting data generating unit 520 according to the first embodiment And supplies it to the gamma reference power supply unit 600. For example, the gamma driving power supply generating unit 530 performs digital-analog conversion on the luminance adjusting data LAD, generates a gamma driving power VDD_GAM corresponding to the converted analog value, and supplies the generated gamma driving power VDD_GAM to the gamma reference power supplying unit 600 Supply.

The gamma driving power supply generation unit 530 according to the second embodiment performs digital-analog conversion on each of the red, green, and blue luminance adjustment data supplied from the luminance adjustment data generation unit 520 according to the second embodiment Green, and blue gamma driving power supplies corresponding to the converted red, green, and blue analog values, respectively, and supplies the generated gamma driving power to the gamma reference power supply unit 600.

Meanwhile, the current predicting unit 300 and the brightness adjusting unit 500 may be incorporated in the timing control unit 400 described above.

1, the gamma reference power supply 600 according to the first embodiment uses the gamma drive power supply VDD_GAM supplied from the gamma drive power supply generator 530 according to the first embodiment to calculate the total number of gradations And supplies the G gamma reference voltages Vgam_G having the different voltage values corresponding to the gamma reference voltages Vgam_G to the data driver 700. [ To this end, the gamma reference power supply unit 600 includes a plurality of resistors connected in series between the gamma drive power supply (VDD_GAM) and the base power supply. The gamma reference power supply unit 600 generates G gamma reference voltages Vgam_G having different voltage values for respective nodes between the plurality of resistors in accordance with the voltage resistance ratio according to the resistance value of each resistor.

The gamma reference power supply unit 600 according to the second embodiment uses the red, green, and blue gamma driving power supplied from the gamma driving power source generating unit 530 according to the second embodiment to generate G Green, and blue gamma reference voltages and supplies them to the data driver 700.

The data driver 700 according to the first embodiment is driven in accordance with the data control signal DCS provided from the timing controller 400 and supplies the G data voltages G supplied from the gamma reference voltage supplier 600 according to the first embodiment Selects a gamma reference voltage corresponding to the alignment data (R / G / B) supplied from the timing control unit 400 among the gamma reference voltages Vgam_G as a data signal and supplies the selected data to the corresponding data line DL.

The data driver 700 according to the second embodiment is driven in accordance with the data control signal DCS provided from the timing controller 400 and supplies the G Green and blue color data signals supplied from the timing controller 400 are converted into red, green, and blue data signals using the red, green, and blue gamma reference voltages, respectively, To the data line DL.

The scan driver 800 generates a gate signal in units of horizontal intervals according to the gate control signal GCS provided from the timing controller 500 and sequentially supplies the plurality of gate lines GL. Accordingly, the switching transistor ST of each sub-pixel Pr / Pg / Pb is turned on by the gate signal supplied to the gate line GL to supply the data signal, which is supplied to the data line DL, DT, and the driving transistor DT supplies a current corresponding to the data signal to the organic light emitting element OLED to emit the organic light emitting element OLED.

The apparatus for driving the organic light emitting display according to the present invention as described above detects whether or not a scene change occurs from an image of each of a current frame and a previous frame and displays the changed image on the display panel 10 for each blanking interval, Or adjusting the luminance of the display panel 10 at least once within one frame, the image quality degradation due to the luminance response characteristic according to the luminance response speed of the panel and the image quality degradation due to the flicker And the image quality can be improved. 8, when the scene of an image is switched as in the first and second frames F1 and F2, the brightness of the display panel 10 in the third frame F3 is changed three times And if the scene of the second through fourth frames F2 through F4 is not switched, the brightness of the display panel 10 can be adjusted for each blanking interval to improve the image quality.

In the driving method of the organic light emitting display according to the embodiment of the present invention as described above, the image corresponding to the red, green, and blue input data is displayed on the display panel 10, The luminance of the display panel 10 is adjusted. At this time, the luminance of the display panel 10 is adjusted for each blanking interval between frames according to whether the image is changed or at least once more for one frame. Here, the luminance of the display panel 10 may be adjusted in units of a plurality of red subpixels, a plurality of green pixels, and a plurality of blue subpixels. The driving method of the organic light emitting diode display according to the embodiment of the present invention will be described below step by step.

First, whether or not the scene is switched on is determined based on the histogram of each of the input data of the current frame and the previous frame, and it can be determined through the following steps.

Generates a histogram corresponding to the input data of the current frame, and stores the generated histogram in the memory unit. The histogram may include generating histograms of red, green, and blue, respectively, corresponding to red, green, and blue input data, respectively; Generating a histogram corresponding to any one of red, green, and blue input data; And generating a histogram corresponding to a gradation sum or an average value of the red, green, and blue input data.

Then, the histogram calculation value is calculated using the histogram of the current frame and the histogram of the previous frame stored in the memory unit. At this time, the histogram computation value can be calculated by summing the histogram of the current frame and the histogram of the previous frame by the gradation according to gradation.

If the histogram operation value is smaller than the set reference value, it is determined that the scene of the image has not been switched. The scene change signal of the first logic state is generated. If the histogram operation value is larger than the reference value, And generates a scene change signal of a second logic state.

Accordingly, the present invention adjusts the brightness of the display panel 10 according to the scene change signal generated according to the scene change of the image.

A process of adjusting the brightness of the display panel according to the first embodiment of the present invention will now be described.

First, current detection data corresponding to a current flowing in each sub-pixel is generated on a frame-by-frame basis, and predictive current data corresponding to the input data is generated.

Then, a first luminance adjustment signal is generated for each blanking interval in accordance with the scene change signal of the first logic state, or at least one second luminance adjustment signal is generated for one frame in accordance with the scene change signal of the second logic state. For example, the first luminance adjustment signal is generated based on driving of the last gate line for each scene change signal of the first logic state, and the second luminance adjustment signal is generated for each scene change signal of the second logic state among the plurality of gate lines and may be generated each time j gate lines are driven.

Then, the current detection data and the predicted current data are compared with each other for each of the first luminance adjustment signal or the second luminance adjustment signal to generate a gamma drive power supply corresponding to the comparison result. The process of generating the gamma driving power will be described as follows.

First, frame current predictive data for each frame is calculated for each of the first luminance adjustment signal or the second luminance adjustment signal using the prediction current data.

Next, the frame current predictive data and the current detection data are compared for each of the first luminance adjustment signal and the second luminance adjustment signal to generate luminance adjustment data for adjusting the level of the gamma driving power supply so that the frame current prediction data and the current detection data become equal do.

Then, a gamma drive power supply corresponding to the brightness adjustment data is generated. At this time, the gamma driving power source may be generated by digital-analog conversion of the luminance adjustment data.

Then, a plurality of different gamma reference voltages are generated using the gamma driving power source.

Then, the red, green, and blue input data are aligned to be suitable for driving the display panel 10 to generate red, green, and blue alignment data.

Then, the gate signal is supplied to the gate line. To synchronize with this, each of the red, green, and blue alignment data is converted into a data signal using a plurality of gamma reference voltages and supplied to the corresponding data line.

The process of adjusting the luminance of the display panel according to the second embodiment of the present invention will now be described.

First, red, green, and blue current detection data corresponding to a current flowing in each of the red, green, and blue subpixels are generated on a frame-by-frame basis.

Then, red, green, and blue current prediction data corresponding respectively to the red, green, and blue input data are separately generated.

Then, a first luminance adjustment signal is generated for each blanking interval in accordance with the scene change signal of the first logic state, or at least one second luminance adjustment signal is generated for one frame in accordance with the scene change signal of the second logic state.

Then, the red, green, and blue current detection data and the corresponding red, green, and blue current prediction data are compared with each other for each of the first luminance adjustment signal and the second luminance adjustment signal, And a blue gamma driving power source separately.

The red, green, and blue gamma driving power sources are then used to separately generate a plurality of different red, green, and blue gamma reference voltages, respectively.

The red, green, and blue input data are then arranged to be suitable for driving the display panel to generate red, green, and blue alignment data.

Then, the gate signal is supplied to the gate line. Green, and blue alignment data using a plurality of different red, green, and blue gamma reference voltages so as to be synchronized with each other, and supplies the data signals to the data lines.

The method of driving the organic light emitting display according to the present invention as described above detects whether or not a scene change occurs from an image of each of a current frame and a previous frame and displays the brightness of the display panel 10 for each blanking interval Or by controlling the luminance of the display panel 10 at least once within one frame, it is possible to prevent the image quality distortion due to the luminance response characteristic according to the luminance response speed of the panel and the flicker- .

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

10: display panel 20: panel driver
200: panel current detecting unit 300: current predicting unit
350: memory unit 400: timing control unit
430: scene change detection unit 440: luminance adjustment control unit
500: luminance controller 600: gamma reference voltage supplier
700: Data driver 800: Gate driver

Claims (27)

A display panel including a plurality of red, green, and blue subpixels formed in an area defined by a plurality of data lines and a plurality of gate lines; And
And a panel driver for displaying an image corresponding to the red, green, and blue input data on the display panel and adjusting the brightness of the display panel according to a scene change of the image in units of frames,
Wherein the panel driver adjusts the luminance of the display panel for each blanking interval between the frames if the scene of the image is not switched and adjusts the luminance of the display panel for one frame when the scene of the image is switched, Wherein the control unit adjusts at least one more time than when the scene is not switched. delete The method according to claim 1,
Wherein the luminance of the display panel is comprised of the plurality of red subpixels, the plurality of green pixels, and the plurality of blue subpixels. 4. The method according to any one of claims 1 to 3,
Wherein the panel driving unit determines whether the scene change is performed using the histogram of each of the input data of the current frame and the previous frame, generates a scene change signal of the first logical state when it is determined that the scene of the image is not changed, And a scene change detection unit for generating a scene change signal of a second logic state when it is determined that a scene of an image has been changed. 5. The method of claim 4,
Wherein the scene change detection unit comprises:
A histogram generator for generating a histogram corresponding to the input data of the current frame;
A memory unit for storing the histogram generated by the histogram generation unit;
A histogram operation unit for calculating a histogram operation value using a histogram of a current frame supplied from the histogram generation unit and a histogram of a previous frame supplied from the memory unit; And
And generates a scene change signal of the first logic state when the histogram operation value is smaller than the set reference value and generates a scene change signal of the second logic state when the histogram operation value is larger than the reference value And a driving circuit for driving the organic light emitting display device. 6. The method of claim 5,
Wherein the histogram generator comprises:
Green, and blue color histograms corresponding to the red, green, and blue input data, respectively,
Generating a histogram corresponding to any one of the red, green, and blue input data,
And generates a histogram corresponding to a gradation sum or an average value of the red, green, and blue input data. 6. The method of claim 5,
Wherein the histogram operation unit calculates the histogram operation value by summing the histogram of the current frame and the histogram of the previous frame on a gray scale basis. 5. The method of claim 4,
Wherein the panel-
A panel current detector for generating current detection data corresponding to currents flowing in all the subpixels of each of the red, green, and blue on a frame-by-frame basis;
A current predicting unit for generating predicted current data corresponding to the red, green, and blue input data;
Generating a first luminance adjustment signal for each blanking interval according to the scene change signal of the first logic state or generating a second luminance adjustment signal at least once for one frame according to the scene change signal of the second logic state, A control unit;
A luminance controller for comparing the current detection data with the predictive current data each time the first luminance adjustment signal or the second luminance adjustment signal is supplied from the luminance adjustment controller to generate a gamma drive power supply corresponding to a comparison result;
A gamma reference voltage generator for generating a plurality of different gamma reference voltages using the gamma driving power supplied from the brightness controller;
A timing controller for generating red, green, and blue alignment data by arranging the red, green, and blue input data to be suitable for driving the display panel;
A data driver for converting each of the red, green, and blue alignment data into a data signal using the plurality of gamma reference voltages under control of the timing controller, and supplying the data signal to the data line; And
And a gate driver for supplying a gate signal to the gate line under the control of the timing control unit. 9. The method of claim 8,
Wherein the brightness adjustment control unit comprises:
And supplies the first luminance adjustment signal to the luminance adjustment unit based on driving of the last gate line when the scene change signal of the first logic state is supplied from the scene change detection unit,
Wherein when a scene change signal of the second logic state is supplied from the scene change detection unit, the second luminance control signal is generated every j (j is a natural number) gate lines among the plurality of gate lines, And supplies it to the regulating unit. 9. The method of claim 8,
Wherein the luminance controller adjusts the level of the gamma driving power so that the predictive current data and the current detection data become equal to each other. 9. The method of claim 8,
Wherein the brightness adjusting unit comprises:
A predicted current calculator that calculates frame current frame predictive data every time the first brightness control signal or the second brightness control signal is supplied from the brightness control unit using the predictive current data;
The frame current prediction data and the current detection data are compared with each other when the first luminance adjustment signal or the second luminance adjustment signal is supplied from the luminance adjustment control unit, A luminance adjustment data generation unit for generating luminance adjustment data for adjusting a level of the gamma driving power supply; And
And a gamma driving power source for generating the gamma driving power corresponding to the brightness adjustment data. 12. The method of claim 11,
And the gamma driving power generator generates the gamma driving power by digital-analog converting the brightness control data. 9. The method of claim 8,
Wherein the timing control unit includes at least one of the brightness adjusting unit, the brightness adjusting controlling unit, and the scene change detecting unit. 9. The method of claim 8,
Wherein the panel current detector separately generates red, green, and blue current detection data corresponding to currents flowing through the red, green, and blue subpixels, respectively,
Wherein the current predicting unit separately generates red, green, and blue current prediction data corresponding to the red, green, and blue input data, respectively,
The luminance controller compares the red, green, and blue current detection data with the red, green, and blue current prediction data corresponding to the first, second, and third luminance control signals, respectively, Generating red, green, and blue gamma driving power sources corresponding to the comparison result,
Wherein the gamma reference voltage generator separately generates a plurality of different red, green, and blue gamma reference voltages using each of the red, green, and blue gamma driving power supplies. A method of driving an OLED display device having a display panel including a plurality of red, green, and blue subpixels formed in a region defined by a plurality of data lines and a plurality of gate lines,
Displaying images corresponding to red, green, and blue input data on the display panel;
Determining whether a scene change of the image is performed on a frame-by-frame basis; And
And adjusting a luminance of the display panel according to the determination result,
The brightness of the display panel is adjusted for each blanking interval between the frames if the scene of the image is not switched. When the scene of the image is switched, the brightness of the display panel is adjusted at least once Wherein the organic light emitting display device is further controlled. delete 16. The method of claim 15,
Wherein the brightness of the display panel is comprised of the plurality of red subpixels, the plurality of green pixels, and the plurality of blue subpixels. 18. The method according to any one of claims 15 to 17,
Wherein the step of determining whether or not the image is to be switched generates a scene change signal of a first logic state when it is determined that the scene of the image has not been switched based on the histogram of each of the input data of the current frame and the previous frame, And generating a scene change signal of a second logic state when it is determined that the scene of the first logic state is changed. 19. The method of claim 18,
The step of judging whether or not the image is to be transitioned comprises the steps of:
Generating a histogram corresponding to input data of the current frame and storing the generated histogram in a memory;
Calculating a histogram computation value using a histogram of the generated current frame and a histogram of a previous frame stored in the memory;
Generating a scene change signal of the first logic state when the histogram operation value is smaller than a set reference value and generating a scene change signal of the second logic state when the histogram operation value is greater than the reference value; A method of driving an organic light emitting display device. 19. The method of claim 18,
Wherein the histogram comprises: generating histograms of red, green, and blue, respectively, corresponding to the red, green, and blue input data, respectively; Generating a histogram corresponding to any one of the red, green, and blue input data; And generating a histogram corresponding to a gradation sum or an average value of the red, green, and blue input data. 20. The method of claim 19,
Wherein the histogram computation value is calculated by summing the histogram of the current frame and the histogram of the previous frame according to gradation by the gradation. 19. The method of claim 18,
Wherein the step of adjusting the brightness of the display panel comprises:
Generating current detection data corresponding to currents flowing in all the subpixels of each of the red, green, and blue on a frame-by-frame basis;
Generating predicted current data corresponding to the red, green, and blue input data;
Generating a first luminance adjustment signal for each blanking interval according to the scene change signal of the first logic state or generating at least one second luminance adjustment signal for one frame according to the scene change signal of the second logic state;
Comparing the current detection data with the predictive current data for each of the first luminance adjustment signal and the second luminance adjustment signal to generate a gamma drive power supply corresponding to a comparison result;
Generating a plurality of different gamma reference voltages using the gamma driving power;
Arranging the red, green, and blue input data to be suitable for driving the display panel to generate red, green, and blue alignment data;
Supplying a gate signal to the gate line; And
And converting each of the red, green, and blue alignment data into a data signal using the plurality of gamma reference voltages, and supplying the data signal to the data line to be synchronized with the gate signal. 23. The method of claim 22,
Wherein the step of generating the first luminance adjustment signal or the second luminance adjustment signal comprises:
Generating the first luminance adjustment signal based on driving of the last gate line for each scene change signal of the first logic state,
Wherein the second luminance adjustment signal is generated every j (j is a natural number) gate lines among the plurality of gate lines for each scene change signal of the second logic state. 23. The method of claim 22,
Wherein the step of generating the gamma driving power adjusts the level of the gamma driving power so that the predicted current data and the current detection data become equal to each other. 23. The method of claim 22,
The step of generating the gamma driving power includes:
Calculating frame current frame predictive data for each of the first luminance adjustment signal or the second luminance adjustment signal using the predictive current data;
For comparing the frame current predictive data with the current detection data for each of the first luminance adjustment signal or the second luminance adjustment signal and adjusting the level of the gamma drive power supply so that the frame current prediction data and the current detection data become equal Generating brightness adjustment data; And
And generating the gamma driving power supply corresponding to the brightness adjustment data. 26. The method of claim 25,
Wherein the gamma driving power source is generated by digital-analog conversion of the luminance adjustment data. 19. The method of claim 18,
Wherein the step of adjusting the brightness of the display panel comprises:
Generating red, green, and blue current detection data corresponding to a current flowing in each of the red, green, and blue subpixels on a frame-by-frame basis;
Separately generating red, green, and blue current prediction data corresponding to the red, green, and blue input data, respectively;
Generating a first luminance adjustment signal for each blanking interval in accordance with the scene change signal of the first logic state or generating at least one second luminance adjustment signal for one frame in accordance with the scene change signal of the second logic state ;
Green, and blue current detection data and the red, green, and blue current prediction data corresponding to the red, green, and blue current detection data for each of the first luminance adjustment signal and the second luminance adjustment signal, , And a blue gamma driving power source;
Separately generating a plurality of different red, green, and blue gamma reference voltages using each of the red, green, and blue gamma driving power supplies;
Arranging the red, green, and blue input data to be suitable for driving the display panel to generate red, green, and blue alignment data;
Supplying a gate signal to the gate line; And
And converting each of the red, green, and blue alignment data into a data signal using the plurality of different red, green, and blue gamma reference voltages and supplying the data signal to the corresponding data line to be synchronized with the gate signal. A method of driving an organic light emitting display device.

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