KR102482993B1 - Organic light emitting diode display device and image snprocessing method thereof - Google Patents

Abstract

The present invention relates to an OLED display device capable of minimizing image quality deterioration while reducing afterimages by using image shift technology, and an image processing method thereof, wherein an image processing unit of an OLED display device according to an embodiment is based on image shift setting information Determines a pixel shift amount including the shift direction component, and determines a compensation line position where the image characteristic difference between adjacent lines in the source image is smaller than a threshold value according to the shift direction based on the determined pixel shift amount, or compensates according to a predetermined compensation position interval The position of the line is determined, compensation data using data of an adjacent line is inserted into the position of the determined compensation line, and an output image obtained by shifting the position of image data after the compensation line is supplied.

Description

Organic light emitting diode display device and image processing method thereof

The present invention relates to an organic light emitting diode display device capable of reducing afterimages using image shift technology and an image processing method thereof.

A display device displaying an image using digital image data mainly uses a liquid crystal display (LCD) using a liquid crystal and an OLED display device using an organic light emitting diode (OLED).

Among these, the OLED display device uses a self-luminous element that emits light through an organic light emitting layer by recombination of electrons and holes, so it has high luminance, low driving voltage, ultra-thin film, and free shape.

When the OLED display device is driven for a long time, an OLED element is deteriorated due to an increase in current stress, and afterimages may occur in a portion where a fixed pattern or logo is displayed for a long time.

In order to solve the afterimage problem, the OLED display device uses an orbit driving method in which stress received by pixels is dispersed by shifting the entire display image according to a predetermined period.

A conventional orbit driving method uses a black data insertion method in which an entire image is shifted in a predetermined direction and black data is displayed in an outer portion where an image is not displayed by the image shift.

However, in the orbit driving method using black data insertion, a black line artifact in which a black line inserted into an image edge is recognized as the entire display image is shifted causes a problem in that image quality deteriorates.

The present invention provides an OLED display device capable of minimizing image quality deterioration while reducing afterimages by using image shift technology and an image processing method thereof.

An OLED display device according to an embodiment of the present invention includes a panel displaying an image, a panel driving unit, and an image processing unit, and the image processing unit according to an embodiment includes a shift direction component based on image shift setting information. Determines a pixel shift amount, determines a compensation line position where a difference in image characteristics between adjacent lines in the source image is less than a threshold value according to a shift direction based on the determined pixel shift amount, or determines a compensation line position according to a predetermined compensation position interval, Compensation data using data of an adjacent line is inserted at the position of the compensation line, and an output image obtained by shifting the position of image data after the compensation line is supplied.

The image processing unit determines, as a compensation line position, a line in which a difference in image characteristics between adjacent lines is less than a threshold value and has a minimum value among a plurality of lines belonging to an operation range from a line spaced by a minimum interval from a starting position or a previous compensation position.

The image processing unit repeats an operation of determining a position of a compensation line by calculating a difference in image characteristics between adjacent lines until a pixel movement amount is reached according to a shift direction.

If the difference in characteristics between adjacent lines is greater than or equal to the threshold value, the image processing unit does not determine the position of the compensation line within the calculation range and proceeds with an operation for determining the position of the next compensation line.

Compensation data is used by interpolating data of adjacent lines, or duplicating and using data of any one of the adjacent lines.

An image processing method of an OLED display device according to an embodiment includes determining a pixel shift amount including a shift direction component based on image shift setting information, and moving between adjacent lines in a source image according to a shift direction based on the determined pixel shift amount. Determining a position of a compensation line having a difference in image characteristics smaller than a threshold value, inserting compensation data using data of an adjacent line into the position of the determined compensation line, shifting the position of video data after the compensation line, and outputting an output video. It includes steps to

An OLED display device and a method of driving the same according to an embodiment distribute stress received by pixels by shifting an image after the compensation line by inserting a compensation line at a position where a difference in image characteristics between adjacent lines is relatively small according to an image shift direction. Afterimages can be reduced, and image quality degradation can be minimized by preventing the compensation line from being perceived as an artifact by displaying compensation data similar to adjacent lines on the compensation line.

1 is a block diagram illustrating an OLED display device according to an exemplary embodiment.
2 is an equivalent circuit diagram illustrating a subpixel configuration of an OLED display according to an embodiment.
3 is a block diagram illustrating an image processing unit of an OLED display device according to an exemplary embodiment.
4 is a diagram illustrating various image shift types according to an exemplary embodiment.
5 is a diagram illustrating a pixel movement amount according to a pixel shift direction according to an exemplary embodiment.
6 is a flowchart illustrating a method for determining a compensation position of an OLED display according to an exemplary embodiment.
7 is a diagram illustrating an image analysis method for determining a compensation position of an OLED display according to an embodiment.
8 is a diagram illustrating an insertion position of a compensation line of an OLED display according to an embodiment.
9 is a diagram showing a comparison of image shift results according to a conventional black line insertion method and compensation line insertion according to an embodiment.

1 is a block diagram showing the configuration of an OLED display device according to an embodiment of the present invention, and FIG. 2 is an equivalent circuit diagram illustrating the configuration of one subpixel shown in FIG. 1 .

Referring to FIG. 1 , an OLED display device includes a panel 100, a gate driver 200, a data driver 300, a timing controller 400, a gamma voltage generator 500, and the like.

The panel 100 displays an image through a pixel array. The panel 100 may use any one of various pixel structures shown in FIG. 1 . The basic pixel of the pixel array may consist of 2-, 3-, or 4-color subpixels among white (W), red (R), green (G), and blue (B) colors. Meanwhile, the panel 100 may be a panel to which a touch sensor is embedded or attached.

Referring to FIG. 2 , each subpixel SP is connected between a high potential driving voltage (first driving voltage; EVDD) line PW1 and a low potential driving voltage (second driving voltage; EVSS) line PW2. An OLED element 10 and a pixel circuit including at least first and second switching TFTs ST1 and ST2, a driving TFT DT, and a storage capacitor Cst to independently drive the OLED element 10. do. Meanwhile, since the pixel circuit is diverse in addition to the configuration of FIG. 2 , various configurations may be applied.

Amorphous silicon (a-Si) TFT, poly-silicon (poly-Si) TFT, oxide TFT, or organic TFT may be used as the switching TFT (ST1, ST2) and the driving TFT (DT). there is.

The OLED device 10 includes an anode connected to the source node N2 of the driving TFT DT, a cathode connected to the EVSS line PW2, and an organic light emitting layer between the anode and the cathode. The anode is independent for each subpixel, but the cathode may be a common electrode shared by all subpixels. In the OLED device 10, when a driving current is supplied from the driving TFT (DT), electrons from the cathode are injected into the organic light emitting layer, and holes from the anode are injected into the organic light emitting layer. By emitting the phosphor, light of brightness proportional to the current value of the driving current is generated.

The first switching TFT (ST1) is driven by the scan pulse (SCn) supplied from the gate driver 200 to one gate line (Gn1), and the data voltage ( Vdata) is supplied to the gate node N1 of the driving TFT (DT).

The second switching TFT (ST2) is driven by the sense pulse (SEn) supplied from the gate driver 200 to the other gate line (Gn2), and the reference voltage ( Vref) is supplied to the source node N2 of the driving TFT (DT).

The storage capacitor Cst connected between the gate node N1 and the source node N2 of the driving TFT DT connects the gate node N1 and the source node ( The difference between the data voltage (Vdata) and the reference voltage (Vref) supplied to N2) is charged as the driving voltage (Vgs) of the driving TFT (DT), and the first and second switching TFTs (ST1, ST2) are turned off. The driving voltage (Vgs) charged during the light emission period is held.

The driving TFT (DT) controls the current supplied from the EVDD line (PW1) according to the driving voltage (Vgs) supplied from the storage capacitor (Cst), and converts the driving current determined by the driving voltage (Vgs) to the OLED device 10. By supplying it, the OLED element 10 emits light.

Meanwhile, in the sensing mode of the sub-pixel SP, the driving TFT DT connects the sensing data voltage Vdata supplied through the data line Dm and the first switching TFT ST1 to the reference line Rm. And it is driven by receiving the reference voltage (Vref) supplied through the second switching TFT (ST2). The pixel current reflecting the electrical characteristics (Vth, mobility) of the driving TFT (DT) is charged as a voltage in the line capacitor of the reference line (Rm) in a floating state through the second switching TFT (ST2). The data driver 300 samples the voltage charged in the reference line Rm, converts it into sensing data of each subpixel SP, and outputs it to the timing controller 400 .

The gate driver 200 and the data driver 300 shown in FIG. 1 may be expressed as a panel driver that drives the panel 100 .

The gate driver 200 receives a plurality of gate control signals from the timing controller 400 and performs a shift operation to individually drive the gate lines of the panel 100 . The gate driver 200 supplies a gate-on voltage scan signal to the corresponding gate line during the driving period of each gate line, and supplies a gate-off voltage to the corresponding gate line during the non-driving period of each gate line.

The gate driver 200 according to an embodiment is composed of one or a plurality of gate ICs (Integrated Circuits), and the gate ICs are individually mounted on a circuit film such as COF (Chip On Film) to form a TAB (TAB) on the panel 100. It may be bonded and connected in a Tape Automatic Bonding (Tape Automatic Bonding) method or mounted on the panel 100 in a COG (Chip On Glass) method. Meanwhile, the gate driver 200 according to an exemplary embodiment is formed on a substrate together with a thin film transistor array constituting a pixel array of the panel 100 and is provided in a non-display area of both sides or one side of the panel 100 (GIP). In Panel) type can be embedded.

The gamma voltage generator 500 generates a reference gamma voltage set including a plurality of reference gamma voltages having different voltage levels and supplies it to the data driver 300 . The gamma voltage generator 500 may adjust the reference gamma voltage level according to the control of the timing controller 400 .

The data driver 300 is controlled according to the data control signal supplied from the timing controller 400, converts the digital data supplied from the timing controller 400 into an analog data signal, and supplies it to the data lines of the panel 100. . At this time, the data driver 300 converts digital data into an analog data signal using grayscale voltages in which a plurality of reference gamma voltages supplied from the gamma voltage generator 500 are subdivided, and converts the analog data signal into a data signal of the panel 100. supply to the lines. The data driver 300 supplies the reference voltage Vref to the reference lines of the panel 100 under the control of the timing controller 400 .

When the data driver 300 is in the sensing mode under the control of the timing controller 400, the data voltage for sensing is supplied to the data line to drive each subpixel, and the pixel current representing the electrical characteristics of the driven subpixel is supplied. It may be sensed as a voltage through a reference line, converted into digital sensing data, and provided to the timing controller 400 .

The data driver 300 is composed of a plurality of data ICs, and the data ICs are individually mounted on a circuit film such as COF (Chip On Film) and bonded to the panel 100 by a TAB (Tape Automatic Bonding) method, or COG ( Chip On Glass) method may be mounted on the panel 100.

The timing controller 400 receives source images and timing control signals from a host system. The host system may be any one of a system of a portable terminal such as a computer, a TV system, a set-top box, a tablet or a mobile phone. The timing control signals may include a dot clock, a data enable signal, a vertical sync signal, a horizontal sync signal, and the like.

The timing controller 400 generates a plurality of data control signals for controlling driving timing of the data driver 300 by using the supplied timing control signals and timing setting information stored therein, and supplies them to the data driver 300. , A plurality of gate control signals for controlling driving timing of the gate driver 200 are generated and supplied to the gate driver 400 .

The timing controller 400 includes an image processing unit 600 that performs various image processing on a source image. The image processing unit 600 performs image shift processing by inserting a compensation line according to an exemplary embodiment. The image processing unit 600 may further perform a plurality of image processing including image quality correction or luminance correction to reduce power consumption before or after the image shift processing. Meanwhile, the image processing unit 600 may be separated from the timing controller 400 and positioned to be connected to an input terminal of the timing controller 400. In this case, the output of the image processing unit 600 is a data driver through the timing controller 400. (300).

The timing controller 400 may further correct the output of the image processor 600 by applying a compensation value for characteristic deviation of each subpixel stored in the memory before supplying the output of the image processor 600 to the data driver 300 . In the sensing mode, the timing controller 400 senses the electrical characteristics (Vth of the driving TFT, mobility, Vth of the OLED, etc.) of each subpixel of the panel 100 through the data driver 300 and returns the sensing result. Compensation values of each sub-pixel stored in the memory 500 may be updated by using.

In particular, the image processing unit 600 according to an embodiment compares image characteristics between adjacent lines (row line and column line) according to an image shift direction, determines a compensation line position where the difference in image characteristics is lower than a threshold value, and determines the position of the compensation line. A compensation line having similar image characteristics to adjacent lines is inserted at the position. By inserting the compensation line, the image data after the compensation line is shifted by the image processing unit 600 line by line according to the image shift direction. A plurality of compensation lines are inserted with a minimum separation distance. The image processing unit 600 outputs the image shift-processed data through the timing controller 400 .

Meanwhile, the image processing unit 600 may preset the positions and intervals of compensation lines to fixed values in order to reduce the amount of calculations. That is, the image processing unit 600 may insert compensation lines at regular intervals determined according to the image shift direction, and may insert compensation data having image characteristics similar to those of adjacent lines into the compensation lines. For example, the interval of the compensation line may be set to an integer between 3 and 30. In this case, since calculation for determining the compensation position can be omitted, the circuit configuration and cost of the image processing unit 600 can be reduced.

3 is a block diagram illustrating an image processing unit of an OLED display device according to an embodiment, FIG. 4 illustrates various image shift types according to an embodiment, and FIG. 5 is a pixel according to a pixel shift direction according to an embodiment. This is an example of movement.

Referring to FIG. 3 , an image processing unit 600 according to an exemplary embodiment includes an image input unit 610, a pixel shift determination unit 620, a compensation position determination unit 630, and a data output unit 640.

An image processing method by the image processing unit 600 according to an exemplary embodiment includes inputting a source image by the image input unit 610, determining a pixel shift movement amount according to a shift direction by the pixel shift determining unit 620, and a compensation position determining unit. The step of determining the position of the compensation line in step 630 and the step of inserting the compensation data and outputting the pixel-shifted image of the data output unit 640 are included.

The video input unit 610 receives and outputs a source video from the host system.

The pixel shift determining unit 620 determines and outputs pixel shift amounts (S _col , S _row ) to be shifted in the source image supplied from the image input unit 610 in the current frame. Scol represents a pixel movement amount in a horizontal direction, and S _row represents a pixel movement amount in a vertical direction. The pixel shift determiner 620 determines and outputs pixel shift amounts (S _col , S _row ) including pixel shift direction components of the current frame according to a predetermined pixel shift movement type, movement range, and shift period.

The pixel shift movement shape can be set in various shapes such as a square shape as shown in FIG. 4(a) and a diamond shape as shown in FIG. 4(b), and the pixel shift movement range can be set to various sizes there is.

Referring to FIG. 5, a value of "S _col " greater than 0 means a pixel shift amount to be shifted in the right direction among horizontal directions, and a value of "S _col " less than 0 means a pixel shift amount to be shifted in the left direction among horizontal directions. , "S _row " value greater than 0 means the pixel movement amount to be shifted downward in the vertical direction, and "S _row " value less than 0 indicates the pixel movement amount to be shifted upward in the vertical direction. can In other words, the pixel shift direction is determined according to the sign (negative or positive) of each coordinate value representing the pixel movement amount (S _col , S _row ), and the pixel movement amount is determined according to the absolute value.

The compensation position determiner 630 compares and analyzes image characteristics between lines in the pixel shift direction according to the pixel shift amounts (S _col , S _row ) supplied from the pixel shift determiner 620 to determine an optimal compensation line position.

6 is a flow chart illustrating a method for determining a compensation position of the compensation position determiner 630 according to an embodiment, and FIG. 7 illustrates an image analysis method for determining a compensation position of the compensation position determiner 630 according to an embodiment. is the drawing shown.

6 and 7 describe a method of determining a position of a compensation line in one frame with respect to a pixel movement amount (S _row ) in a downward direction among vertical directions when S _row is greater than 0, as an example.

In FIG. 6, row means the row coordinates (1 ≤ row ≤ Image Height) of the current frame, and R _i is the insertion position of the compensation line for the i-th of the Row movement amount (S _row ) (1 ≤ i ≤ S _row, R ₀ = 0 ), x indicates the row range (row ≤ x ≤ row + n) for calculating the characteristic difference between lines (Diff) and its minimum value (argmin), Th _R is the minimum interval for inserting the compensation line , and Th _D represents a threshold value for a difference in image characteristics.

The compensation position determining unit 630 determines the row movement amount (Srow) to be shifted in the vertical direction from the pixel shift amount (Scol, Srow) supplied from the pixel shift determining unit 620 (S402).

The compensation position determining unit 630 increases the number of row counts by 1 from the starting point (R ₀ =0) or the previous compensation position (R _{i - 1} ) if there is a previous compensation position, while increasing the row spaced apart by the minimum interval (Th _R ). A row is selected (S404, S406). The minimum interval Th _R is an interval for minimizing deterioration of image quality due to insertion of compensation data, and may be set to, for example, a positive integer within 3<Th _R <20.

The compensation position determining unit 630 compares and analyzes the image characteristics between adjacent lines within the row line range (row + n) determined from the selected row line (row) as shown in FIG. x)) is detected as the lowest row line (R _i ) (S408 and S410). The search range (n) for comparative analysis of the image characteristics may be set to, for example, a positive integer within 3<Th _R <20 equal to or similar to the minimum interval (Th _R ).

The compensation location determiner 630 may calculate the image characteristic difference (Diff) between adjacent lines using various methods other than the method of calculating the RGB Euclidian distance of the adjacent lines as shown in Equation 1 below. For example, an image characteristic difference value of adjacent lines may be calculated using a luminance difference, a color difference difference, a gray level difference, and the like between adjacent lines for each pixel.

[Equation 1]

In Equation 1, (c, r) and (c, r + 1) denote pixel positions of adjacent row lines (r, r + 1), and r, g, and b represent R, G, and B subpixels, respectively. means the data, and Width means the total number of columns in the source image.

Compensation location determiner 630 determines that there is an appropriate compensation location within the calculation range (n) if the image characteristic difference (Diff) between adjacent lines is less than or equal to the threshold value (Th _D ) and the minimum value (argmin(Dfiff(x)) exists). (S408, Y), and one of the row lines having the minimum value (argmin(Dfiff(x)) is selected as the compensation line insertion position (R _i = argmin(Dfiff(x)) (S410), and then the starting position (Row) for pixel shift is updated to R _i (S412).

On the other hand, if the image characteristic difference (Diff) between adjacent lines does not exist below the threshold value (Th _D ), the compensation position determination unit 630 determines that there is no appropriate compensation position within the calculation range (n) (S408, N). , The compensation line position is not determined for the current pixel shift (R _i =null), and the start position (Row) for the next pixel shift is updated to row+n (S416, S418).

The compensation position determining unit 630 increases i by 1 (S422) until i reaches the row _i of the range (1≤ i ≤ S _row ) determined by the pixel movement amount (S _row ) (S420), and One compensation positioning operation is repeated (S404 to S422).

When the compensation positioning unit 630 repeats the compensation positioning operation until i is the pixel movement amount (S _row ) (S420, Y), the compensation position determining unit 630 proceeds to the next step to determine the compensation line insertion position for the current frame (S424). , quit

On the other hand, when the shift direction is the upper direction (S _row <0) of the vertical direction, the compensation positioning unit 630 performs the same compensation positioning operation as in FIG. 6 in the reverse direction from the lower end (row = Height) of the source image. is performed to determine the position of inserting the compensation line in units of row lines.

Even when the shift direction is the horizontal direction, the compensation position determining unit 630 performs the same compensation position determination operation as in FIG. 6 for the pixel movement amount S _col in the left and right directions to determine the compensation line insertion position C in units of column lines. _i ) is determined.

On the other hand, the compensation position determiner 630 may preset the position of the compensation line and its interval to a fixed value in order to reduce the amount of calculation. That is, the compensation position determiner 630 may determine the position of the compensation line at regular intervals determined according to the image shift direction. For example, the compensation line interval may be set to an integer between 3 and 30. In this case, since calculation for determining the compensation position can be omitted, the circuit configuration and cost of the image processing unit 600 can be reduced.

The data output unit 640 inserts compensation data at an optimal compensation line position using the pixel shift direction, interval, and compensation line insertion position supplied from the pixel shift determiner 620 and the compensation position determiner 630, By shifting image data after the compensation line, an output image in which the compensation line is inserted and the position of the source image is shifted is generated and output.

8 is a diagram illustrating an insertion position of a compensation line of an OLED display according to an embodiment.

Referring to FIG. 8 , the data output unit 640 inserts compensation data into the compensation line insertion position supplied from the compensation position determination unit 630, and subsequent lines are shifted line by line by the inserted compensation line. The data output unit 640 interpolates and uses data of an adjacent line for compensation data of a compensation line, or duplicates and uses data of any one of the adjacent lines, so that the compensation line insertion position has a relatively small difference in characteristics between adjacent lines. Compensation data similar to the adjacent line can be inserted in .

The data output unit 640 may insert compensation data into the next row line based on the insertion position (row1, rowi) of the compensation line determined by the compensation position determination unit 630, and compensation is obtained by inserting the compensation line. Image data after the line is shifted by one row, so that an output image in which the position of the source image is changed by inserting the compensation line can be output. Similar to the orbit driving method, a part of the image due to the shift is cut off.

In this way, the OLED display device according to an embodiment can reduce afterimages by distributing the stress received by each pixel by changing the position of the source image by inserting the compensation line, and the difference in image characteristics between adjacent lines is the greatest. Since compensation data similar to an adjacent line is inserted at a small compensation line position and is not recognized, image quality deterioration due to compensation line insertion can be minimized.

9 is a diagram showing a comparison of image shift results according to a conventional black line insertion method and compensation line insertion according to an embodiment.

Referring to FIG. 9 , while orbit driving using a conventional method of inserting a black line deteriorates image quality due to the recognition of black line artifacts, the image shift method using insertion of a compensation line according to an embodiment has an effect in which the compensation line is not recognized. it can be seen that there is

As a simulation result of applying the image shift method using compensation line insertion to various images, the afterimage lifetime can be similar to or increased compared to the existing orbit driving technology, and the image quality degradation including the black line artifact of the existing orbit driving is greatly reduced, resulting in the original video The difference between comparison images to which an embodiment of contrast is applied may be reduced to 1JND or less, which does not recognize artifacts compared to the original.

Through the above description, those skilled in the art will understand that various changes and modifications are possible without departing from the spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be determined by the claims.

100: panel 200: gate driver
300: data driver 400: timing controller
500: gamma voltage generator 600: image processor
610: image input unit 620: pixel shift determination unit
630: compensation positioning unit 640: data output unit

Claims (11)

a panel displaying an image;
a panel driver for driving the panel;
A pixel shift amount including a shift direction component is determined based on image shift setting information, a compensation line position is determined according to the shift direction based on the determined pixel shift amount, and compensation data using data of a line adjacent to the determined compensation line position and an image processing unit supplying an output image obtained by shifting the position of image data after the compensation line to the panel driver. The method of claim 1,
The image processing unit determines the compensation line position according to a preset compensation position interval. The method of claim 1,
The image processing unit
For a plurality of lines belonging to the calculation range from a line separated by a minimum interval from a starting position or a previous compensation position, a difference in image characteristics between adjacent lines using at least one of a luminance difference, a grayscale difference, and a color difference difference between adjacent lines is greater than a threshold value. An OLED display device for determining a line having a small and minimum value as the position of the compensation line. The method of claim 3,
The image processing unit
An operation of determining a position of the compensation line by calculating a difference in image characteristics between the adjacent lines is repeated until the pixel shift amount is reached according to the shift direction. The method of claim 4,
The image processing unit
If the characteristic difference between the adjacent lines is equal to or greater than the threshold value, an operation for determining a position of a next compensation line is performed without determining a position of the compensation line within the calculation range. The method of claim 1,
The compensation data is used by interpolating data of the adjacent lines, or by duplicating and using data of any one of the adjacent lines. determining a pixel shift amount including a shift direction component based on image shift setting information;
determining a position of a compensation line according to the shift direction based on the determined pixel shift amount;
An image processing method of an OLED display device comprising the step of inserting compensation data using data of an adjacent line into the position of the determined compensation line, shifting the position of image data following the compensation line, and outputting an output image. The method of claim 7,
Determining the position of the compensation line
An image processing method of an OLED display device for determining the position of the compensation line according to a preset compensation position interval. The method of claim 7,
Determining the position of the compensation line
For a plurality of lines belonging to a calculation range from a line spaced by a minimum interval from a starting position or a previous compensation position, an image characteristic difference between adjacent lines is smaller than a threshold value and a line having a minimum value is determined as the position of the compensation line. image processing method. The method of claim 9,
Determining the position of the compensation line
The image processing method of the OLED display device repeating the operation of determining the position of the compensation line by calculating the difference in image characteristics between the adjacent lines until the pixel movement amount is reached according to the shift direction. The method of claim 9,
Determining the position of the compensation line
If the characteristic difference between the adjacent lines is equal to or greater than the threshold value, an operation for determining a position of a next compensation line is performed without determining a position of the compensation line within the calculation range.

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