KR102450545B1 - Organic light emitting display device, timing controller and method for driving the timing controller - Google Patents

Abstract

The present invention relates to an organic light emitting display device, a timing controller included in the organic light emitting display device, and a driving method of the timing controller, comprising compensating for a luminance deviation for each position in an organic light emitting display panel of the organic light emitting display device through grayscale compensation. It's about technology. According to the present invention, in converting image data into grayscale data, grayscale data is compensated by applying grayscale compensation data set for each grayscale of the grayscale data, each position in the organic light emitting display panel, and each color to the converted grayscale data, It is possible to remove the luminance deviation for each position in the organic light emitting display panel that remains even after compensating for the deviation of the characteristic value of the driving transistor and to improve the overall luminance uniformity of the organic light emitting display panel.

Description

Organic light emitting display device, timing controller, and driving method thereof

The present invention relates to an organic light emitting display device, a timing controller included in the organic light emitting display device, and a driving method of the timing controller.

The organic light-emitting display device, which has recently been spotlighted as a display device, has advantages in that the response speed is fast and the contrast ratio, luminous efficiency, luminance, and viewing angle are large by using an organic light-emitting diode (OLED) that emits light by itself.

In such an organic light emitting display device, subpixels including an organic light emitting diode (OLED) and a driving transistor driving the same are arranged in a matrix form, and the brightness of the subpixels selected by a scan signal is controlled according to the grayscale of data.

In such an organic light emitting display device, circuit elements such as an organic light emitting diode (OLED) and a driving transistor in each sub-pixel each have unique characteristics (eg, threshold voltage, mobility, etc.). In addition, each driving transistor may be deteriorated according to a driving time, so that a unique characteristic value of the driving transistor may be changed.

Accordingly, the luminance characteristic of the corresponding sub-pixel may be changed according to the change in the characteristic value, and when the characteristic value or the characteristic value change between circuit elements is different, the luminance uniformity of the organic light emitting display panel is deteriorated by causing a luminance deviation between the sub-pixels. A problem exists.

In order to solve this problem, a technology for sensing and compensating for a characteristic value of a circuit element in each sub-pixel has been developed.

However, even if the threshold voltage and mobility, which are characteristic values of the circuit elements in each sub-pixel, are measured and compensated, there is a problem that the difference in luminance between the sub-pixels may still occur due to the efficiency deviation of the organic light-emitting diode (OLED). do. Accordingly, there is a need for a method for improving the luminance uniformity of the organic light emitting display panel by compensating for the luminance difference.

It is an object of the present exemplary embodiments to provide an organic light emitting diode display capable of compensating for a luminance deviation between sub-pixels that exists even after compensating for a characteristic value deviation of a driving transistor within a sub-pixel.

Another object of the present embodiments is to provide an organic light emitting display device capable of compensating for a luminance deviation between sub-pixels in consideration of different luminance deviations for each color by compensating using compensation data set for each color. have.

Another object of the present exemplary embodiments is to provide an organic light emitting diode display capable of compensating for luminance deviations for all grayscales by calculating compensation data for a low grayscale in which luminance cannot be measured due to low luminance.

According to an embodiment, an organic light emitting display panel including a plurality of pixels disposed in a region where a plurality of gate lines and a plurality of data lines intersect, and a plurality of pixels disposed in a region where the gate line and the data line intersect; a gate driver driving gate lines, a data driver supplying data voltages to the plurality of data lines, controlling driving of the gate driver and the data driver, and converting image data received from the outside into grayscale data a timing controller, wherein the timing controller compensates the grayscale data by using grayscale compensation data for each position calculated through luminance measurement of the organic light emitting display panel, and wherein the grayscale compensation data is grayscale compensation data set for each color A light emitting display device may be provided.

In the organic light emitting display device, in the grayscale compensation data, the white grayscale compensation data may be set to be larger than the grayscale compensation data for each other color.

In the organic light emitting display device, the timing controller stores the grayscale compensation data set for each color and compensates the grayscale data using the stored grayscale compensation data. If the grayscale compensation data for the grayscale data is not stored, the The grayscale compensation data for the grayscale data may be calculated using a straight line slope of two grayscale compensation data among the stored grayscale compensation data, and the grayscale data may be compensated.

In such an organic light emitting display device, the timing controller may store coefficients for calculating white grayscale compensation data and grayscale compensation data for each color, and compensate the grayscale data by using the stored white grayscale compensation data and coefficients. The timing controller may be configured to multiply the white grayscale compensation data by the coefficient to calculate the grayscale compensation data for each color, and the coefficient may be set to be greater than 0 and less than 0.85.

Another embodiment provides a grayscale data conversion unit for converting image data received from the outside into grayscale data, and grayscale compensation for storing grayscale compensation data for each position calculated by measuring the luminance of a display panel on which the image data is displayed for each color. The timing controller may include a data storage unit and a grayscale data compensator configured to compensate for the converted grayscale data using the grayscale compensation data stored in the grayscale compensation data storage unit.

In another embodiment, converting image data received from the outside into grayscale data, and selecting grayscale compensation data for the grayscale data from among grayscale compensation data calculated and stored by measuring the luminance of a display panel displaying the image data and compensating for the grayscale data using the selected grayscale compensation data, but compensating for the grayscale data using grayscale compensation data stored for each color.

According to the present exemplary embodiments, by compensating for grayscale data using compensation data calculated through luminance measurement, it is possible to minimize the luminance deviation remaining even after compensating for the characteristic value deviation of the driving transistor.

According to the present exemplary embodiments, when the grayscale data is compensated, the grayscale data is compensated using the compensation data set for each color, so that the luminance deviation between the subpixels can be accurately compensated for each color.

According to the present exemplary embodiments, by enabling grayscale compensation for low grayscale data, it is possible to compensate for luminance deviation in all grayscales.

1 is a schematic system configuration diagram of an organic light emitting diode display according to example embodiments.
2 is a diagram illustrating an overall flow of a process of compensating for a luminance deviation of an organic light emitting diode display according to the present exemplary embodiment.
3 to 5 are diagrams for explaining an embodiment of compensating for a luminance deviation through grayscale compensation of the organic light emitting diode display according to the present embodiments.
6 to 11 are diagrams for explaining the difference in the amount of grayscale compensation according to the cause of the luminance deviation in the organic light emitting diode display according to the present exemplary embodiment.
12 and 13 are diagrams for explaining an embodiment in which the organic light emitting display device according to the present embodiments applies the grayscale compensation amount to each color.
14 is a diagram for explaining an embodiment in which the organic light emitting diode display according to the present exemplary embodiment calculates a grayscale compensation amount at a low grayscale.
15 is a configuration diagram of a timing controller according to the present exemplary embodiment.
16 is a flowchart illustrating a process of a method of driving a timing controller according to the present exemplary embodiments.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to components of each drawing, the same components may have the same reference numerals as much as possible even though they are indicated in different drawings. In addition, in describing the present invention, when it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted.

In addition, in describing the components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the nature, order, order, or number of the elements are not limited by the terms. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but other components may be interposed between each component. It will be understood that each component may be “interposed” or “connected”, “coupled” or “connected” through another component.

1 is a schematic system configuration diagram of an organic light emitting diode display 100 according to the present exemplary embodiments.

Referring to FIG. 1 , in the organic light emitting diode display 100 according to the present exemplary embodiments, a plurality of data lines DL and a plurality of gate lines GL are disposed, and a plurality of sub-pixels (SP) are provided. The organic light emitting display panel 110 , the data driver 120 driving the plurality of data lines DL, the gate driver 130 driving the plurality of gate lines GL, and the data driver 120 are disposed. and a timing controller T-CON 140 for controlling the gate driver 130 .

The data driver 120 drives the plurality of data lines DL by supplying data voltages to the plurality of data lines DL.

The gate driver 130 sequentially drives the plurality of gate lines GL by sequentially supplying scan signals to the plurality of gate lines GL.

The timing controller 140 supplies various control signals to the data driver 120 and the gate driver 130 to control the data driver 120 and the gate driver 130 .

The timing controller 140 starts scanning according to the timing implemented in each frame, and converts input image data input from the outside to match the data signal format used by the data driver 120 to output the converted image data. and control the data drive at an appropriate time according to the scan.

The gate driver 130 sequentially supplies a scan signal of an ON voltage or an OFF voltage to the plurality of gate lines GL according to the control of the timing controller 140 to the plurality of gate lines GL. run sequentially.

The gate driver 130 may be located on only one side of the organic light emitting display panel 110 or located on both sides according to a driving method.

Also, the gate driver 130 may include one or more gate driver integrated circuits.

Each gate driver integrated circuit is connected to a bonding pad of the organic light emitting display panel 110 by a tape automated bonding (TAB) method or a chip-on-glass (COG) method, or a gate in (GIP) method. Panel) type and may be directly disposed on the organic light emitting display panel 110 . In addition, the organic light emitting display panel 110 may be integrated and disposed, or may be implemented in a chip-on-film (COF) method mounted on a film connected to the organic light emitting display panel 110 .

When a specific gate line GL is opened, the data driver 120 converts the image data received from the timing controller 140 into an analog data voltage and supplies it to the plurality of data lines DL. ) is driven

The data driver 120 may include at least one source driver integrated circuit to drive a plurality of data lines DL.

Each source driver integrated circuit is connected to a bonding pad of the organic light emitting display panel 110 by a tape automated bonding (TAB) method or a chip-on-glass (COG) method, or the organic light emitting display panel. It may be disposed directly on the 110 , or may be integrated and disposed on the organic light emitting display panel 110 .

In addition, each source driver integrated circuit may be implemented in a chip-on-film (COF) method. In this case, one end of each source driver integrated circuit is bonded to at least one source printed circuit board, and the other end is bonded to the organic light emitting display panel 110 .

The timing controller 140 includes various timing signals including a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, an input data enable (DE) signal, and a clock signal CLK together with input image data. are received from the outside (eg host system).

The timing controller 140 converts the input image data input from the outside to match the data signal format used by the data driver 120 and outputs the converted image data, as well as the data driver 120 and the gate driver 130 . ), a data driver receives timing signals such as a vertical sync signal Vsync, a horizontal sync signal Hsync, an input data enable signal DE, and a clock signal CLK, and generates various control signals to control the data driver. 120 and the gate driver 130 .

For example, the timing controller 140 controls the gate driver 130 , a gate start pulse (GSP), a gate shift clock (GSC), and a gate output enable signal (GOE). : Outputs various gate control signals (GCS: Gate Control Signal) including Gate Output Enable).

Here, the gate start pulse GSP controls the operation start timing of one or more gate driver integrated circuits constituting the gate driver 130 . The gate shift clock GSC is a clock signal commonly input to one or more gate driver integrated circuits and controls shift timing of a scan signal (gate pulse). The gate output enable signal GOE specifies timing information of one or more gate driver integrated circuits.

In addition, the timing controller 140 controls the data driver 120 , a source start pulse (SSP), a source sampling clock (SSC), and a source output enable signal (SOE: Source). Output Enable) and output various data control signals (DCS: Data Control Signal).

Here, the source start pulse SSP controls the data sampling start timing of one or more source driver integrated circuits constituting the data driver 120 . The source sampling clock SSC is a clock signal that controls sampling timing of data in each of the source driver integrated circuits. The source output enable signal SOE controls the output timing of the data driver 120 .

The timing controller 140 is a control printed circuit connected to the source printed circuit board to which the source driver integrated circuit is bonded through a connection medium such as a flexible flat cable (FFC) or a flexible printed circuit (FPC). It may be disposed on a control printed circuit board.

The control printed circuit board includes a power controller (not shown) that supplies various voltages or currents to the organic light emitting display panel 110 , the data driver 120 , and the gate driver 130 , or controls various voltages or currents to be supplied. more can be placed. Such a power controller is also called a power management integrated circuit (Power Management IC).

In the organic light-emitting display device 100 , each sub-pixel disposed on the organic light-emitting display panel 110 includes circuit elements such as an organic light-emitting diode (OLED), two or more transistors, and at least one capacitor. can be

The type and number of circuit elements constituting each sub-pixel may be variously determined according to a provided function and a design method.

In the organic light emitting display panel 110 , each sub-pixel has a characteristic value (eg, threshold voltage, etc.) of an organic light emitting diode (OLED) and a characteristic value (eg, threshold voltage, mobility, etc.) of a driving transistor driving the organic light emitting diode (OLED). ) may include a circuit structure for compensating for sub-pixel characteristics, such as. Accordingly, it is possible to compensate for a characteristic value deviation between sub-pixels disposed on the organic light emitting display panel 110 and to maintain the overall luminance uniformity of the organic light emitting display panel 110 .

FIG. 2 illustrates an overall process of compensating for a luminance deviation between subpixels disposed on the organic light emitting display panel 110 by the organic light emitting display device 100 according to the present exemplary embodiments.

Referring to FIG. 2 , the organic light emitting display device 100 senses factors affecting the luminance deviation between sub-pixels disposed on the organic light emitting display panel 110 , and calculates a compensation value based on the sensed value. It compensates for the luminance deviation by applying. The sensing and compensation process can be divided into a voltage sensing, compensation process, and grayscale sensing and compensation process. Sensing is performed from the device to the system, and compensation is performed from the system to the device.

Referring to the sensing and compensating part of voltage in FIG. 2 , the organic light emitting diode display 100 senses a threshold voltage (Vth), mobility (α), which are characteristic values of a driving transistor disposed in each subpixel, and the like. and calculate the characteristic value deviation of the driving transistor based on the sensed value. Then, a compensation value for compensating the threshold voltage Vth and the mobility α is calculated according to the calculated deviation, and the deviation of the characteristic value of the driving transistor is compensated by applying the calculated compensation value. Accordingly, it is possible to compensate for a luminance deviation between sub-pixels by compensating for a characteristic value deviation of the driving transistor.

However, even after compensating for the deviation in the characteristic value of the driving transistor, there is still a difference in luminance for each position in the organic light emitting diode display panel 110 due to the efficiency deviation of the organic light emitting diode (OLED).

The present exemplary embodiments include a process of compensating for a luminance deviation between sub-pixels disposed in the organic light emitting display panel 110 that occurs even after compensation for a characteristic value deviation of the driving transistor through grayscale compensation.

Referring to the sensing and compensating part for grayscale in FIG. 2 , in order to measure the overall luminance uniformity of the organic light emitting display panel 110 , the luminance characteristics versus voltage are measured. The luminance uniformity according to the position of the organic light emitting display panel 110 is measured through the measured luminance characteristics, and the gradation compensation amount is calculated according to the measured luminance deviation and applied to the gradation data. Make it possible to compensate for the luminance deviation.

The luminance characteristics for each position of the organic light emitting display panel 110 may be measured using a camera. That is, a luminance characteristic versus voltage of the organic light emitting display panel 110 is measured through a camera, and a grayscale compensation amount capable of compensating for a luminance deviation for each location is calculated according to the measured luminance characteristic. Then, by applying the calculated grayscale compensation amount to output grayscale data, the luminance deviation remaining after compensation for the characteristic value deviation of the driving transistor can be compensated.

3 to 5 show an embodiment in which the organic light emitting diode display 100 according to the present exemplary embodiment compensates for the luminance deviation remaining even after compensation for the characteristic value deviation of the driving transistor.

3 shows the luminance uniformity of the organic light emitting display panel 110 before and after gray level compensation is applied to the organic light emitting display panel 110, and shows an example in which gray level compensation is applied at 16 gray levels.

Referring to FIG. 3 , when the luminance characteristics of the organic light emitting display panel 110 are measured through a camera before gradation compensation is performed, it can be seen that the luminance is not uniform depending on the position of the organic light emitting display panel 110 . . In the present embodiments, the luminance deviation for each position of the organic light emitting display panel 110 is calculated through the measurement of the luminance characteristic, and grayscale compensation is performed according to the luminance deviation for each position. Looking at the luminance characteristics measured through the camera after the grayscale compensation is performed, it can be seen that the luminance of the organic light emitting display panel 110 is uniformly compensated as a whole.

FIG. 4 shows an example of generating a luminance profile for each position of the organic light emitting display panel 110 by using the luminance characteristics of the organic light emitting display panel 110 measured by the camera before gradation compensation is performed in FIG. 3 . , FIG. 4 shows luminance characteristics for each position of the organic light emitting display panel 110 measured at 32 grayscales.

Referring to FIG. 4 , it can be seen that the luminance is not uniform according to the position of the organic light emitting display panel 110 . In addition to the deviation in the characteristic value of the driving transistor, the deviation in the luminance characteristic for each location of the organic light emitting display panel 110 is caused by the efficiency deviation of the organic light emitting diode (OLED) and the effect of kickback.

That is, the luminance characteristic deviation may occur according to the efficiency deviation of the organic light emitting diode (OLED) for each position of the organic light emitting display panel 110 . In addition, a deviation in luminance characteristics may occur due to a kickback phenomenon. The kickback phenomenon is when a switching transistor included in a sub-pixel is turned off. It means a phenomenon in which the gate voltage of the driving transistor falls according to the difference. This is due to parasitic capacitance and current flowing at turn off.

Differences in luminance characteristics for each position of the organic light emitting display panel 110 may occur due to the efficiency deviation of the organic light emitting diode (OLED) and the kickback phenomenon. (110) to compensate the luminance deviation for each position.

5 illustrates a process of compensating for a luminance deviation for each position of the organic light emitting display panel 110 in the organic light emitting display device 100 according to the present exemplary embodiment.

Referring to FIG. 5 , a luminance characteristic is measured at each gray level through a camera. An image measured by a camera is analyzed to generate a luminance profile at each gray level.

5 shows an example of measuring the luminance characteristics for each position of the organic light emitting display panel 110 at 32 grayscales and 64 grayscales.

As shown in FIG. 5 , it can be seen that the luminance characteristic measured by the camera is different for each position of the organic light emitting display panel 100 , and the luminance characteristic is also formed differently in each grayscale.

When the luminance profile is generated by measuring the luminance characteristics for each position of the organic light emitting display panel 100 at each gradation, gradation compensation data is calculated based on the luminance profile to compensate for the luminance deviation for each position. Also, in expressing each gray level, preset gray level compensation data is applied to output gray level data, so that the luminance deviation for each position can be compensated for in the organic light emitting display panel 110 .

6 to 11 show grayscale compensation data and a kickback phenomenon according to the efficiency deviation of the organic light emitting diode (OLED) in compensating for the luminance characteristic deviation for each position of the organic light emitting display panel 110 according to the present exemplary embodiment. grayscale compensation data according to

6 to 8 are diagrams illustrating an efficiency deviation of an organic light emitting diode (OLED) and grayscale compensation data corresponding thereto.

FIG. 6 shows the efficiency deviation of the organic light emitting diode (OLED) according to the position in the organic light emitting display panel 110 . Referring to FIG. 6 , it can be seen that the efficiency of the organic light emitting diode (OLED) decreases as the distance from the center of the organic light emitting display panel 110 increases.

7 shows the luminance ratios according to positions in the organic light emitting display panel 110, and shows the luminance ratios for each color. Referring to FIG. 7 , it can be seen that the luminance ratio according to the position of the organic light emitting display panel 110 is formed similarly to the efficiency of the organic light emitting diode (OLED) for each position of the organic light emitting display panel 110 shown in FIG. 6 . have.

Accordingly, it can be seen that the luminance ratio for each position of the organic light emitting display panel 110 also decreases as the distance from the center of the organic light emitting display panel 110 increases. In addition, although there is a slight difference in the luminance ratio for each color, it can be seen that they are formed almost the same. That is, it can be seen that the luminance deviation due to the efficiency deviation of the organic light emitting diode (OLED) occurs according to the efficiency of the organic light emitting diode (OLED) regardless of the color.

FIG. 8 shows the amount of grayscale adjustment (grayscale compensation data) according to the position of the organic light emitting display panel 110 . Referring to FIG. 8 , in order to compensate for the deviation of the luminance ratio for each position of the organic light emitting display panel 110 shown in FIG. 7 , the grayscale adjustment amount is calculated based on the luminance ratio for each position of FIG. 7 . That is, since the luminance ratio decreases as the distance from the center of the organic light emitting display panel 110 is lowered, the gray scale adjustment amount is set larger at the position where the luminance ratio is lower in the organic light emitting display panel 110 so that the organic light emitting display panel 110 as a whole is To maintain luminance uniformity.

9 to 11 show the luminance ratio and grayscale adjustment amount for each position of the organic light emitting display panel 110 due to a kickback phenomenon.

9 and 10 , it can be seen that the kickback voltage linearly decreases according to the position of the organic light emitting display panel 110 . In addition, it can be seen that the luminance ratio increases linearly according to the position of the organic light emitting display panel 110 .

That is, it can be seen that the luminance ratio increases as the effect of the kickback phenomenon decreases. At this time, referring to FIG. 10 , it can be seen that the luminance ratio of each position of the organic light emitting display panel 110 is different for each color.

This is due to the difference in efficiency between the white (W) sub-pixel and the other color (red (R), green (G), blue (B)) sub-pixels. Since the efficiency of the white (W) sub-pixel is better than that of the red (R), green (G), and blue (B) sub-pixels, the data voltage of the white (W) sub-pixel is different from the color (R, G, B) ) is lower than the data voltage of the sub-pixel. Accordingly, white (W) subpixels are proportionally affected by kickback to a large extent, and subpixels of other colors (R, G, B) are relatively less affected by kickback.

11 is a graph showing the amount of grayscale adjustment according to the effect of a kickback phenomenon for each position of the organic light emitting display panel 110, and shows colors (R, G, and It can be seen that the gray scale adjustment amount for the sub-pixel of B) is larger than the amount of adjustment.

In addition, the difference in the luminance ratio between the red (R), green (G), and blue (B) subpixels is smaller than the difference in the luminance ratio between the white (W) subpixels, but the color according to the efficiency deviation of the organic light emitting diode (OLED) It can be seen that the difference in the luminance ratio of stars is larger than the difference.

Accordingly, the amount of grayscale adjustment (grayscale compensation data) for maintaining luminance uniformity for each position of the organic light emitting display panel 110 should be set differently for each color in consideration of the kickback phenomenon, and the organic light emitting display according to the present embodiments The device 100 provides a method of compensating for a luminance deviation through grayscale compensation data that reflects not only the efficiency deviation of the organic light emitting diode (OLED), but also the effect of the kickback phenomenon.

12 and 13 show an embodiment of compensating the luminance deviation for each position of the organic light emitting display panel 110 through grayscale compensation in the organic light emitting display device 100 according to the present exemplary embodiment.

Referring to FIG. 12 , when the timing controller 140 of the organic light emitting diode display 100 according to the present exemplary embodiment receives image data from an external (eg, a system), it converts the received image data into grayscale data. The grayscale data is grayscale data for each of red (R), green (G), and blue (B) colors. Then, grayscale data for red (R), green (G), and blue (B) is converted into grayscale data for red (R), green (G), blue (B), and white (W).

When grayscale compensation is not performed, the timing controller 140 transmits grayscale data converted from image data to the data driver 120 , and the data driver 120 converts digital grayscale data into analog voltage. to each data line DL. At this time, a voltage for which the threshold voltage (Vth), the mobility (α), etc. are compensated according to the deviation of the characteristic value of the driving transistor is output.

Before the timing controller 140 transmits the converted grayscale data to the data driver 120 , in the organic light emitting display device 100 according to the present exemplary embodiments, the grayscale of the grayscale data and the organic light emitting display panel 110 are performed. It is characterized in that the grayscale data is compensated using the grayscale compensation data according to the displayed position, and the grayscale data is transmitted to the data driver 120 .

Furthermore, the gradation compensation data for compensating for the gradation data is gradation compensation data set for each color.

The grayscale compensation data may be stored in a memory in the timing controller 140 as a value calculated and stored through luminance measurement through a camera.

When the timing controller 140 converts the image data received from the outside into grayscale data for red (R), green (G), blue (B), and white (W), the grayscale of each color and the organic light emitting display are displayed. The grayscale data is compensated with the grayscale compensation data according to the position displayed on the panel 110 . Also, in the grayscale compensation data, even if the grayscale and the position (pixel) displayed on the organic light emitting display panel 110 are the same, a value set for each color exists. That is, each grayscale compensation data exists according to a position (pixel) displayed on the organic light emitting display panel 110 , a displayed grayscale, and a color thereof.

For example, when the grayscale data for red (R) corresponds to 32 grayscales, the timing controller 140 may determine a position displayed on the organic light emitting display panel 110 and a color (R) of the 32 grayscale. Check the grayscale compensation data according to Then, a value obtained by applying the grayscale compensation data to the converted grayscale data is output as grayscale data.

When grayscale data for green (G) corresponds to 16 grayscales, grayscale data is obtained by applying grayscale compensation data for green (G) among grayscale compensation data for 16 grayscales at a position displayed on the organic light emitting display panel 110 . compensate for

When the grayscale data for blue (B) corresponds to the 48 grayscale, grayscale data is obtained by applying the grayscale compensation data for blue (B) among the grayscale compensation data for the 48 grayscale at a position displayed on the organic light emitting display panel 110 . compensate for

When grayscale data for white (W) corresponds to 64 grayscales, grayscale data is obtained by applying grayscale compensation data for white (W) among grayscale compensation data for 64 grayscales at a position displayed on the organic light emitting display panel 110 . compensate for

Accordingly, by compensating for the grayscale data using grayscale compensation data set according to the position displayed on the organic light emitting display panel 110, the displayed grayscale, and the displayed color, the overall luminance of the organic light emitting display panel 110 is uniform. to improve performance.

Meanwhile, grayscale compensation data for grayscale adjustment may be different for each color, and white (W) is more affected by a kickback phenomenon among factors of luminance deviation than other colors (R, G, B). Accordingly, in consideration of this, the present embodiments also provide a method of compensating for grayscale data of different colors (R, G, and B) based on grayscale compensation data for white (W). That is, a method is provided in which grayscale compensation data for a color that is most affected by a kickback phenomenon due to the lowest data voltage in the same grayscale is set large.

13 is a diagram illustrating a case in which the timing controller 140 of the organic light emitting diode display 100 according to the present exemplary embodiment compensates for grayscale data for different colors (R, G, and B) based on grayscale compensation data for white (W). ) of calculating and applying the grayscale compensation data is shown.

Referring to FIG. 13 , the timing controller 140 stores each gray level calculated through luminance measurement by a camera and gray level compensation data for white (W) at each position. In addition, coefficients for calculating grayscale compensation data of different colors (R, G, and B) are stored based on grayscale compensation data of white (W) at each grayscale and each position.

Since the gradation compensation data of the other colors (R, G, and B) is smaller than the gradation compensation data of the white (W), the coefficient may be set to a value between 0 and 1. And, as a result of calculating the grayscale compensation data based on the luminance measurement through the camera, the coefficient may be set in the range of 0.85 or less.

The timing controller 140 stores grayscale compensation data for white (W) and each color (R, G, and B), respectively, and selects grayscale compensation data according to a position where the grayscale data is displayed, a grayscale, and a color thereof However, it is also possible to store only the grayscale compensation data for white (W) and apply the grayscale compensation data using coefficients for each color (R, G, B).

For example, when grayscale is expressed at a specific position of the organic light emitting display panel 110, grayscale compensation data for 16 grayscale white W stored in the timing controller 140 is applied to 16 grayscale white W. do. Then, with respect to 16 grayscale red (R), grayscale data is compensated by applying grayscale compensation data obtained by multiplying grayscale compensation data for 16th grayscale white (W) by 0.85, which is a coefficient for 16th grayscale red (R).

In the same way, for the 16-gradation green (G), the gray-scale compensation data obtained by multiplying the 16-gradation white (W) by multiplying the gray-scale compensation data for the 16-gradation green (G) by 0.40 is applied, and the 16-gradation blue ( For B), gradation compensation data obtained by multiplying gradation compensation data for 16 gradation white (W) by a factor of 0.55 for 16 gradation blue (B) is applied.

Coefficients for calculating grayscale compensation data for white (W) and grayscale compensation data for other colors (R, G, and B) are stored for 32 grayscales and 64 grayscales, respectively. And, for the 32 grayscales of red (R), green (G), and blue (B), coefficients of 0.60, 0.65, and 0.65 for each color (R, G, B) in the 32 grayscale are applied to the 32 grayscale white (W). The gradation compensation data for each color (R, G, B) is generated by multiplying the gradation compensation data for The gradation compensation data for each color (R, G, B) is generated by multiplying the gradation compensation data for the 64 gradation white (W) by 0.55, 0.60, and 0.60, which are coefficients for R, G, and B).

That is, the gradation compensation data for white (W), which has the largest gradation compensation data, and coefficients for calculating gradation compensation data for each color (R, G, B) based on this are stored and stored in the white (W). By calculating and applying the gradation compensation data for each color (R, G, B) using the gradation compensation data and coefficients for each color, compensation can be made in consideration of the luminance deviation for each color. To maintain the overall luminance uniformity.

On the other hand, there is a problem that low gradations (eg, 4 gradations, 8 gradations) cannot be measured in luminance measurement through a camera. The present embodiments provide an embodiment in which grayscale compensation data is applied even to grayscales for which grayscale compensation data cannot be calculated through measurement by a camera.

14 illustrates an embodiment in which the timing controller 140 of the organic light emitting diode display 100 according to the present exemplary embodiment calculates grayscale compensation data for grayscale data at a low grayscale.

Referring to FIG. 14 , luminance is measured with respect to 16 grayscales, 32 grayscales, 64 grayscales, etc. that can be measured for luminance through a camera, and the organic light emitting display panel 110 is based on the center of the organic light emitting display panel 110 . Generates luminance distribution data for each location.

As a result, as shown in the graph of FIG. 14 , the relationship between the luminance distribution at the center of the organic light emitting display panel 110 and the luminance distribution at other positions within the organic light emitting display panel 110 can be represented at 16 grayscales or more. .

In this case, since the luminance is low at low gradations such as 4 or 8 gradations, the luminance cannot be measured by the camera, so that the luminance distribution data for each position of the organic light emitting display panel 110 cannot be generated.

The timing controller 140 according to the present exemplary embodiments calculates grayscale compensation data at a low grayscale by using the luminance distribution data for each location of 16 grayscales or more that can be measured through a camera.

For example, using the luminance distribution data graph of the center of the organic light emitting display panel 110 at the 16 gray scale or higher, the center of the organic light emitting display panel 110 at the 4 or 8 gray scales lower than the 16 gray scale is used. Create a luminance scatter graph. In addition, a luminance distribution graph is derived from a luminance distribution graph at a gradation lower than 16 gradations from the luminance distribution graph at 16 gradations or more at other positions in the organic light emitting display panel 110 .

Through this, it is possible to calculate a difference in luminance between the center of the organic light emitting display panel 110 and other positions in the 4th and 8th grayscales. And, by calculating the grayscale adjustment amount that compensates for the calculated luminance difference, grayscale compensation data to be applied when displaying data of low grayscales (eg, 4th grayscale and 8th grayscale) at the corresponding position can be calculated.

Alternatively, grayscale compensation data at a grayscale lower than 16 grayscales may be estimated from the slope of the graph with respect to the grayscale compensation data in the 16th grayscale or higher.

Therefore, by enabling the gradation compensation data to be derived even at a low gradation for which gradation compensation data cannot be calculated through luminance measurement by a camera, the luminance deviation for each position of the organic light emitting display panel 110 can be compensated for at all gradations. do.

15 is a block diagram illustrating the configuration of the timing controller 140 according to the present exemplary embodiments.

Referring to FIG. 15 , the timing controller 140 according to the present exemplary embodiment includes a grayscale data conversion unit 141 , a grayscale compensation data storage unit 142 , and a grayscale data compensator 143 .

When the image data is received from the outside, the grayscale data conversion unit 141 converts the received image data into grayscale data. The grayscale data may be converted into grayscale data for red (R), green (G), blue (B), and white (W).

The timing controller 140 may directly transmit the grayscale data converted by the grayscale data converter 141 to the data driver 120 . In this case, the data driver 120 converts the received digital-type grayscale data into an analog-type voltage and compensates for a characteristic value deviation of the driving transistor and outputs it. At this time, even if the characteristic value deviation of the driving transistor is compensated, the luminance deviation for each location may remain in the organic light emitting display panel 110. In the present embodiments, grayscale compensation data is applied to the converted grayscale data to improve the luminance deviation. characterized in that

The gray level compensation data storage unit 142 stores gray level compensation data for compensating for a luminance deviation for each position of the organic light emitting display panel 110 . The grayscale compensation data is calculated by measuring the luminance through a camera to measure the luminance uniformity of the organic light emitting display panel 110 , and calculating the grayscale adjustment amount for compensating for the luminance deviation for each position of the organic light emitting display panel 110 .

The grayscale compensation data exists for each position of the organic light emitting display panel 110 and exists for each grayscale. In addition, as a value set for each color, separate gradation compensation data for each color may be stored, and gradation compensation data for white (W) and gradation compensation data for other colors (R, G, B) may be calculated. It may be stored in the form of coefficients for

In this case, grayscale compensation data for low grayscales (eg, 4 grayscales and 8 grayscales) that are difficult to measure with a camera may not be stored, and this may be derived and applied by the grayscale data compensation unit 143 to be described later.

When the grayscale data compensator 143 receives the converted grayscale data from the grayscale data conversion unit 141 , the grayscale data compensator 143 compensates the converted grayscale data using the grayscale compensation data stored in the grayscale compensation data storage unit 142 and compensates the grayscale data. This grayscale data is transferred to the data driver 120 .

The grayscale data compensator 143 compensates for the grayscale data by applying grayscale compensation data set according to the position (pixel) at which the grayscale data is displayed on the organic light emitting display panel 110 , the grayscale of the grayscale data, and the color.

That is, the luminance of the organic light emitting display panel 110 is different depending on the position and different according to the gray level, and grayscale compensation data is applied to compensate for different points depending on the color even at the same location and the same gray level.

The grayscale data compensator 143 may compensate for the grayscale data by using the grayscale compensation data for each location, each grayscale, and each color stored in the grayscale compensation data storage unit 142 . Alternatively, a coefficient for calculating the grayscale compensation data for white (W) and grayscale compensation data for different colors (R, G, and B) may be stored, and the grayscale data may be compensated using the stored coefficients.

In this case, the grayscale compensation data for red (R), green (G), and blue (B) may be set to be smaller than the grayscale compensation data for white (W). This is because white (W) is more affected by a kickback phenomenon than other colors (R, G, B) among factors affecting the luminance deviation for each position of the organic light emitting display panel 110 . That is, in the present embodiments, luminance uniformity can be improved by setting the grayscale compensation data for a color most affected by a kickback phenomenon due to the lowest data voltage in the same grayscale.

The grayscale data compensator 143 may calculate and compensate grayscale compensation data even for low grayscales (eg, 4th grayscale and 8th grayscale) for which grayscale compensation data is not stored because luminance measurement cannot be performed through the camera.

For example, the luminance distribution in grayscales lower than 16 grayscales is calculated by using the luminance distribution data in the 16 grayscales or more of the center of the organic light emitting display panel 110 . Then, the luminance distribution at the grayscale lower than the 16th grayscale is calculated by using the luminance distribution data at the 16th grayscale or higher at the position where the grayscale compensation is desired. The luminance deviation between the center of the organic light emitting display panel 110 and the position at which the gradation is to be compensated is calculated using the luminance distribution at gradations lower than 16 gradations, and the gradation adjustment amount, that is, the gradation compensation data, is calculated based on this. do.

Alternatively, grayscale compensation data at a grayscale lower than 16 grayscales may be estimated from the slope of the graph with respect to the grayscale compensation data in the 16th grayscale or higher.

Accordingly, according to the present exemplary embodiments, grayscale compensation data can be calculated even when grayscale data for which luminance cannot be measured through the camera is calculated, so that the luminance deviation for each position of the organic light emitting display panel 110 in all grayscales is displayed. to be able to compensate for

16 is a flowchart illustrating a process of a method of driving the timing controller 140 according to the present exemplary embodiments.

The timing controller 140 according to the present embodiments receives image data from the outside (S1600).

When the timing controller 140 receives image data from the outside, it converts the received image data into grayscale data ( S1620 ). That is, it is converted into grayscale data for red (R), green (G), blue (B), and white (W) for expressing the received image data.

When the timing controller 140 converts the image data into grayscale data, the timing controller 140 selects grayscale compensation data for the converted grayscale data ( S1640 ).

The grayscale compensation data is a grayscale adjustment amount for compensating for a luminance deviation for each location in the organic light emitting display panel 110 and corresponds to a value set for each grayscale, each location, and each color. In addition, in the grayscale compensation data for each color, the grayscale compensation data for white (W) may have a larger value than the grayscale compensation data for other colors (R, G, and B).

The timing controller 140 compensates the grayscale data by using the grayscale data, the grayscale compensation data set according to the position in the organic light emitting display panel 110, and the color (S1660). Then, the grayscale data that has been compensated for the grayscale is transmitted to the data driver 120 to be output.

At this time, the grayscale compensation data for the low grayscale (eg, 4 grayscale, 8 grayscale), which is difficult to measure luminance through the camera, can be estimated from the grayscale compensation data for the high grayscale (eg, 16 grayscale or more) to compensate the grayscale data. have.

Accordingly, according to the present exemplary embodiments, when the timing controller 140 outputs grayscale data converted from image data, grayscale compensation is applied to the grayscale data and transferred to the data driver 120 , thereby causing a deviation in the characteristic value of the driving transistor. It is possible to remove the luminance deviation in the organic light emitting display panel 110 that remains even after compensation.

In addition, by setting the grayscale compensation data for each location and each grayscale as well as for each color and compensating for the grayscale data, it is possible to improve the overall luminance uniformity by performing grayscale compensation in consideration of the luminance deviation according to the characteristics of each color.

Also, with respect to a low gray level for which it is difficult to measure luminance through a camera, gray level compensation can be performed for all gray levels by estimating the gray level compensation data using the gray level compensation data for the high gray level.

The above description is merely illustrative of the technical idea of the present invention, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains. The embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but rather to explain, so the scope of the technical spirit of the present invention is not limited by these embodiments.

100: organic light emitting display device 110: organic light emitting display panel
120: data driver 130: gate driver
140: timing controller 141: grayscale data conversion unit
142: gray level compensation data storage unit 143: gray level data compensation unit

Claims (15)

an organic light emitting display panel comprising: an organic light emitting display panel in which a plurality of gate lines and a plurality of data lines cross each other, and a plurality of pixels disposed in a region where the gate line and the data line cross;
a gate driver driving the plurality of gate lines;
a data driver supplying a data voltage to the plurality of data lines; and
a timing controller that controls driving of the gate driver and the data driver and converts image data received from the outside into grayscale data,
The timing controller is
Compensating the grayscale data by using grayscale compensation data for each position calculated by measuring the luminance of the organic light emitting display panel, wherein the grayscale compensation data is grayscale compensation data set for each color;
Among the grayscale compensation data set for each color, white grayscale compensation data is greater than grayscale compensation data for other colors, and the grayscale compensation data has the largest grayscale compensation data for a color having the lowest data voltage in the same grayscale.
delete delete According to claim 1,
The timing controller is
The organic light emitting display device stores the grayscale compensation data set for each color, and compensates the grayscale data by using the stored grayscale compensation data.
5. The method of claim 4,
The timing controller is
When the grayscale compensation data for the grayscale data is not stored, the grayscale compensation data for the grayscale data is calculated using the linear slope of two grayscale compensation data among the stored grayscale compensation data, and the organic light emitting device compensates the grayscale data display device.
According to claim 1,
The timing controller is
The organic light emitting display device stores a coefficient for calculating the white grayscale compensation data and the grayscale compensation data for each other color, and compensates the grayscale data using the stored white grayscale compensation data and the coefficient.
7. The method of claim 6,
The timing controller is
The white gradation compensation data is multiplied by the coefficient to calculate the gradation compensation data for each color, wherein the coefficient is greater than 0 and less than 0.85.
According to claim 1,
The grayscale compensation data for compensating the grayscale data is set for each grayscale.
a grayscale data conversion unit that converts image data received from the outside into grayscale data;
a gradation compensation data storage unit configured to store gradation compensation data for each position calculated by measuring the luminance of the display panel on which the image data is displayed for each color; and
and a grayscale data compensator for compensating for the converted grayscale data using the grayscale compensation data stored in the grayscale compensation data storage unit;
In the gradation compensation data stored in the gradation compensation data storage unit, white gradation compensation data is larger than gradation compensation data for each other color, and the gradation compensation data stored in the gradation compensation data storage unit corresponds to a color having the lowest data voltage at the same gradation. Timing controller with the largest gradation compensation data.
delete delete 10. The method of claim 9,
The grayscale compensation data storage unit stores the coefficients for calculating the white grayscale compensation data and the grayscale compensation data for different colors;
The grayscale data compensator is configured to compensate the grayscale data by using the white grayscale compensation data and the coefficient.
converting the image data received from the outside into grayscale data;
selecting grayscale compensation data for the grayscale data from among the grayscale compensation data calculated and stored by measuring the luminance of a display panel displaying the image data; and
Compensating for the grayscale data using the selected grayscale compensation data, and compensating for the grayscale data using grayscale compensation data stored for each color;
Compensating the grayscale data includes:
Compensating for the grayscale data using white grayscale compensation data for the grayscale data and grayscale compensation data for each color set to be smaller than the white grayscale compensation data,
The gradation compensation data is a driving method of a timing controller having the largest gradation compensation data for a color having the lowest data voltage in the same gradation.
delete 14. The method of claim 13,
Compensating the grayscale data includes:
checking a coefficient for calculating the white grayscale compensation data for the grayscale data and the grayscale compensation data for each other color, and calculating grayscale compensation data for the grayscale data using the white grayscale compensation data and the coefficient A method of driving a timing controller comprising a.

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