KR102119091B1 - Display device and driving method thereof - Google Patents

Abstract

The present invention performs a data compensation control and backlight control together for mura compensation, thereby performing a suitable compensation control for mura of various shapes according to various causes of occurrence, and a display device and a driving method for preventing image quality degradation caused by mura It is about.

Description

Display device and its driving method {DISPLAY DEVICE AND DRIVING METHOD THEREOF}

The present invention relates to a display device and a method for driving the same.

With the development of the information society, the demand for display devices for displaying images is increasing in various forms, and in recent years, liquid crystal displays (LCDs), plasma display panels (PDPs), and organic light-emitting. Various display devices such as an organic light emitting display device (OLED) are used.

In the display devices, various display defects (mura) may be found in the testing process. Mura refers to display unevenness accompanied by a luminance difference on the display screen, and Mura caused by panel defects and Mura caused by backlight are typical.

Display stains due to panel defects are generated in the manufacturing process of liquid crystal panels, and depending on the cause, they may have a regular shape such as dots, lines, bands, circles, polygons, or irregular shapes.

Mura by the backlight is caused by the structure of the backlight unit, and is generated as light from the light source disposed under the display panel leaks out toward the display area of the display panel.

1 is a diagram showing an example of a shape of a mura appearing in a general display device, and is an exemplary view showing a shape of a mura by a backlight.

As shown in Fig. 1 (a), each of the upper and lower ends of the screen appears horizontally in a band shape, or as shown in Fig. 1 (b), respectively, in the left end and right end in a vertical band shape. Alternatively, as shown in FIG. 1(c), the periphery of the upper portion, the lower portion, the center portion, and the edge portion of the display area may be formed in a circle or polygonal shape.

The image displayed at the location of the mura-generating region is darker or brighter than the surrounding non-mura region, and the color difference is different than the non-mura region.

Accordingly, display defects caused by Mura may lead to product defects depending on the degree, and product defects decrease yield, which is associated with an increase in cost. In addition, if a product in which such Mura is found is shipped as a good product in the testing stage, the reliability of the product is deteriorated as the image quality deteriorates due to Mura.

Against this background, an object of the present invention is to provide a display device and a driving method thereof to prevent image degradation caused by Mura by performing appropriate compensation control for Mura of various shapes according to various causes of occurrence in one aspect. will be.

In another aspect, an object of the present invention is to provide a display device and a driving method for performing compensation control on mura that occurs as light from a backlight leaks into a display area at low gradations.

In order to achieve the above object, in one aspect, the present invention, the data line and the gate line are crossed, a plurality of pixels are defined display panel; A scan driver supplying a scan signal to the gate lines; A data driver supplying a data voltage to the data lines; And a timing controller that performs data compensation control and backlight control on image data for Mura compensation when Mura pixels in which Mura occurs based on Mura distribution data.

In another aspect, the present invention provides a data compensation control step of performing data compensation control on image data for Mura compensation when Mura pixels in which Mura occurs based on Mura distribution data; And a backlight control performing step of performing backlight control on the image data according to the performance of the data compensation control.

As described above, according to the present invention, by performing appropriate compensation control irrespective of gradation for mura of various shapes according to various causes of occurrence, it is possible to prevent deterioration of image quality caused by mura, increase product yield, and improve product There is an effect that can improve the quality of the image output through.

In addition, according to the present invention, more accurate compensation control can be performed by performing data compensation control and backlight control together for Mura compensation, and there is an effect of reducing power consumption of the product.

1 is an exemplary view showing an example of a shape of a mura appearing in a general display device, and is a diagram showing a shape of a mura by a backlight.
2 is a system configuration diagram of a display device to which an embodiment is applied.
3 is a diagram illustrating a step-by-step graph of Mura compensation control in the display device according to the embodiment.
4 and 5 are specific embodiments in which Mura compensation control is performed in the display device according to the embodiment.
6 is an exemplary diagram illustrating an example of Mura distribution data in the display device according to the embodiment.
7 is a graph illustrating a shape of a convex function for each gradation in the display device according to the embodiment.
8 is a graph showing backlight control in a display device according to an exemplary embodiment.
9 is a diagram illustrating a duty ratio of a driving signal applied to a backlight unit according to mura compensation control in the display device according to the embodiment.
10 is a flowchart illustrating a method of driving a display device according to an embodiment.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. It should be noted that in adding reference numerals to the components of each drawing, the same components have the same reference numerals as possible even though they are displayed on different drawings. In addition, in describing embodiments of the present invention, when it is determined that detailed descriptions of related well-known configurations or functions may obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

In addition, in describing the components of the invention, terms such as first, second, A, B, (a), and (b) can be used. These terms are only for distinguishing the component from other components, and the nature, order, or order of the component is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected to or connected to the other component, but another component between each component It should be understood that elements may be "connected", "coupled" or "connected". In the same vein, when it is stated that a component is formed "above" or "below" another component, that component is all formed directly or indirectly through another component in the other component. It should be understood as including.

2 is a system configuration diagram of a display device to which an embodiment is applied.

Referring to FIG. 2, the display device 100 may include a timing controller 110, a data driver 120, a gate driver 130, and a display panel 140.

Also, the backlight unit 150 and the backlight driver 160 may be included.

The timing controller 110 controls the data driver 120 based on external timing signals such as vertical/horizontal synchronization signals (Vsync, Hsync), image data (RGB), and clock signal (CLK) input from the host system. The data control signal DCS for the control and the gate control signal GCS for controlling the gate driver 130 are output. In addition, the timing controller 110 converts the image data RGB input from the host system 150 into a data signal format used by the data driver 120, and the converted image data R'G'B'. Can be supplied to the data driver 120. For example, the timing controller 110 may convert the converted image data R'G'B' to fit the resolution or pixel structure of the display panel 140 and supply the converted image data R'G'B' to the data driver 120.

The data driver 120 receives the converted video signal R'G'B' in response to the data control signal DCS input from the timing controller 110 and the converted video signal R'G'B'. It is converted to a data voltage (data signal or analog pixel signal) that is a voltage value corresponding to a gradation value and supplied to a data line.

The gate driver 130 sequentially supplies a scan signal (gate pulse or scan pulse, gate on signal) to the gate line in response to the gate control signal GCS input from the timing controller 110.

The display panel 140 defines a plurality of pixels at the intersection of the plurality of gate lines G1 to Gn and the plurality of data lines D1 to Dm. Each pixel is connected to at least one organic electroluminescent device including an anode as a first electrode, a cathode as a second electrode, and a light emitting layer, or by switching a liquid crystal between two substrates using a transistor. It may also include a liquid crystal cell to emit light. In other words, the display panel 140 may be an organic light emitting display panel or a liquid crystal display panel, but the present invention is not limited thereto, and any display panel may be used.

The backlight unit (BLU, 150) provides light to the display panel.

The backlight unit 150 includes a plurality of light sources, and the light source may be any one or more of a Hot Cathode Fluorescent Lamp (HCFL), Cold Cathode Fluorescent Lamp (CCFL), External Electrode Fluorescent Lamp (EEFL), and Light Emitting Diode (LED). Can be configured. The backlight unit 150 may include an optical member including a light guide plate, a diffusion plate, a prism sheet, a lens sheet, and a protective sheet for efficient light emission and provision.

The light source may be disposed in the non-display area of the display panel to emit light through the light guide plate to the entire surface of the display panel, or may be disposed on the rear surface of the display panel to directly emit light to the entire display area.

The backlight driver 160 controls the backlight driving signal applied to the light source according to the control signal from the timing controller 110. The backlight driving signal may be applied to each light source in the form of PWM. The backlight driving unit 160 controls the duty ratio of the PWM signals dim1 to dimk under the control of the timing controller 110 to control the amount of light emitted from the light source. Can be adjusted.

The timing controller 110 according to the embodiment may perform data compensation control and backlight control on image data for Mura compensation when Mura pixels in which Mura occurs based on Mura distribution data, The duty ratio of the backlight driving signal output from the backlight driving unit is changed according to the backlight control by the timing controller 110.

In addition, the timing controller may determine and apply the data compensation amount according to the luminance of the mura pixel in each gradation based on the data compensation amount for mura compensation when the gradation value in all pixels is 0 and the gain set for each gradation. .

The backlight driving signal may include a global dimming signal and/or a local dimming signal. The global dimming method may improve a dynamic contrast ratio measured between the previous frame and the next frame, and The local dimming method can improve the static contrast ratio, which is difficult to improve with global dimming, by locally controlling the luminance of the image data signal within one frame period.

The timing controller 110 of the display device 100 according to an embodiment may perform data compensation control and backlight control on image data of pixels based on the Mura distribution data.

3 is a diagram illustrating a step-by-step graph of Mura compensation control in a display device according to an embodiment, and is a diagram showing an example in which Mura displayed brighter than the surroundings on both left and right or up and down is taken as an example.

The timing controller 110 according to the embodiment calculates a convex function for mura compensation control based on the mura distribution data as shown in FIG. 3( a ).

The timing controller 110, based on the calculated convex function, calculates compensation values for the pixels, and compensates the data by applying the calculated compensation values to the image data for each pixel, as shown in FIG. 3(b). Perform control.

The timing controller 110 may calculate a compensation value for each pixel so that luminance in all pixels is uniform within a certain range based on the calculated convex function.

At this time, the convex function and the compensation values for each pixel may be stored in memory (not shown) in advance. A more detailed description of the convex function will be described later with reference to FIG. 7.

As illustrated in FIG. 3C, when the luminance between pixels is uniform through the data compensation control, the timing controller 110 performs backlight control so that the uniformly increased luminance is lowered by the backlight reference luminance. In this case, the backlight reference luminance refers to luminance intended to be output through the display panel 140 and represents luminance of pixels in which mura has not occurred before performing data compensation control.

In an embodiment, the timing controller 110 may set the average luminance of the pixels in which no mura occurs based on the Mura distribution data as the backlight reference luminance, and the luminance changes according to the gradation, so the backlight reference luminance is also set to a different value according to the gradation. Can be.

Referring to FIG. 3 again, the Mura compensation control according to the embodiment, the timing controller 110 according to the embodiment is the image data of the pixels of the display panel 140 when Mura having a luminance higher than the surrounding occurs ( +) Compensation is performed so that the luminance of all the pixels is as high as the luminance of the Mura pixels, and the luminance of all the pixels is controlled to be uniform so that Mura is not recognized.

In addition, the timing controller 110 adjusts the backlight gain to a low level through backlight control so that the luminance of pixels uniformed with a high luminance is lowered to the backlight reference luminance so that the desired luminance can be displayed.

The mura compensation control of the timing controller according to the above-described embodiment will be described in more detail with a specific example.

4 and 5 are specific embodiments in which Mura compensation control is performed in the display device according to the embodiment.

For convenience of description, as shown in FIG. 4, the amount of light per unit area (l) applied to one pixel (p), the image data value (d) and the luminance (b) applied to the pixel are each pixel For each example, the luminance (b) of each pixel will be described by assuming that it is calculated by summing the amount of light (l) per unit area of the pixel and the image data value (d).

In the case of 4X4 size pixels as shown in FIG. 4, the Mura distribution data is matched, and four pixels located at (0,0), (0,1), (0,2) and (0,3) The four pixels located at, (3,0), (3,1), (3,2), and (3,3) are identified as Mura pixels that have been determined to cause Mura, and the remaining pixels have Mura. It may be identified as a non-Mura pixel determined not to be.

When the amount of light emitted from the light source is 1 for these 4×4 pixels, and the image data of 1 is applied, the luminance of 8 pixels identified as non-mura pixels may be 2.

However, the four pixels located at (0,0), (0,1), (0,2) and (0,3) identified as Mura pixels, and (3,0), (3,1), For the four pixels located in (3, 2) and (3, 3), the control signal was output so that the amount of light was 1 in the backlight driver 160, but the light is leaking due to the backlight structure and the like to be recognized by the naked eye. The amount of light per unit area in the corresponding pixel may be 1.5 greater than 1, and accordingly, it may appear to have a luminance of 2.5.

If the Mura compensation control is described for the pixels located at (0,0), (1,0), (2,0), (3,0) among these 4X4 pixels, (0,0) and (3, Since the luminance of the Mura pixels located at 0) is 2.5, the timing controller 110 compensates (+) the image data so that the luminance of the pixels located at (1,0) and (2,0) other than the Mura pixels is 2.5. Can be.

That is, although the image data of the (1,0) pixel was 1, 0.5 can be further compensated to be 1.5 to make the luminance 2.5, and the (2,0) pixel is also compensated by the same 0.5 more image data Can be 1.5.

However, the luminance (target luminance) intended to be output from the pixels of (0,0), (1,0), (2,0), and (3,0) is 2, so the target is based on the compensated image data and the amount of light. The amount of light is lowered by adjusting the backlight gain so that luminance 2 can be output.

That is, as shown in FIG. 5, in the case of (0,0) pixels, the image data has a value of 1, so the luminance per unit area must be 1 in order to have luminance of 2. However, since the amount of light per unit area of (0,0) pixels is 1.5 as shown in FIG. 4, the timing controller 110 applies a backlight gain of 2/3 to control the backlight driving signal to be output (0, 0) Let the amount of light per unit area in a pixel be 1.

In addition, in the case of (1,0) pixels, since the compensation value of 0.5 is added to the image data and has a value of 1.5, the luminance per unit area should be 0.5 in order to achieve luminance of 2. However, as shown in FIG. 4, since the amount of light per unit area of (1,0) pixels is 1, the timing controller 110 applies a backlight gain of 1/2 to control the backlight driving signal to be output (1,0). ) The amount of light per unit area in a pixel is 0.5.

In the case of (2,0) pixels, the image data is 1.5, so the luminance per unit area should be 0.5 to achieve a luminance of 2, so the timing controller 110 applies a backlight gain of 1/2 to output the backlight driving signal. By controlling as much as possible, the amount of light per unit area in the (2,0) pixel is reduced from 1 to 0.5.

In the case of (3,0) pixels, the image data is 1, so the luminance per unit area must be 1 in order to have a luminance of 2, so the timing controller 110 applies a backlight gain of 2/3 to output the backlight driving signal. By controlling as much as possible, the light amount per unit area in the (3,0) pixel is controlled to decrease from 1.5 to 1.

Accordingly, the pixels of (0,0), (1,0), (2,0), and (3,0) all have a luminance value of 2, and (0,0), (3,0) Mura pixels located in) also have the same luminance, so that the occurrence of Mura cannot be recognized by the naked eye, and can be output as a natural image.

In particular, by reducing the backlight gain according to the degree of compensation applied to the image data of the pixels in which no mura has occurred, power consumption for lighting the light source of the backlight unit can be reduced.

6 is an exemplary diagram illustrating an example of Mura distribution data in the display device according to the embodiment.

The Mura distribution data includes Mura location information displayed on the display area of the display panel while the same light amount and the same image data are applied to all pixels.

In an embodiment, the Mura distribution data may be generated based on image data obtained by capturing a display area at 0 gray by setting the gradation of all pixels to 0 to include information about Mura displayed brighter than the surroundings.

As illustrated in FIG. 6, when the display area is imaged after making it 0gray for 8×6 pixels, areas brighter than the surroundings M1 and M2 may appear in a vertically long bar shape at the left and right ends. , These areas can be identified by Mura.

By correlating the resolution of the image data with the number of pixels of the display panel, position information on the display panel corresponding to the regions M1 and M2 identified as non-line in the image data can be derived.

Further, the luminance information measured for the display area at 0 gray can be transmitted from the means for measuring luminance such as a contact-type luminance meter, and the actual luminance in the regions M1 and M2 identified as non-line visually is measured. The luminance information measured by the actual luminance in the normal pixel region identified as having no luminance information and the occurrence of Mura may be reflected in the Mura distribution data.

Therefore, as shown in FIG. 6, the Mura distribution data may include both the size of Mura and the luminance value at that time in the form of a map representing pixels.

At this time, since the Mura distribution data is generated based on the screen displayed on the actual display panel, the display area of the display panel is divided into Mura (M1, M2) and non-Mura regions without distinguishing Mura due to backlight unit structure or Mura due to panel defects. Can be identified.

The Mura distribution data may be generated by an external compensation means and stored in the memory of the timing controller 110 or may be generated by the timing controller 110.

In addition, the luminance difference between the gray levels is clearly recognized in the low gray level, whereas the luminance difference between the gray levels in the high gray level may be less recognized than in the low gray level. Therefore, the size of the Mura recognized in each gray level or the luminance difference between the Mura and non-Mura regions is different. Can be.

Accordingly, the Mura distribution data according to the embodiment may be generated for each predetermined grayscale, such as 0gray, 8gray, or 16gray, or stored in memory.

On the other hand, as shown in Figure 6, even if it belongs to the same Mura region, the luminance measured according to its position may vary.

In the case of Mura, which is displayed brighter than the surroundings in the embodiment, as described above, image data of each pixel is compensated so that luminance in all pixels is equal to Mura's luminance in a certain range. The amount of compensation in compensation control is changed.

Therefore, the timing controller according to the embodiment may derive a convex function based on the Mura distribution data to calculate a luminance change for the pixels.

7 is a graph illustrating a shape of a convex function for each gradation in the display device according to the embodiment.

Referring to FIG. 7 and FIG. 3 described above, when a luminance change occurs according to a position in a horizontal direction, a vertical direction, or a diagonal direction by Mura, the timing controller 110 is based on the luminance in any one Mura. It is possible to derive a convex function that gradually decreases the value from the point to the other Mura in the same direction from the point to the luminance of the farthest point.

Accordingly, the luminance change in the horizontal direction of the display panel in which the vertically elongated mura is generated at the left end and the right end is shown in FIG. 3(a), as shown in FIG. 3(a). It can be derived in increasing form toward the left end and the right end based on the luminance, and the value in the convection function corresponding to the left end is the highest value among the luminances of Mura or the average value of Mura luminance or randomly selected at the left end. It can be any value.

Similarly, the value in the convection function corresponding to the right end may be the highest value of the luminance of Mura displayed at the right end, the average value of the Mura luminance, or any one of the values randomly selected.

In the convection function, since the luminance according to the location of Mura has a relatively continuous value, the amount of compensation may vary depending on where the luminance is to perform data compensation control, and data compensation is applied to all pixels except the pixels at that point. Control can be performed. That is, (+) compensation may be performed on the image data even in a region visually identified as belonging to Mura.

Such a convection function can be derived based on the mura distribution data at 0gray. As with the mura distribution data, the luminance change may be different for each gradation, so convection at a predetermined gradation by applying a convection gain based on the convection function at 0gray Each function can be derived.

At this time, the convection function according to gradation may be derived as a shape in which the difference between the maximum value and the minimum value decreases and the curvature increases as the gradation goes from low gradation to high gradation as illustrated in FIG. 7.

At this time, the convection function according to gradation may be derived as a shape in which the difference between the maximum value and the minimum value decreases and the curvature increases as the gradation goes from low gradation to high gradation as illustrated in FIG. 7.

In other words, in the embodiment, when a mura that is displayed brighter than the surroundings occurs, the luminance distribution in the display panel is implemented as a convection function, and the image data in each pixel is compensated for as data compensation control based on the implemented convection function. Make the luminance at s uniform.

These convection functions can be derived for each gradation, and more accurate data compensation can be achieved in high gradations by performing data compensation control based on convection functions derived not only in low gradations but also in high gradations.

8 is a graph showing backlight control in a display device according to an exemplary embodiment.

As shown in FIG. 8, in the case of Mura having a luminance higher than the surrounding area, comparing the backlight gain for outputting the target luminance at each gradation and the backlight gain for outputting the luminous luminance of the Mura pixel at each gradation, the sensation is reduced. Since the luminance is higher than the target luminance, the backlight gain value for outputting at the luminance equivalent to the perceived luminance of the Mura pixel at the same gradation is higher than the backlight gain value for outputting at the target luminance.

As described above, the timing controller compensates to have a luminance as high as that of the Mura pixel by performing (+) compensation for the pixels in which Mura does not occur through the data compensation control, so that the compensated image data is applied to the pixel. The backlight gain must be lowered in order for the luminance to be the luminance when the image data before compensation is applied.

9 is a diagram illustrating a duty ratio of a driving signal applied to a backlight unit according to mura compensation control in the display device according to the embodiment.

That is, as shown in FIG. 9(a), when the Mura region (A) and the non-mura region (B) can be distinguished, as shown in FIG. 9(b), the Mura region (A) The duty ratio of the backlight driving signal for adjusting the light amount may have a larger value than the duty ratio of the backlight driving signal for adjusting the light amount for the non-mura region B.

Referring to FIGS. 4 and 5 together, four pixels located at (0,0), (0,1), (0,2), and (0,3), and (3,0), ( Four pixels located in 3, 1), (3, 2), and (3, 3) may correspond to the mura region, and the remaining eight pixels may correspond to the non-mura region. When comparing the backlight gain of (0,0), (3,0) pixels belonging to the Mura region and (1,0), (2,0) pixels belonging to the non-Mura region, (0,0), The backlight gain applied to the (3,0) pixel is 2/3, while the backlight gain applied to the (1,0) and (2,0) pixels is 1/2.

When the reference duty ratio of the backlight driving signal is 1, the duty ratio of the backlight driving signal applied to the light source corresponding to the Mura region A is 1*2/3 to 2/3, and corresponds to the non-Mura region B Since the duty ratio of the backlight driving signal applied to the light source is 1/2 to 1*1/2, the light source corresponding to the Mura area A is turned on rather than the time when the light source corresponding to the non-Mura area B is turned on. The power consumption of the display device is reduced because the time is longer and the time when the light source is lit is shorter than the time when the light is driven by the backlight driving signal having the reference duty ratio.

The above-described embodiment can be applied more effectively in low gradations in which the gradation is less than or equal to the reference gradation. Conventionally, in the case where mura appearing brighter than the surroundings in the low gradation, there is a limit in applying (-) compensation to image data, resulting in light leakage In some cases, compensation control for Mura could not be performed.

However, in the embodiment, when mura due to light leakage occurs, (+) compensation is performed on image data of other pixels where mura does not occur, and backlight control is performed so that the backlight gain is lowered according to the compensation degree. Mura compensation control can be made.

On the other hand, Mura means that the luminance difference is large enough to be recognized by the naked eye with the adjacent pixels even though the same image data is applied. The level of Mura compensation at high gradation above or above the reference gradation may be less than the level of Mura compensation at low gradation.

That is, even in a small amount of light in low gradation, the luminance difference between pixels is clearly recognized, whereas in a high gradation, even if a small amount of light is added, if the luminance difference between pixels is not recognized, Mura compensation control through data compensation control and backlight control is performed. It may not, and even if it is performed, a small amount of compensation control may be performed.

In addition, in the grayscale or the high grayscale, since the luminance is increased, even if (-) compensation is applied to the image data, the grayscale can be sufficiently expressed, so that only the data compensation control can sufficiently perform mura compensation control.

In this case, the timing controller 110 performs data compensation control that applies a (-) compensation value to the image data for the Mura pixel, so that the luminance of the Mura pixel is the same as the luminance of the pixel judged as having no Mura. It can be controlled so that Mura cannot be perceived by the naked eye, and more accurate compensation can be achieved by differentially applying a compensation value to Mura pixels having different luminance based on a convex function representing a luminance distribution in a corresponding gradation.

In addition, the above has been described in detail to perform the mura compensation control for the mura displayed brighter than the surroundings, but is not limited and applied according to the type of mura. Accordingly, when a mura displayed darker than the surroundings is identified based on the mura distribution data, the timing controller 110 compensates for the image data of the mura pixels to perform data compensation control or to drive a backlight applied as a light source corresponding to the mura pixels. By controlling the duty ratio of the signal, the luminance of the Mura pixel may be the same as the luminance of the pixel judged to have no Mura within a certain range, thereby preventing Mura from being recognized.

10 is a flowchart illustrating a method of driving a display device according to an embodiment.

Referring to FIG. 10, a method of driving a display device according to an embodiment includes data for performing data compensation control on image data for Mura compensation when Mura pixels in which Mura occurs based on Mura distribution data And a backlight control performance step of performing backlight control on the image data according to the performance of the data compensation control.

Before the data compensation control performing step, the Mura distribution data generation step may be performed. In the Mura distribution data generation step, the Mura distribution data may be generated based on the image data in which the display area of the display panel is captured. (S110)

That is, image data is applied so that gradation values in all pixels of the display panel become 0 so that the mura region and the non-mura region can be clearly identified. At this time, the location information of the Mura region or the location information of the non-Mura region is acquired based on the image data obtained by capturing the display region, and Mura distribution data for the corresponding display panel is generated based on the acquired location information.

At this time, the Mura distribution data may include luminance values measured for a display area in which the gradation values of all pixels are 0. Luminance of Mura pixels and luminance of non-Mura pixels or luminance difference between Mura pixels and non-Mura pixels Including, it may be reflected in determining the amount of compensation when performing data compensation control.

In addition, the Mura distribution data can be generated for each gradation. For example, the Mura distribution data in 32 gray is applied with image data such that the gradation value in all pixels of the display panel is 32, and an image captured at this time is displayed It can be generated based on the location information of the Mura area obtained based on the data.

The data compensation control execution step and the backlight control execution step may operate differently depending on the gradation. First, in the case of low gradation, for example, 0 gray to 16 gray, in the data compensation control execution step, the Mura distribution data and the 0 gray derived based on it Based on the convex function at, the image data compensation values of the pixels are determined such that the luminance of the non-Mura pixels is uniform within a certain range with the luminance of the Mura pixels, and the determined compensation values are respectively applied to the image data of the corresponding pixels. (S130)

Next, in the backlight control step, the backlight gain is calculated according to the compensation value applied to the image data, and the control signal is generated and applied to the backlight driver to apply the calculated backlight gain (S140). Is output from the backlight driver and can be applied as a light source (S150).

However, for grayscale and high grayscale, for example, 16 gray or more, it is possible to derive a convex function in each grayscale step based on a previously derived convex function at 0 gray and a predetermined convex gain for each grayscale step. In addition, based on the Mura distribution data in each gradation step and the convex function in the corresponding gradation step, the (-) compensation value for the pixels is determined so that the luminance of the Mura pixels is uniform within a certain range with the luminance of the non-Mura pixels. The determined compensation value is applied to image data of pixels corresponding thereto.

In grayscale and high grayscale, overall luminance uniformity can be maintained by performing (-) compensation on the image data of pixels, and backlight control may not be performed because it is compensated for luminance to be expressed.

The terms "include", "compose" or "have" as described above mean that the corresponding component can be inherent unless otherwise stated, and do not exclude other components. It should be construed that it may further include other components. All terms, including technical or scientific terms, have the same meaning as generally understood by a person skilled in the art to which the present invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted as being consistent with the meaning of the context of the related art, and are not to be interpreted as ideal or excessively formal meanings unless explicitly defined in the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the claims below, and all technical spirits within the equivalent range should be interpreted as being included in the scope of the present invention.

110: timing controller 150: backlight unit
160: backlight driver

Claims (10)

A display panel in which a plurality of pixels are defined by crossing data lines and gate lines;
A scan driver supplying a scan signal to the gate lines;
A data driver supplying a data voltage to the data lines; And
When there is a Mura pixel in which Mura has occurred based on Mura distribution data captured at a low gradation below the reference gradation, image data of the non-Mura pixel determined to have not occurred is compensated with the Mura pixel image data. Data compensation control, and backlight control to control the luminance of the Mura pixel and the non-Mura pixel to be equal to a target luminance and within a certain range by adjusting the backlight gain to compensate the amount of light per unit area of the Mura pixel for which the image data is compensated Timing controller
Display device comprising a. According to claim 1,
The target luminance is
A display device determined by the sum of the image data and the amount of light per unit area. According to claim 1,
The timing controller,
The larger the compensation value according to the data compensation control, the display device characterized in that to perform the backlight control so that the amount of light of the backlight is reduced. delete According to claim 1,
The timing controller,
When the gradation of the image data is equal to or greater than the reference gradation, the luminance of the mura pixel is based on the mura distribution data so that the luminance of the mura pixel is the same as the luminance of the pixel determined to have not occurred, within a certain range. Display device characterized in that for performing data compensation control. According to claim 1,
And the mura distribution data includes location information on a mura-generating region when grayscale values in all pixels of the display panel are zero. delete According to claim 1,
The target luminance is
A display device corresponding to the luminance of a non-mura pixel before performing the data compensation control and the backlight control. When there is a Mura pixel in which Mura has occurred based on Mura distribution data obtained at a low gradation below the reference gradation, the image data of the non-Mura pixel determined to have not occurred is compensated with the Mura pixel image data. Performing data compensation control; And
A backlight control step of controlling the luminance of the Mura pixel and the non-Mura pixel to be equal to a target luminance and within a predetermined range by adjusting the backlight gain to compensate the amount of light per unit area of the Mura pixel for which the image data is compensated.
Method of driving a display device comprising a. delete

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