KR102581850B1 - Method and apparatus for generating compensation data of display panel - Google Patents

Abstract

The present invention relates to a method and device for generating compensation data for a display panel. In the present invention, the XYZ deviation value, which is the difference between the XYZ measurement values measured at each of the plurality of measurement points and the target Additionally, in the present invention, the converted linear RGB deviation value is converted into a panel RGB deviation value, and the panel RGB deviation value converted in this way becomes the final compensation data.

Description

Method and apparatus for generating compensation data of display panel {METHOD AND APPARATUS FOR GENERATING COMPENSATION DATA OF DISPLAY PANEL}

The present invention relates to a method and device for generating compensation data for a display panel.

Flat panel displays to replace existing cathode ray tube display devices include liquid crystal display, field emission display, and plasma display panel. ) and Organic Light-Emitting Diode Display (OLED Display).

Among these display devices, organic light-emitting diodes (OLEDs), which are light-emitting elements used in organic light-emitting displays, have high brightness and low operating voltage characteristics. In addition, since organic light emitting diodes are devices that emit light on their own, they have high contrast ratio and are easy to implement ultra-thin displays. In addition, organic light-emitting diodes have the advantage of being easy to implement moving images with a response time of several microseconds (㎲), having no viewing angle limitations, and being stable even at low temperatures.

In an organic light emitting display device, pixels including organic light emitting diodes are arranged in a matrix form. A data voltage corresponding to externally input image data is applied to each pixel. Accordingly, when a driving current flows through the organic light emitting diode, the organic light emitting diode emits light with a certain brightness.

The ideal state of an organic light emitting display device is a state in which the luminance of all pixels constituting the display panel is uniform. However, luminance uniformity between pixels decreases due to variations in electrical characteristics of driving transistors between pixels, variations in cell driving voltages between pixels, and variations in deterioration of organic light emitting diodes between pixels. In particular, variations in the deterioration of organic light emitting diodes cause afterimage phenomenon and deteriorate the image quality of organic light emitting display devices.

In order to improve this problem of display quality deterioration, compensation data to compensate for the above-mentioned luminance deviation is stored in the display device, and when images are output through the display panel, the stored compensation data is applied to make the luminance between each pixel uniform. It can be maintained.

However, the conventional compensation data generation method has a problem in that it does not reflect the characteristics of the panel itself in the process of generating compensation data. For example, according to the conventional compensation data generation method, conversion between XYZ data and RGB data is performed using a conversion matrix in the process of compensating the luminance or chromaticity of the panel. However, the conversion matrix used conventionally is not created to reflect the panel's unique characteristics, but rather represents the relationship between XYZ data and RGB data defined by a specific standard or organization, such as CIE (Commission Internationale de l'clairage). The transformation matrix is used as is.

If the conventionally defined conversion matrix is used as is, the unique characteristics of the panel are not properly reflected in the compensation data generation process, so there is a problem that accurate compensation cannot be performed with compensation data generated through this process.

Additionally, according to the prior art, luminance compensation and chromaticity compensation of the panel are each performed in separate processes. If luminance compensation and chromaticity compensation are performed in separate processes, there is a problem that it takes too much time to generate compensation data.

Additionally, in the compensation data generation method according to the prior art, compensation data is generated based on measurement values for specific points on the panel, so there is a problem in that it is difficult to accurately compensate for all points on the panel using such compensation data.

The purpose of the present invention is to provide a method and device for generating compensation data for a display panel that enables more accurate compensation by generating compensation data by reflecting the unique characteristics of the panel.

Another object of the present invention is to provide a method and device for generating compensation data for a display panel that can reduce the time required to generate compensation data by simultaneously reflecting the luminance and chromaticity characteristics of the panel to generate compensation data.

Another object of the present invention is to provide a method and device for generating compensation data for a display panel that enable more accurate compensation for the panel by generating compensation data for a plurality of measurement points.

The objects of the present invention are not limited to the objects mentioned above, and other objects and advantages of the present invention that are not mentioned can be understood by the following description and will be more clearly understood by the examples of the present invention. Additionally, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof indicated in the patent claims.

In the present invention, the XYZ deviation value, which is the difference between the XYZ measurement values measured at each of the plurality of measurement points and the target Additionally, in the present invention, the converted linear RGB deviation value is converted into a panel RGB deviation value, and the panel RGB deviation value converted in this way becomes the final compensation data.

That is, in the present invention, the XYZ deviation value is not directly converted to a panel RGB deviation value, but is converted to a linear RGB deviation value using a color space conversion matrix, and the linear RGB value is converted to a panel RGB value. The color space conversion matrix used in this process is created based on the actual RGB values of the panel and the XYZ measurement values actually measured on the panel. For example, in the present invention, in order to reflect the relationship between the panel's A color space conversion matrix is created to convert to a linear RGB value. Therefore, according to the present invention, the panel's unique characteristics can be reflected in compensation data.

Additionally, in the present invention, target XYZ values are generated using the luminance deviation value and chromaticity deviation value in the process of generating compensation data. That is, in the present invention, since the luminance and chromaticity characteristics of the panel are simultaneously reflected in the process of generating compensation data, compensation data can be generated more quickly than in the prior art in which luminance compensation and chromaticity compensation are performed separately.

Additionally, in the present invention, a plurality of measurement points are set on the panel, and compensation data for each measurement point is calculated based on XYZ measurement values measured at each of the plurality of measurement points. Therefore, as the number of measurement points increases, compensation accuracy based on compensation data also increases.

A method of generating compensation data for a display panel according to an embodiment of the present invention includes obtaining XYZ measurement values for each of a plurality of measurement points set on a panel on which a plurality of pattern images with different gray scale values are displayed, Calculating a color space transformation matrix for all pixels of the panel using XYZ measurement values for each of the plurality of measurement points, obtaining XYZ measurement values for all pixels, XYZ measurement for all pixels calculating luminance values and chromaticity values for all pixels using values, calculating luminance deviation values and chromaticity deviation values for all pixels using the luminance values and chromaticity values for all pixels, and and calculating compensation data for all pixels using a color space conversion matrix, the luminance deviation value, and the chromaticity deviation value.

In addition, a compensation data generating device for a display panel according to an embodiment of the present invention obtains A measurement value acquisition unit, a color space transformation matrix calculation unit for calculating a color space transformation matrix for all pixels of the panel using the XYZ measurement values for each of the plurality of measurement points, and a color space transformation matrix calculation unit obtained by the A luminance/chromaticity value calculation unit that calculates luminance and chromaticity values for all pixels using the A luminance/chromaticity deviation value calculation unit that calculates a luminance deviation value and a chromaticity deviation value, and a compensation data calculation unit that calculates compensation data for all pixels using the color space conversion matrix, the luminance deviation value, and the chromaticity deviation value. Includes.

According to the present invention, there is an advantage in that more accurate compensation can be performed by generating compensation data by reflecting the unique characteristics of the panel.

Additionally, the present invention has the advantage of reducing the time required to generate compensation data by simultaneously reflecting the luminance and chromaticity characteristics of the panel to generate compensation data.

Additionally, the present invention has the advantage of enabling more accurate compensation for the panel by generating compensation data for a plurality of measurement points.

1 is a configuration diagram of a compensation data generating device according to an embodiment of the present invention.
Figure 2 shows a plurality of pattern images with different grayscale values displayed on a panel in an embodiment of the present invention.
Figure 3 shows a gamma curve calculated by the color space conversion matrix calculation unit in one embodiment of the present invention.
FIG. 4 is a diagram illustrating a process of converting panel RGB values into linear RGB values by a color space conversion matrix calculation unit in one embodiment of the present invention.
Figure 5 is a graph showing a non-linear gamma curve for an arbitrary pixel generated according to an embodiment of the present invention and a linear gamma curve corresponding to the non-linear gamma curve.
Figure 6 is a diagram for explaining a compensation process using compensation data generated by an embodiment of the present invention.
Figure 7 is a table for comparing the compensation results according to the prior art and the compensation results according to the present invention.
Figure 8 is a flowchart of a compensation data generation method according to an embodiment of the present invention.

The above-mentioned objects, features, and advantages will be described in detail later with reference to the attached drawings, so that those skilled in the art will be able to easily implement the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of known technologies related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. In the drawings, identical reference numerals are used to indicate identical or similar components.

1 is a configuration diagram of a compensation data generating device according to an embodiment of the present invention.

Referring to FIG. 1, the compensation data generating device 102 according to an embodiment of the present invention includes an ), a luminance/chromaticity deviation value calculation unit 110, and a compensation data calculation unit 112.

The XYZ measurement value acquisition unit 104 acquires XYZ measurement values for each of a plurality of measurement points set on a panel where a plurality of pattern images with different gray scale values are displayed. In one embodiment of the present invention, the XYZ measurement value acquisition unit 104 may acquire XYZ measurement values for each of a plurality of measurement points from a device such as a surface measuring instrument or a camera.

Additionally, the XYZ measurement value acquisition unit 104 may acquire XYZ measurement values for all pixels of the panel rather than a plurality of measurement points.

The color space transformation matrix calculation unit 106 calculates a color space transformation matrix for all pixels of the panel using the XYZ measurement values for each of the plurality of measurement points. In one embodiment of the present invention, the color space conversion matrix calculation unit 106 generates a gamma curve for each of the plurality of measurement points using the XYZ measurement values for each of the plurality of measurement points, and uses the generated gamma curve. Thus, the panel RGB value of each of the plurality of measurement points can be converted into a linear RGB value.

Additionally, the color space transformation matrix calculation unit 106 may calculate a color space transformation matrix for each of the plurality of measurement points using the converted linear RGB values and the XYZ measurement values for each of the plurality of measurement points. Additionally, the color space transformation matrix calculation unit 106 may calculate a color space transformation matrix for all pixels of the panel using the color space transformation matrix for each of the plurality of measurement points.

The luminance value/chromaticity value calculation unit 108 calculates the luminance value and chromaticity value for all pixels using the XYZ measurement values for all pixels obtained by the XYZ measurement value acquisition unit 104. In one embodiment of the present invention, the luminance/chromaticity value calculation unit 108 may calculate the Y value among the XYZ measured values as the luminance value. Additionally, in one embodiment of the present invention, the luminance value/chromaticity value calculation unit 108 may calculate the chromaticity value using the X value, Y value, and Z value among the XYZ measured values.

The luminance/chromaticity deviation value calculation unit 110 calculates the luminance deviation value and chromaticity deviation value for all pixels using the luminance value and chromaticity value for all pixels calculated by the luminance value/chromaticity value calculating unit 108. do. In one embodiment of the present invention, the luminance/chromaticity deviation value calculation unit 110 may calculate the difference between a predetermined reference luminance value and the luminance value as a luminance deviation value. Additionally, in one embodiment of the present invention, the luminance/chromaticity deviation value calculation unit 110 may calculate the difference between a predetermined reference chromaticity value and the chromaticity value as a chromaticity deviation value.

The compensation data calculation unit 112 calculates compensation data for all pixels using the previously calculated color space transformation matrix, luminance deviation value, and chromaticity deviation value. In one embodiment of the present invention, the compensation data calculation unit 112 calculates a target The difference between measured values is calculated as the XYZ deviation value for all pixels. In addition, the compensation data calculation unit 112 converts the XYZ deviation value for all pixels into a linear RGB deviation value for all pixels using the previously calculated color space conversion matrix for all pixels, and Convert the value to the panel RGB deviation value for all pixels. The panel RGB deviation value for all pixels converted in this way becomes compensation data for all pixels.

Hereinafter, the compensation data generation process by the compensation data generation device 102 according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 6.

First, the XYZ measurement value acquisition unit 104 acquires the

In the present invention, a plurality of pattern images with different gray scale values and RGB values can be displayed on the panel to obtain XYZ measurement values. Figure 2 shows a plurality of pattern images with different grayscale values displayed on a panel in an embodiment of the present invention. In the present invention, as shown in FIG. 2, N pattern images (I ₁ to I _N ) can each be displayed on the panel. The N pattern images (I ₁ to I _N ) each have different grayscale values (O ₁ to O _N ) and different panel RGB values (RGB ₁ to RGB _N ). For example, the pattern image (I ₂ ) may have a grayscale value (O ₂ ) and a panel RGB value (RGB ₂ ). Here, the panel RGB value includes the R value, G value, and B value of the pattern image.

Additionally, in the present invention, a plurality of measurement points (P ₁ to P ₉ ) are set on the panel as shown in FIG. 2. In the present invention, after displaying N pattern images (I ₁ to I _N ) as described above on a panel, XYZ measurement values can be measured respectively on a plurality of measurement points (P ₁ to P ₉ ). For example, if a total of 9 measurement points are set as shown in Figure 2 and 5 pattern images are used, the XYZ measurement values will be measured 45 times. Here, the XYZ measurement values include the X value, Y value, and Z value of the measurement point.

The number of pattern images and the number of measurement points described above may vary depending on the embodiment.

In one embodiment of the present invention, XYZ measurements may be measured by a surface measuring instrument or a camera. For example, XYZ measurement values can be obtained using surface measuring instruments on a plurality of measurement points (P ₁ to P ₉ ) set on the panel. As another example, after photographing the front of a panel on which a pattern image is displayed with a camera, XYZ measurement values at positions corresponding to a plurality of measurement points (P ₁ to P ₉ ) can be calculated through image analysis.

Next, the color space transformation matrix calculation unit 106 calculates a color space transformation matrix for all pixels of the panel using the XYZ measurement values for each of the plurality of measurement points (P ₁ to P ₉ ).

To explain more specifically, the color space conversion matrix calculation unit 106 first generates a gamma curve for each of the plurality of measurement points (P ₁ to P 9 ) using the XYZ measurement values for each of the plurality of measurement points (P 1 to P ₉ ). Figure 3 shows a gamma curve calculated by the color space conversion matrix calculation unit 106 in one embodiment of the present invention. In the present invention, as in the embodiment of FIG. 2, N pattern images (I ₁ to I _N ) with different grayscale values (O ₁ to O _N ) are displayed on the panel and a plurality of measurement points (P ₁ to P ₉ ) are displayed on the panel. ) Measure the XYZ measurement values for each. The gamma curve of FIG. 3 may be generated based on the Y value among the XYZ measurement values, that is, the luminance value of each of the plurality of measurement points (P ₁ to P ₉ ).

When measurement is performed at a total of 9 measurement points (P ₁ to P ₉ ) as in the embodiment of FIG. 2, ₉ gamma curves (S 1 to S 1 ) corresponding to each of the measurement points (P ₁ to P ₉ ) as shown in FIG. 3 S ₉ ) is created. In FIG. 3 , one gamma curve, for example, the gamma curve S ₁ , may be generated through regression analysis based on N Y values (same as the number of pattern images). Accordingly, the color space conversion matrix calculation unit 106 can generate the same number of gamma curves as the number of measurement points.

The gamma curve generated in this way can be used in the conversion process of panel RGB values to linear RGB values, which will be described later, or in the correction of linear RGB deviation values to panel RGB deviation values.

Next, the color space conversion matrix calculation unit 106 converts the panel RGB values (RGB ₁ to RGB _N ) of each of the plurality of measurement points (P ₁ to P ₉ ) into linear RGB using the gamma curve generated as shown in FIG. 3. Convert to value.

FIG. 4 is a diagram illustrating a process of converting panel RGB values into linear RGB values by a color space conversion matrix calculation unit in one embodiment of the present invention. In FIG. 4, when the measurement point is P _i and the pattern image is I _j , the gamma curve of the ith measurement point previously created is expressed as S _i . As shown in FIG. 4, the color space conversion matrix calculation unit 106 can obtain a linear RGB value (DeRGB _j,i ) by substituting the panel RGB value (RGB _j ) of the jth image into the gamma curve (S _i ). there is. In this way, the color space conversion matrix calculation unit 106 converts the panel RGB value (RGB _j ) into a linear RGB value (DeRGB _j,i ) using the previously generated gamma curve.

Next, the color space conversion matrix calculation unit 106 uses the converted linear RGB value (DeRGB _j,i ) and the XYZ measurement value (X _j,i ) for each of the plurality of measurement points to each of the plurality of measurement points. Calculate the color space transformation matrix (M _T(i) ) for. The following relationship is established between linear RGB values (DeRGB _j,i ) and XYZ measurement values (X _j,i ).

In [Equation 1], DeR _j,i , DeG _j,i , and DeB _j,i each represent linear RGB values, and X _j,i , Y _j,i , and Z _j,i represent XYZ measurement values, respectively. And M _T(i) represents the color space transformation matrix for the ith measurement point, that is, P _i . Additionally, N refers to the number of the last pattern image among multiple pattern images used to calculate the color space conversion matrix.

The color space transformation matrix calculation unit 106 calculates the color space transformation matrix (M _T(i) ) for all measurement points (P _i ) through [Equation 1]. For example, when a total of 9 measurement points (P ₁ to P ₉ ) are set as shown in FIG. 2, the color space transformation matrix calculation unit 106 calculates 9 color space transformation matrices (M _{T (1)} to M _{T (9)} ) is calculated.

The color space transformation matrix (M _T(i) ) for each measurement point (P _i ) calculated previously is a color space transformation matrix for 9 pixels among all pixels of the panel. However, in order to obtain more accurate compensation data, it is necessary to obtain a color space conversion matrix for all pixels, not just some pixels of the panel. Therefore, the color space transformation matrix calculation unit 106 calculates a color space transformation matrix for all pixels of the panel using the color space transformation matrix (M _T(i) ) for each measurement point (P _i ) calculated previously. do.

In one embodiment of the present invention, the color space transformation matrix calculation unit 106 uses a two-dimensional interpolation algorithm to calculate the color space transformation matrix (M) for each measurement point (P _i ), that is, some point of the panel. Based on _{T (i)} ), the color space transformation matrix for all points on the panel, that is, all pixels, can be calculated. When the coordinates of an arbitrary pixel of the panel are (a, b), the color space transformation matrix (M _{T (a, b)} ) for the pixel of (a, b) is as follows.

In [Equation 2], C means a constant calculated for each coordinate (a, b) by two-dimensional interpolation.

Ultimately, the color space transformation matrix calculation unit 106 calculates all color space transformation matrices (M _{T (a, b)) for all pixels of the panel, that is, arbitrary coordinates (a, b} ), according to the process described above. . In this way, in the present invention, a color space transformation matrix (M _{T (a, b)} ) is determined for each pixel, and compensation data for each pixel is determined by this color space transformation matrix (M _{T (a, b)} ). Because it is calculated, it becomes possible to perform more accurate compensation than before.

Next, the luminance value/chromaticity value calculation unit 108 calculates the luminance value and chromaticity value for all pixels using the XYZ measurement values for all pixels obtained by the XYZ measurement value acquisition unit 104.

In one embodiment of the present invention, XYZ measurement values for all pixels may be measured by a surface measuring instrument or a camera. For example, XYZ measurement values can be obtained at each pixel location on the panel using a surface measuring device. As another example, the front of a panel on which a pattern image is displayed can be photographed with a camera, and then the XYZ measurement values of the positions corresponding to each pixel can be calculated through image analysis. The XYZ measurement values for each pixel calculated in this way include the X value, Y value, and Z value.

The luminance value/chromaticity value calculation unit 108 may calculate the Y value among the XYZ measurement values for all pixels obtained by the XYZ measurement value acquisition unit 104 as the luminance value of each pixel. In addition, the luminance value/chromaticity value calculation unit 108 can calculate chromaticity values (x and y) using the X value, Y value, and Z value for all pixels obtained by the there is. In one embodiment of the present invention, the luminance/chromaticity value calculation unit 108 can calculate chromaticity values (x and y) for an arbitrary pixel located at coordinates (a, b) as follows.

In this way, in the present invention, the luminance value and chromaticity value for each pixel can be easily calculated using only XYZ measurement values.

Next, the luminance/chromaticity deviation value calculation unit 110 uses the luminance value and chromaticity value for all pixels calculated by the luminance value/chromaticity value calculating unit 108 to determine the luminance deviation value and chromaticity deviation for all pixels. Calculate the value.

The luminance/chromaticity deviation value calculation unit 110 can calculate the luminance deviation value (ΔY) as follows.

In [Equation 4], j represents the number of the pattern image (I ₁ ~I _N ), that is, 1~N. Also, (a, b) are coordinates indicating the pixel location on the panel. In addition, Y[j] _{(a, b)} represents the luminance value when the pixel located at coordinates (a, b) has a grayscale value (O _j ) by the j-th pattern image. Additionally, Y[j] _spce is a reference luminance value predicted to appear when the panel outputs a pattern image with grayscale values (O _j ) and RGB values (RGB _j ). This reference luminance value is a reference value that is preset for each gray level value when manufacturing a panel.

Therefore, in [Equation 4], ΔY[j] _{(a, b)} means the luminance deviation value when the pixel located at the coordinates (a, b) has a grayscale value (O _j ).

Additionally, the luminance/chromaticity deviation value calculation unit 110 can calculate the chromaticity deviation values (Δx and Δy) as follows.

In [Equation 5], j represents the number of the pattern image (I ₁ ~I _N ), that is, 1~N. Also, (a, b) are coordinates indicating the pixel location on the panel. In addition, x[j] _{(a, b)} and y[j] _{(a, b)} are the chromaticity when the pixel located at the coordinates (a, b) has the grayscale value (O _j ) by the jth pattern image, respectively. Indicates the value. Additionally, x[j] _spce and y[j] _spce are reference chromaticity values predicted to be displayed when the panel outputs a pattern image with grayscale values (O _j ) and RGB values (RGB _j ), respectively. This reference chromaticity value is a reference value that is preset for each grayscale value when manufacturing a panel.

Therefore, in [Equation 4], Δx[j] _{(a, b)} and Δy[j] _{(a, b)} are the chromaticity when the pixel located at the coordinates (a, b) has the grayscale value (O _j ), respectively. It means deviation value.

Next, the compensation data calculation unit 112 calculates compensation data for all pixels using the previously calculated color space transformation matrix, luminance deviation value, and chromaticity deviation value for all pixels. The specific process by which the compensation data calculation unit 112 calculates compensation data is described as follows.

,

,

)을 산출한다.
The compensation data calculation unit 112 first calculates a random pixel located at coordinates (a, b) using the luminance deviation value and chromaticity deviation value for each pixel previously calculated by the luminance/chromaticity deviation value calculation unit 110. Target XYZ values for (

,

,

) is calculated.

For reference, when T=X+Y+Z, the relationships x=X/T, y=Y/T, and z=Z/T are established. Also, the relationship x+y+z=1 is established. [Equation 6] can be derived from this relational expression. Also, in [Equation 6], G _lum represents luminance gain and G _col represents chromaticity gain, respectively. The luminance gain and chromaticity gain can be set in advance as correction values to correct errors that may occur during the panel manufacturing process or the luminance measurement process. If there are no errors occurring during the panel manufacturing process or the luminance measurement process, the luminance gain and chromaticity gain can each be set to 1.

Meanwhile, in the prior art, compensation data for luminance and compensation data for chromaticity are generated in separate processes. However, in the present invention, the luminance deviation and chromaticity deviation are simultaneously reflected when generating compensation data as shown in [Equation 6]. Therefore, the compensation data generation time according to the present invention appears shorter than that of the prior art.

,

,

)은 각각 다음과 같이 나타낼 수 있다.
The compensation data calculation unit 112 calculates the difference between the target XYZ value for all pixels calculated as above and the XYZ measured value for all pixels as the XYZ deviation value for all pixels. XYZ deviation value (

,

,

) can each be expressed as follows.

,

,

)으로의 변환은 아래와 같은 수학식에 의해 수행될 수 있다.
The compensation data calculation unit 112 converts the XYZ deviation value for all pixels into a linear RGB deviation value for all pixels using the previously calculated color space conversion matrix for all pixels. Linear RGB deviation value of XYZ deviation value (

,

,

) can be performed by the equation below.

,

,

)을 전체 픽셀에 대한 패널 RGB 편차값(

,

,

)으로 변환한다. [수학식 9]에 따라 생성되는 전체 픽셀에 대한 패널 RGB 편차값이 각 픽셀에 대한 보상 데이터가 된다.
Finally, the compensation data calculation unit 112 calculates the linear RGB deviation value for all pixels (

,

,

) to the panel RGB deviation value for all pixels (

,

,

) is converted to The panel RGB deviation value for all pixels generated according to [Equation 9] becomes compensation data for each pixel.

In [Equation 9], RGB _j represents the panel RGB value at the grayscale value (O _j ), and GMA represents the gamma value of the gamma curve of the pixel located at the coordinates (a, b). For reference, the gamma curve of the pixel located at the coordinates (a, b) may be generated based on the XYZ value of each pixel previously acquired by the XYZ measurement value acquisition unit 104. Additionally, DeRGB _j represents a linear RGB value corresponding to the panel RGB value (RGB _j ) when the grayscale value (O _j ) is present. The method of calculating DeRGB _j is explained in more detail as follows.

Figure 5 is a graph showing a non-linear gamma curve for an arbitrary pixel generated according to an embodiment of the present invention and a linear gamma curve corresponding to the non-linear gamma curve.

The non-linear gamma curve 402 shown in FIG. 5 is a curve representing the distribution of panel RGB values of pixels located at coordinates (a, b). Additionally, the linear gamma curve 404 is a curve representing the distribution of linear RGB values generated by converting the panel RGB values of pixels located at coordinates (a, b), as described above.

According to the non-linear gamma curve 402 of FIG. 5, when the panel RGB value (RGB _j ) is substituted into the linear gamma curve 404, the linear RGB value (DeRGB _j ) of [Equation 9] can be obtained.

Meanwhile, as shown in FIG. 5, in the present invention, the linear RGB deviation value (ΔDeRGB) is converted into a panel RGB deviation value (ΔRGB), and the converted panel RGB deviation value (ΔRGB) becomes compensation data. By applying this compensation data (ΔRGB) to the panel RGB value (RGB _j ), the final compensated panel RGB value (RGB _target ) can be obtained.

Ultimately, in the present invention, instead of generating compensation data using only the linear RGB deviation value (ΔDeRGB) as in the prior art, compensation data is generated by converting the linear RGB deviation value (ΔDeRGB) into the panel RGB deviation value (ΔRGB). Therefore, compared to before, the characteristics of the panel can be more accurately reflected in the compensation data.

,

,

)을 전체 픽셀에 대한 패널 RGB 편차값(

,

,

)으로 변환함으로써 보상 데이터가 생성된다. 종래 기술에 따르면 선형 RGB값을 기초로만 보상 데이터를 생성하기 때문에 정확한 보상 데이터 생성이 어렵다는 문제가 있다. 그러나 본 발명에 따르면 패널의 실제 특성이 반영된 패널 RGB값을 기초로 보상 데이터가 생성되기 때문에 보다 정확한 보상 데이터 생성이 가능하다는 장점이 있다.As previously explained through [Equation 9], in the present invention, the linear RGB deviation value (

,

,

) to the panel RGB deviation value for all pixels (

,

,

), compensation data is generated by converting to According to the prior art, there is a problem in that it is difficult to generate accurate compensation data because compensation data is generated only based on linear RGB values. However, according to the present invention, compensation data is generated based on panel RGB values that reflect the actual characteristics of the panel, so there is an advantage in that more accurate compensation data can be generated.

Additionally, as described above, the present invention has the advantage of being able to perform more accurate compensation because compensation data is generated for each pixel.

Figure 6 is a diagram for explaining a compensation process using compensation data generated according to an embodiment of the present invention.

A total of three curves are shown in Figure 6. In FIG. 6 , the curve S _spec is a reference gamma curve of a pixel having preset reference luminance and chromaticity. Additionally, the curve (S _{(50, 50)} ) represents the gamma curve of the pixel located at coordinates (50, 50), and the curve (S _{(100, 100)} ) represents the gamma curve of the pixel located at coordinates (100, 100). represents.

When the pixel-specific compensation data of the present invention generated as described above is applied to each pixel, the gamma curve of each pixel converges to the reference gamma curve, as shown in FIG. 6. For example, if a pixel located at coordinates (50, 50) and having a grayscale value (O ₂ ) is compensated with compensation data (ΔRGB[2] _{(50, 50)} ) generated as described above, the coordinates (50, 50) The panel RGB value of the pixel located in is changed to the panel RGB value above the standard gamma curve (S _spec ). Similarly, if a pixel located at coordinates (100, 100) and having a grayscale value (O ₂ ) is compensated with compensation data (ΔRGB[2] _{(100, 100)} ) generated as described above, it is located at coordinates (100, 100). The panel RGB value of the located pixel is changed to the panel RGB value above the standard gamma curve (S _spec ).

Meanwhile, as described above, in the present invention, compensation data is generated using N pattern images (I ₁ to I _N ) having different grayscale values (O ₁ to O _N ). Therefore, as the number of pattern images increases, more accurate compensation data can be generated. Depending on the embodiment, when a gamma curve as shown in FIG. 6 is generated based on N gray level values (O ₁ to O _N ), compensation data corresponding to gray level values existing between each gray level value are generated for each gray level. It can be generated by 2D interpolation of compensation data corresponding to the values (O ₁ to O _N ).

Figure 7 is a table for comparing the compensation results according to the prior art and the compensation results according to the present invention.

The table in FIG. 7 shows the gamma deviation (ΔY value, gamma value) and chromaticity deviation (Δx, Δy) measured for an arbitrary panel, respectively. The smaller the gamma deviation and chromaticity deviation values, the more accurate compensation can be interpreted.

Referring to FIG. 7, more accurate compensation is achieved when compensation is performed with compensation data generated by the compensation data generation method according to the present invention than when compensation is performed with compensation data generated by the compensation data generation method according to the prior art. You can confirm that this has been accomplished.

Also, as shown in FIG. 7, the time to generate compensation data by the compensation data generation method according to the present invention appears shorter than the time to generate compensation data by the compensation data generation method according to the prior art. This is because, as described above, in the prior art, compensation data for luminance and compensation data for chromaticity are generated in separate processes, whereas in the present invention, when generating compensation data, the luminance deviation and chromaticity deviation are reflected simultaneously.

Figure 8 is a flowchart of a compensation data generation method according to an embodiment of the present invention.

Referring to FIG. 8, the compensation data generating device according to an embodiment of the present invention first obtains XYZ measurement values for each of a plurality of measurement points set on a panel on which a plurality of pattern images with different gray scale values are displayed. Do it (702). Then, the compensation data generating device calculates a color space transformation matrix for all pixels of the panel using the XYZ measurement values for each of the plurality of measurement points (704).

In one embodiment of the present invention, calculating a color space transformation matrix (704) includes generating a gamma curve for each of a plurality of measurement points using XYZ measurement values for each of a plurality of measurement points, and generating a gamma curve. Converting the panel RGB value of each of the plurality of measurement points into a linear RGB value using the linear RGB value and the XYZ measurement value of each of the plurality of measurement points to calculate a color space conversion matrix for each of the plurality of measurement points It may include calculating a color space transformation matrix for all pixels using a color space transformation matrix for each of a plurality of measurement points.

Referring again to FIG. 8, the compensation data generating device acquires XYZ measurement values for all pixels (706). Then, the compensation data generating device calculates the luminance value and chromaticity value for all pixels using the XYZ measurement values for all pixels (708).

In one embodiment of the present invention, calculating the luminance value and chromaticity value (708) includes calculating a Y value among the XYZ measured values for all pixels as a luminance value, an X value among the XYZ measured values for all pixels, It may include calculating the chromaticity value using the Y value and the Z value.

Referring again to FIG. 8, the compensation data generating device calculates the luminance deviation value and chromaticity deviation value for all pixels using the luminance value and chromaticity value for all pixels (710). Then, the compensation data generating device calculates compensation data for all pixels using the color space conversion matrix, luminance deviation value, and chromaticity deviation value (712).

In one embodiment of the present invention, the step of calculating compensation data (712) includes calculating target XYZ values for all pixels using the luminance deviation value and chromaticity deviation value, Calculating the difference value between the XYZ measurement values for the XYZ deviation value for all pixels, converting the The step may include converting the linear RGB deviation value for all pixels into a panel RGB deviation value for all pixels.

The above-described present invention may be subject to various substitutions, modifications, and changes without departing from the technical spirit of the present invention to those skilled in the art to which the present invention pertains. It is not limited by .

Claims (10)

Obtaining XYZ measurement values for each of a plurality of measurement points set on a panel on which a plurality of pattern images with different gray scale values are displayed;
calculating a color space transformation matrix for all pixels of the panel using XYZ measurement values for each of the plurality of measurement points;
Obtaining XYZ measurement values for all pixels;
calculating luminance and chromaticity values for all pixels using XYZ measurement values for all pixels;
calculating a luminance deviation value and a chromaticity deviation value for all pixels using the luminance value and chromaticity value for all pixels; and
Comprising: calculating compensation data for all pixels using the color space conversion matrix, the luminance deviation value, and the chromaticity deviation value,
In the step of calculating the luminance deviation value and the chromaticity deviation value for all pixels, the difference between a predetermined reference luminance value and the luminance value is calculated as the luminance deviation value, and the difference between the predetermined reference chromaticity value and the chromaticity value is calculated as the luminance deviation value. Calculated by chromaticity deviation value
How to generate compensation data for the display panel.
According to paragraph 1,
The step of calculating the color space transformation matrix for all pixels is
generating a gamma curve for each of the plurality of measurement points using XYZ measurement values for each of the plurality of measurement points;
converting panel RGB values of each of the plurality of measurement points into linear RGB values using the gamma curve;
calculating a color space transformation matrix for each of the plurality of measurement points using the linear RGB values and XYZ measurement values for each of the plurality of measurement points; and
Comprising the step of calculating a color space transformation matrix for all pixels using a color space transformation matrix for each of the plurality of measurement points.
How to generate compensation data for the display panel.
According to paragraph 1,
The step of calculating the luminance value and chromaticity value for all pixels is
calculating a Y value among the XYZ measurement values for all pixels as the luminance value;
Comprising the step of calculating the chromaticity value using the X value, Y value, and Z value among the XYZ measurement values for all pixels.
How to generate compensation data for the display panel.
delete According to paragraph 1,
The step of calculating compensation data for all pixels is
calculating target XYZ values for all pixels using the luminance deviation value and the chromaticity deviation value;
calculating a difference value between the target XYZ value for all pixels and the XYZ measured value for all pixels as an XYZ deviation value for all pixels;
converting the XYZ deviation value for all pixels into a linear RGB deviation value for all pixels using the color space conversion matrix for all pixels; and
Converting the linear RGB deviation value for all pixels into a panel RGB deviation value for all pixels.
How to generate compensation data for the display panel.
an XYZ measurement value acquisition unit that acquires XYZ measurement values for each of a plurality of measurement points set on a panel on which a plurality of pattern images with different gray scale values are displayed;
a color space transformation matrix calculation unit that calculates a color space transformation matrix for all pixels of the panel using XYZ measurement values for each of the plurality of measurement points;
a luminance value/chromaticity value calculation unit that calculates a luminance value and a chromaticity value for all pixels using the XYZ measured values for all pixels obtained by the XYZ measured value acquisition unit;
a luminance/chromaticity deviation value calculation unit that calculates a luminance deviation value and a chromaticity deviation value for all pixels using the luminance value and chromaticity value for all pixels; and
A compensation data calculation unit that calculates compensation data for all pixels using the color space conversion matrix, the luminance deviation value, and the chromaticity deviation value,
The luminance/chromaticity deviation value calculation unit calculates the difference between a predetermined reference luminance value and the luminance value as the luminance deviation value, and calculates the difference between a predetermined reference chromaticity value and the chromaticity value as the chromaticity deviation value.
Compensation data generating device on the display panel.
According to clause 6,
The color space transformation matrix calculation unit
Generate a gamma curve for each of the plurality of measurement points using XYZ measurement values for each of the plurality of measurement points, and convert the panel RGB value of each of the plurality of measurement points into a linear RGB value using the gamma curve. Calculate a color space transformation matrix for each of the plurality of measurement points using the linear RGB values and the XYZ measurement values for each of the plurality of measurement points, and calculate a color space transformation matrix for each of the plurality of measurement points. Calculate the color space transformation matrix for all pixels using
Compensation data generating device on the display panel.
According to clause 6,
The luminance value/chromaticity value calculation unit
Calculating the Y value among the XYZ measurement values for all pixels as the luminance value, and calculating the chromaticity value using the
Compensation data generating device on the display panel.
delete According to clause 6,
The compensation data calculation unit
A target XYZ value for all pixels is calculated using the luminance deviation value and the chromaticity deviation value, and the difference between the target XYZ value for all pixels and the Calculate the XYZ deviation value, convert the Converting to panel RGB deviation values for all pixels.
Compensation data generating device on the display panel.

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