Display device compensation method

Abstract

To provide a method of compensating a display device where a defect compensation effect is maximized.SOLUTION: A method includes: displaying a first display image of a calibration pattern by using a display device that includes a plurality of display subpixels; generating a first photograph image of the calibration pattern by capturing the first display image using a camera including a plurality of sensor subpixels; generating measurement representative position data corresponding to the calibration pattern by measuring the first photograph image; generating third-order fitting representative position data by performing a two-dimensional third-order fitting for the measurement representative position data; displaying a second display image of a full white display using the display device; generating a second photograph image of the full white display by capturing the second display image using the camera; generating a first crop image by performing a size adjustment of the second photograph image based on the third-order fitting representative position data; calculating a luminance compensation value by comparing a measured luminance of the first crop image with a target luminance; and generating compensated image data by applying the luminance compensation value to image data.SELECTED DRAWING: Figure 17

Description

[Technical Field]

[0001] The present invention relates to a compensation method for a display device, and more particularly to a compensation method for a display device that maximizes the effect of defect compensation by improving positional accuracy in camera compensation. [Background technology]

[0002] With the information society, the display field is also developing rapidly. Accordingly, flat panel display devices (FPDs), which have advantages such as thinness, light weight and low power consumption, are rapidly replacing the existing cathode ray tubes (CRTs), including liquid crystal display devices (LCDs), plasma display panel devices (PDPs), organic light emitting diode display devices (OLEDs) and field emission display devices (FEDs).

[0003] Among such flat panel display devices, organic light emitting diode (OLED) display devices display images by having the LEDs of each subpixel emit light corresponding to a data voltage. However, the light emitting layer of the LED, which is made of organic material, has a problem in that brightness variations occur in the display panel due to the characteristics of the material, which can lead to defects such as unevenness.

[0004] To solve this problem, a camera compensation method has been proposed in which a display image on a completed display panel is photographed with a camera to detect brightness at different positions, and image data is modulated to compensate for the brightness variations.

[0005] In this camera compensation method, since the resolution of the multiple display sub-pixels on the display panel does not match the resolution of the multiple sensor sub-pixels on the camera, the image captured by the camera is mapped to correspond to the image displayed on the display panel.

[0006] However, due to various reasons, the accuracy of the position data can be reduced, resulting in an inaccurate positioning of defects in the captured image, especially in areas where the modulation transfer function (MTF), which indicates the accuracy of the reproduction of the image captured by the camera relative to the image displayed on the display panel, is relatively high.

[0007] As a result, defects in the display panel are not compensated for, and non-defective portions of the display panel are distorted, reducing the compensation effect and degrading the image display quality. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been proposed to solve such problems, and aims to provide a compensation method for a display device that performs two-dimensional cubic polynomial fitting on the generated position data, thereby eliminating errors in the position data, increasing continuity, reducing variation, and maximizing the defect compensation effect.

[0009] Another object of the present invention is to provide a compensation method for a display device that improves the alignment of position data and kernels by performing shifting using symmetry operations on the generated position data, thereby reducing variations between captured images and maximizing the effect of defect compensation. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, the present invention provides a compensation method for a display device, including: displaying a first display image of a calibration pattern using a display device including a plurality of display sub-pixels; capturing the first display image using a camera including a plurality of sensor sub-pixels to generate a first captured image of the calibration pattern; measuring the first captured image and generating measured representative position data corresponding to the calibration pattern; performing 2D tertiary fitting on the measured representative position data to generate tertiary fitting representative position data; displaying a second display image of an entirely white display using the display device; capturing the second display image using the camera to generate a second captured image of an entirely white display; adjusting the size of the second captured image based on the tertiary fitting representative position data to generate a first cropped image; comparing the measured luminance of the first cropped image with a target luminance to calculate a luminance compensation value; and applying the luminance compensation value to image data to generate compensated image data.

[0011] The fitting surface (x, y) of the two-dimensional cubic fitting by the x-axis and y-axis can be expressed as follows: fitting surface (x, y) = p00 + p10 × x + p01 × y + p20 × x 2 +p11×xy+p02×y 2 +p30×x 3 +p21×x 2 y+p12×xy 2 +p03×y 3

[0012] p00 is the zeroth-order fitting coefficient, p10 and p01 are the first-order fitting coefficients, p20, p11, p02 are the second-order fitting coefficients, and p30, p21, p12, p03 are the third-order fitting coefficients.

[0013] The first display image of the calibration pattern may include a plurality of blocks arranged along an x-axis and a y-axis, and each of the plurality of blocks may include one light-emitting display sub-pixel and a plurality of non-light-emitting display sub-pixels.

[0014] The compensation method for the display device may further include generating all position data by making the distance between the tertiary fitting representative position data corresponding to two adjacent light-emitting display sub-pixels among the plurality of blocks equal.

[0015] The compensation method for the display device may further include the steps of: displaying a third display image at a partial point using the display device; capturing the third display image using the camera to generate a third captured image at the partial point; and shifting the third captured image to calculate an optimal shift value.

[0016] In addition, the step of calculating the optimal shift value may include the steps of: adding a first shift value to the coordinate value of the center of the partial point in the third captured image, adjusting the size of the third captured image, and generating a second cropped image; performing a symmetry operation on the partial point in the second cropped image to calculate a first overall symmetry value; repeating the size adjustment and the symmetry operation using a plurality of shift values ​​different from the first shift value to calculate a plurality of overall symmetry values ​​different from the first overall symmetry value; and calculating a maximum value among the first overall symmetry value and the plurality of overall symmetry values ​​as the optimal shift value.

[0017] The partial points in the second crop image include first to ninth crop sub-pixels arranged in three rows and three columns, and the calculating of the first overall symmetric value may include calculating a ratio of a minimum luminance value of the first and third crop sub-pixels to a maximum luminance value of the first and third crop sub-pixels, a ratio of a minimum luminance value of the fourth and sixth crop sub-pixels to a maximum luminance value of the fourth and sixth crop sub-pixels, and a ratio of a minimum luminance value of the seventh and ninth crop sub-pixels to a maximum luminance value of the seventh and ninth crop sub-pixels. calculating average values ​​of a ratio of a minimum luminance value of the first crop subpixel and the seventh crop subpixel to a maximum luminance value of the first crop subpixel and the seventh crop subpixel, a ratio of a minimum luminance value of the second crop subpixel and the eighth crop subpixel to a maximum luminance value of the second crop subpixel and the eighth crop subpixel, and a ratio of a minimum luminance value of the third crop subpixel and the ninth crop subpixel to a maximum luminance value of the third crop subpixel and the ninth crop subpixel, as horizontally symmetrical values; and calculating an average value of the horizontally symmetrical values ​​and the vertically symmetrical values ​​as the first overall symmetrical value.

[0018] In addition, the second cropped image may include red, green, and blue cropped sub-pixels, and the green cropped sub-pixel may be subjected to the size adjustment and the symmetry operation repeatedly using the first shift value and the plurality of shift values ​​in a range of -1.0 to +1.0, and the blue cropped sub-pixel and the red cropped sub-pixel may be subjected to the size adjustment and the symmetry operation repeatedly using the first shift value and the plurality of shift values ​​in a range of -2.0 to +2.0.

[0019] Meanwhile, the present invention provides a method for displaying a first display image of a calibration pattern using a display device including a plurality of display sub-pixels, capturing the first display image using a camera including a plurality of sensor sub-pixels to generate a first captured image of the calibration pattern, measuring the first captured image and generating measurement representative position data corresponding to the calibration pattern, displaying a second display image of a partial point using the display device, capturing the second display image using the camera to generate a second captured image of the partial point, shifting the second captured image and calculating an optimal shift value, and measuring the first captured image. a compensation method for a display device, the compensation method including: adding the optimal shift value to constant representative position data to generate shifting representative position data; displaying a third display image with an all-white display using the display device; capturing the third display image with the camera to generate the third captured image with an all-white display; adjusting the size of the third captured image based on the shifting representative position data to generate a first cropped image; comparing a measured luminance of the first cropped image with a target luminance to calculate a luminance compensation value; and applying the luminance compensation value to image data to generate compensated image data. [Effects of the Invention]

[0020] The present invention has the effect of eliminating errors in the position data, increasing continuity, reducing variation, and maximizing the defect compensation effect by performing two-dimensional cubic polynomial fitting on the generated position data.

[0021] In addition, the present invention performs shifting using symmetry operations on the generated position data, thereby improving the alignment of the position data and kernel, reducing variations between captured images, and maximizing the defect compensation effect. [Brief explanation of the drawings]

[0022] [Figure 1] 10A and 10B are diagrams illustrating a compensation method for a display device according to an embodiment of the present invention; [Figure 2]1A and 1B are diagrams illustrating a captured image and a cropped image of a display device according to an embodiment of the present invention. [Figure 3] 1A and 1B are diagrams showing a displayed image and a captured image of a display device according to an embodiment of the present invention. [Figure 4A] 10A and 10B are diagrams showing ideal representative position data and measured representative position data reflecting measurement errors of a display device according to an embodiment of the present invention. [Figure 4B] 10A and 10B are diagrams showing the y-axis coordinates and y-axis intervals of ideal representative position data and measured representative position data reflecting measurement errors of a display device according to an embodiment of the present invention. [Figure 5A] 5A and 5B are diagrams showing ideal representative position data and primary fitting representative position data of a display device according to an embodiment of the present invention. [Figure 5B] 10A and 10B are diagrams showing the y-axis coordinates and y-axis intervals of ideal representative position data and primary fitting representative position data of the display device according to the embodiment of the present invention. [Figure 6A] 1 is a diagram showing an imaging system for a display device according to an embodiment of the present invention; [Figure 6B] 10A and 10B are diagrams illustrating tilt of an image captured by a display device according to an embodiment of the present invention. [Figure 6C] 10A and 10B are diagrams illustrating distortion of an image captured by a display device according to an embodiment of the present invention; [Figure 7A] 10A and 10B are diagrams illustrating ideal representative position data and actual representative position data reflecting distortion of a display device according to an embodiment of the present invention; [Figure 7B] 10 is a diagram illustrating the y-axis coordinates and y-axis intervals of ideal representative position data and actual representative position data reflecting distortion of a display device according to an embodiment of the present invention. FIG. [Figure 8A] 10A and 10B are diagrams showing measurement representative position data and third fitting representative position data of the display device according to the embodiment of the present invention. [Figure 8B] 10A and 10B are diagrams showing the y-axis coordinates and y-axis intervals of the measurement representative position data and the tertiary fitting representative position data of the display device according to the embodiment of the present invention. [Figure 9A]10A and 10B are diagrams showing distributions of x-axis intervals of measurement representative position data and tertiary fitting representative position data of the display device according to the embodiment of the present invention. [Figure 9B] FIG. 9B is a diagram showing the x-axis interval along the first line segment of FIG. 9A. [Figure 9C] 10A and 10B are diagrams showing distributions of y-axis intervals of measurement representative position data and tertiary fitting representative position data of the display device according to the embodiment of the present invention. [Figure 9D] FIG. 9D shows the y-axis spacing along the second line segment of FIG. 9C. [Figure 10] 10A and 10B are diagrams illustrating size adjustment of a captured image of a display device according to an embodiment of the present invention. [Figure 11] 10A and 10B are diagrams illustrating shifting in a display device according to an embodiment of the present invention. [Figure 12] 10A and 10B are diagrams for explaining a symmetry operation of shifting in a display device according to an embodiment of the present invention; [Figure 13A] 10A and 10B are diagrams illustrating a cropped image that has been fitted according to an embodiment of the present invention. [Figure 13B] 10A and 10B are diagrams illustrating a cropped image that has been fitted according to an embodiment of the present invention. [Figure 14] 10A and 10B are diagrams illustrating a cropped image that has been shifted according to an embodiment of the present invention; [Figure 15] FIG. 10 is a diagram showing the distribution of crop sub-pixels and optimal shift values ​​in a display device according to an embodiment of the present invention. [Figure 16A] FIG. 10 is a diagram showing the distribution of optimal shift values ​​of crop sub-pixels in a display device according to an embodiment of the present invention. [Figure 16B] FIG. 10 is a diagram showing the distribution of optimal shift values ​​of crop sub-pixels in a display device according to an embodiment of the present invention. [Figure 17] 1 is a flowchart illustrating a compensation method for a display device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, a display device and a compensation method thereof according to the present invention will be described with reference to the drawings.

[0024] FIG. 1 is a diagram illustrating a compensation method for a display device according to an embodiment of the present invention, and the display device may be an organic light emitting diode (OLED) display device.

[0025] As shown in FIG. 1, in the compensation method for a display device according to an embodiment of the present invention, a camera 170 is disposed above a display panel 120 of a display device 110, and the camera 170 captures an image displayed on the display panel 120 to generate a captured image including measured brightness at each position.

[0026] Here, the display image can correspond to the case where all the display sub-pixels of the display panel 120 emit light (full white display).

[0027] Then, the measured luminance for each position of the captured image is compared with the target luminance to calculate a luminance compensation value for each position.

[0028] For example, if the measured luminance is smaller than the target luminance, a positive (+) luminance compensation value can be calculated, and if the measured luminance is larger than the target luminance, a negative (-) luminance compensation value can be calculated.

[0029] Then, the calculated position-specific brightness compensation value is stored in the storage unit 154 of the printed circuit board 156 of the display device 110, and the driver 150 of the flexible printed circuit 152 of the display device 110 applies the position-specific brightness compensation value of the storage unit 154 to the image data to generate compensated image data, and supplies a data voltage according to the compensated image data to the display panel 120.

[0030] For example, the driver 150 may generate compensated image data by increasing the gray level of the image data according to a positive (+) position-specific brightness compensation value, and may generate compensated image data by decreasing the gray level of the image data according to a negative (-) position-specific brightness compensation value.

[0031] In this way, the camera compensation method can minimize the luminance variation in the display device 110 and improve the display quality of the image.

[0032] In such a display device, since the resolution of the plurality of display subpixels in the display panel 120 differs from the resolution of the plurality of sensor subpixels in the camera 170, a calibration pattern is captured to generate all position data including golden positions GP corresponding to the display subpixels, and then the captured image of the camera is mapped to correspond to the displayed image on the display panel based on the all position data. This will be described with reference to the drawings.

[0033] 2 is a diagram showing a captured image and a cropped image of a display device according to an embodiment of the present invention, which will be described with reference to FIG.

[0034] As shown in FIG. 2, the image SI captured by the camera 170 on the display panel 120 of the display device 110 according to the embodiment of the present invention includes a plurality of sensor sub-pixels SSP, for example, 6576 and 4384 sensor sub-pixels SSP can be arranged on the x-axis and y-axis, respectively.

[0035] Because the resolution of the display panel 120 and the resolution of the camera 170 differ, the size and number of the sensor subpixels SSP in the captured image SI may differ from the size and number of the display subpixels DSP in the display panel 120. Therefore, the golden position (e.g., center position) GP corresponding to each of the display subpixels DSP is not located at the center of each of the sensor subpixels SSP. That is, the center position of each display subpixel (DSP) does not correspond to the center position of the corresponding sensor subpixel (SSP).

[0036] Thereafter, the captured image SI is adjusted in size to fit the display panel 120, and mapping is performed to generate the cropped image CI.

[0037] The cropped image CI includes a plurality of cropped sub-pixels CSP, and for example, 2532 and 1170 cropped sub-pixels CSP can be arranged on the x-axis and y-axis, respectively.

[0038] The plurality of crop sub-pixels CSP in the crop image CI may correspond to the plurality of display sub-pixels DSP in the display panel 120. Furthermore, the golden positions GP corresponding to each of the plurality of display sub-pixels DSP are located at the centers of the respective plurality of crop sub-pixels CSP.

[0039] Therefore, the cropped image CI can be analyzed to accurately detect the location of defects in the display panel 120.

[0040] Mapping of the captured image SI is performed based on representative position data generated from the calibration pattern, which will be described with reference to the drawings.

[0041] 3 is a diagram showing a display image and a captured image of a display device according to an embodiment of the present invention, which will be described with reference to both FIGS.

[0042] As shown in FIG. 3, the display image DI of the display panel 120 representing the calibration pattern CP includes a plurality of blocks BL arranged on the x-axis and y-axis, and each block BL includes one light-emitting display sub-pixel DSPe and a plurality of non-light-emitting display sub-pixels DSPn.

[0043] For example, each block BL may include one light-emitting display sub-pixel DSPe and eleven non-light-emitting display sub-pixels DSPn, for a total of twelve display sub-pixels DSP.

[0044] The camera 170 photographs the display panel 120 to generate a photographed image SI for the calibration pattern CP, measures the photographed image SI, detects the measured light-emitting display sub-pixel mDSPe corresponding to the light-emitting display sub-pixel DSPe of each block BL as a golden position GP, ​​which is a reference point, and generates representative position data including the golden position GP, ​​which is the reference point.

[0045] Then, the distance between the measurement light emitting display sub-pixels mDSPe of two adjacent blocks BL is set to an equal interval, golden positions GP corresponding to all display sub-pixels DSP are calculated, and all position data including all golden positions GP is generated.

[0046] For example, the distance between two measurement luminescence display sub-pixels mDSPe in two adjacent blocks BL can be divided into 12 equal parts, and two golden positions GP corresponding to the two measurement luminescence display sub-pixels mDSPe and 11 golden positions GP between the two measurement luminescence display sub-pixels mDSPe can be calculated. In this way, the golden position GP, ​​which is one reference point in each block BL, is detected from the captured image SI, and the remaining 11 golden positions GP in each block BL can be calculated by spacing each block BL equally apart.

[0047] In this way, all golden positions GP are calculated from a plurality of blocks BL along the x-axis and y-axis, thereby generating all position data of the display panel 120.

[0048] The difference between the ideal representative position data and the measured representative position data can be minimized by fitting, which will be described with reference to the drawings.

[0049] Fig. 4A is a diagram showing ideal representative position data and measured representative position data reflecting measurement errors of a display device according to an embodiment of the present invention, and Fig. 4B is a diagram showing the y-axis coordinates and y-axis intervals of the ideal representative position data and measured representative position data reflecting measurement errors of a display device according to an embodiment of the present invention. Fig. 5A is a diagram showing ideal representative position data and first fitting representative position data of a display device according to an embodiment of the present invention, and Fig. 5B is a diagram showing the y-axis coordinates and y-axis intervals of the ideal representative position data and first fitting representative position data of a display device according to an embodiment of the present invention. The following description will be made with reference to Figs. 1 to 3.

[0050] As shown in FIG. 4A , when measuring a captured image SI of ideal representative position data corresponding to the ideal coordinates of the luminous display sub-pixels DSPe of the calibration pattern CP, due to measurement errors, a captured image SI of the measured representative position data is generated that includes a golden position GP whose coordinates are different from the ideal coordinates.

[0051] 4B, the light-emitting display sub-pixels DSPe of the first through sixth blocks BL sequentially arranged along the y-axis at the center of the ideal representative position data have linearly increasing y-axis coordinates (y) and constant y-axis intervals (Δy).On the other hand, the measurement light-emitting display sub-pixels mDSPe of the first through sixth blocks BL sequentially arranged along the y-axis at the center of the measured representative position data have irregularly increasing y-axis coordinates (y) and irregular y-axis intervals (Δy) that are smaller, larger, or equal to a constant value.

[0052] Here, each block BL may consist of 12 display sub-pixels DSP. Eleven display sub-pixels DSP are arranged between the light-emitting display sub-pixels DSPe of two adjacent blocks BL and between the measurement light-emitting display sub-pixels mDSPe of the first through sixth blocks BL. The positions of the eleven display sub-pixels DSP can be calculated by dividing the distance between the light-emitting display sub-pixels DSPe and the distance between the measurement light-emitting display sub-pixels mDSPe by 12.

[0053] As a result, in the ideal representative position data, the light-emitting display sub-pixels DSPe of each block BL are arranged at equal intervals, and the non-light-emitting display sub-pixels DSPn of the first through sixth blocks BL and their corresponding golden positions GP are also arranged at equal intervals. On the other hand, in the measured representative position data, the non-light-emitting display sub-pixels DSPn of each block BL and their corresponding golden positions GP are arranged at equal intervals, but the measured light-emitting display sub-pixels mDSPe of the first through sixth blocks BL are arranged irregularly, and the non-light-emitting display sub-pixels DSPn of another block BL and their corresponding golden positions GP are arranged at different intervals.

[0054] As a result, when mapping is performed based on the measured representative position data and the measured total position data calculated therefrom, the positions of the display sub-pixels DSP of the display panel 120 may be inaccurate, and the defect compensation effect may be reduced.

[0055] As shown in FIG. 5A , when a primary fitting is performed after measuring a captured image SI of ideal representative position data corresponding to the ideal coordinates of the luminous display sub-pixels DSPe of the calibration pattern CP, the measurement error is compensated for, and a captured image SI of primary fitting representative position data including a golden position GP with coordinates substantially identical to the ideal coordinates is generated.

[0056] As shown in FIG. 5B, the light-emitting display sub-pixels DSPe of the first to sixth blocks BL, which are sequentially arranged along the y-axis at the center of the ideal representative position data, have linearly increasing y-axis coordinates (y) and constant y-axis intervals (Δy), and the light-emitting display sub-pixels DSPe of the first to sixth blocks BL, which are sequentially arranged along the y-axis at the center of the primary fitting representative position data, also have linearly increasing y-axis coordinates (y) and constant y-axis intervals (Δy).

[0057] Here, each block BL may consist of 12 display sub-pixels DSP, and 11 display sub-pixels DSP are arranged between the light-emitting display sub-pixels DSPe of two adjacent blocks BL, and the positions of the 11 display sub-pixels DSP can be calculated by dividing the distance between the light-emitting display sub-pixels DSPe by 12.

[0058] Furthermore, linear fitting can be a method of correcting coordinate values ​​so that the x-axis coordinate and y-axis coordinate of the measurement light-emitting display subpixel mDSPe of the measurement representative position data each become the most similar linear graph (straight line).

[0059] As a result, in the ideal representative position data, the light-emitting display sub-pixels DSPe of each block BL are arranged at equal intervals, and the non-light-emitting display sub-pixels DSPn of the first to sixth blocks BL and their corresponding golden positions GP are also arranged at equal intervals.Furthermore, in the primary fitting representative position data, the light-emitting display sub-pixels DSPe of each block BL are arranged at equal intervals, and the non-light-emitting display sub-pixels DSPn of the first to sixth blocks BL and their corresponding golden positions GP are also arranged at equal intervals.

[0060] As a result, when mapping is performed based on the primary fitting representative position data and the primary fitting total position data calculated therefrom, the variations in the positions of the display subpixel DSPs in the display panel 120 can be compensated for, and the defect compensation effect can be improved.

[0061] However, the ideal position data may differ from the actual position data due to tilt and distortion caused by the imaging system. This will be explained with reference to the drawings.

[0062] 6A is a diagram showing a photographing system of a display device according to an embodiment of the present invention, FIG. 6B is a diagram showing tilt of an image photographed by the display device according to an embodiment of the present invention, and FIG. 6C is a diagram showing distortion of an image photographed by the display device according to an embodiment of the present invention. The following description will be given with reference to FIGS. 1 to 5.

[0063] As shown in Figures 6A and 6B, the imaging system captures an image of the display panel 120 of the display device 110 according to an embodiment of the present invention and generates a captured image SI, but the image is captured in a state in which the display panel 120 of the display device 110 and the sensor panel SP of the camera 170 are not arranged parallel to each other, and a tilted captured image SI is generated.

[0064] For example, a captured image SI may be generated that has a width that increases from top to bottom along the y-axis.

[0065] As shown in FIGS. 6A and 6C, the imaging system includes an optical system that processes light from the display panel 120 and transmits it to the camera 170, and a distorted captured image SI is generated by a plurality of lenses LS of the optical system.

[0066] For example, in a captured image SI without distortion, the width and height of the center along the x-axis and y-axis may be the same as the width and height of the edge, whereas in a captured image SI with barrel distortion, the width and height of the center along the x-axis and y-axis may be greater than the width and height of the edge, and in a captured image SI with pincushion distortion, the width and height of the center along the x-axis and y-axis may be smaller than the width and height of the edge.

[0067] The difference between the ideal representative position data and the actual representative position data can be minimized by fitting, which will be described with reference to the drawings.

[0068] Fig. 7A is a diagram showing ideal representative position data and actual representative position data reflecting distortion of a display device according to an embodiment of the present invention, and Fig. 7B is a diagram showing the y-axis coordinates and y-axis intervals of the ideal representative position data and actual representative position data reflecting distortion of a display device according to an embodiment of the present invention. Fig. 8A is a diagram showing measured representative position data and third fitting representative position data of a display device according to an embodiment of the present invention, and Fig. 8B is a diagram showing the y-axis coordinates and y-axis intervals of the measured representative position data and third fitting representative position data of a display device according to an embodiment of the present invention. The following description will be made with reference to Figs. 1 to 6C.

[0069] As shown in FIG. 7A , when capturing a display image DI of a calibration pattern CP, instead of capturing an image SI of ideal representative position data corresponding to the ideal coordinates of the luminous display sub-pixels DSPe of the calibration pattern CP, a captured image SI of actual representative position data including a golden position GP with actual coordinates different from the ideal coordinates is generated due to distortion.

[0070] 7B, the light-emitting display sub-pixels DSPe of the first through sixth blocks BL sequentially arranged along the y-axis at the center of the ideal representative position data have linearly increasing y-axis coordinates (y) and constant y-axis intervals (Δy).On the other hand, the measurement light-emitting display sub-pixels mDSPe of the first through sixth blocks BL sequentially arranged along the y-axis at the center of the actual representative position data have y-axis coordinates (y) that decrease in slope and then increase again, and y-axis intervals (Δy) that become smaller than a certain value and then increase again.

[0071] Here, each block BL may consist of 12 display sub-pixels DSP. Eleven display sub-pixels DSP are arranged between the light-emitting display sub-pixels DSPe of two adjacent blocks BL and between the measurement light-emitting display sub-pixels mDSPe of the first through sixth blocks BL. The positions of the eleven display sub-pixels DSP can be calculated by dividing the distance between the light-emitting display sub-pixels DSPe and the distance between the measurement light-emitting display sub-pixels mDSPe by 12.

[0072] As a result, in ideal representative position data, the light-emitting display sub-pixels DSPe of each block BL are arranged at equal intervals, and the non-light-emitting display sub-pixels DSPn of the first to sixth blocks BL and their corresponding golden positions GP are arranged at equal intervals. On the other hand, in actual representative position data, the non-light-emitting display sub-pixels DSPn of each block BL and their corresponding golden positions GP are arranged at equal intervals, but the light-emitting display sub-pixels DSPe of the first to sixth blocks BL are arranged at different intervals, and the non-light-emitting display sub-pixels DSPn of another block BL and their corresponding golden positions GP are arranged at different intervals.

[0073] As shown in FIG. 8A, a display image DI of the calibration pattern CP is photographed, a photographed image SI of actual representative position data is generated, the photographed image SI of the actual representative position data is measured, and the photographed image SI of the measured representative position data reflecting measurement errors and distortion is generated. Then, when a third fitting is performed on the photographed image SI of the measured representative position data, the measurement errors are compensated for, and a photographed image SI of the third fitting representative position data including a golden position GP with coordinates substantially identical to the actual coordinates is generated.

[0074] 8B, the measurement light-emitting display sub-pixels mDSPe of the first through sixth blocks BL sequentially arranged along the y-axis at the center of the measurement representative position data have y-axis coordinates (y) whose slope decreases and then increases again, unlike the ideal representative position data, due to measurement errors, and y-axis intervals (Δy) that decrease below a certain value and then increase again, unlike the ideal representative position data. Meanwhile, the light-emitting display sub-pixels DSPe of the first through sixth blocks BL sequentially arranged along the y-axis at the center of the third fitting representative position data have y-axis coordinates (y) whose slope decreases and then increases again, substantially similar to the ideal representative position data, and y-axis intervals (Δy) that decrease below a certain value and then increase again, substantially similar to the ideal representative position data.

[0075] Here, each block BL may consist of 12 display sub-pixels DSP, and 11 display sub-pixels DSP are arranged between the light-emitting display sub-pixels DSPe of two adjacent blocks BL, and the positions of the 11 display sub-pixels DSP can be calculated by dividing the distance between the light-emitting display sub-pixels DSPe by 12.

[0076] Also, cubic fitting can be a method of correcting coordinate values ​​so that the x-axis coordinate and y-axis coordinate of the measurement light-emitting display subpixel mDSPe of the measurement representative position data are each the most similar cubic graph (curve).

[0077] For example, a cubic fitting surface (fitting surface(x, y)) for two dimensions of the x and y axes can be expressed as follows:

[0078] fitting surface(x, y)=p00+p10×x+p01×y+p20×x 2 +p11×xy+p02×y 2 +p30×x 3 +p21×x 2 y+p12×xy 2 +p03×y 3

[0079] p00 is the zeroth-order fitting coefficient, p10 and p01 are the first-order fitting coefficients, p20, p11, p02 are the second-order fitting coefficients, and p30, p21, p12, p03 are the third-order fitting coefficients.

[0080] Therefore, in the measured representative position data, the light-emitting display sub-pixels DSPe of the first through sixth blocks BL and their corresponding golden positions GP may be positioned differently from the actual representative position data reflecting distortion. Meanwhile, in the third-fitted representative position data, the measurement error is compensated for, and the light-emitting display sub-pixels DSPe of the first through sixth blocks BL and their corresponding golden positions GP are positioned substantially the same as the actual representative position data reflecting distortion.

[0081] As a result, when mapping is performed based on the two-dimensional three-dimensional fitting representative position data according to the x-axis and y-axis and the two-dimensional three-dimensional fitting total position data calculated therefrom, the variations in the positions of the display subpixel DSPs on the display panel 120 can be compensated for, and the defect compensation effect can be improved.

[0082] The results of such two-dimensional cubic fitting will be explained with reference to the drawings.

[0083] Fig. 9A is a diagram showing the distribution of x-axis intervals of measurement representative position data and third fitting representative position data of a display device according to an embodiment of the present invention, Fig. 9B is a diagram showing the x-axis intervals along the first line segment in Fig. 9A, Fig. 9C is a diagram showing the distribution of y-axis intervals of measurement representative position data and third fitting representative position data of a display device according to an embodiment of the present invention, and Fig. 9D is a diagram showing the y-axis intervals along the second line segment in Fig. 9C. The following description will be made with reference to Figs. 1 to 8B.

[0084] As shown in FIG. 9A, the x-axis intervals (Δx) of the measurement representative position data exhibit an irregular distribution in the captured image SI, whereas the x-axis intervals (Δx) of the tertiary fitting representative position data exhibit a uniform distribution in the captured image SI.

[0085] As shown in Figure 9B, the x-axis interval (Δx) along the first line segment L1 of the measured representative position data has a small error in the center and a large error at the ends, while the x-axis interval (Δx) along the first line segment L1 of the third-order fitting representative position data gradually increases without showing any error. In this case, the second-order and third-order coefficients of the third-order fitting surface are relatively small, so the contributions of the second-order and third-order terms may be relatively small.

[0086] As shown in FIG. 9C, the y-axis intervals (Δy) of the measurement representative position data exhibit an irregular distribution in the captured image SI, whereas the y-axis intervals (Δy) of the tertiary fitting representative position data exhibit a uniform distribution in the captured image SI.

[0087] As shown in Figure 9D, the y-axis interval (Δy) along the second line segment L2 of the measured representative position data has a small error in the center and a large error at the ends, while the y-axis interval (Δy) along the second line segment L2 of the third-order fitting representative position data gradually decreases without showing any error. In this case, the contribution of the second-order and third-order terms may be relatively small because the second-order and third-order coefficients of the third-order fitting surface are relatively small.

[0088] As described above, in the display device 110 according to the embodiment of the present invention, the generated measurement position data is subjected to two-dimensional cubic polynomial fitting along the x-axis and y-axis, thereby eliminating measurement errors, improving the continuity of the position data, reducing variability, and maximizing the defect compensation effect.

[0089] On the other hand, in the present invention, shifting is performed on the captured image, which will be described with reference to the drawings.

[0090] 10 is a diagram illustrating the size adjustment of an image captured by a display device according to an embodiment of the present invention, which will be described with reference to FIGS. 1 to 9D.

[0091] As shown in FIG. 10, the display panel 120 displays a display image DI having a black dot of a 3x3 display subpixel DSP in the center, and the camera 170 captures the display image DI to generate a captured image SI having a black dot in the center.

[0092] For ease of explanation, FIG. 10 shows an enlarged black dot in the center of the captured image SI.

[0093] Then, the brightness of the sensor sub-pixel SSP of the captured image SI with a black dot in the center is measured, and a discontinuous graph of the intensity of each position of the sensor sub-pixel SSP is generated. i , G.P. i+1 can be located between the sensor sub-pixels SSP.

[0094] Then, a continuous kernel of intensity by position is generated from the discontinuous graph of the intensity by position of the sensor sub-pixel SSP by an interpolation method such as interpolation, and the maximum point of the kernel can be set as the golden position GP corresponding to the display sub-pixel DSP.

[0095] However, the modulation transfer function (MTF) increases, and it may happen that the golden position GP for each captured image SI does not exactly match the maximum point of the kernel.

[0096] If the golden position GP does not coincide with the kernel maximum point, adjusting the size of the captured image SI to generate a cropped image CI will result in misalignment, in which the black dot will not be positioned exactly in the center of the cropped image CI, reducing the accuracy of defect position detection and the effect of defect compensation.

[0097] Therefore, in the embodiment of the present invention, the captured image SI is shifted, so that the golden position GP of the display sub-pixel DSP and the crop sub-pixel CSP of the kernel's maximum point can be accurately matched.

[0098] Since the golden position GP and the kernel maximum point coincide with each other, when the size of the captured image SI is adjusted and a cropped image CI is generated, the black dots in the cropped image CI are aligned so that they are accurately positioned in the center, thereby improving the accuracy of defect position detection and maximizing the defect compensation effect.

[0099] Shifting of the captured image SI can be performed by repeatedly adjusting the size according to a shift value within a predetermined range, which will be described with reference to the drawings.

[0100] 11 is a diagram for explaining shifting in a display device according to an embodiment of the present invention, and FIG. 12 is a diagram for explaining symmetry operation of shifting in a display device according to an embodiment of the present invention. The description will be made with reference to FIGS. 1 to 10.

[0101] As shown in FIG. 11, a display image DI having a black dot of a 3×3 size display sub-pixel DSP in the center is captured, and a captured image SI having a black dot in the center is generated.

[0102] For example, the center of a black spot in the displayed image DI may have coordinate values ​​(1356, 614) on the x-axis and y-axis, and the center of a black spot in the captured image SI may have coordinate values ​​(3325.5, 2203.6) on the x-axis and y-axis.

[0103] After adding one shift value to the coordinate value of the center of a black point in the captured image SI, size adjustment is performed to generate a cropped image CI having a black point in the center, and a symmetry operation is performed on the black point of the cropped image CI to calculate the symmetry.

[0104] The resizing and symmetry operations are then repeated using other shift values.

[0105] For example, the shift values ​​used in resizing and symmetry operations can range from -2.0 to +2.0.

[0106] Also, in the first iteration, a shift value of (-0.5, -0.5) is applied to the center of the black spot at (3325.5, 2203.6) (3325.5-0.5, 2203.6-0.5) to perform size adjustment and symmetry operation; in the 72nd iteration, a shift value of (+1.0, +1.0) is applied to the center of the black spot at (3325.5, 2203.6) (3325.5+1.0, 2203.6+1.0) to perform size adjustment and symmetry operation; and in the 111th iteration, a shift value of (+2.0, -0.5) is applied to the center of the black spot at (3325.5, 2203.6) (3325.5+2.0, 2203.6-0.5) to perform size adjustment and symmetry operation.

[0107] 12, the black spot in the center of the cropped image CI can include the first crop sub-pixel CSP1 through the ninth crop sub-pixel CSP9, which are arranged in a 3-row, 3-column array. The first, fourth, and seventh crop sub-pixels CSP1, CSP4, and CSP7 in the left column of the centrally located fifth crop sub-pixel CSP5 are compared with the third, sixth, and ninth crop sub-pixels CSP3, CSP6, and CSP9 in the right column of the fifth crop sub-pixel CSP5, respectively, and the bilateral symmetry is determined from the average of the results.

[0108] For example, the symmetric value LRSV can be calculated as the average of the following ratios: the ratio of the minimum luminance value (min(CSP1, CSP3)) of the first and third cropped sub-pixels CSP1 and CSP3 to the maximum luminance value (max(CSP1, CSP3)) of the first and third cropped sub-pixels CSP1 and CSP3; the ratio of the minimum luminance value (min(CSP4, CSP6)) of the fourth and sixth cropped sub-pixels CSP4 and CSP6 to the maximum luminance value (max(CSP4, CSP6)) of the fourth and sixth cropped sub-pixels CSP4 and CSP6; and the ratio of the minimum luminance value (min(CSP7, CSP9)) of the seventh and ninth cropped sub-pixels CSP7 and CSP9 to the maximum luminance value (max(CSP7, CSP9)) of the seventh and ninth cropped sub-pixels CSP7 and CSP9.

[0109] LRSV=AVG[{MIN(CSP1, CSP3) / MAX(CSP1, CSP3)}, {MIN(CSP4, CSP6) / MAX(CSP4, CSP6)}, {MIN(CSP7, CSP9) / MAX(CSP7, CSP9)}]

[0110] Here, it can be determined that the closer the LRSV is to 1, the more similar the luminance of the cropped sub-pixels CSP in the left and right columns is, and the greater the symmetry of the black spots in the cropped image CI is.

[0111] Additionally, the first, second, and third crop sub-pixels CSP1, CSP2, and CSP3 in the upper row of the centrally located fifth crop sub-pixel CSP5 are compared with the seventh, eighth, and ninth crop sub-pixels CSP7, CSP8, and CSP9 in the lower row of the fifth crop sub-pixel CSP5, respectively, and the vertical symmetry is determined from the average value of the results.

[0112] For example, the vertical symmetry value UDSV can be calculated as the average of the following ratios: the ratio of the minimum luminance value (min(CSP1, CSP7)) of the first and seventh crop subpixels CSP1 and CSP7 to the maximum luminance value (max(CSP1, CSP7)) of the first and seventh crop subpixels CSP1 and CSP7; the ratio of the minimum luminance value (min(CSP2, CSP8)) of the second and eighth crop subpixels CSP2 and CSP8 to the maximum luminance value (max(CSP2, CSP8)) of the second and eighth crop subpixels CSP2 and CSP8; and the ratio of the minimum luminance value (min(CSP3, CSP9)) of the third and ninth crop subpixels CSP3 and CSP9 to the maximum luminance value (max(CSP3, CSP9)) of the third and ninth crop subpixels CSP3 and CSP9.

[0113] UDSV=AVG[{MIN(CSP1, CSP7) / MAX(CSP1, CSP7)}, {MIN(CSP2, CSP8) / MAX(CSP2, CSP8)}, {MIN(CSP3, CSP9) / MAX(CSP3, CSP9)}]

[0114] Here, as the vertical symmetry value UDSV approaches 1, the brightness of the upper and lower rows of cropped sub-pixels CSP is more similar, and it can be determined that the vertical symmetry of black spots in the cropped image CI is greater.

[0115] Furthermore, the average value of the left-right symmetric value LRSV and the top-bottom symmetric value UDSV of the black points in the cropped image CI can be calculated as the overall symmetric value TSV, as shown in the following formula.

[0116] TSV=AVG[LRSV,UDSV]

[0117] Here, the closer the total symmetry value TSV is to 1, the more similar the brightness of the cropped sub-pixels CSP in the upper, lower, left, and right rows are, and the more symmetric the black spots are in the cropped image CI.

[0118] As a result, after repeating size adjustment and symmetry calculation for multiple shift values ​​and calculating multiple overall symmetry value TSVs, the shift value corresponding to the overall symmetry value TSV closest to 1 (largest) can be determined as the optimal shift value.

[0119] For example, if the total symmetry value TSV of the 72nd iteration is greater than the total symmetry values ​​TSV of other iterations including the 1st to 111th iterations, the cropped image CI of the 72nd iteration has greater vertical and horizontal symmetry than the cropped images CI of other iterations, and the shift value (+1.0, +1.0) of the 72nd iteration can be determined as the optimal shift value.

[0120] In an embodiment of the present invention, by shifting the captured image SI, the golden position GP and the kernel maximum point are aligned, and the black dot in the cropped image CI is aligned to be accurately located in the center, thereby improving the accuracy of defect position detection and maximizing the defect compensation effect.

[0121] The correspondence / mismatch between display sub-pixels and crop sub-pixels depending on whether fitting and shifting are applied will be described with reference to the drawings.

[0122] 13A and 13B are diagrams showing a cropped image subjected to fitting according to an embodiment of the present invention, and FIG. 14 is a diagram showing a cropped image subjected to shifting according to an embodiment of the present invention. The following description will be given with reference to FIGS. 1 to 12.

[0123] As shown in FIG. 13A, in the comparative example of a cropped image CI of a 3D pattern in which shifting is applied but fitting is not applied, the edges of the notch are displayed as zigzag curves rather than straight lines, resulting in misalignment with the display panel 120, and in the comparative example of a 3x3 black dot cropped image CI, the symmetry of the black dots in the center of the display panel 120 is reduced, resulting in misalignment with the display panel 120.

[0124] On the other hand, in the cropped image CI of the 3D pattern according to an embodiment of the present invention to which shifting and fitting have been applied, the edges of the notch are displayed in a straight line and are aligned with the display panel 120, and in the cropped image CI of the 3x3 black dots according to an embodiment of the present invention, the symmetry of the black dots in the center of the display panel 120 is improved and aligned with the display panel 120.

[0125] As shown in FIG. 13B, in the cropped image CI of the comparative example 3D pattern with shifting applied but not fitting applied, the right edge of the notch is misaligned with the display panel 120 by 0.5 crop sub-pixels CSP, and the top right edge is misaligned with the display panel 120 by 1 crop sub-pixel CSP.

[0126] On the other hand, in the cropped image CI of the stereoscopic pattern according to the embodiment of the present invention to which shifting and fitting are applied, the notch edge and the upper right edge are aligned with the display panel 120 .

[0127] As shown in FIG. 14, in the 3×3 grid cropped image CI of Comparative Example 1, to which fitting is applied but shifting is not applied, misalignment occurs in which the width of the high-luminance grid (bright areas) increases in the upper left, center, and upper right sides and the width of the low-luminance grid (dark areas) decreases, and in the 3×3 black dot cropped image CI of Comparative Example 1, misalignment occurs in which the low-luminance cropped sub-pixels (dark areas) are dispersed in the upper left, center, and upper right sides.

[0128] Furthermore, in the 3x3 grid cropped image CI according to Comparative Example 2, which has fitting applied and has an arbitrary shift value but does not apply shifting, misalignment occurs in which the width of the high-brightness grid (bright areas) in the upper left, center, and upper right sides decreases and the width of the low-brightness grid (dark areas) increases; and in the 3x3 black dot cropped image CI according to Comparative Example 2, misalignment occurs in which the low-brightness cropped sub-pixels (dark areas) in the upper left, center, and upper right sides are concentrated in the upper left.

[0129] On the other hand, in the 3x3 grid cropped image CI according to the embodiment of the present invention to which fitting and shifting have been applied, the high-luminance grids (bright areas) and low-luminance grids (dark areas) in the upper left, center, and upper right sides are aligned so that their widths remain constant, and in the 3x3 black dot cropped image CI according to the embodiment, the low-luminance cropped sub-pixels (dark areas) in the upper left, center, and upper right sides are aligned so that they are concentrated in the center.

[0130] As described above, in the display device 110 according to the embodiment of the present invention, measurement error is eliminated, the continuity of the position data is improved, the variance is reduced, and the defect compensation effect is maximized by performing two-dimensional cubic polynomial fitting on the measurement position data along the x-axis and y-axis.

[0131] In addition, by shifting the captured image SI, the golden position GP and the kernel maximum point coincide with each other, and the black dot in the cropped image CI is aligned so that it is accurately positioned in the center, thereby improving the accuracy of defect position detection and maximizing the defect compensation effect.

[0132] In the embodiments of FIGS. 10 to 14, shifting is performed using the captured image SI containing black spots, but in other embodiments, shifting may be performed using the captured image SI containing white spots.

[0133] Meanwhile, different ranges of shift values ​​can be set for the red, green, and blue crop sub-pixels CSP, which will be described with reference to the drawings.

[0134] FIG. 15 is a diagram showing the distribution of crop sub-pixels and optimal shift values in the display device according to an embodiment of the present invention, and FIGS. 16A and 16B are diagrams showing the distribution of optimal shift values of different crop sub-pixels in the display device according to an embodiment of the present invention. Referring to FIGS. 1 to 14 together, the description will be given.

[0135] As shown in FIG. 15, in the display device 110 of the first case (case1), the crop sub-pixel CSP of blue B is separated from the crop sub-pixel CSP of green G at the coordinates (Sx, Sy) which is the reference position by xb and yb on the x-axis and y-axis respectively, and the crop sub-pixel CSP of red R is separated from the crop sub-pixel CSP of green G by xr and yr on the x-axis and y-axis respectively.

[0136] Therefore, the crop sub-pixel CSP of blue B has the coordinates (Sx + xb, Sy + yb). xb can be greater than 0 and less than or equal to 2 (0 < xb ≦ 2), and yb can be greater than -2 and less than or equal to 0 (-2 < yb ≦ 0).

[0137] The crop sub-pixel CSP of red R has the coordinates (Sx + xr, Sy + yr). xr can be greater than 0 and less than or equal to 2 (0 < xr ≦ 2), and yr can be greater than 0 and less than or equal to 2 (0 < yr ≦ 2).

[0138] In the display device 110 of the second case (case2), the crop sub-pixel CSP of blue B is separated from the crop sub-pixel CSP of green G at the coordinates (Sx, Sy) which is the reference position by xb and yb on the x-axis and y-axis respectively, and the crop sub-pixel CSP of red R is separated from the crop sub-pixel CSP of green G by xr and yr on the x-axis and y-axis respectively.

[0139] Thus, the blue B crop sub-pixel CSP has coordinates (Sx+xb, Sy+yb), where xb can be greater than or equal to −2 and less than 0 (−2≦xb<0), and yb can be greater than or equal to 0 and less than 2 (0≦yb<2).

[0140] The red R crop sub-pixel CSP has coordinates (Sx+xr, Sy+yr), where xr can be greater than or equal to −2 and less than 0 (−2≦xr<0), and yr can be greater than or equal to −2 and less than 0 (−2≦yr<0).

[0141] In the display device 110 of the third case (case 3), the blue B cropped subpixel CSP is spaced apart on the x-axis by xb from the green G cropped subpixel CSP at the reference position, coordinates (Sx, Sy), and the red R cropped subpixel CSP is spaced apart on the x-axis by xr from the green G cropped subpixel CSP.

[0142] Thus, the blue B crop sub-pixel CSP has coordinates (Sx+xb, Sy), where xb can be greater than or equal to 0 and less than 2 (0≦xb<2).

[0143] The red R crop sub-pixel CSP has coordinates (Sx+xr, Sy), where xr can be greater than or equal to 0 and less than 2 (0≦xr<2).

[0144] In the display device 110 in the fourth case (case 4), the blue B crop subpixel CSP is spaced yb on the y-axis from the green G crop subpixel CSP at the reference position coordinates (Sx, Sy), and the red R crop subpixel CSP is spaced yr on the y-axis from the green G crop subpixel CSP.

[0145] Thus, the blue B crop sub-pixel CSP has coordinates (Sx, Sy+yb), where yb can be greater than or equal to −2 and less than 0 (−2≦yb<0).

[0146] The red R crop sub-pixel CSP has coordinates (Sx, Sy+yr), where yr can be greater than or equal to −2 and less than 0 (−2≦yr<0).

[0147] That is, in the first to fourth cases (case 1 to case 4), the blue B and red R cropped sub-pixels CSP have optimal shift values ​​in the range of −2 to +2 relative to the green G cropped sub-pixel CSP, respectively.

[0148] As shown in FIG. 16A, for the first to tenth samples, the green G cropped sub-pixel CSP has an optimal shift value in the range of approximately −0.2 to approximately 0.3, the blue B cropped sub-pixel CSP has an optimal shift value in the range of approximately 0.8 to approximately 1.2, and the red R cropped sub-pixel CSP has an optimal shift value in the range of approximately 0.8 to approximately 1.4.

[0149] As shown in FIG. 16B, for the first through tenth samples, the green G cropped sub-pixel CSP has an optimal shift value in the range of approximately −0.8 to approximately 0.2, the blue B cropped sub-pixel CSP has an optimal shift value in the range of approximately −1.5 to approximately −0.4, and the red R cropped sub-pixel CSP has an optimal shift value in the range of approximately −0.3 to approximately 0.7.

[0150] Therefore, in the display device 110 according to an embodiment of the present invention, for a green G crop sub-pixel CSP, shifting can be repeated using a shift value in the range of approximately -1.0 to approximately +1.0 relative to the reference position coordinates (Sx, Sy) ((Sx, Sy) ±1.0 → (Sx ±1.0, Sy ±1.0)).

[0151] In addition, for the blue B and red R cropped sub-pixels CSP, shifting can be repeated using a shift value in the range of approximately -2.0 to approximately +2.0 relative to the reference position coordinates (Sx, Sy) ((Sx, Sy) ±2.0 → (Sx ±2.0, Sy ±2.0)).

[0152] Here, the repetition interval can be set to approximately 0.2 or less.

[0153] A compensation method for the display device 110 will be described with reference to the drawings.

[0154] 17 is a flowchart illustrating a compensation method for a display device according to an embodiment of the present invention, which will be described with reference to FIGS.

[0155] 17, in step 110 (st110), a first display image DI of the calibration pattern CP is captured by the camera 170 to generate a first captured image SI. Here, the display panel 120 displays the first display image DI of the calibration pattern CP, and the calibration pattern CP may include a plurality of blocks BL.

[0156] In step 112 (st112), the first captured image is measured to generate first measurement representative position data corresponding to the calibration pattern CP, where the first measurement representative position data reflects measurement error and distortion.

[0157] In step 114 (st114), two-dimensional cubic fitting is performed on the first measurement representative position data to generate cubic fitting representative position data, where measurement errors are compensated for, so that the golden position GP of the cubic fitting representative position data can have the same coordinates as the actual coordinates.

[0158] In step 116 (st116), a second display image DI of the partial point is captured by the camera 170 to generate a second captured image. Here, the display panel 120 displays the second display image of the partial point, and the partial point may include a black dot of a 3×3 display sub-pixel DSP in the center.

[0159] In step 118 (st118), the second captured image SI is measured to generate second measurement representative position data corresponding to the partial points.

[0160] In step 120 (st120), shifting is performed on the second captured image SI to calculate an optimal shift value. Here, size adjustment and symmetry calculation are repeated to calculate multiple total symmetry values ​​TSV, and the shift value corresponding to the total symmetry value TSV closest to 1 can be determined as the optimal shift value.

[0161] In step 122 (st122), the optimum shift value is added to the second measurement representative position data to generate shifted representative position data, where the golden position GP and the kernel maximum point are aligned with each other, and the partial point can be accurately positioned at the center of the second captured image.

[0162] In step 124 (st124), the third display image DI in full white display is captured by the camera 170 to generate a third captured image SI. Here, the display panel 120 can display the third display image DI in full white display.

[0163] In step 126 (st126), the size of the third captured image SI is adjusted based on the tertiary representative position data and the shifting representative position data, thereby generating a first cropped image CI.

[0164] In step 128 (st128), the measured luminance of the first cropped image is compared with the target luminance to calculate a luminance compensation value.

[0165] In step 130 (st130), the brightness compensation value is applied to the image data to generate compensated image data.

[0166] In the embodiment shown in FIG. 17, both the third-order fitting in step 114 (st114) and the shifting in step 120 (st120) were performed, but in other embodiments, either the third-order fitting in step 114 (st114) or the shifting in step 120 (st120) may be omitted.

[0167] 17, the first display image DI of the calibration pattern CP and the second display image DI of the partial points of the black dots are all displayed, but in other embodiments, the display of the second display image DI of the partial points may be omitted. For example, the first display image DI of the calibration pattern CP may include a white dot of a 3×3 display sub-pixel DSP in the center, and the first display image DI of the white dot may be captured to generate the second captured image SI.

[0168] Although the present invention has been described above with reference to preferred embodiments, it will be understood by those skilled in the art that various modifications and changes can be made to the present invention without departing from the technical spirit and scope of the present invention as set forth in the claims. [Explanation of symbols]

[0169] 110...display device, 120...display panel, DI...displayed image, SI...captured image, CI...cropped image

Claims

1. displaying a first display image of a calibration pattern using a display device including a display panel having a plurality of display subpixels, the first display image of the calibration pattern including a plurality of blocks arranged on an x-axis and a y-axis, each of the plurality of blocks including one light-emitting display subpixel and a plurality of non-light-emitting display subpixels; capturing the first display image using a camera including a plurality of sensor sub-pixels to generate a first captured image of the calibration pattern; measuring the first captured image, calculating a measurement light-emitting display sub-pixel corresponding to the light-emitting display sub-pixel of each block as a center position serving as a reference point, and generating measurement representative position data including the center position; performing two-dimensional cubic fitting on the first captured image of the measurement representative position data to generate cubic fitting representative position data; displaying a second display image in a full white display mode using the display panel of the display device; capturing the second display image using the camera to generate a second captured image, the second captured image including a first portion corresponding to the display panel and a second portion corresponding to an outer portion of the display panel, the first portion being an entirely white display; performing a first size adjustment to remove the second portion of the second captured image based on the third fitting representative position data, and generating a first cropped image corresponding to the display panel; calculating a brightness compensation value by comparing the measured brightness of the first cropped image with a target brightness; The compensation method for a display device includes applying the luminance compensation value to image data to generate compensated image data.

2. 2. The compensation method of claim 1, wherein a fitting surface (x, y) of the two-dimensional cubic fitting along x and y axes is expressed as follows: x=x, y=y (x, y) / y ( ... fitting surface(x、y)=p00+p10×x+p01×y+p20×x ２ +p11×xy+p02×y ２ +p30×x ３ +p21×x ２ y+p12×xy ２ +p03×y ３ (p00 is the zeroth-order fitting coefficient, p10 and p01 are the first-order fitting coefficients, p20, p11, p02 are the second-order fitting coefficients, and p30, p21, p12, p03 are the third-order fitting coefficients.)

3. After the step of generating the measured representative position data, 2. The compensation method of claim 1, further comprising: generating all position data by making equal intervals between the tertiary fitting representative position data corresponding to two adjacent light-emitting display sub-pixels among the plurality of blocks; mapping the first captured image to the first display image of the display panel based on the all position data; and generating a captured image of the measured representative position data reflecting measurement error and distortion.

4. After the step of generating the third fitting representative position data, displaying a third display image in which a partial point having a black or white dot is positioned at the center of the display panel using the display device; capturing the third display image using the camera to generate a third captured image of the partial point including a third portion corresponding to the partial point and a fourth portion corresponding to an outer portion of the partial point; and calculating an optimal shift value by performing a shifting operation on the third captured image by a second size adjustment to remove the fourth portion and a symmetry operation using a shift value within a predetermined range on the third captured image, wherein one shift value is added to a coordinate value of a center of a black point or a white point in the third captured image, and then performing the second size adjustment on the third captured image to generate a second cropped image. The step of calculating the optimum shift value comprises: In the shift value range of −2.0 to +2.0, adding a first shift value to coordinate values ​​of the center of the partial point in the third captured image, and performing the second size adjustment on the third captured image to generate the second cropped image; calculating first vertical and horizontal symmetry values ​​by performing a symmetry operation on the partial point in the second cropped image; using a plurality of shift values ​​different from the first shift value, and then repeating the second size adjustment and the symmetry calculation to calculate a plurality of vertical and horizontal symmetry values ​​different from the first vertical and horizontal symmetry value; calculating a maximum value among the first vertically and horizontally symmetrical value and the plurality of vertically and horizontally symmetrical values ​​as the optimum shift value; The compensation method includes: measuring the third captured image after the generating of the second captured image and generating second measured representative position data corresponding to the partial point; further comprising adding the optimum shift value to the second measured representative position data to generate shifted representative position data; 2. The compensation method of claim 1, wherein the generating the first cropped image comprises performing a first size adjustment to remove the second portion of the second captured image based on the tertiary fitting representative position data and the shifting representative position data, thereby generating the first cropped image corresponding to the display panel.

5. the partial points in the second crop image include first to ninth crop sub-pixels arranged in three rows and three columns, The step of calculating the first vertical and horizontal symmetry values ​​includes: calculating average values ​​of ratios of the minimum luminance value of the first and third crop subpixels to the maximum luminance value of the first and third crop subpixels, ratios of the minimum luminance value of the fourth and sixth crop subpixels to the maximum luminance value of the fourth and sixth crop subpixels, and ratios of the minimum luminance value of the seventh and ninth crop subpixels to the maximum luminance value of the seventh and ninth crop subpixels, as bilaterally symmetric values; calculating average values ​​of ratios of the minimum luminance value of the first crop subpixel and the seventh crop subpixel to the maximum luminance value of the first crop subpixel and the seventh crop subpixel, ratios of the minimum luminance value of the second crop subpixel and the eighth crop subpixel to the maximum luminance value of the second crop subpixel and the eighth crop subpixel, and ratios of the minimum luminance value of the third crop subpixel and the ninth crop subpixel to the maximum luminance value of the third crop subpixel and the ninth crop subpixel, as vertically symmetrical values; The compensation method of claim 4 , further comprising calculating an average value of the left-right symmetrical value and the top-bottom symmetrical value as the first top-bottom-left-right symmetrical value.

6. the second cropped image includes red, green, and blue cropped sub-pixels; for the green cropped sub-pixels, repeating the second size adjustment and the symmetry operation with the first shift value and the plurality of shift values ​​ranging from −1.0 to +1.0; 5. The compensation method of claim 4, wherein for the blue cropped sub-pixel and the red cropped sub-pixel, the second size adjustment and the symmetry operation are repeated with the first shift value and the plurality of shift values ​​in a range of −2.0 to +2.

0.

7. displaying a first display image of a calibration pattern using a display device including a display panel having a plurality of display subpixels, the first display image of the calibration pattern including a plurality of blocks arranged on an x-axis and a y-axis, each of the plurality of blocks including one light-emitting display subpixel and a plurality of non-light-emitting display subpixels; capturing the first display image using a camera including a plurality of sensor sub-pixels to generate a first captured image of the calibration pattern; measuring the first captured image, calculating a measurement light-emitting display sub-pixel corresponding to the light-emitting display sub-pixel of each block as a center position serving as a reference point, and generating first measurement representative position data including the center position; displaying a second display image having a partial point where a center position of the display panel is a black point or a white point using the display device; capturing the second display image using the camera to generate a second captured image of the partial point including a first portion corresponding to the partial point and a second portion corresponding to an outer portion of the partial point; measuring the second captured image and generating second measurement representative position data corresponding to the partial points; a step of calculating an optimal shift value by performing a first size adjustment to remove the second portion on the second captured image and performing a symmetry calculation using a shift value within a predetermined range on the second captured image, the optimal shift value being calculated by adding one shift value to a coordinate value of a center of a black point or a white point in the second captured image, and then performing the first size adjustment on the second captured image to generate a first cropped image; adding the optimum shift value to the second measured representative position data to generate shifting representative position data; displaying a third display image in a full white display mode using the display device; capturing the third display image using the camera to generate a third captured image, the third captured image including a third portion corresponding to the display panel and a fourth portion corresponding to an outer portion of the display panel, the third portion being an entirely white display; performing a second size adjustment to remove the fourth portion of the third captured image based on the shifting representative position data, and generating a second cropped image corresponding to the display panel; calculating a brightness compensation value by comparing the measured brightness of the second cropped image with a target brightness; applying the luminance compensation value to image data to generate compensated image data; The step of calculating the optimum shift value comprises: In the shift value range of −2.0 to +2.0, adding a first shift value to coordinate values ​​of the center of the partial point in the second captured image, and performing the first size adjustment on the second captured image to generate the first cropped image; calculating first vertical and horizontal symmetry values ​​by performing a symmetry operation on the partial points in the first cropped image; using a plurality of shift values ​​different from the first shift value, and then repeating the first size adjustment and the symmetry calculation to calculate a plurality of vertical and horizontal symmetry values ​​different from the first vertical and horizontal symmetry value; A compensation method for a display device, comprising: calculating a maximum value among the first vertical and horizontal symmetrical value and the plurality of vertical and horizontal symmetrical values ​​as the optimum shift value.

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