KR101981137B1 - Apparatus and Method for Generating of Luminance Correction Data - Google Patents

Abstract

The present invention relates to an apparatus and method for generating luminance correction data for compensating image distortion, such as spot defects, and a method for correcting luminance of a display device.
In accordance with another aspect of the present invention, an apparatus for generating correction data includes: a reference correction data generator configured to generate first reference correction data and second reference correction data for correcting luminance distortion of a first reference gray image and a second reference gray image; A gamma curve generation unit configured to calculate a gamma curve of a third reference gray image and the fourth reference gray image based on the first reference correction data and the second reference correction data; And third reference correction data and a fourth reference for correcting luminance distortion of the third reference gray image and the fourth reference gray image based on a gamma curve of the third reference gray image and the fourth reference gray image. And a luminance correction data generator for generating correction data.

Description

Apparatus and Method for Generating of Luminance Correction Data

The present invention relates to an apparatus and method for generating luminance correction data for compensating image distortion, such as spot defects, and a method for correcting luminance of a display device.

With the development of various portable electronic devices such as mobile communication terminals and notebook computers, there is an increasing demand for a flat panel display device that can be applied thereto.

The flat panel display device includes a liquid crystal display device (LCD), a field emission display device (FED), a plasma display panel (PDP) and an organic light emitting diode display device (OLED) light emitting diode display device) has been developed.

Among the flat panel display devices, the self-luminous organic light emitting diode display device is attracting attention as a next generation display device because it has an advantage of realizing high response speed, low power consumption, high resolution, and a large screen.

1 is a circuit diagram schematically illustrating a pixel structure of an organic light emitting diode display device according to the related art.

Referring to FIG. 1, a pixel of a conventional organic light emitting diode display device includes a switching thin film transistor ST, a driving thin film transistor DT, a capacitor C, and a light emitting device OLED.

The light emitting device OLED is electrically connected between the source terminal of the driving thin film transistor DT and the ground power supply Vss to emit light by the data current idata supplied from the driving thin film transistor DT.

The pixel of the conventional organic light emitting diode display device includes a data current idata flowing from the driving power supply Vdd to the light emitting device OLED by switching the driving thin film transistor DT according to the data voltage Vdata. By controlling the size, the light emitting device OLED emits light, thereby displaying a predetermined image.

In general, when the same manufacturing process is applied, all the OLED panels produced should have the same brightness characteristics, but in actual manufacturing process, there is a deviation so that all the OLED panels do not show the same brightness characteristics.

In addition, deviations may occur between the initially designed luminance characteristics and the luminance characteristics after the manufacture is completed. Such variation in luminance characteristics may be different for each OLED panel and may be different for each pixel in one OLED panel.

As a result, even when the same data voltage Vdata is supplied to all the pixels, a difference is generated in the threshold voltage deviation and channel mobility of the driving thin film transistor DT included in each pixel. Accordingly, there is a problem in that luminance deviation occurs and image quality distortion phenomenon such as mura occurs.

2 is a view showing a mura detection method according to the prior art, Figure 3 is a view showing a brightness correction method according to the prior art.

2 and 3, after fabrication of the OLED panel is completed, screen inspection of the OLED panel is performed before release to the product to correct spot defects and luminance distortion for all pixels.

In order to reduce the amount of calculation for calculating the luminance correction data, luminance correction data is generated for four reference grays among the entire luminances (gradations), and luminance correction data is generated by applying linear interpolation to the remaining luminance.

After displaying images of 32, 64, 128, and 192 gray, which are the reference among 0 to 255 gray, on the display panel, reference gray images are taken by a CCD camera to generate luminance data of four reference grays.

Thereafter, luminance compensation data is generated for the reference grays 32, 64, 128, and 192 grays by performing an image processing process and a Mura detection process, and then the interpolation method using the reference gray is applied to the luminance compensation data of the remaining grays. To create.

Here, in the image processing process, a moire pattern of the image is reduced, and image distortion is corrected through calibration. During the Mura detection process, the target luminance in the row direction is set, and the luminance of the entire display panel is measured to derive the difference between the luminance of the image displayed on the screen and the target luminance. The difference between the target luminance and the measured luminance thus obtained becomes luminance compensation data of the corresponding gray.

In the prior art, an image must be captured in 32, 64, 128, and 192 grays by a CCD camera during the Mura detection process. That is, since at least four reference images must be captured by a CCD camera to obtain luminance compensation data, a tact time of generating luminance correction data is long.

In addition, in the prior art, the luminance correction data causes an error when the four reference gray (32, 64, 128, 192 gray) images are not normally captured or the image data obtained through the imaging is damaged, or in the severe case, the luminance correction data. There is a problem that cannot be generated.

In particular, in the low gradation region, a certain part of the error occurs in the luminance correction data due to the characteristics of the gamma curve. In the low gradation region, when a deviation between the gamma curve without mura and the gamma curve with mura occurs occurs There is a problem that an error occurs in the low gray level luminance compensation data.

For example, 32 luminance or less has a nonlinear characteristic, and thus an error occurs in luminance correction data generated through linear interpolation. Due to the difference between the actual luminance and the luminance and the luminance correction data, a problem arises in that the luminance is excessively compensated (over compensated) or uncompensated (weak compensated) at low luminance (low gradation). In addition, there is a problem that the contour of the object is distorted.

Such image quality distortion occurs not only in the organic light emitting diode display device but also in other display devices. Furthermore, the image quality distortion may increase as the screen size of the display device increases. Accordingly, there is a need for a new method capable of improving or preventing image quality distortion caused by luminance unevenness of each pixel of the display device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an apparatus and method for generating luminance correction data capable of preventing image quality distortion such as spot defects.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problem, and an object of the present invention is to provide an apparatus and method for generating luminance correction data that can reduce a tact time required for detecting image distortion.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and it is an object of the present invention to provide an apparatus and method for generating luminance correction data that can reduce an error generated in a process of detecting image distortion.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problem, and an object of the present invention is to provide an apparatus and method for generating luminance correction data capable of recovering loss of luminance correction data.

In addition to the technical task of the present invention mentioned above, other features and advantages of the present invention will be described below, or from such description and description will be clearly understood by those skilled in the art.

The correction data generating apparatus according to the embodiment of the present invention for achieving the above-described technical problem is the first reference correction data and the second reference correction data for correcting the luminance distortion of the first reference gray image and the second reference gray image A reference correction data generation unit to generate; A gamma curve generation unit configured to calculate a gamma curve of a third reference gray image and the fourth reference gray image based on the first reference correction data and the second reference correction data; And third reference correction data and a fourth reference for correcting luminance distortion of the third reference gray image and the fourth reference gray image based on a gamma curve of the third reference gray image and the fourth reference gray image. And a luminance correction data generator for generating correction data.

According to an aspect of the present invention, a method of generating correction data according to an exemplary embodiment of the present invention may be performed by capturing a first gray image displayed on a screen and correcting first reference correction data for correcting luminance distortion of the first reference gray image. Generating; Imaging the second gray image to generate second reference correction data for correcting luminance distortion of the second reference gray image; Calculating a gamma curve of a third reference gray image and the fourth reference gray image based on the first reference correction data and the second reference correction data; Generating third reference correction data for correcting luminance distortion of the third reference gray image based on a gamma curve of the third reference gray image; And generating fourth reference correction data for correcting luminance distortion of the fourth reference gray image based on the gamma curve of the fourth reference gray image.

According to the above solution, the apparatus and method for generating luminance correction data according to an embodiment of the present invention can reduce a tact time required for detecting image quality distortion.

According to the above solution, an error generated in the process of detecting image distortion can be reduced.

According to the above solution, the loss of the luminance correction data can be restored.

According to the solving means of the above, the apparatus and method for generating luminance correction data according to an embodiment of the present invention can improve or prevent image quality distortion caused by luminance unevenness of pixels.

In addition to the features and effects of the present invention mentioned above, other features and effects of the present invention may be newly understood through the embodiments of the present invention.

1 is a circuit diagram schematically illustrating a pixel structure of an organic light emitting diode display device according to the related art.
2 is a view showing a mura detection method according to the prior art.
3 is a view showing a luminance correction method according to the prior art.
4 is a diagram illustrating an organic light emitting display device to which luminance correction data is applied according to an exemplary embodiment of the present invention.
5 is a diagram illustrating a method of generating reference luminance data by measuring luminance of a test image displayed on an organic light emitting display device.
6 is a diagram illustrating an apparatus for generating luminance correction data according to an exemplary embodiment of the present invention.
7 to 12 are views illustrating a method of generating luminance correction data and a luminance correction method of an organic light emitting display device according to an exemplary embodiment of the present invention.

Hereinafter, a preferred embodiment of an apparatus and method for generating luminance correction data according to the present invention will be described in detail with reference to the accompanying drawings.

4 is a diagram illustrating an organic light emitting display device to which luminance correction data is applied according to an exemplary embodiment of the present invention.

Referring to FIG. 4, the organic light emitting display device 100 includes an OLED panel 110 and a panel driver.

The panel driver of the OLED display device 100 includes a gate driver 120, a data driver 130, a timing controller 140, and a memory 150, and generates a data signal corresponding to data input from the outside. Supply to each pixel.

The OLED panel 110 emits an organic light emitting diode OLED formed in each sub pixel according to the data voltage Vdata supplied from the data driver 130 to display an image. To this end, the OLED panel 110 includes a plurality of power lines formed to intersect with each other to define a pixel area, a plurality of power lines parallel to the plurality of scan lines SL, and a plurality of data lines DL. PL is formed.

The sub-pixel may be divided into a red sub-pixel, a green sub-pixel, and a blue sub-pixel, and the red sub-pixel, the green sub-pixel, and the blue sub-pixels constitute one pixel.

As another example, a sub pixel may be divided into a red sub pixel, a green sub pixel, a blue sub pixel, and a white sub pixel, and the red sub pixel, the green sub pixel, the blue sub pixel, and the white sub pixels may be divided into one. Constitutes a pixel.

The organic light emitting diode OLED includes an organic light emitting cell that emits light of any one of red, green, blue, and white colors. The organic light emitting cell may be formed to have a structure of a hole transport layer / organic light emitting layer / electron transport layer or a structure of a hole injection layer / hole transport layer / organic light emitting layer / electron transport layer / electron injection layer. Furthermore, the organic light emitting cell may be further formed with a functional layer for improving the luminous efficiency and / or lifespan of the organic light emitting layer.

The pixel circuit corresponds to the data signal Vdata supplied from the data driver 130 to the data line DL in response to the scan signal SS supplied from the gate driver 120 to the scan line SL. Is allowed to flow through the organic light emitting element (OLED).

To this end, the pixel circuit PC includes a switching transistor, a driving transistor, and at least one capacitor formed on a substrate by a thin film transistor forming process.

The switching transistor is switched according to the scan signal SS supplied to the scan line SL to supply a data voltage Vdata supplied from the data line DL to the driving transistor.

The driving transistor is switched according to the data voltage Vdata supplied from the switching transistor to generate a data current based on the data voltage Vdata and to supply the OLED to the organic light emitting diode OLED so that the driving transistor is proportional to the amount of data current. Emits light. The at least one capacitor maintains the data voltage supplied to the driving transistor for one frame.

The timing controller 140 controls driving timing of each of the gate driver 120 and the data driver 130 according to a timing synchronization signal sync input from an external system main body (not shown) or a graphics card (not shown). do.

The memory 150 is included in the organic light emitting display device 100, and the memory 150 includes luminance correction data to prevent image quality distortion such as spot defects due to luminance unevenness of all pixels of the OLED panel 110. Stored.

Here, the luminance correction data may be generated and stored for individual pixels, or the luminance correction data may be generated and stored in units of blocks by configuring a predetermined number of pixels in blocks.

The memory 150 in which the luminance correction data is stored may be formed in an independent configuration in the organic light emitting display device 100. As another example of the present invention, the memory 150 may be implemented in a form embedded in the timing controller 140 or the data driver 130.

The timing controller 140 generates a scan control signal and a data control signal based on timing synchronization signals such as the vertical synchronization signal Vsync, the horizontal synchronization signal Hsync, the data enable DE, the clock DCLK, and the like. . The driving timing of the gate driver 120 is controlled through the scan control signal. Then, the driving timing of the data driver 130 is controlled through the data control signal DCS.

In addition, the timing controller 140 loads the luminance correction data stored in the memory 150 and corrects the luminance of all pixels by reflecting the luminance correction data to the image data supplied to the OLED panel 110. In this case, the timing controller 140 aligns red, green, blue, and white data so as to be suitable for driving the OLED panel 110, and supplies the sorted data RGBW to the data driver 130.

The gate driver 120 generates the scan signal SS according to the scan control signal SCS supplied from the timing controller 140 and sequentially supplies the scan signal SS to the plurality of scan lines SL.

The data driver 130 receives the data RGBW and the data control signal DCS supplied from the timing controller 140, and receives a plurality of reference gamma voltages from an external power supply (not shown). The data driver 130 converts the alignment data RGBW into an analog data voltage Vdata using a plurality of reference gamma voltages according to the data control signal DCS, and converts the converted data voltage into a corresponding data line DL. Supplies).

5 is a diagram illustrating a method of generating reference luminance data by measuring luminance of a test image displayed on an organic light emitting display device.

Referring to FIG. 5, the test image supply unit generates first to fourth test image data of different grays, and supplies the first to fourth test image data to the organic light emitting display device 100. For example, the first test image may be displayed in 32 gray, the second test image in 64 gray, the third test image in 128 gray, and the fourth test image in 192 gray.

Here, the test image supply unit may sequentially arrange two test images from the first to fourth test images and supply them to the organic light emitting display device 100.

In the present invention, the luminance which corrects the luminance distortion of the 0-255 gray image using two reference grays among the four reference grays by setting 32, 64, 128, and 192 grays as the reference gray among 0-255 grays. Calibration data can be generated.

However, the present invention is not limited thereto, and one gray among 0 to 31 gray as well as 32, 64, 128, and 192 grays may be set as the reference gray.

In addition, one gray among 33 to 63 grays may be set as a reference gray, one gray among 65 to 127 grays may be set as a reference gray, and one gray among 193 to 255 grays may be set as a reference gray.

As described above, the luminance correction data for correcting the luminance distortion of the entire gray (0 to 255 gray) image may be generated using two reference grays among the set four reference grays.

The OLED panel 110 displays the first test image of the first gray supplied from the test image supply unit, and displays the second test image of the second gray.

The luminance measuring apparatus measures the luminance of the first test image by measuring the first test image and the second test image displayed on the OLED panel 110, and measures the luminance of the second test image.

The luminance measuring apparatus measures the luminance of the first test image to generate first reference luminance data, and measures the luminance of the second test image to generate second reference luminance data. The generated first reference luminance data and the second reference luminance data are provided to the luminance correction data generating apparatus 200. Such a luminance measuring device may be formed of a digital camera or an image sensor.

6 is a diagram illustrating an apparatus for generating luminance correction data according to an exemplary embodiment of the present invention, and FIGS. 7 to 12 are views illustrating a method for generating luminance correction data and a luminance correction method for an organic light emitting display device according to an exemplary embodiment of the present invention. to be.

Hereinafter, the configuration of the luminance correction data generating apparatus 200 and the luminance correction data generating method according to the exemplary embodiment of the present invention illustrated in FIG. 5 will be described with reference to FIGS. 6 to 12, and the luminance correction method of the organic light emitting display device will be described. Explain.

Referring to FIG. 6, the luminance correction data generating apparatus 200 according to an embodiment of the present invention generates luminance correction data so that the luminance according to the input image data is correctly displayed on the pixel, and supplies the luminance correction data to the organic light emitting display device 100. do.

When a luminance deviation in which the actual luminance becomes higher than the input image data is generated, negative luminance correction data for lowering the gray of the image data input to the pixel is generated to correct the luminance of the image displayed on the organic light emitting display device 100.

On the contrary, in the case where a luminance deviation in which the actual luminance becomes lower than the input image data is generated, positive luminance correction data for increasing gray of the image data input to the pixel is generated to generate luminance of the image displayed on the organic light emitting display device 100. Correct.

Here, the luminance correction data generating apparatus 200 generates luminance correction data of two reference grays among four reference grays, and based on the luminance correction data of the first reference gray and the luminance correction data of the second reference gray, Luminance correction data of the three reference grays (the third reference gray and the fourth reference gray) are generated. Thereafter, linear interpolation may be applied to luminance correction data of four reference grays to generate luminance correction data of all grays from 0 gray to 255 gray.

To this end, the luminance correction data generating apparatus 200 according to an embodiment of the present invention includes a reference correction data generator 210, a gamma curve calculator 220, and a luminance correction data generator 230.

Referring to FIG. 7, the reference correction data generating unit 210 may include first reference luminance data and second reference luminance data, that is, a first reference obtained by capturing images of two reference grays. The first reference correction data and the second reference correction data are generated based on the luminance data and the second reference luminance data.

Here, the first test image of 64 gray and the second tester image of 192 gray are supplied to the OLED panel 110, and the actual luminance of the first test image and the second test image displayed on the OLED panel 110 is measured. First reference luminance data and second reference luminance data are generated.

Specifically, based on the luminance data of the 64 gray image, that is, the first reference luminance data, among the 32, 64, 128, and 192 grays, first reference correction data for luminance correction of the 64 gray images is generated. Also, based on the luminance data of the 192 gray image, that is, the second reference luminance data, second reference correction data for luminance correction of the 192 gray image is generated.

Here, the first reference correction data is luminance correction data of the 64 gray image, and the second reference correction data is luminance correction data of the 192 gray image.

As another example, based on the luminance data of the 32 gray image, that is, the first reference luminance data, first reference correction data for luminance correction of the 32 gray image is generated. Also, based on the luminance data of the 128 gray image, that is, the second reference luminance data, the second reference correction data for luminance correction of the 128 gray image may be generated.

Here, the first reference correction data is luminance correction data of a 32 gray image, and the second reference correction data is luminance correction data of a 128 gray image.

As another example, first reference correction data for luminance correction of the 32 gray images is generated based on the luminance data of the 32 gray images, that is, the first reference luminance data. In addition, based on the luminance data of the 192 gray image, that is, the second reference luminance data, second reference correction data for luminance correction of the 192 gray image may be generated.

Here, the first reference correction data is luminance correction data of the 32 gray image, and the second reference correction data is luminance correction data of the 192 gray image.

As another example, based on the luminance data of the 64 gray image, that is, the first reference luminance data, first reference correction data for luminance correction of the 64 gray image is generated. Also, based on the luminance data of the 128 gray image, that is, the second reference luminance data, the second reference correction data for luminance correction of the 128 gray image may be generated.

Here, the first reference correction data is luminance correction data of a 64 gray image, and the second reference correction data is luminance correction data of a 128 gray image.

The first reference correction data and the second reference correction data for correcting the luminance of the 32 gray and 64 gray images are generated based on the first luminance data of the 32 gray images and the second luminance data of the 64 gray images. can do. In addition, based on the first luminance data of the 128 gray image and the second luminance data of the 192 gray image, first reference correction data and second reference correction data for correcting the luminance of the 128 gray and 192 gray images may be generated. .

For gray interpolation, correction data of four reference grays 32, 64, 128, and 192 are used. Two reference gray images are captured to generate two reference correction data.

The correction data of the two reference grays, that is, the third reference correction data and the fourth reference correction data, are generated using the correction data of the two reference grays, that is, the first reference correction data and the second reference correction data.

To this end, the gamma curve calculator 220 calculates a gamma curve of the remaining two reference grays having luminance distortion based on the first reference correction data and the second reference correction data. That is, the gamma curve calculator 220 calculates a gamma curve of the third reference gray image and the fourth reference gray image based on the first reference correction data and the second reference correction data.

For example, by using the first reference correction data for luminance correction of a 64 gray image and the second reference correction data for luminance correction of a 192 gray image, a gamma curve of a 32 gray image having a luminance distortion and a 128 gray image A gamma curve can be calculated.

The luminance correction data generator 230 may generate third reference correction data for correcting the luminance distortion of the third reference gray image based on the gamma curve of the third reference gray image. In addition, the luminance correction data generator 230 may generate fourth reference correction data for correcting the luminance distortion of the fourth reference gray image based on the gamma curve of the fourth reference gray image.

Referring to FIG. 8, a deviation may occur between a theoretical luminance value of image data supplied to the OLED panel 110 and a luminance of an actual image displayed on a screen.

As shown in Equation 1 below, the degree of luminance is distorted through the deviation of the gamma curve (for example, 2.2 gamma curve) of the region without mura and the gamma curve of the region where mura is generated. Therefore, luminance correction data can be generated based on the deviation between the theoretical gamma curve of the region without Mura and the gamma curve of the region where Mura has occurred.

In Equation 1, "comp" denotes a correction value for ray, "k" denotes a variable of an r_mura graph, and "r_mura" denotes a Gamma Curve value of a region where mura is present. In Equation 1, inferring the values of "r_mura" and "k" may generate luminance correction data for all grays in a Gamma Curve in which Mura exists.

First, a method of generating reference correction data of a 32 gray image, which is two reference grays, and reference correction data of a 192 gray image, will be described.

For example, suppose that a formula for generating reference correction data of a 32 gray image and reference correction data of a 192 gray image is obtained. The following process is performed to perform reference correction data of a 32 gray image and a reference of a 192 gray image. You can create calibration data.

In Equation 2, as an example, +21 luminance distortion is generated in the 192 gray image and +6 luminance distortion is generated in the 32 gray image.

Through Equation 2, the deviation of the gamma curve of the actual image and the 2.2 gamma of 192 gray and the gamma curve of the actual image can be known.

Through the deviation of the gamma curve, it is possible to know how distorted the reference gray image displayed on the OLED panel 110 is. When image data originally intended to display 32 luminance is input, it is possible to know whether the OLED panel 110 displays the luminance lower than the 32 luminance or the luminance higher than the 32 luminance. That is, it can be seen that luminance distortion has occurred by the deviation of the gamma, and through this, reference compensation data of 32 gray and 192 gray can be generated.

In Equation 2, the logarithm of both sides of Equation 2 can be obtained.

]은 상수이므로, 앞에서 구한[

] 수식을 하기의 수학식 4과 같이 나타낼 수 있다.Right side in Equation 3 [

] Is a constant, so we can get

] Can be expressed as Equation 4 below.

"K" and "r_mura" may be calculated using 32 gray and 192 gray of Equation 4, and a gamma curve of a 64 gray image may be calculated using Equation 5 below.

Referring to FIG. 9, the luminance correction data generator 230 may generate reference correction data of a 64 gray image by using a calculated gamma curve of 64 gray.

Through the processes of Equations 1 to 5, a gamma curve of a 64 gray image may be calculated without capturing an actual screen.

The deviation of the theoretical 2.2 gamma curve without luminance distortion and the calculated 64 gray gamma curve can be known, and thus, the luminance correction value of the 64 gray image, that is, the reference correction data of 64 gray can be calculated.

The luminance correction data for correcting the luminance distortion may be generated by using the deviation between the gamma curve without the luminance distortion and the gamma curve with the luminance distortion.

As described above, the gamma curve of the 64 gray image may be calculated using the reference correction data of 32 gray and 192 gray, and the reference correction data of the 64 gray image may be generated using the gamma curve of the 64 gray image.

In the same manner as generating the luminance correction data of 64 gray, the gamma curve of the 128 gray image is calculated using the luminance correction data of 32 gray and 192 gray, and the luminance correction of the 128 gray image using the gamma curve of the 128 gray image. You can generate data.

As another example of the present invention, referring to FIG. 10, a gamma curve of a 64 gray image and a gamma curve of a 192 gray image are calculated using luminance correction data of a 32 gray image and luminance correction data of a 128 gray image. The luminance correction data of the 64 gray image and the luminance correction data of the 192 gray image may be generated based on the calculated gamma curve of the 64 gray image and the gamma curve of the 192 gray image.

As another example of the present invention, referring to FIG. 11, a gamma curve of a 64 gray image and a gamma curve of a 128 gray image are calculated using luminance correction data of a 32 gray image and luminance correction data of a 192 gray image. The luminance correction data of the 64 gray image and the luminance correction data of the 128 gray image may be generated based on the calculated gamma curve of the 64 gray image and the gamma curve of the 128 gray image.

As another example of the present invention, referring to FIG. 12, a gamma curve of a 32 gray image and a gamma curve of a 192 gray image are calculated using luminance correction data of a 64 gray image and luminance correction data of a 128 gray image.

The luminance correction data of the 32 gray image and the luminance correction data of the 192 gray image may be generated based on the calculated gamma curve of the 32 gray image and the gamma curve of the 192 gray image.

Subsequently, the luminance correction data generator 230 applies linear interpolation to the reference correction data of four reference gray images, that is, the luminance correction data of 32, 64, 128, and 192 gray images, and thus luminance of all grays (0 to 255). Generate calibration data.

In the above description, the entire gray of the image has been described as being composed of 256 steps (0 to 255), but this is one of various embodiments of the present invention. The entire gray of the image may be configured in 128, 512, or 1024 steps. In this case, the luminance correction data of all grays may be generated using the luminance correction data of the four reference gray images.

For example, the luminance correction data generator 230 may generate luminance correction data of 0 to 31 gray images by applying a linear interpolation method to luminance correction data of a 32 gray image.

In addition, the luminance correction data generator 230 may generate luminance correction data of 33 to 63 gray images by applying linear interpolation to luminance correction data of 32 gray images and luminance correction data of 64 gray images.

In addition, the luminance correction data generator 230 may generate luminance correction data of 65 to 127 gray images by applying linear interpolation to luminance correction data of a 64 gray image and luminance correction data of a 128 gray image.

In addition, the luminance correction data generator 230 may generate luminance correction data of 129 to 191 gray images by applying linear interpolation to luminance correction data of 128 gray images and luminance correction data of 192 gray images.

Also, the luminance correction data generator 230 may generate luminance correction data of 193 to 255 gray images by applying linear interpolation to luminance correction data of a 192 gray image.

The luminance correction data generator 230 provides the generated luminance correction data of all grays 0 to 255 to the memory 150 of the organic light emitting display device 100. In this case, luminance correction data of 0 to 255 gray may be stored in a lookup table of the memory 150.

An error may occur in the process of detecting an image distortion, and an apparatus and method for generating luminance correction data according to an embodiment of the present invention may generate luminance correction data of two reference grays by capturing two gray images and using the same. By generating luminance correction data of all grays, an error generated in the process of detecting image quality distortion can be reduced.

In addition, when the deviation between the theoretical gamma curve for the two reference grays and the gamma curve calculated by capturing the actual image exceeds the reference value, the corresponding OLED panel 110 is determined to be defective, and then the luminance correction data generation process is performed. Do not proceed. Therefore, it is possible to determine whether the OLED panel 110 is normal or defective by only capturing two reference gray images.

As another example, the luminance correction data generating apparatus 200 according to an embodiment of the present invention may map luminance correction data of 0 to 255 gray in a table form to correspond to each pixel.

However, the present invention is not limited thereto, and the luminance correction data generating apparatus 200 may configure a plurality of blocks in units of 4 × 4 pixels or 8 × 8 pixels, and may include a plurality of blocks in a pixel included in one block. The same luminance correction data may be applied to the luminance correction.

The apparatus and method for generating luminance correction data according to an embodiment of the present invention may generate luminance correction data of all grays using luminance correction data generated by imaging two reference grays. As a result, it is possible to reduce the tact time required for detecting the image quality distortion.

In addition, the apparatus and method for generating luminance correction data according to an embodiment of the present invention can improve or prevent image quality distortion caused by luminance unevenness of pixels.

In addition, it is possible to prevent errors in luminance correction data with respect to luminance in which the gamma curve has nonlinear characteristics, thereby improving or preventing image quality distortion caused by luminance unevenness of the pixel. In addition, it is possible to prevent the occurrence of distortion in the contour of the object, over-correction, uncorrection of the luminance caused by the limitation of the conventional linear interpolation method.

Those skilled in the art to which the present invention pertains will understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. Therefore, it is to be understood that the embodiments described above are exemplary in all respects and not restrictive.

The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

100: organic light emitting display device 110: OLED panel
120: gate driver 130: data driver
140: timing controller 150: memory
200: luminance correction data generating device 210: reference correction data generating unit
220: gamma curve calculator 230: luminance correction data generator

Claims (11)

A reference correction data generator configured to generate first reference correction data and second reference correction data for correcting luminance distortion of the first reference gray image and the second reference gray image;
A gamma curve generator configured to calculate a gamma curve of a third reference gray image and a fourth reference gray image based on the first reference correction data and the second reference correction data; And
Third reference correction data and fourth reference correction for correcting luminance distortion of the third reference gray image and the fourth reference gray image based on a gamma curve of the third reference gray image and the fourth reference gray image And a luminance correction data generator for generating data. According to claim 1,
The luminance correction data generator corrects the luminance distortion of the first to fourth reference gray images by using a deviation between the gamma curve without luminance distortion of the first to fourth reference gray images and the gamma curve from which the luminance distortion is generated. A luminance correction data generating device for generating luminance correction data for use. According to claim 1,
And the luminance correction data generation unit generates luminance correction data of a 0 to 255 gray image based on the first reference correction data to the fourth reference correction data. The method of claim 3, wherein
The luminance correction data generation unit generates luminance correction data of 0 to 31 gray images by applying linear interpolation to luminance correction data of a 32 gray image. The method of claim 3, wherein
The luminance correction data generating unit generates luminance correction data of 33 to 63 gray images by applying linear interpolation to luminance correction data of a 32 gray image and luminance correction data of a 64 gray image. The method of claim 3, wherein
The luminance correction data generating unit generates luminance correction data of 65 to 127 gray images by applying linear interpolation to luminance correction data of a 64 gray image and luminance correction data of a 128 gray image. The method of claim 3, wherein
A luminance correction data generating device for generating luminance correction data of 129 to 191 gray images by applying linear interpolation to luminance correction data of 128 gray images and luminance correction data of 192 gray images. The method of claim 3, wherein
And the luminance correction data generator generates luminance correction data of 193 to 255 gray images by applying linear interpolation to luminance correction data of a 192 gray image. Imaging the first reference gray image displayed on the screen to generate first reference correction data for correcting luminance distortion of the first reference gray image;
Photographing a second reference gray image to generate second reference correction data for correcting luminance distortion of the second reference gray image;
Calculating a gamma curve of a third reference gray image and a fourth reference gray image based on the first reference correction data and the second reference correction data;
Generating third reference correction data for correcting luminance distortion of the third reference gray image based on a gamma curve of the third reference gray image; And
Generating fourth reference correction data for correcting luminance distortion of the fourth reference gray image based on the gamma curve of the fourth reference gray image. The method of claim 9,
Luminance correction data for correcting luminance distortion of the first to fourth reference gray images is obtained by using a deviation between a gamma curve without luminance distortion of the first to fourth reference gray images and a gamma curve from which luminance distortion is generated. A method of generating luminance correction data. The method of claim 9,
And generating luminance correction data of the entire gray image based on the first reference correction data and the fourth reference correction data.

Images