KR102138590B1 - 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 capable of preventing image distortion such as spotting defects.
A method for generating luminance correction data according to an embodiment of the present invention includes generating reference correction data for correcting a deviation between luminance of a test image supplied to a display panel and actual measured reference luminance; Setting a correction section in which luminance correction is performed based on the reference luminance; Generating correction data for luminance included in the correction period by applying a linear interpolation method; Calculating a gain reflecting gamma characteristics for each luminance; And generating luminance correction data by reflecting the gain in the 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 capable of preventing image distortion such as uneven defects, and a method for correcting luminance of a display apparatus.

The flat panel display 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 (OLED). emitting diode display device).

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

1 is a circuit diagram schematically showing a pixel structure of an organic light emitting diode display according to the prior 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 switching thin film transistor ST is switched according to the scanning signal supplied to the scanning line SL to supply the data voltage Vdata supplied to the data line DL to the driving thin film transistor DT.

The driving thin film transistor DT is switched according to the data voltage Vdata supplied from the switching thin film transistor ST to control the data current idata flowing from the driving power source Vdd to the light emitting device OLED.

The capacitor C is connected between the gate terminal of the driving thin film transistor DT and the ground line VL to store a voltage corresponding to the data voltage Vdata supplied to the gate terminal of the driving thin film transistor DT, and stores the stored voltage. In turn, the turn-on state of the driving thin film transistor DT is kept constant for one frame.

The light emitting element OLED is electrically connected between the source terminal of the driving thin film transistor DT and the ground power source Vss to emit light by the data current idata supplied from the driving thin film transistor DT. In this case, the data current idata flowing through the light emitting device OLED includes the voltage Vgs between the gate-source of the driving thin film transistor DT, the threshold voltage Vth of the driving thin film transistor DT, and the data voltage Vdata. ).

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

In general, all OLED panels produced when the same manufacturing process is applied should have the same luminance characteristics, but there is a deviation in the actual manufacturing process, so all OLED panels do not exhibit the same luminance characteristics. In addition, deviations may occur in the luminance characteristics that are initially designed and the luminance characteristics after manufacturing is completed. The variation in luminance characteristics may be different for each OLED panel, or may be different for each pixel in one OLED panel.

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

2 is a view showing a luminance correction method of an organic light emitting display device according to the prior art.

Referring to FIG. 2, after manufacturing of the OLED panel is completed, screen inspection of the OLED panel is performed before it is released as a product to correct stain defects on all pixels.

In order to reduce the amount of calculation for calculating the luminance correction data, luminance correction data for the representative luminance (gradation) among the entire luminance (gradation) is generated, and the luminance correction data is generated by applying a linear interpolation method to the remaining luminance.

For example, after generating luminance compensation data for the reference luminance (eg, 32, 64, 128, 255 luminance), the remaining gray luminance compensation data is applied by interpolation using the reference luminance. To create.

At this time, since the low luminance, for example, 32 luminance or less, has nonlinear characteristics, an error occurs in luminance correction data generated through linear interpolation. Due to the difference between the actual luminance and the luminance and luminance correction data, a problem occurs in which luminance is excessively compensated (overcompensated) or not compensated (weakly compensated) at low luminance (low gradation). In addition, there is a problem in that the contour of the object is distorted.

In order to solve this problem, luminance correction data can be generated for all pixels and all luminances, but there is another problem in that manufacturing costs increase due to an increase in memory. In addition, there is another problem that it is difficult to apply to high-speed/high-resolution products because it takes much time to generate and load luminance correction data.

This image distortion phenomenon occurs not only in the organic light emitting diode display device but also in other display devices. Furthermore, the image 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 the image distortion caused by luminance non-uniformity of each pixel of the display device.

The present invention is to solve the above-mentioned problems, and it is a technical problem to provide an apparatus and method for generating luminance correction data capable of preventing image distortion such as unevenness.

The present invention is to solve the above-mentioned problems, and provides an apparatus and method for generating luminance correction data that can prevent excessive compensation of luminance, non-compensation, and distortion of an outline of an object due to limitations of a conventional linear interpolation method Doing so is a technical task.

The present invention is to solve the above-mentioned problems, and it is a technical problem to provide an apparatus and method for generating luminance correction data capable of preventing errors in luminance correction data for luminance having a non-linear gamma curve.

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

A method for generating luminance correction data according to an embodiment of the present invention for achieving the above-described technical problem includes: generating reference correction data for correcting a deviation between luminance of a test image supplied to a display panel and actual measured reference luminance; Setting a correction section in which luminance correction is performed based on the reference luminance; Generating correction data for luminance included in the correction period by applying a linear interpolation method; Calculating a gain reflecting gamma characteristics for each luminance; And generating luminance correction data by reflecting the gain in the correction data.

A luminance correction data generating apparatus according to an embodiment of the present invention for achieving the above-described technical problem is a reference correction for generating reference correction data for correcting a deviation between the luminance of the test image supplied to the display panel and the actually measured reference luminance A data generator; A correction section setting unit for setting a correction section in which brightness correction is performed based on the reference brightness; An interpolation unit to generate correction data for luminance included in the correction section by applying a linear interpolation method; And a gain calculator configured to calculate a gain reflecting gamma characteristics for each luminance and generate luminance correction data by reflecting the gain in the correction data.

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

According to the solving means of the above problems, the apparatus and method for generating luminance correction data according to an embodiment of the present invention are capable of over-compensating for luminance, non-compensating, and distortion in the contour of an object generated due to limitations of the conventional linear interpolation method. Can be prevented.

According to the solving means of the above problems, the apparatus and method for generating luminance correction data according to an embodiment of the present invention can prevent errors in luminance correction data for luminance in which a gamma curve has nonlinear characteristics.

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

1 is a circuit diagram schematically showing a pixel structure of an organic light emitting diode display according to the prior art.
2 is a view showing a luminance correction method of an organic light emitting display device according to the prior art.
3 is a view showing an organic light emitting display device to which luminance correction data is applied according to an embodiment of the present invention.
4 is a view showing an apparatus for generating luminance correction data according to an embodiment of the present invention.
5 to 10 are views showing a method for generating luminance correction data and a method for correcting luminance in an organic light emitting display device according to an embodiment of the present invention.

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

3 is a diagram illustrating an organic light emitting display device to which luminance correction data is applied according to an embodiment of the present invention, and FIG. 4 is a diagram illustrating an apparatus for generating luminance correction data according to an embodiment of the present invention.

3 and 4, the organic light emitting display device 100 includes an OLED panel 110 and a panel driver. The luminance correction data generation apparatus 200 according to an embodiment of the present invention includes a reference correction data generation unit 210, a correction interval setting unit 220, an interpolation unit 230, and a gain calculation unit 240.

The panel driver of the organic light emitting 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 input data input from the outside. And supply to each pixel.

The OLED panel 110 displays an image by emitting an organic light emitting diode (OLED) formed in each sub pixel according to the data voltage Vdata supplied from the data driver 130. To this end, the OLED panel 110 is formed to intersect with each other, and includes a plurality of first data lines DL, a plurality of scan lines SL, and a plurality of first data lines DL. The power line PL1 and the plurality of second power lines PL2 formed to cross the plurality of first power lines PL1 are formed.

The plurality of data lines DL are formed at regular intervals along the first direction, and the plurality of scan lines SL are formed at regular intervals along the second direction intersecting the first direction. In addition, the first power lines PL1 are formed in parallel so as to be adjacent to each of the plurality of data lines DL to receive the first driving power from the outside.

Each of the plurality of second power lines PL2 is formed to cross the plurality of first power lines PL1 to receive the second driving power from the outside. In this case, the second driving power source may have a lower potential voltage level than the first driving power source, or may have a ground (or ground) voltage level.

Meanwhile, the OLED panel 110 may include a common electrode instead of the plurality of second power lines PL2. In this case, the common electrode is formed on the entire display area of the OLED panel 110 to receive a second driving power from the outside.

As an example, the sub-pixel may be divided into a red sub-pixel, a green sub-pixel, and a blue sub-pixel, and constitutes one pixel with such a red sub-pixel, a green sub-pixel, and a blue sub-pixel.

As another example, the sub-pixel may be divided into a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel, and such a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel Constructs a pixel.

The organic light emitting diode (OLED) is formed between the anode electrode (or pixel electrode) connected to the pixel circuit, the cathode electrode (or reflective electrode) connected to the second driving power supply line (PL2), and the anode electrode and the cathode electrode. It comprises an organic light emitting cell that emits light of any one of green, blue, and white.

Here, 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, a functional layer for improving light emission efficiency and/or lifespan of the organic light emitting layer may be further formed in the organic light emitting cell.

The pixel circuit responds to the scan signal SS supplied from the gate driver 120 to the scan line SL, and the data current corresponding to the data voltage Vdata supplied from the data driver 130 to the data line DL. Let it flow to the organic light emitting device (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 the 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 supplies it to the organic light emitting device (OLED) so that it 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 the 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 timing controller 140 generates scan control signals and data control signals based on timing synchronization signals such as a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), a data enable (DE), and a clock (DCLK). , 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.

The memory 150 is included in the organic light emitting display device 100, and the memory 150 includes luminance correction data to prevent image distortion, such as unevenness due to luminance non-uniformity of all pixels of the OLED panel 110. Is stored. At this time, luminance correction data may be generated and stored for individual pixels, or luminance correction data may be generated and stored in units of each block by configuring pixels of a certain outline as blocks.

The timing controller 140 loads the luminance correction data stored in the memory 150 and reflects it in the image data supplied to the OLED panel 110 to correct luminance of all pixels. At this time, the timing controller 140 aligns the data of red, green, blue, and white to suit the driving of the OLED panel 110 and supplies the aligned data RGBW to the data driver 130. Meanwhile, the memory 150 in which the luminance correction data is stored may be implemented in a form embedded in the timing controller 140.

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 it to the plurality of scan lines SL.

The data driver 130 receives data RGBW and data control signals 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 to the corresponding data line DL ).

5 to 10 are diagrams illustrating a method for generating luminance correction data and a method for correcting luminance in an organic light emitting display device according to an embodiment of the present invention.

Hereinafter, a luminance correction data generating apparatus and a method for generating luminance correction data according to an embodiment of the present invention will be described with reference to FIGS. 5 to 10 and a luminance correction method of the organic light emitting display device will be described.

Referring to FIG. 5, the test image supply unit generates first to fourth test images having different gradation values, and supplies data of the generated first to fourth test images to the organic light emitting display device 100. For example, the first test image may be displayed with 32 luminance (gray level), the second test image with 64 luminance, the third test image with 128 luminance, and the fourth test image with 255 luminance. 32, 64, 128, 255 luminance is set as the reference luminance to perform luminance correction of 0 to 255 luminance.

In this case, the test image supply unit may sequentially arrange the first to fourth test images and supply them to the organic light emitting display device 100, and the organic light emitting display device 100 may test one of the first to fourth test images. It can also be supplied to.

The OLED panel 110 displays the test image supplied from the test image supply unit, and the luminance measurement device measures the luminance of the test image displayed on the OLED panel 110. In this case, the OLED panel 110 may sequentially display the first to fourth test images of different gray levels, or may display one test image.

The luminance measurement device provides reference luminance data of the test image obtained by imaging the test image displayed on the front of the OLED panel 110 to the luminance correction data generation device 200. At this time, when the first to fourth test images are displayed on the OLED panel 110, corresponding first to fourth reference luminance data is generated and provided to the luminance correction data generating apparatus 200.

Meanwhile, when only one test image is displayed among the first to fourth test images on the OLED panel 110, one reference luminance data corresponding thereto is generated and provided to the luminance correction data generating apparatus 200. The luminance measurement device may be a digital camera or an image sensor.

Since the luminance of 32 or less is large, the error in the luminance correction data generated through the linear interpolation method may be larger than that of other luminances (luminances exceeding 32 luminance).

The luminance correction data generating apparatus 200 according to an embodiment of the present invention corrects luminance such that luminance according to input image data is accurately displayed in a pixel, and when a luminance deviation in which actual luminance is increased compared to input image data occurs The luminance is corrected by lowering the gradation of the image data input to the pixel.

Conversely, when a luminance deviation occurs in which the actual luminance is lower than the input image data, the luminance is corrected by increasing the gradation of the image data input to the pixel.

The luminance correction data generating apparatus 200 generates reference correction data for 32 luminance, 64 luminance, 128 luminance, and 255 luminance, and applies gain obtained by reflecting gamma characteristics to 0-255 luminance obtained through a linear interpolation method. It prevents an error from occurring in the luminance correction data.

Here, since 32 gamma, 64 luminance, 128 luminance, and 255 luminance have different gamma characteristics, errors due to the application of linear interpolation by applying different gains reflecting gamma characteristics to 32 luminance, 64 luminance, 128 luminance, and 255 luminance Correct.

The reference correction data generation unit 210 generates reference correction data for 32 luminance, 64 luminance, 128 luminance, and 255 luminance based on the reference luminance data supplied from the luminance measurement device.

Here, the 32 luminance, 64 luminance, 128 luminance and 255 luminance test images are supplied to the OLED panel 110, and the actual luminance of the test image displayed on the OLED panel 110 is measured to provide a theoretical luminance value and luminance measurement device. The reference correction data for correcting the deviation of the reference luminance data supplied from are generated.

When a test image of 32 luminance is displayed on the OLED panel 110, when the luminance of the actually measured image is higher than the 32 luminance, reference correction data is generated to lower the luminance of the pixel so that negative compensation is performed. Conversely, when the luminance of the actually measured image is lower than the luminance of 32, reference correction data is generated so that positive compensation is achieved, thereby increasing the luminance of the pixel.

Here, reference correction data may be generated for all four reference luminances (32, 64, 128, and 255 luminances), and reference correction data may be generated for some of the four reference luminances (32, 64, 128, and 255 luminances). You can also create

Meanwhile, when the reference correction data generation unit 210 generates luminance correction data for the reference luminance (32, 64, 128, 255 luminance), the luminance distortion value of the reference luminance (32, 64, 128, 255 luminance) ( r_mura) as 8-bit data, and the luminance distortion values (r_mura) of the generated reference luminances (32, 64, 128, and 255 luminance) can be stored in a lookup table. Here, the look-up table is provided as a memory in the luminance correction data generating device 200.

It can be seen how the reference luminances 32, 64, 128, and 255 displayed on the OLED panel 110 are distorted through the luminance distortion value r_mura. When image data representing the original 32 luminance is input, it can be seen whether the OLED panel 110 is actually displayed with a luminance lower than 32 luminance or, conversely, a luminance higher than 32 luminance. In addition, the deviation between the luminance originally intended to be displayed and the actual displayed luminance can be seen.

The correction section setting unit 220 determines an interval to which the interpolation method is applied based on the image data of the test image displayed on the OLED panel 110 and the reference correction data provided by the reference correction data generation unit 210. That is, it is determined which of the four reference luminances is the reference luminance data of the four reference luminances (32, 64, 128, and 255 luminance), and a correction period to which an interpolation method is applied is determined. The correction section setting unit 220 provides the determined interpolation section information to the interpolation unit 230.

For example, when the reference correction data of 32 luminance is input, the correction period setting unit 220 determines the 0 to 32 luminance period as the correction period.

For example, when reference correction data of 32 luminance and 64 luminance is input, the correction period setting unit 220 determines the 32 to 64 luminance period as the correction period.

For example, when the reference correction data of 64 luminance and 128 luminance is input, the correction period setting unit 220 determines the 64 to 128 luminance period as the correction period.

For example, when the reference correction data of 128 luminance and 255 luminance is input, the correction period setting unit 220 determines the 128 to 255 luminance period as the correction period.

The interpolation unit 230 performs a linear interpolation method on luminances of the interpolation section determined by the correction section setting unit 220 to calculate a center value, and generates the intermediate value as correction data. Then, the generated correction data is provided to the gain calculator 240.

At this time, since the reference correction data of the reference luminance (32, 64, 128, 255 luminance) is already generated by the reference correction data generator 210, the correction data for the reference luminance (32, 64, 128, 255 luminance) is It may not be created separately.

Specifically, when the 0 to 32 luminance section is determined as the correction period in the correction section setting unit 220, the interpolation unit 230 is linear with respect to the remaining luminance (0 to 31 luminance) excluding 32 luminance among the 0 to 32 luminance. Intermediate values obtained by interpolation are generated as correction data.

In addition, the interpolation unit 230 is obtained by performing linear interpolation on the remaining luminances (33 to 63 luminance) except 32 luminance and 64 luminance among the 32 to 64 luminance when the 32 to 64 luminance period is determined as the correction period. Values are generated as correction data.

In addition, when the 64 to 128 luminance period is determined as the correction period, the interpolation unit 230 is obtained by performing linear interpolation on the remaining luminance (65 to 127 luminance) excluding 64 luminance and 128 luminance among the 64 to 128 luminance. Values are generated as correction data.

In addition, the interpolation unit 230 is an intermediate obtained by performing linear interpolation on the remaining luminance (129 to 254 luminance) except for 128 luminance and 255 luminance among the 128 to 255 luminance when the 128 to 255 luminance period is determined as the correction period. Values are generated as correction data.

Referring to FIGS. 6 to 8, the gain calculator 240 generates luminance correction data by applying different gains reflecting gamma characteristics of 0 to 255 luminance to prevent errors in the luminance correction data. . Through this, errors due to the application of the linear interpolation method can be corrected.

As another example, the gain calculator 240 generates luminance correction data by applying different gains having gamma characteristics to 0 to 32 luminance, 33 to 64 luminance, 65 to 128 luminance, and 129 to 255 luminance. Through this, errors due to the application of the linear interpolation method can be corrected.

The gain calculation unit 240 is the reference luminance (32, 64, 128, 255 luminance) generated by the image data and the reference correction data generation unit 210 of the test image displayed on the OLED panel 110, as shown in Equation 1 below. The luminance distortion value r_mura is calculated based on the reference correction data of ), and the calculated luminance distortion value r_mura is stored in the lookup table LUT.

[Equation 1]

In Equation 1, "GRAY" is the luminance of the test image input to the OLED panel 110, and means the reference luminance (32, 64, 128, 255 luminance). In addition, "A" is the reference correction data generated for the reference luminance (32, 64, 128, 255 luminance) after measuring luminance using a luminance measuring device at a sampling point (sampling point) of the OLED panel 110 to be. And, “r_mura” is a luminance distortion value, and “r” is a gamma value, and 2.2 gamma is applied.

Subsequently, the gain calculating unit 240 is 0 to 255 based on the image data, the correction data B generated by the interpolation unit 230, and the previously calculated luminance distortion value r_mura, as shown in Equation 2 below. The luminance correction data of luminance is generated.

As illustrated in FIG. 8, since 0 to 32 luminance, 33 to 64 luminance, 65 to 128 luminance, and gamma characteristics in 129 to 255 are different from each other, 0 to 32 luminance, 33 to 64 luminance, 65 to 128 luminance, and The luminance correction data for the luminance of 0 to 255 is generated by applying different gains (k) reflecting gamma characteristics to the luminance of 129 to 255.

In this case, luminance correction data of 0 to 255 luminance may be generated by reflecting gain (k) generated for each luminance in the correction data generated for the luminance of 0 to 255.

[Equation 2]

In Equation 1, when the reference luminances (32, 64, 128, and 255 luminance) are substituted for “GRAY”, only the luminance distortion value “r_mura” becomes an unknown value. At this time, complex hardware logic is required to calculate the luminance distortion value r_mura for the entire luminance.

Therefore, when the reference correction data generation unit 210 generates luminance correction data for the reference luminance (32, 64, 128, 255 luminance) in advance, the luminance distortion of the reference luminance (32, 64, 128, 255 luminance) The value r_mura is generated as 8-bit data, and the luminance distortion value r_mura of the generated reference luminance (32, 64, 128, 255 luminance) is stored in a lookup table.

The luminance distortion value (r_mura) of the reference luminance (32, 64, 128, 255 luminance) stored in the lookup table is substituted into Equation 2, and the reference luminance (32, 64, 128, 255 luminance) is excluded from "gray". , Substitute the desired luminance (0 to 31 luminance, 33 to 63 luminance, 65 to 127 luminance, and 129 to 254 luminance). Then, the correction data generated by applying the linear interpolation method in the interpolation unit 230 is substituted into "B" to calculate a gain (k) of 0 to 255 luminance. By applying the calculated gain to the luminance correction data, errors in luminance correction data according to the application of the linear interpolation method can be reduced or prevented.

In particular, the gain (k) calculated for the luminance range of 0 to 31 is reflected in the luminance range of 0 to 31 to reduce errors in luminance correction data due to the application of the linear interpolation method at low gradations of 32 luminance or less with a large nonlinear characteristic, or Can be prevented.

In addition, the gain k calculated for the 33 to 63 luminance section may be reflected in the 33 to 63 luminance section, thereby reducing or preventing errors in luminance correction data according to the application of the linear interpolation method in the 33 to 63 luminance section.

In addition, the gain (k) calculated for the luminance section of 65 to 127 may be reflected in the luminance section of 65 to 127 to reduce or prevent errors in luminance correction data according to the application of the linear interpolation method in the luminance section of 65 to 127.

In addition, the gain (k) calculated for the luminance periods 129 to 254 may be reflected in the luminance periods 129 to 254 to reduce or prevent errors in luminance correction data according to the application of the linear interpolation method in the luminance periods 129 to 254.

When calculating the gain (k) by performing each operation, complicated hardware logic is required, so the gain (k) according to the input luminance (0 to 255 luminance), luminance distortion value (r_mura), and correction data (B) obtained through linear interpolation ) Is calculated for 0 to 255 luminance, and the calculated gain value is stored in a lookup table (LUT).

Referring to FIG. 8, a luminance distortion region A in which luminance is distorted lower than that of the correction data center obtained through the preceding interpolation may be generated. On the contrary, a luminance distortion region B in which luminance is distorted higher than that of the correction data center obtained through the preceding interpolation may be generated.

Referring to FIG. 9, when a luminance distortion region A in which luminance is distorted lower than that in comparison with the correction data center obtained through the preceding interpolation method is generated, the luminance correction data generating apparatus 200 according to an embodiment of the present invention Generates positive luminance correction data that increases the gradation of image data input to the OLED panel 110 and stores it in the memory 150 of the organic light emitting display device 100.

Referring to FIG. 10, when a luminance distortion region B in which luminance is distorted higher than that in comparison with the correction data center obtained through the preceding interpolation method is generated, the luminance correction data generating apparatus 200 according to an embodiment of the present invention Generates negative luminance correction data that lowers the gradation of image data input to the OLED panel 110 and stores it in the memory 150 of the organic light emitting display device 100.

The apparatus 200 for generating luminance correction data according to an embodiment of the present invention may map the luminance correction data in a table form to correspond to each pixel. When a plurality of blocks are configured in units of 4x4 pixels, luminance correction may be performed by applying the same luminance correction data to pixels included in one block.

In the above-described luminance correction data generation apparatus and a method for generating luminance correction data using the same according to an embodiment of the present invention, the test image supply unit generates each of the first to fourth test images, and the luminance measurement apparatus comprises the OLED panel 110 Although it has been described as obtaining luminance information of the test image by imaging the test image displayed in the present invention, it is not limited thereto.

In another example of the present invention, the luminance measurement information of each pixel may be obtained by sensing a current flowing through a pixel of the OLED panel 110 according to input data without using a luminance measurement device.

The apparatus and method for generating luminance correction data according to an embodiment of the present invention prevents errors in luminance correction data for luminance in which gamma curves have nonlinear characteristics, thereby improving or preventing image distortion caused by luminance irregularity of pixels. Can be. In addition, it is possible to prevent excessive compensation of luminance, non-compensation, and distortion of an outline of an object, which are generated due to limitations of the conventional linear interpolation method.

Meanwhile, although the above-described luminance correction data generating apparatus and a method for generating luminance correction data using the same are described as correcting the luminance of the pixels of the OLED panel 110, the present invention is not limited thereto, and each sub-pixel may be formed of a liquid crystal cell or a discharge cell. have. That is, a liquid crystal panel or a plasma display panel may be applied by replacing the OLED panel 110 described above, and a method of generating luminance correction data and correcting the luminance of a pixel using the same may be applied even if the display panel is changed. .

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

The scope of the present invention is indicated by the following claims rather than the above detailed description, and it should be interpreted that all changes or modifications derived from the meaning and scope of the claims and equivalent concepts are 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
210: reference correction data generation unit 220: correction section setting unit
230: interpolation unit 240: gain calculation unit

Claims (10)

Generating reference correction data for correcting a deviation between the luminance of the test image supplied to the display panel and the actually measured reference luminance;
Setting a correction section in which luminance correction is performed on the input image data based on the reference luminance;
Generating correction data for each luminance included in the correction period from the reference correction data using a linear interpolation method;
Calculating a gain for each luminance indicating a gamma characteristic for each luminance; And
And generating luminance correction data by reflecting the gain for each luminance in the correction data for each luminance generated by the linear interpolation method,
The generating of the luminance correction data may include calculating the gain for each luminance; And generating the luminance correction data by reflecting gains of different luminance for at least two different luminances,
The step of calculating the gain for each luminance is
A luminance distortion value is calculated based on the reference luminance and the reference correction data,
The gain is calculated based on the luminance distortion value, the correction data, and each luminance value included in the correction section.
Method for generating luminance correction data. According to claim 1,
A method of generating luminance correction data, characterized in that the reference correction data of 32, 64, 128 and 255 luminance is generated from 0 to 255 luminance. According to claim 1,
Luminance characterized by calculating a gain for each luminance corresponding to 0 to 255 luminance based on the test image, the luminance distortion value, and the correction data calculated through the linear interpolation method, and storing the gain for each luminance in a lookup table. How to generate calibration data. The method of claim 3,
A method of generating luminance correction data, wherein the gain of 0 to 255 luminance is calculated based on the test image, the luminance distortion value, and the correction data calculated through the linear interpolation method, and the gain is stored in a lookup table. The method of claim 4,
A method for generating luminance correction data, wherein the luminance correction data is generated by applying the gain for each luminance to the correction data for 0 to 255 luminance. delete A reference correction data generator for generating reference correction data for correcting a deviation between the luminance of the test image supplied to the display panel and the actually measured reference luminance;
A correction section setting unit for setting a correction section in which luminance correction is performed on the input image data based on the reference luminance;
An interpolation unit that generates correction data for each luminance included in the correction period from the reference correction data using a linear interpolation method; And
Includes a gain calculation unit that calculates a gain for each luminance representing a gamma characteristic for each luminance corresponding to each luminance generated by the linear interpolation method, and generates luminance correction data by reflecting the gain for each luminance in the correction data for each luminance and,
The gain calculation unit,
A luminance distortion value is calculated based on the reference luminance and the reference correction data,
A gain is calculated based on the luminance distortion value, the correction data, and each luminance value included in the correction section,
A luminance correction data generating apparatus characterized in that the luminance correction data is generated by reflecting gains of different luminance for at least two different luminances. The method of claim 7,
The reference correction data generation unit,
When generating reference correction data for the reference luminance, a luminance distortion value indicating how distorted the reference luminance is is generated from the luminance of the test image, and the generated luminance distortion value is stored in a lookup table, and 0 to A luminance correction data generating apparatus, characterized in that it generates reference correction data of 32, 64, 128 and 255 luminance among 255 luminance. The method of claim 8,
The gain calculation unit,
Luminance characterized by calculating a gain for each luminance corresponding to 0 to 255 luminance based on the test image, the luminance distortion value, and the correction data calculated through the linear interpolation method, and storing the gain for each luminance in a lookup table. Calibration data generation device. The method of claim 9,
A luminance correction data generating apparatus, characterized in that the luminance correction data is generated by applying the gain for each luminance to the correction data for 0 to 255 luminance.

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