Display device

Abstract

The present invention provides a display device, comprising: a display panel including a plurality of pixels; a first correction unit, which performs gamma correction on first image data input from the outside using a gamma correction value; a second correction unit, which performs grayscale compensation on the gamma-corrected first image data to generate second image data; and a data driving unit, which provides a data signal corresponding to the second image data to the plurality of pixels, wherein the second correction unit performs the grayscale compensation based on a characteristic value measured for each of the pixels and the gamma correction value.

Description

Technical Field

[0001] The present invention relates to a display device and a method for driving the display device. Background Art

[0002] The display device includes a display panel and a display panel driving unit. The display panel includes scan lines, data lines and pixels. The display panel driving unit includes a controller, a scan driving unit and a data driving unit.

[0003] Each pixel includes multiple transistors, storage capacitors, and organic light-emitting diodes. When brightness differences between pixels occur due to variations in transistor threshold voltages, users of the display device may perceive them as smearing. To address this smearing, threshold voltage compensation of the image signal can be employed.

[0004] Recently, as the resolution of display devices increases, in order to shorten the processing time of threshold voltage compensation, the compensation value is determined for only one color in RGB, and the same compensation value is used for all other colors. However, this method cannot accurately control the required grayscale. Summary of the Invention

[0005] An object of the present invention is to provide a display device and a method for driving the display device, which can use threshold voltage compensation without color variation for an image signal.

[0006] Another object of the present invention is to provide a display device and a method for driving the display device, which utilize an ACC LUT to perform threshold voltage compensation on image data.

[0007] A display device according to one embodiment of the present invention includes: a display panel including a plurality of pixels; a first correction unit that performs gamma correction on first image data input from an external device using a gamma correction value; a second correction unit that performs grayscale compensation on the gamma-corrected first image data to generate second image data; and a data driving unit that provides data signals corresponding to the second image data to the plurality of pixels; the second correction unit performs the grayscale compensation based on characteristic values ​​measured for each of the pixels and the gamma correction value.

[0008] In addition, the first correction unit may obtain a pre-stored gamma correction value corresponding to the first image data, and apply the gamma correction value to the first image data to perform the gamma correction.

[0009] In addition, the second correction unit can determine the grayscale compensation level for the first image data based on the measured characteristic value, apply the gamma correction value to the determined grayscale compensation level to determine the grayscale compensation value for the first image data, and apply the determined grayscale compensation value to the gamma-corrected first image data to generate the second image data.

[0010] Furthermore, the second correction unit may determine the grayscale compensation level based on the measured characteristic value of the pixel displaying the first color, and determine the determined grayscale compensation level as the grayscale compensation value for the image data of the first color.

[0011] Furthermore, the second correction unit may determine a ratio of a gamma correction value of the second color to a gamma correction value of the first color, and apply the determined ratio to the grayscale compensation level to determine a grayscale compensation value for the second color.

[0012] In addition, the first correction section may acquire the gamma correction value from a pre-stored lookup table.

[0013] Additionally, the characteristic value may be a threshold voltage of the pixel.

[0014] In addition, a driving method for a display device according to an embodiment of the present invention is used to drive a display device including multiple pixels, and the driving method includes: a step of performing gamma correction on first image data input from the outside using a gamma correction value; a step of performing grayscale compensation on the gamma-corrected first image data to generate second image data; and a step of outputting an image corresponding to the second image data; the step of generating the second image data includes: a step of determining a grayscale compensation value based on a characteristic value measured for the pixel and the gamma correction value; and a step of applying the grayscale compensation value to the gamma-corrected first image data to generate the second image data.

[0015] In addition, the step of performing the gamma correction may include: a step of acquiring a pre-stored gamma correction value corresponding to the first image data; and a step of applying the gamma correction value to the first image data.

[0016] In addition, the step of generating the second image data may include: a step of determining a grayscale compensation level for the first image data based on the measured characteristic value; a step of applying the gamma correction value to the determined grayscale compensation level to determine the grayscale compensation value for the first image data; and a step of applying the determined grayscale compensation value to the gamma-corrected first image data to generate the second image data.

[0017] In addition, the step of determining the grayscale compensation level may include: the step of determining the grayscale compensation level based on the characteristic value measured of the pixel displaying the first color; the step of determining the grayscale compensation value includes: the step of determining the determined grayscale compensation level as the grayscale compensation value relative to the image data of the first color.

[0018] In addition, the step of determining the grayscale compensation value may also include: a step of determining the ratio of the gamma correction value of the second color relative to the gamma correction value of the first color; and a step of applying the determined ratio to the grayscale compensation level to determine the grayscale compensation value for the second color.

[0019] In addition, the step of acquiring the pre-stored gamma correction value may include the step of loading the gamma correction value corresponding to the first image data from a pre-stored lookup table.

[0020] Additionally, the characteristic value may be a threshold voltage of the pixel.

[0021] (Effects of the Invention)

[0022] According to the display device and the method for driving the display device of the present invention, threshold voltage compensation can be employed without causing color variation in an image signal.

[0023] According to the display device and the method for driving the display device of the present invention, stains on the display device can be effectively removed, and color distortion caused by the stain removal can be prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a block diagram showing a display device according to an embodiment of the present invention.

[0025] Figure 2 It shows Figure 1 A circuit diagram of an example of a pixel shown.

[0026] Figure 3 More specifically, Figure 1 Block diagram of the timing control unit.

[0027] Figure 4 and Figure 5 This is a diagram for explaining compensation of video data by the timing control unit.

[0028] Figure 6 This is a flowchart illustrating a method for driving a display device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same or similar symbols are used for the same structural elements in the accompanying drawings.

[0030] Figure 1 This is a block diagram showing a display device according to an embodiment of the present invention.

[0031] Reference Figure 1 A display device 100 according to an embodiment of the present invention may include a display panel 110, a scan driver 120, a data driver 130, a detector 140, a timing controller 150, and a memory 160. The display device 100 may be a device that outputs an image based on externally provided image data (e.g., first image data DATA1). For example, the display device 100 may be an organic light-emitting display device.

[0032] The display panel 110 may include a plurality of first scan lines S11 to S1n, a plurality of second scan lines S21 to S2n, a plurality of data lines D1 to Dm, a plurality of detection lines SS1 to SSm, and a plurality of pixels PX (or sub-pixels), where n and m may be integers greater than or equal to 2.

[0033] The pixels PX may be disposed at intersections of the first scan lines S11 to S1n, the second scan lines S21 to S2n, the data lines D1 to Dm, and the detection lines SS1 to SSm.

[0034] Each pixel PX may emit light based on a first scan signal supplied to the first scan lines S11 to S1n, a second scan signal supplied to the second scan lines S21 to S2n, and a data signal supplied to the data lines D1 to Dm. Figure 2 , the structure of the pixel PX is described in more detail.

[0035] The scan driver 120 may generate a first scan signal and a second scan signal based on the scan driver control signal SCS. Specifically, the scan driver 120 may provide the first scan signal to the pixels PX via the first scan lines S11 to S1n during a display period, and may provide the second scan signal to the pixels PX via the second scan lines S21 to S2n during a detection period for detecting characteristics of the pixels PX.

[0036] The timing control unit 150 may provide a scan driving control signal SCS to the scan driving unit 120. The scan driving control signal SCS may include a start pulse and a clock signal. The scan driving unit 120 may include a shift register that sequentially generates scan signals in response to the start pulse and the clock signal.

[0037] The data driver 130 can generate a data signal based on the data drive control signal DCS and image data (e.g., second image data DATA2). The data driver 130 can provide the data signal generated by the data drive control signal DCS during a display period within a frame to the display panel 110. Specifically, the data driver 130 can provide the data signal to the pixel PX via the data lines D1 to Dm. The data drive control signal DCS can be provided to the data driver 130 by the timing control unit 150.

[0038] The detection unit 140 can be connected to the detection lines SS1 to SSm and can measure (or sense or detect) the characteristics of the pixel PX based on the detection control signal SSCS. The characteristics of the pixel PX can be the characteristics of the driving transistor included in each pixel PX, for example, the threshold voltage Vth, mobility, etc. of the driving transistor. In various embodiments, the characteristics of the pixel PX can also be the characteristics of the light-emitting element provided in each pixel PX. The detection unit 140 can transmit the measured characteristic information of the pixel PX, such as the threshold voltage Vth, to the timing control unit 150.

[0039] In an embodiment, the data driving unit 130 may apply a detection voltage to a specific data line (e.g., the mth data line Dm) in response to a detection control signal SSCS during a detection period, and the detection unit 140 measures the characteristics of each pixel PX from the current or voltage fed back through the detection line (e.g., the mth detection line SSm) in response to the detection voltage.

[0040] The timing control unit 150 can control the operations of the scan driver 120, the data driver 130, and the detection unit 140. The timing control unit 150 can generate a scan driver control signal SCS, a data driver control signal DCS, and a detection control signal SSCS, and control the scan driver 120, the data driver 130, and the detection unit 140 based on the generated signals.

[0041] In various embodiments of the present invention, the timing control unit 150 can correct the input image data (e.g., the first image data DATA1) by taking into account the gamma characteristics of the display device 100. Specifically, the timing control unit 150 can perform gamma correction on the red image data, green image data, and blue image data included in the input image data, thereby generating red corrected data, green corrected data, and blue corrected data. This gamma correction of the input image data can be referred to as ACC (Adaptive Color Correction) processing.

[0042] In various embodiments, the timing control unit 150 can refer to an ACC lookup table (LUT) stored in the memory 160 to perform ACC processing on the input image data. Specifically, the timing control unit 150 can load gamma correction values ​​corresponding to the red, green, and blue image data of the image data from the ACC LUT and apply the loaded gamma correction values ​​to correct the image data. However, the technical concept of the present invention is not limited to this. In various embodiments, the timing control unit 150 can also perform ACC processing on the input image data through real-time calculations.

[0043] In addition, in various embodiments of the present invention, the timing control unit 150 can compensate the gamma-corrected image data based on the threshold voltage Vth of each pixel PX measured by the detection unit 140, and provide the compensated image data (e.g., the second image data DATA2) to the data driving unit 130.

[0044] For example, the timing control unit 150 can determine the grayscale compensation level for the image data based on the threshold voltage Vth of the pixel PX measured during the detection period, and determine the grayscale compensation value based on the grayscale compensation level. In this case, the timing control unit 150 can determine the grayscale compensation value based on the gamma correction value for the input image data DATA1. For example, the timing control unit 150 can use the gamma correction value of the input image data DATA1 loaded from the ACC LUT to determine the grayscale compensation value based on the grayscale compensation level.

[0045] Regarding the image data compensation method of the timing control unit 150, refer to the following Figure 3 and Figure 6 A more specific explanation will be given.

[0046] The memory 160 may store data required to drive the display device 100. For example, the memory 160 may store the ACC LUT described above. The ACC LUT may be pre-set and stored in the memory 160 when the display device 100 is manufactured, or received from an external host device and stored in the memory 160.

[0047] In addition, Figure 1 Although the detection unit 140 is shown as a separate, independent component, the technical concept of the present invention is not limited thereto. Specifically, in various embodiments, the detection unit 140 may be incorporated into the data driver 130 or the timing control unit 150, or may be integrally formed with the data driver 130 or the timing control unit 150. In such embodiments, the detection lines SS1 to SSm are replaced by the data lines D1 to Dm, which are then utilized as the detection lines SS1 to SSm through time-division driving.

[0048] While the following description uses the timing control unit 150 as an example to illustrate the image data compensation of the present invention, the technical concept of the present invention is not limited thereto. Specifically, in various embodiments of the present invention, a separate image compensation unit, for example, may perform the image data compensation of the present invention and directly transmit the compensated image data to the timing control unit 150 or the data driver unit 130.

[0049] Figure 2 It shows Figure 1 For the convenience of explanation, the circuit diagram of an example of a pixel is shown. Figure 2 , a pixel PX connected to the i-th first scan line S1i, the i-th second scan line S2i, the j-th data line Dj, and the j-th detection line SSj is shown.

[0050] Reference Figure 2 Pixel PX may include first to third transistors T1 to T3, a storage capacitor Cst, and an organic light-emitting diode OLED. Such a pixel PX may be connected to the data driver 130 via a data line Dj and to the detection unit 140 via a detection line SSj. Furthermore, the pixel PX may be connected to the scan driver 120 via a first scan line S1i and a second scan line S2i.

[0051] The organic light emitting diode OLED may have an anode connected to the second electrode of the first transistor T1 (ie, the second node N2) and a cathode connected to the second driving power source ELVSS. The organic light emitting diode OLED generates light of predetermined brightness corresponding to the amount of current supplied from the first transistor T1.

[0052] A first transistor (T1; driving transistor) may have a first electrode connected to a first driving power source ELVDD, and a second electrode connected to an anode electrode (i.e., a second node N2) of the organic light emitting diode OLED. A gate electrode of the first transistor T1 may be connected to a first node N1. The first transistor T1 controls the amount of current flowing into the organic light emitting diode OLED in response to the voltage at the first node N1.

[0053] A first electrode of the second transistor T2 may be connected to the data line Dj, and a second electrode thereof may be connected to the first node N1. A gate electrode of the second transistor T2 may be connected to the first scan line S1i. The second transistor T2 may be turned on when a first scan signal is supplied to the first scan line S1i, thereby transmitting a voltage from the data line Dj to the first node N1.

[0054] In various embodiments of the present invention, a data signal may be provided to the data line Dj in synchronization with a first scan signal provided during a display period, and a detection voltage may be provided to the data line Dj in synchronization with the first scan signal provided during a detection period.

[0055] The third transistor T3 can be connected between the detection line SSj and the second electrode of the first transistor T1 (i.e., the second node N2). The gate electrode of the third transistor T3 is connected to the second scan line S2i. The third transistor T3 can be turned on when the second scan signal is supplied to the second scan line S2i, thereby electrically connecting the detection line SSj and the second node N2.

[0056] In various embodiments of the present invention, a reference voltage may be provided to the detection line SSj in synchronization with the second scan signal provided during the display period, and an arbitrary current or voltage may be provided from the second node N2 to the detection line SSj in synchronization with the second scan signal provided during the detection period. The current or voltage provided to the detection line SSj during the detection period may be transmitted to the detection unit 140 and utilized to measure the characteristics of the pixel PX. Here, the characteristics of the pixel PX may include the threshold voltage Vth of the first transistor T1.

[0057] The storage capacitor Cst may be connected between the first node N1 and the second node N2. The storage capacitor Cst may store a voltage corresponding to a voltage difference between the first node N1 and the second node N2.

[0058] In various embodiments of the present invention, the brightness of the aforementioned pixel PX is primarily determined by the data signal. However, the characteristics of the first transistor T1 can be additionally reflected in the brightness of the pixel PX. Specifically, the present invention can employ compensation by detecting the characteristics of the first transistor T1 during a detection period and, in response to the detected characteristics, modifying the image data (e.g., first image data DATA1) to be displayed during a display period. In such an embodiment, a uniform image quality can be displayed regardless of variations in the characteristics of the first transistor T1 among the pixels PX constituting the display panel 110.

[0059] In particular, the present invention compensates the image data's grayscale according to the gamma correction value when compensating the image data based on the characteristics of the first transistor. Specifically, the present invention performs gamma correction on the image data first, and then performs grayscale compensation on the image data second, reflecting the characteristics of the first transistor according to the gamma correction value. In various embodiments, gamma correction can be performed with reference to an ACC LUT. Furthermore, grayscale compensation can be performed with reference to the characteristic value of the first transistor and the gamma correction value used in gamma correction.

[0060] Regarding the image data compensation method of the present invention, refer to Figures 3 to 6Provide more specific explanation.

[0061] In various embodiments of the present invention, the detection period for measuring the characteristics of pixel PX can be configured as part of the vertical blanking period between periods in which the display device 100 displays an image. In this case, even if the characteristics of the first transistor T1 (i.e., the driving transistor) included in each pixel PX change while the display device 100 is being driven, the characteristic information is updated in real time and can be reflected in the generation of the data signal. As a result, the display panel 110 can continuously display images with uniform image quality while the display device 100 is being driven.

[0062] In various embodiments of the present invention, the structure of the pixel PX and the driving method for characteristic detection are not limited to the above-described structures and methods.

[0063] In addition, Figure 2 , the first transistor T1 to the third transistor T3 are shown as an example of n-type transistors, but the technical concept of the present invention is not limited to this. That is, in various embodiments, at least a part or all of the first transistor T1 to the third transistor T3 can be replaced by p-type transistors. Figure 2 The circuit of the pixel PX shown in FIG. 1 can be modified in various ways accordingly.

[0064] Figure 3 More specifically, Figure 1 Block diagram of the timing control unit, Figure 4 and Figure 5 This is a diagram for explaining compensation of video data by the timing control unit.

[0065] Reference Figure 3 In one embodiment of the present invention, the timing control unit 150 may include a first correction unit 151 and a second correction unit 152 .

[0066] The first correction unit 151 may receive first image data DATA1 from an external host device, etc. In various embodiments, the first image data DATA1 may include red image data R, green image data G, and blue image data B.

[0067] The first correction unit 151 can perform gamma correction, or ACC, on the input first image data DATA1. Specifically, the first correction unit 151 can determine gamma correction values ​​for the red image data R, the green image data G, and the blue image data B based on the gamma characteristics of the display device 100, and apply the determined gamma correction values ​​to the red image data R, the green image data G, and the blue image data B to correct the first image data DATA1.

[0068] For example, the first correction unit 151 may add, subtract, or multiply the determined gamma correction value to the first image data DATA1 to correct the first image data DATA1. Alternatively, the first correction unit 151 may apply the determined gamma correction value and the first image data DATA1 to a preset calculation formula to correct the first image data DATA1.

[0069] In various embodiments of the present invention, the first correction unit 151 may perform ACC processing on the first image data DATA1 by referring to an ACC LUT stored in the memory 160. The ACC LUT may include information that maps gamma correction values ​​for image data on a 1:1 basis, taking into account the gamma characteristics of the display device 100. For example, the ACC LUT may include red gamma correction values ​​ΔR corresponding to arbitrary red image data R, green image data G, and blue image data B, green gamma correction values ​​ΔG corresponding to arbitrary red image data R, green image data G, and blue image data B, and blue gamma correction values ​​ΔB corresponding to arbitrary red image data R, green image data G, and blue image data B. Such an ACCLUT may be pre-set during the manufacture of the display device 100, or received from an external host device and stored in the memory 160.

[0070] The first correction unit 151 can load red gamma correction values ​​ΔR, green gamma correction values ​​ΔG, and blue gamma correction values ​​ΔB corresponding to the red image data R, green image data G, and blue image data B of the first image data DATA1 from the ACC LUT. Furthermore, the first correction unit 151 can apply the loaded gamma correction values ​​ΔR, ΔG, and ΔB to the red image data R, green image data G, and blue image data B of the first image data DATA1, respectively, and output the loaded gamma correction values ​​ΔR, ΔG, and ΔB to the first image data DATA1' processed by the ACC. The gamma correction values ​​ΔR, ΔG, and ΔB can be applied to the image data by adding, subtracting, or multiplying the gamma correction values ​​ΔR, ΔG, and ΔB to the red image data R, green image data G, and blue image data B.

[0071] However, in the present invention, the ACC processing of the first image data DATA1 is not limited to being based on the ACC LUT. In various embodiments, the ACC LUT can be replaced by various types of operators.

[0072] The second correction unit 152 may receive the ACC-processed first image data DATA1′ from the first correction unit 151. The second correction unit 152 may apply characteristic compensation of a driving transistor to the ACC-processed first image data DATA1′.

[0073] Specifically, the second correction unit 152 can determine the grayscale compensation level for the first image data DATA1′ processed by the ACC, corresponding to the threshold voltage Vth of the drive transistor provided in each pixel PX measured by the detection unit 140. The grayscale compensation level can be determined based on the difference between the reference threshold voltage of the drive transistor and the measured threshold voltage Vth. For example, the grayscale compensation level can be determined by the difference between the reference threshold voltage and the measured threshold voltage itself, or by an arbitrary preset value corresponding to the difference. Depending on the implementation, the grayscale compensation level can be determined using another LUT that maps the grayscale compensation level corresponding to the threshold voltage Vth of the drive transistor in a 1:1 manner, but the present invention is not limited to this.

[0074] In various embodiments of the present invention, the second correction unit 152 may determine a grayscale compensation level based on a threshold voltage Vth of a pixel PX of a specific color (hereinafter referred to as a reference color) among the threshold voltages Vth of the pixels PX measured by the detection unit 140. For example, the second correction unit 152 may determine a grayscale compensation level for the first image data DATA1 based on the threshold voltage Vth of the pixel PX for displaying red.

[0075] In such an embodiment, the second correction unit 152 may refer to the ACC LUT to determine the grayscale compensation value based on the grayscale compensation level. Specifically, the second correction unit 152 may refer to the ACC LUT to obtain the red gamma correction value ΔR, the green gamma correction value ΔG, and the blue gamma correction value ΔB for the first image data DATA1. The second correction unit 152 may also determine the ratio between the gamma correction value for the reference color and the gamma correction values ​​for the other colors.

[0076] The second correction unit 152 may determine a predetermined grayscale compensation level as the grayscale compensation value of the reference color. Furthermore, the second correction unit 152 may reflect the ratio of the gamma correction value for the reference color to the gamma correction value for the other colors in the predetermined grayscale compensation level, thereby determining the grayscale compensation values ​​for the other colors.

[0077] For example, in the above-described embodiment, the second correction unit 152 may determine a predetermined grayscale compensation level as a red grayscale compensation value. The second correction unit 152 may determine the ratio of the green gamma correction value ΔG to the red gamma correction value ΔR (ΔG / ΔR, a first ratio) and the ratio of the blue gamma correction value ΔB to the red gamma correction value ΔR (ΔB / ΔR, a second ratio). The second correction unit 152 may reflect the first ratio in the predetermined grayscale compensation level to determine the green grayscale compensation value, and reflect the second ratio in the predetermined grayscale compensation level to determine the blue grayscale compensation value.

[0078] The second correction unit 152 may apply the determined red, green, and blue grayscale compensation values ​​to the first image data DATA1' processed by the ACC, thereby correcting the first image data DATA1' processed by the ACC. For example, the second correction unit 152 may correct the image data by adding, subtracting, or multiplying the determined red, green, and blue grayscale compensation values ​​to the first image data DATA1' processed by the ACC. The second correction unit 152 may output the corrected image data as second image data DATA2.

[0079] like Figure 4 As shown, when grayscale compensation is typically performed using the threshold voltage change for one of red, green, and blue colors, once the grayscale compensation level for a specific color is determined, the determined grayscale compensation level is uniformly applied to the red, green, and blue image data. In this case, after threshold voltage compensation is performed based on ACC, the ratio between RGB is altered, making it impossible to accurately represent the desired color.

[0080] In the present invention, the grayscale compensation level determined by referring to the ACC LUT is applied to the red, green and blue image data, such as Figure 5 As shown, the ratio between the color image data before grayscale compensation can be maintained even after grayscale compensation. Therefore, in the present invention, even after grayscale compensation based on the threshold voltage, the RGB mixing ratio is maintained, so the required brightness and grayscale can be accurately expressed without color blurring.

[0081] Figure 6 This is a flowchart illustrating a method for driving a display device according to an embodiment of the present invention.

[0082] Reference Figure 6 The display device 100 of the present invention may receive first image data (601) from an external host device, etc. The first image data may include, for example, red image data, green image data, and blue image data.

[0083] Next, the display device 100 may perform gamma correction on the first image data (602). Specifically, the display device 100 may load red gamma correction values, green gamma correction values, and blue gamma correction values ​​for the red image data, green image data, and blue image data of the first image data from a pre-stored ACC LUT. The display device 100 may apply the obtained gamma correction values ​​to the first image data to generate gamma-corrected first image data.

[0084] Next, the display device 100 may perform grayscale compensation on the gamma-corrected first image data to generate second image data (603). The display device 100 may perform grayscale compensation on the gamma-corrected first image data by reflecting the characteristics of the driving transistor.

[0085] Specifically, the display device 100 may measure the threshold voltage of the pixel PX displaying a reference color. The reference color may be, for example, red, but the present invention is not limited thereto.

[0086] The display device 100 can determine the grayscale compensation level for the first image data by comparing the measured threshold voltage with the reference threshold voltage. Furthermore, the display device 100 can determine the grayscale compensation value for the first image data from the grayscale compensation level based on the gamma correction value of the first image data.

[0087] For example, the display device 100 may obtain the red gamma correction value, the green gamma correction value, and the blue gamma correction value of the first image data used in the gamma correction step. In addition, the display device 100 may determine the ratio of the gamma correction values ​​of other colors relative to the gamma correction value of the reference color.

[0088] The display device 100 may determine the determined grayscale compensation level as the grayscale compensation value for the reference color. Furthermore, the display device 100 may determine the grayscale compensation value for other colors other than the reference color by applying the ratio of the gamma correction value determined above to the determined grayscale compensation level.

[0089] The display device 100 may apply the determined grayscale compensation value to the gamma-corrected first image data to generate the second image data.

[0090] The display device 100 may output an image based on the second image data (604). When outputting an image using the second image data, the display device 100 may accurately display an image having a desired grayscale after gamma correction and threshold voltage compensation without causing color blur.

[0091] Those skilled in the art will appreciate that the present invention can be implemented in other specific forms without changing the technical concept or essential features of the present invention. Therefore, the embodiments described above should be understood to be illustrative in all aspects and not restrictive. The scope of the present invention should be presented by the appended claims, rather than the detailed description described above, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be understood to fall within the scope of the present invention.

Claims

1. A display device comprising: a display panel comprising a plurality of pixels; a first correction unit that performs gamma correction on first image data input from the outside using a gamma correction value; a second correction unit, performing grayscale compensation on the gamma-corrected first image data to generate second image data; as well as The data driving unit provides a data signal corresponding to the second image data to the plurality of pixels, The second correction unit performs the grayscale compensation based on the characteristic value measured for each pixel and the gamma correction value. The second correction unit determines a grayscale compensation level based on the measured characteristic value of the pixel displaying the first color, and determines the determined grayscale compensation level as a grayscale compensation value for the image data of the first color. The second correction unit determines a ratio of a gamma correction value of a second color to a gamma correction value of the first color, and applies the determined ratio to the grayscale compensation level to determine a grayscale compensation value for the second color.

2. The display device according to claim 1, wherein The first correction unit acquires a pre-stored gamma correction value corresponding to the first image data, and applies the gamma correction value to the first image data to perform the gamma correction.

3. The display device according to claim 2, wherein: The first correction section acquires the gamma correction value from a pre-stored lookup table.

4. The display device according to claim 1, wherein The characteristic value is a threshold voltage of the pixel.

Images