Compensation method for display device

Abstract

The present invention relates to a compensation method for a display device, which includes: sensing a first brightness of the display device when a first pattern is displayed on the display device; calculating a brightness prediction value corresponding to a second pattern to be displayed on the display device based on the first brightness, wherein the second pattern is different from the first pattern; sensing a second brightness of the display device when the second pattern is displayed on the display device; adjusting a current flowing in a first power line of the display device until the second brightness reaches the brightness prediction value; and storing compensation data corresponding to the adjusted current in a lookup table when the second brightness reaches the brightness prediction value.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and all benefits of Korean Patent Application No. 10-2019-0175576, filed on December 26, 2019, which is hereby incorporated by reference herein in its entirety. Technical Field

[0003] Embodiments of the present invention relate to a compensation method for a display device. Background Art

[0004] Recently, various display devices with reduced weight and volume have been developed. Such display devices include liquid crystal displays, field emission displays, plasma display panels, and organic light emitting displays.

[0005] A display device typically includes pixels defined by gate lines and data lines, a gate driver for driving the gate lines, and a data driver for driving the data lines.

[0006] The gate driver supplies gate signals to multiple gate lines in sequence, and the data driver supplies data voltages to multiple data lines in synchronization with the gate signals. In this case, the pixels selected by the gate signals emit light with a predetermined brightness in response to the data voltages, and the light emission of the pixels displays an image. Summary of the Invention

[0007] In a display device, a data voltage corresponding to a data signal should be stably supplied to a pixel within a predetermined time (e.g., a period during which a gate signal is supplied) to stably display an image. However, due to an increase in resolution and size of a panel, the data voltage may not be sufficiently charged or discharged to reach a desired voltage (target voltage) during the period during which a gate signal is supplied.

[0008] Embodiments of the present invention relate to a compensation method of a display device to calculate compensation data in order to sufficiently charge or discharge a data voltage to reach a target voltage.

[0009] An embodiment of the present invention relates to a compensation method of a display device to calculate compensation data with respect to a highest grayscale (white grayscale) and a lowest grayscale (black grayscale).

[0010] An embodiment of the present invention provides a compensation method for a display device, which includes: sensing a first brightness of the display device when a first pattern is displayed on the display device; calculating a brightness prediction value corresponding to a second pattern to be displayed on the display device based on the first brightness, wherein the second pattern is different from the first pattern; sensing a second brightness of the display device when the second pattern is displayed on the display device; adjusting a current flowing in a first power line of the display device until the second brightness reaches the brightness prediction value; and storing compensation data corresponding to the adjusted current in a lookup table when the second brightness reaches the brightness prediction value.

[0011] In an embodiment, the first brightness may be greater than each of the second brightness and the brightness prediction value, and adjusting the current may include increasing the current until the second brightness reaches the brightness prediction value.

[0012] In an embodiment, the display device may include a first pixel connected to a first power line, a second power line, a first data line and a first scan line, and a second pixel connected to the first power line, the second power line, the first data line and the second scan line, the first pixel may include a first light-emitting diode connected between the first power line and the second power line, the second pixel may include a second light-emitting diode connected between the first power line and the second power line, the first pattern may be a pattern displayed when both the first light-emitting diode and the second light-emitting diode emit light, and the second pattern may be a pattern displayed when the first light-emitting diode emits light and the second light-emitting diode does not emit light.

[0013] In an embodiment, the first power line of the first pixel and the first power line of the second pixel may be connected to each other at the same node.

[0014] In an embodiment, when at least one of the first and second patterns is displayed, a period during which an on-level scan signal is supplied to the first scan line and a period during which an on-level scan signal is supplied to the second scan line may partially overlap with each other.

[0015] In an embodiment, the first pixel may include three sub-pixels of different colors.

[0016] In an embodiment, a combination of light emitted from the three sub-pixels in the first pattern may be white light.

[0017] In an embodiment, adjusting the current may include increasing the current by increasing the grayscale value for the first pixel in the second pattern until the second brightness reaches the brightness prediction value.

[0018] In an embodiment, the compensation data stored in the lookup table may include an increased grayscale value relative to the first pixel.

[0019] In an embodiment, the compensation data stored in the lookup table includes a magnitude of the current corresponding to the increased grayscale value.

[0020] Another embodiment of the present invention provides a compensation method for a display device, comprising: sensing a first current flowing in a first power line of the display device when a first pattern is displayed on the display device; calculating a current prediction value corresponding to a second pattern to be displayed on the display device based on the first current, wherein the second pattern is different from the first pattern; sensing a second current flowing in the first power line when the second pattern is displayed on the display device; adjusting the second current until the second current reaches the current prediction value; and storing compensation data corresponding to the adjusted second current in a lookup table when the second current reaches the current prediction value.

[0021] In an embodiment, the magnitude of the first current may be greater than each of the magnitude of the second current and the current prediction value; and adjusting the second current may include increasing the second current until the magnitude of the second current reaches the current prediction value.

[0022] In an embodiment, the display device may include a first pixel connected to a first power line, a second power line, a first data line and a first scan line, and a second pixel connected to the first power line, the second power line, the first data line and the second scan line, the first pixel may include a first light-emitting diode connected between the first power line and the second power line, the second pixel may include a second light-emitting diode connected between the first power line and the second power line, the first pattern may be a pattern displayed when both the first light-emitting diode and the second light-emitting diode emit light, and the second pattern may be a pattern displayed when the first light-emitting diode emits light and the second light-emitting diode does not emit light.

[0023] In an embodiment, the first power line of the first pixel and the first power line of the second pixel may be connected to each other at the same node.

[0024] When at least one of the first pattern and the second pattern is displayed, a period during which an on-level scan signal is supplied to the first scan line and a period during which an on-level scan signal is supplied to the second scan line may partially overlap with each other.

[0025] In an embodiment, the first pixel may include three sub-pixels of different colors.

[0026] In an embodiment, a combination of light emitted from the three sub-pixels in the first pattern may be white light.

[0027] In an embodiment, adjusting the second current may include increasing the second current by increasing the grayscale value for the first pixel in the second pattern until the magnitude of the second current reaches the current prediction value.

[0028] In an embodiment, the compensation data stored in the lookup table may include an increased grayscale value relative to the first pixel.

[0029] In an embodiment, the compensation data stored in the lookup table may include a magnitude of the second current corresponding to the increased grayscale value.

[0030] Another embodiment of the present invention provides a compensation method for a display device, which includes: storing a first reference data voltage of a pixel of a reference display device when a first pattern is displayed on the reference display device with a first brightness; storing a second reference data voltage of a pixel of the reference display device when a second pattern different from the first pattern is displayed on the reference display device with a second brightness; storing the first data voltage of a pixel of the display device when the first pattern is displayed on the display device with a first brightness; calculating a second data voltage to be provided to the pixel of the display device when the second pattern is displayed on the display device with a second brightness based on a ratio of the first data voltage to the first reference data voltage; and storing compensation data corresponding to the second data voltage in a lookup table.

[0031] In an embodiment, the display device may include a first pixel connected to a first power line, a second power line, a first data line and a first scan line, and a second pixel connected to the first power line, the second power line, the first data line and the second scan line, the first pixel may include a first light-emitting diode connected between the first power line and the second power line, the second pixel may include a second light-emitting diode connected between the first power line and the second power line, the first pattern may be a pattern displayed when both the first light-emitting diode and the second light-emitting diode emit light, and the second pattern may be a pattern displayed when the first light-emitting diode emits light and the second light-emitting diode does not emit light.

[0032] In an embodiment, the second data voltage may be calculated based on a difference between the first reference data voltage and the second reference data voltage and a ratio of the first data voltage to the first reference data voltage.

[0033] In an embodiment, the first brightness may be greater than the second brightness, and the second reference data voltage may be greater than the first reference data voltage.

[0034] In the embodiment of the present invention, as described above, in order to sufficiently charge or discharge the data voltage to reach the target voltage, compensation data is calculated.

[0035] In such an embodiment, compensation data is calculated with respect to the highest grayscale (white grayscale) and the lowest grayscale (black grayscale). BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1Schematic diagrams for explaining a display device according to an embodiment of the present invention are shown.

[0037] Figure 2 Schematic diagrams for explaining a display portion according to an embodiment of the present invention are shown.

[0038] Figure 3 An equivalent circuit diagram of a pixel according to an embodiment of the present invention is shown.

[0039] Figure 4 Shown in Figure 1 An embodiment of the first pattern displayed in the display device shown in .

[0040] Figure 5 FIG. 1 shows a signal timing diagram of a pixel driving method according to an embodiment of the present invention.

[0041] Figure 6 Shown in Figure 1 An embodiment of the second pattern displayed in the display device shown in .

[0042] Figure 7 A signal timing diagram of a pixel driving method according to an alternative embodiment of the present invention is shown.

[0043] Figure 8 A schematic diagram for explaining a problem that occurs when a lookup table storing compensation data based on grayscale values is set is shown.

[0044] Figure 9 A schematic diagram illustrating a compensation method for a display device according to an embodiment of the present invention is shown.

[0045] Figure 10 A schematic diagram illustrating a compensation method for a display device according to an alternative embodiment of the present invention is shown.

[0046] Figure 11 A graph showing a relationship between a data voltage corresponding to a grayscale value and a current flowing in a first power line.

[0047] Figure 12 A schematic diagram illustrating a compensation method for a display device according to an alternative embodiment of the present invention is shown. DETAILED DESCRIPTION

[0048] The present invention will now be described more fully below with reference to the accompanying drawings showing various embodiments. However, the present invention can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be exhaustive and complete and will fully convey the scope of the invention to those skilled in the art. Throughout, similar reference numerals refer to similar elements.

[0049] It will be understood that when an element is referred to as being "on" another element, the element can be directly on the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements.

[0050] It will be understood that although the terms "first," "second," "third," etc. may be used herein to describe various elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Thus, a first "element," "component," "region," "layer," or "section" discussed below may be referred to as a second "element," "component," "region," "layer," or "section" without departing from the teachings herein.

[0051] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms "a" and "the" are intended to include plural forms, and the plural forms include "at least one". "Or" means "and / or". As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It will also be understood that the term "comprising", when used in this specification, indicates the presence of stated features, regions, integers, steps, operations, elements and / or parts, but does not exclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, parts and / or groups thereof.

[0052] In addition, relational terms, such as "lower" or "bottom" and "upper" or "top," may be used herein to describe the relationship of one element to another element as shown in the figures. It will be understood that relational terms are intended to encompass different orientations of the device in addition to the orientation shown in the figures. For example, if the device in one of the multiple figures is turned over, the element described as being on the "lower" side of the other elements will then be oriented to be on the "upper" side of the other elements. Thus, depending on the specific orientation of the drawings, the exemplary term "lower" can encompass both the "lower" and "upper" orientations. Similarly, if the device in one of the multiple figures is turned over, the element described as being "below" or "beneath" the other elements will then be oriented to be "above" the other elements. Thus, the exemplary terms "lower" or "beneath" can encompass both the "lower" and "upper" orientations.

[0053] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present disclosure belongs. It will also be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal manner unless expressly defined as such herein.

[0054] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0055] Figure 1 shows a schematic diagram of a display device 10 according to an embodiment of the present invention, and Figure 2 A schematic diagram showing the display section 14 according to an embodiment of the present invention is shown.

[0056] Reference Figure 1 , an embodiment of the display device 10 may include a timing controller 11 , a data driver 12 , a scan driver 13 , a display portion 14 , a current sensor 15 , and a compensator 16 .

[0057] The timing controller 11 may receive various grayscale values (or grayscale data) and control signals for each image frame from an external processor (not shown).

[0058] The timing controller 11 may provide the image data DATA' compensated by the compensator 16 to the data driver 12. In such an embodiment, the image data DATA' may include a corrected grayscale value in which the source emphasis value reflects the original grayscale value used to display the image. In such an embodiment, the image data DATA' may be image data of one of red (R), green (G), and blue (B) to be supplied to each pixel.

[0059] The timing controller 11 can render grayscale values to correspond to the specifications of the display device 10. In one embodiment, for example, an external processor can provide red grayscale values, green grayscale values, and blue grayscale values for each unit point of the image. However, if the display unit 14 has a pentile structure, adjacent unit points share pixels, so that pixels may not correspond one-to-one with grayscale values. In this case, grayscale values can be rendered. In such an embodiment, if pixels correspond one-to-one with grayscale values, grayscale values may not be rendered. Rendered or unrendered grayscale values can be provided to the data driver 12.

[0060] The timing controller 11 may provide control signals suitable for the specifications of the display device 10 to the data driver 12 , the scan driver 13 , the current sensor 15 , and the like for displaying a frame image.

[0061] The timing controller 11 may output a data control signal DCS for controlling an operation timing of the data driver 12 and a gate control signal GCS for controlling an operation timing of the scan driver 13 .

[0062] The data driver 12 can be connected to a plurality of data lines D1, D2, D3, ..., Dj, D(j+1), ..., Dn and can generate data voltages (or data signals) to be provided to the display unit 14 through the plurality of data lines D1, D2, D3, ..., Dj, D(j+1), ..., Dn based on grayscale values and a control signal (e.g., a data control signal DCS). In one embodiment, for example, the data driver 12 can sample grayscale values using a clock signal and apply data voltages corresponding to the grayscale values to the plurality of data lines D1 to Dn in units of pixel rows. Here, n can be a natural number. In such an embodiment, the data driver 12 can convert the digital image data DATA' supplied from the timing controller 11 into analog data voltages.

[0063] The data driver 12 may supply a data voltage corresponding to the image data DATA′ during each horizontal period.

[0064] The scan driver 13 receives a clock signal, a scan start signal, a gate control signal GCS and the like from the timing controller 11 to generate scan signals to be supplied to a plurality of scan lines S1, S2, S3, ..., Si, S(i+1), ..., Sm. Here, m may be a natural number.

[0065] The scan driver 13 may sequentially supply a scan signal having a pulse of an on level to a plurality of scan lines S1 , S2 , S3 , . . . , Si, S(i+1), . . . , Sm.

[0066] In an embodiment, the scan driver 13 may supply a scan signal to a current scan line during a portion of a period in which a scan signal is supplied to a previous scan line, so that the data voltage is sufficiently charged to reach a predetermined voltage. Figure 7 and Figure 8 Give its detailed description.

[0067] The display portion 14 may include a plurality of pixels PXij, PX(i+1)j, ..., PXi(j+1), .... Each of the plurality of pixels PXij, PX(i+1)j, ..., PXi(j+1), ... may be connected to a corresponding data line and a corresponding scan line.

[0068] In one embodiment, for example, the scan transistor in the pixel PXij may be connected to the i-th scan line Si and the j-th data line Dj. The pixel PXij may be referred to as a first pixel.

[0069] In such an embodiment, the scan transistor in the pixel PX(i+1)j can be connected to the (i+1)th scan line S(i+1) and the jth data line Dj. The pixel PX(i+1)j can be referred to as a second pixel.

[0070] In such an embodiment, the scan transistor in the pixel PXi(j+1) can be connected to the i-th scan line Si and the (j+1)-th data line D(j+1). The pixel PXi(j+1) can be referred to as a third pixel.

[0071] In an embodiment, a plurality of pixels PXij, PXi(j+1), ..., PX(i+1)j, ... can be commonly connected to a first power line ELVDDL and can be commonly connected to a second power line ELVSSL. In an alternative embodiment, a plurality of pixels PXij, PXi(j+1), ..., PX(i+1)j, ... can be commonly connected to a first power line ELVDDL and can be connected to different second power lines. In such an embodiment, the first power line ELVDDL of one pixel (e.g., pixel PXij) and the first power line ELVDDL of another pixel (e.g., pixel PXi(j+1)) can be connected to each other at the same node. According to another alternative embodiment, a plurality of pixels PXij, PXi(j+1), ..., PX(i+1)j, ... can be commonly connected to a second power line ELVSSL, and a plurality of pixels PXij, PXi(j+1), ..., PX(i+1)j, ... can be connected to different first power lines.

[0072] Reference Figure 2 , the display section 14 may be divided into a plurality of blocks BLK11 to BLK35. Each of the plurality of blocks BLK11 to BLK35 may be a group of pixels of a predetermined ratio among the plurality of pixels included in the display section 14. In one embodiment, for example, the number of pixels included in one block may correspond to 1% of all pixels included in the display section 14. In such an embodiment, the number of blocks may be 100. However, the present invention is not limited thereto, and for convenience of illustration, Figure 2The display portion 14 is shown to include 15 blocks BLK11 to BLK35. In one embodiment, for example, each of the plurality of blocks BLK11 to BLK35 may include at least one pixel. In one embodiment, for example, each of the plurality of pixels PXij, PX(i+1)j, ..., PXi(j+1), ... may be divided into a specific block BLK among the plurality of blocks. The block BLK may be Figure 2 1 to BLK35. Hereinafter, for the convenience of description, the block BLK23 corresponding to the block BLK23 will be described in detail. Figure 1 An embodiment of the present invention of block BLK is shown in FIG.

[0073] The block BLK is a virtual element that defines a control unit for a plurality of pixels PXij, PX(i+1)j, ..., PXi(j+1), ..., and therefore may not be a physical element. The block BLK may be written and defined in a memory before the product is shipped or may be actively redefined during the use of the product. In an embodiment, each of the plurality of blocks BLK may include the same number of pixels, and the plurality of blocks BLK may not overlap with each other. In an alternative embodiment, the plurality of blocks BLK may include different numbers of pixels. In another alternative embodiment, the plurality of blocks BLK may share at least some of the plurality of pixels PXij, PX(i+1)j, ..., PXi(j+1), ... (i.e., overlap at least some of the plurality of pixels PXij, PX(i+1)j, ..., PXi(j+1), ...).

[0074] In such an embodiment, the display unit 14 may have a constant luminous efficiency. Here, the luminous efficiency may mean the luminous intensity (unit: candela, Cd) compared to the current (unit: ampere, A) when the display unit 14 emits light at a specific brightness (for example, 500nit). The unit of the luminous efficiency may be candela per ampere (Cd / A). Here, the current may mean the global current flowing in the first power line ELVDDL before being shunted to each pixel. Here, the luminous intensity of the display unit 14 can be measured by an image sensor (not shown). Although not shown, the luminous efficiency of the display unit may be different for each display device, and the luminous efficiency of the display unit in the display device according to an embodiment of the present invention and the second luminous efficiency of the display unit included in the display device according to another embodiment of the present invention may be different from each other.

[0075] In an embodiment, the current sensor 15 may be connected to the first power line ELVDDL. In such an embodiment, the current sensor 15 may sense the current flowing in the first power line ELVDDL to provide a current sensing value Sen.

[0076] In an embodiment, the current sensor 15 may be connected to a common second power line ELVSSL of the plurality of pixels PXij, PX(i+1)j, ..., PXi(j+1), .... In such an embodiment, the current sensor 15 may sense a current flowing in the second power line ELVSSL to provide a current sensing value Sen.

[0077] In an embodiment, when the display device 10 displays a specific pattern by sequentially emitting light from a plurality of blocks BLK11 to BLK35, the current sensor 15 may provide a current sensing value Sen corresponding to the current flowing in the first power line ELVDDL. In such an embodiment, a plurality of current sensing values Sen may be stored sequentially. In one embodiment, for example, when the display device 10 displays a first pattern, the current sensor 15 may sense a first current to provide a first current sensing value. In such an embodiment, when the display device 10 displays a second pattern, the current sensor 15 may sense a second current to provide a second current sensing value. This will be referred to hereinafter. Figures 7 to 9 The first pattern and the second pattern are described in more detail.

[0078] In such an embodiment, the current sensor 15 is connected to a common power line of all pixels of the display portion 14 , and the display device 10 may include a single current sensor 15 .

[0079] In an embodiment, the process of storing the current sensing value Sen may be performed once when the display device 10 is powered on. In alternative embodiments, the time point of performing the process may be set in various ways and may be performed multiple times.

[0080] The compensator 16 may be connected to the current sensor 15 and the timing controller 11. The compensator 16 may compensate the image data so that an image corresponding to the image data including the original grayscale value input from the outside can be properly displayed on the display part 14, and the compensator 16 may provide the compensated image data DATA′ to the timing controller 11.

[0081] The compensator 16 can compensate for the grayscale value in the current horizontal period by comparing the grayscale value in the previous horizontal period with the grayscale value in the current horizontal period. In an embodiment, the compensator 16 can compensate for the grayscale value in the current horizontal period by comparing the grayscale value in the previous horizontal period with the grayscale value in the current horizontal period and then obtaining compensation data corresponding to the comparison result based on a pre-stored lookup table LUT.

[0082] Here, the lookup table LUT may refer to a lookup table that stores or records compensation data corresponding to grayscale values in a previous horizontal period and grayscale values in a current horizontal period. The compensation data included in the lookup table LUT may be determined experimentally or statistically based on the tuning results of testing the display device 10. The method of setting and recording the compensation data stored in the lookup table LUT will be described in more detail below.

[0083] The compensator 16 can calculate a scaling factor by comparing the current sensing value Sen provided by the current sensor 15 with the target current value. The compensator 16 can calculate a scaling factor that amplifies the grayscale value of the pixel when the current sensing value Sen is less than the target current value. The compensator 16 can calculate a scaling factor that reduces the grayscale value of the pixel when the current sensing value Sen is greater than the target current value. In addition, the compensator 16 can scale the grayscale value by using the calculated scaling factor. The driving process described above may mean global current management (GCM).

[0084] In an embodiment, Figure 1 As shown in , the compensator 16 may exist outside the timing controller 11. Alternatively, the compensator 16 may be included in the timing controller 11 or integrated with the timing controller 11 as a single configuration or chip.

[0085] Figure 3 An equivalent circuit diagram of a pixel PXij according to an embodiment of the present invention is shown.

[0086] Reference Figure 3 , the pixel PXij includes a plurality of transistors T1 and T2, a storage capacitor Cst, a light emitting diode LD, and the like.

[0087] Hereinafter, for the convenience of description, an embodiment of a pixel PXij including a circuit consisting of an N-type transistor will be described in detail. However, it will be understood by those skilled in the art that such an embodiment can be modified to include a circuit consisting of a P-type transistor by changing the polarity of the voltage applied to the gate terminal. Similarly, it will be understood by those skilled in the art that such an embodiment can be modified to include a circuit consisting of a combination of a P-type transistor and an N-type transistor. A P-type transistor refers to a transistor in which the magnitude of the current conducted increases when the voltage difference between the gate terminal and the source terminal increases in the negative direction. An N-type transistor refers to a transistor in which the magnitude of the current conducted increases when the voltage difference between the gate terminal and the source terminal increases in the positive direction. The transistor can be one of various types such as a thin film transistor (TFT), a field effect transistor (FET), and a bipolar junction transistor (BJT).

[0088] The first transistor T1 may be referred to as a driving transistor. A gate electrode of the first transistor T1 may be connected to a first electrode of the storage capacitor Cst, a first electrode of the first transistor T1 may be connected to the first power line ELVDDL, and a second electrode of the first transistor T1 may be connected to a second electrode of the storage capacitor Cst.

[0089] The second transistor T2 may be referred to as a scan transistor. A gate electrode of the second transistor T2 may be connected to the i-th scan line Si, a first electrode of the second transistor T2 may be connected to the j-th data line Dj, and a second electrode of the second transistor T2 may be connected to the gate electrode of the first transistor T1.

[0090] The light emitting diode LD may be an organic light emitting diode, an inorganic light emitting diode, a quantum dot light emitting diode, or the like. In an embodiment, the anode of the light emitting diode LD may be connected to the second electrode of the first transistor T1, and the cathode of the light emitting diode LD may be connected to the second power line ELVSSL. In an alternative embodiment, the anode of the light emitting diode LD may be connected to the first power line ELVDDL, and the cathode of the light emitting diode LD may be connected to the first electrode of the first transistor T1.

[0091] A first power voltage may be applied to the first power line ELVDDL, and a second power voltage may be applied to the second power line ELVSSL. The first power voltage may be greater than the second power voltage.

[0092] In an embodiment, when a scan signal of a turn-on level (here, a logic high level) is applied through the scan line Si, the second transistor T2 is turned on. When the second transistor T2 is turned on, the data voltage applied to the data line Dj is stored in the first electrode of the storage capacitor Cst.

[0093] Therefore, a positive driving current corresponding to the voltage difference between the first and second electrodes of the storage capacitor Cst flows between the first and second electrodes of the first transistor T1. Consequently, the light-emitting diode LD emits light having a brightness corresponding to the data voltage. The current sensing value Sen provided by the current sensor 15 may be the sum of the driving current values flowing through all pixels of the display unit 14. Since the data voltage is adjusted by the compensator 16 and the timing controller 11, the driving current value of the pixel can be adjusted.

[0094] In such an embodiment, when a scan signal of an off level (here, a logic low level) is applied through the scan line Si, the second transistor T2 is turned off, and the data line Dj and the first electrode of the storage capacitor Cst are electrically separated. Therefore, even if a data voltage is applied to the data line Dj, the data voltage is not charged in the first electrode of the storage capacitor Cst.

[0095] Figure 1 The pixel PXij shown in the figure may be a sub-pixel of one of red (R), green (G), and blue (B), or a unit pixel (or dot) including a sub-pixel of red (R), a sub-pixel of green (G), and a sub-pixel of blue (B). In an embodiment, when the pixel PXij includes three different sub-pixels, when the first pattern is displayed, a combination of light emitted from the sub-pixels included in the pixel PXij may be white light.

[0096] Figure 3 The pixels PXij shown in FIG. 1 are merely exemplary, and pixels of alternative embodiments may also include other circuits. In one embodiment, for example, pixels with more complex circuits may also receive an emission control signal so that the emission period may be adjusted.

[0097] Figure 4 Shown in Figure 1 , and Figure 5 FIG. 1 shows a signal timing diagram of a pixel driving method according to an embodiment of the present invention.

[0098] exist Figure 4 , block BLK23 may correspond to Figure 1 As shown in the block BLK, the block BLK23 may include Figure 1The multiple pixels PXij, PX(i+1)j,..., PXi(j+1),... shown in .

[0099] Reference Figure 4 , the first pattern may be a pattern displayed when a plurality of pixels PXij, PX(i+1)j, ..., PXi(j+1), ... included in a specific block BLK23 of the display unit 14 emit light at the highest brightness or grayscale (white grayscale) and the pixels included in the remaining blocks do not emit light at the lowest brightness or grayscale (black grayscale). In an embodiment, when the number of blocks included in the display unit 14 is 100, the first pattern may mean a pattern displayed when a plurality of pixels PXij, PX(i+1)j, ..., PXi(j+1), ... included in a specific block BLK23 among the 100 blocks emit light at the highest brightness or grayscale (white grayscale) and the pixels included in each of the remaining 99 blocks do not emit light. This first pattern may be referred to as a 1% full white pattern.

[0100] In such an embodiment, when the number of blocks included in the display unit 14 is 100, when the first pattern is displayed on the display unit 14 included in the display device 10, the current flowing in the first power line ELVDDL can be the driving current of multiple pixels PXij, PX(i+1)j,..., PXi(j+1),... that emit light with the highest brightness or grayscale (white grayscale) in a specific block BLK23.

[0101] Reference Figure 1 、 Figure 4 and Figure 5 , in the (N-1)th frame, when the scan signal of the on level is supplied to the i-th scan line Si, the data voltage may be supplied to the j-th data line Dj. In this case, the second transistor T2 included in the pixel PXij is turned on, and the data voltage applied to the j-th data line Dj is stored in the first electrode of the storage capacitor Cst included in the pixel PXij, and the light emitting diode LD included in the pixel PXij emits light by the driving current flowing between the first electrode and the second electrode of the first transistor T1 included in the pixel PXij.

[0102] In such an embodiment, in the (N-1)th frame, during a period in which a scan signal of an on-level is supplied to the i-th scan line Si, a scan signal of an on-level may be supplied to the (i+1)-th scan line S(i+1). That is, a period in which a scan signal of an on-level is supplied to the i-th scan line Si and a period in which a scan signal of an on-level is supplied to the (i+1)-th scan line S(i+1) may overlap with each other.

[0103] During the overlap period, the data voltage supplied to the pixel PXij may be supplied to the pixel PX(i+1)j, and the pixel PX(i+1)j may be precharged by the data voltage supplied to the pixel PXij.

[0104] When a scan signal of a cut-off level is supplied to the i-th scan line Si, a data voltage to be transmitted to the pixel PX(i+1)j is supplied to the j-th data line Dj, and since the data voltage is precharged in the capacitor Cst included in the pixel PX(i+1)j, the time for charging the data voltage in the capacitor Cst can be shortened, and the light emitting diode LD included in the pixel PX(i+1)j can emit light having a brightness corresponding to the data voltage.

[0105] In such an embodiment, Figure 5 As shown in , the driving timing of the pixel PXij and the pixel PX(i+1)j in the Nth frame may be the same as the driving timing of the pixel PXij and the pixel PX(i+1)j in the (N-1)th frame described above.

[0106] In such an embodiment, pixels included in the remaining blocks except for the specific block BLK23 among the plurality of blocks included in the display section 14 may not emit light.

[0107] When the first pattern is displayed on the display device 10 according to the embodiment of the driving method as described above, even if the resolution is increased or the panel is enlarged, the data voltage can be sufficiently charged to reach the desired voltage (target voltage), and multiple pixels PXij, PX(i+1)j,..., PXi(j+1),... can emit light with a brightness corresponding to the data voltage.

[0108] Figure 6 Shown in Figure 1 , and Figure 7 A signal timing diagram of a pixel driving method according to an alternative embodiment of the present invention is shown.

[0109] exist Figure 6 , block BLK23 may correspond to Figure 1 The block BLK shown in .

[0110] Reference Figure 6, the second pattern may mean a regular pattern displayed when one pixel PXij included in a specific block BLK23 emits light at the highest brightness or grayscale (white grayscale), the other pixels PX(i+1)j and PXi(j+1) adjacent to the pixel PXij do not emit light, and another pixel PX(i+1)(j+1) adjacent to each of the other pixels PX(i+1)j and PXi(j+1) emits light at the highest brightness or grayscale (white grayscale). Such a second pattern may be called a 1% checkered pattern.

[0111] The brightness of the second pattern when displayed on the display device 10 may be lower than the brightness of the first pattern when displayed on the display device 10. Figure 6 In the example, since the number of luminous pixels is Figure 4 Therefore, the brightness when the second pattern is displayed on the display device 10 may correspond to half the brightness when the first pattern is displayed on the display device 10.

[0112] Figure 6 The second pattern shown in is only exemplary, and the present invention is not limited to Figure 6 Alternatively, the second pattern may be a pattern displayed when one pixel PXij included in the specific block BLK23 does not emit light and other pixels PX(i+1)j and PXi(j+1) adjacent to the one pixel PXij emit light with the highest brightness or grayscale (white grayscale).

[0113] In an embodiment, when the number of blocks included in the display portion 14 is 100, the magnitude of the current flowing in the first power line ELVDDL when the second pattern is displayed on the display portion 14 included in the display device 10 may be smaller than the magnitude of the current flowing in the first power line ELVDDL in the 1% full white pattern described above. In an embodiment, the magnitude of the current when the second pattern is displayed on the display device 10 may be half the magnitude of the current when the first pattern is displayed on the display device 10.

[0114] Reference Figure 1 、 Figure 6 and Figure 7 , in the (N-1)th frame, when the scan signal of the on level is supplied to the i-th scan line Si, the data voltage may be supplied to the j-th data line Dj. In this case, the light emitting diode LD included in the pixel PXij may be as described above with reference to Figure 4 and Figure 5 Light is emitted in the same manner as described.

[0115] In such an embodiment, as described above in the (N-1)th frame, the time period in which the on-level scan signal is supplied to the i-th scan line Si and the time period in which the on-level scan signal is supplied to the (i+1)th scan line S(i+1) can overlap with each other.

[0116] During the overlap period, the data voltage supplied to the pixel PXij may be supplied to the pixel PX(i+1)j, and the pixel PX(i+1)j may be precharged by the data voltage supplied to the pixel PXij.

[0117] In such an embodiment, when a scan signal of a cutoff level is supplied to the i-th scan line Si, a data voltage corresponding to the lowest grayscale (black grayscale) may be supplied to the pixel PX(i+1)j through the j-th data line Dj. In this case, since the data voltage corresponding to the white grayscale is precharged in the capacitor Cst of the pixel PX(i+1)j, the time for charging the data voltage of the black grayscale is longer than in the case of no precharging. Therefore, the light emitting diode LD of the pixel PX(i+1)j, which is not expected to emit light, may emit light at a predetermined brightness. Therefore, since light having a predetermined brightness may be emitted in the pixel PX(i+1)j, the desired black grayscale may not be displayed on the display unit 14.

[0118] In such an embodiment, Figure 7 As shown in , the driving timing of the pixel PXij and the pixel PX(i+1)j in the Nth frame may be the same as the driving timing of the pixel PXij and the pixel PX(i+1)j in the (N-1)th frame described above.

[0119] Although not shown, in the case where a plurality of pixels PXi(j+1) and PX(i+1)(j+1) are connected to the (j+1)th data line D(j+1), the light emitting diode LD of the pixel PX(i+1)(j+1) can emit light at a grayscale lower than the highest grayscale (white grayscale) because the data voltage corresponding to the black grayscale is pre-charged in the capacitor Cst of the pixel PX(i+1)(j+1).

[0120] Therefore, the brightness when the second pattern is displayed on the display device 10 may be measured to be less than half of the brightness when the first pattern is displayed on the display device 10. In an embodiment, the brightness of the second pattern may be measured to be less than half of the brightness when the first pattern is displayed on the display device 10. Figure 8 , so that each pixel emits light at a predetermined or desired brightness as the resolution and size of the panel increase.

[0121] Figure 8 A schematic diagram for explaining a problem that occurs when setting a lookup table in which compensation data based on grayscale values is stored is shown.

[0122] Reference Figure 8 The first lookup table LUT1 may mean a lookup table storing compensation data for compensating the grayscale value of the current horizontal line (e.g., the (i+1)th horizontal line) based on a comparison between the grayscale value of the previous horizontal line (e.g., the i-th horizontal line) and the grayscale value of the current horizontal line (e.g., the (i+1)th horizontal line). Here, a horizontal line may mean a row of pixels connected to the same scan line.

[0123] The grayscale values (0G to 255G) in the vertical direction in the first lookup table LUT1 represent the grayscale values of the current horizontal line (for example, the (i+1)th horizontal line), and the grayscale values (0G to 255G) in the horizontal direction in the first lookup table LUT1 represent the grayscale values of the previous horizontal line (for example, the i-th horizontal line).

[0124] The first lookup table LUT1 may include a low grayscale group LG and a high grayscale group HG.

[0125] The data included in each of the low gray group LG and the high gray group HG may be compensation data. The compensation data may be Figure 8 , and as described below, the compensation data may correspond to a compensation value of the current flowing in the first power line ELVDDL, or a combination of gray values for each of three colors (RGB) representing gray values.

[0126] In the first lookup table LUT1, data not included in the low grayscale group LG and the high grayscale group HG is located diagonally. This data corresponds to a case where the grayscale value of the current horizontal line is the same as the grayscale value of the previous horizontal line and there is no change in the voltage level of the data voltage. Since the low grayscale group LG at the upper right in the diagonal direction corresponds to the case of a drop from high grayscale to low grayscale, the low grayscale group LG corresponds to the falling edge of the voltage level of the data voltage. Since the high grayscale group HG at the lower left in the diagonal direction corresponds to the case of a rise from low grayscale to high grayscale, the high grayscale group HG corresponds to the rising edge of the voltage level of the data voltage.

[0127] The compensator 16 can compensate the image data based on the first lookup table LUT1, which stores compensation data corresponding to the grayscale value of the previous horizontal line and the grayscale value of the current horizontal line. In such an embodiment, intermediate values not in the first lookup table LUT1 can be determined by interpolation.

[0128] In one embodiment, for example, when the grayscale value of the current horizontal line is 32 grayscales and the grayscale value of the previous horizontal line is 32 grayscales, the compensation data may be determined as 32 grayscales.

[0129] In such an embodiment, when the grayscale value of the current horizontal line is grayscale 96 and the grayscale value of the previous horizontal line is grayscale 0, the compensation data is determined to be grayscale 106. In an embodiment, when the driving transistor T1 is an N-type metal-oxide-semiconductor (NMOS) transistor, since the data voltage of the current horizontal line is higher than the data voltage of the previous horizontal line, the image data DATA' may be determined such that the higher data voltage is applied to the current horizontal line.

[0130] In such an embodiment, the low grayscale group LG may include a first low grayscale subgroup LG1 and a second low grayscale subgroup LG2. The first low grayscale subgroup LG1 refers to a group excluding the second low grayscale subgroup LG2 from the low grayscale group LG, and the second low grayscale subgroup LG2 may mean a group of compensation data in which the grayscale value of the current horizontal line is the lowest grayscale value (e.g., 0 grayscale) and the grayscale value of the previous horizontal line corresponds to a grayscale value greater than the lowest grayscale value (e.g., 0 grayscale). Since the compensation data of the first lookup table LUT1 compensates for the grayscale value of the current horizontal line by comparing the grayscale value of the current horizontal line with the grayscale value of the previous horizontal line, when the lowest grayscale value (e.g., 0 grayscale) is included in the second low grayscale subgroup LG2, the grayscale value may not become less than the lowest grayscale value.

[0131] In this embodiment, the high grayscale group HG may include a first high grayscale subgroup HG1 and a second high grayscale subgroup HG2. The first high grayscale subgroup HG1 refers to a group excluding the second high grayscale subgroup HG2 from the high grayscale group HG, while the second high grayscale subgroup HG2 may refer to a group of compensation data in which the grayscale value of the current horizontal line is the highest grayscale value (e.g., grayscale 255) and the grayscale value of the previous horizontal line corresponds to a grayscale value less than the highest grayscale value (e.g., grayscale 255). Similar to the above, when the highest grayscale value (e.g., grayscale 255) is included in the second high grayscale subgroup HG2, the grayscale value may not be higher than the highest grayscale value.

[0132] Therefore, it is desirable to compensate for the lowest grayscale value and the highest grayscale value of the lookup table. Figure 9 and Figure 10 An embodiment of a compensation method of the display device 10 using the grayscale-luminance-current table GLCT is described.

[0133] Figure 9 1 is a schematic diagram showing a compensation method of the display device 10 according to an embodiment of the present invention, Figure 10 A schematic diagram illustrating a compensation method for a display device 10 according to an alternative embodiment of the present invention is shown, and Figure 11A graph showing a relationship between a data voltage corresponding to a grayscale value and a current flowing in the first power line ELVDDL.

[0134] Reference Figure 9 and Figure 10 , an embodiment of the compensation method of the display device 10 according to the present invention may mean a method of calculating compensation data by using characteristics when each of the first pattern and the second pattern is displayed on the display device 10 and storing the calculated compensation data in a lookup table.

[0135] In an embodiment, a compensation method of the display device 10 may include sensing a first brightness of the display device 10 when a first pattern is displayed on the display device 10, and calculating a brightness prediction value based on the first brightness when a second pattern different from the first pattern is displayed on the display device 10. Here, the brightness of the display device 10 may be sensed by an image sensor (not shown) as described above.

[0136] Reference Figure 10 For example, when a first pattern with 224 grayscales is displayed on the display device 10, the first brightness of the display device 10 may be sensed as 375.9 nits (or candela per square meter). In this case, the brightness prediction value corresponding to the case where the second pattern is displayed on the display device 10 may be calculated as 187.9 nits, which is half of the first brightness. In other words, the first brightness may be greater than the brightness prediction value.

[0137] In an embodiment, the compensation method of the display device 10 may further include sensing a second brightness of the display device 10 when the second pattern is displayed on the display device 10 .

[0138] Reference Figure 10 For example, when the second pattern of actual 224 grayscales is displayed on the display device 10, the second brightness of the display device 10 may be sensed as approximately 150.4 nit. That is, the second brightness may be less than the brightness prediction value, and the first brightness may be greater than each of the second brightness and the brightness prediction value. In this case, as Figure 10 As shown in FIG, the current flowing in the first power line ELVDDL may be 300.8 milliamperes (mA).

[0139] In such an embodiment, the compensation method of the display device 10 may further include adjusting the current flowing in the first power line ELVDDL of the display device 10 until the second brightness reaches the brightness prediction value.

[0140] Reference Figure 9In one embodiment, since the second brightness is about 150.4 nit and the brightness prediction value is about 187.9 nit, the current flowing in the first power line ELVDDL may be increased until the second brightness reaches the brightness prediction value. In this case, Figure 9 The current flowing in the first power line ELVDDL is calculated using the grayscale-luminance-current table GLCT shown in FIG. That is, referring to the grayscale-luminance-current table GLCT, since the predicted luminance value (approximately 187.9 nit) is very close to the second luminance (approximately 188.1 nit), when the second pattern of 248 grayscales is displayed on the display device 10, the current flowing in the first power line ELVDDL may increase from 300.8 mA to 376.2 mA. Here, the current flowing in the first power line ELVDDL may be adjusted multiple times or repeatedly until the second luminance reaches the predicted luminance value.

[0141] Reference Figure 10 In an alternative embodiment, since the grayscale value of the first pixel (e.g., PXij) in the second pattern of 224 grayscale is 224, the grayscale value of the first pixel (e.g., PXij) in the second pattern may not increase from 224 to 248 until the second brightness (approximately 150.4 nit) reaches the brightness prediction value (approximately 187.9 nit), and the current flowing in the first power line ELVDDL may also increase together with the increase of the grayscale value of the first pixel (e.g., PXij) in the second pattern.

[0142] In an embodiment, the compensation method of the display device 10 may further include storing compensation data corresponding to the current when the second brightness reaches the brightness prediction value in a lookup table. Here, the compensation data may be a free emphasis value.

[0143] Reference Figure 9 In one embodiment, the current when the second brightness reaches the brightness prediction value is approximately 376.2 mA, which corresponds to the current measured when the second pattern of 248 grayscales is displayed on the display device 10. Therefore, at the grayscale value of 0 of the previous horizontal line, the compensation data for the grayscale value of 224 of the current horizontal line is calculated to be approximately 376.2 mA, which is the current measured when the second pattern of 248 grayscales is displayed on the display device 10 to be stored in the second lookup table LUT2. That is, the compensation data may be a current value (e.g., approximately 376.2 mA) of the current corresponding to the increased grayscale value (e.g., 248 grayscales increased from 224 grayscales). Although not shown, the compensation data may be an increased grayscale value (e.g., 248 grayscales increased from 224 grayscales) rather than a current value of the current.

[0144] By performing the above-described operations for all grayscales (0 grayscale to 255 grayscale), the second lookup table LUT2 can be finally set. That is, the compensation data included in the first high grayscale subgroup HG1 of the second lookup table LUT2 can be determined, and the compensation data included in the second high grayscale subgroup HG2 can also be determined. Although not shown, the compensation data included in the second low grayscale subgroup LG2 of the second lookup table LUT2 can also be set in a manner similar to that described above.

[0145] Here, the compensation data stored in the second lookup table LUT2 may be the current flowing in the first power line ELVDDL, but is not limited thereto, may be the increased grayscale value as described above, and may be a combination of red grayscale value, green grayscale value, and blue grayscale value determined based on an Accurate Color Capture (ACC) block for implementing grayscale values.

[0146] The ACC block may gamma-correct the red, green, and blue grayscale values based on a preset correction gamma value based on a gamma characteristic of the display device 10 , thereby outputting corrected red, green, and blue grayscale values.

[0147] The red grayscale value, green grayscale value, and blue grayscale value determined based on the ACC block can be implemented using, for example, 13 bits. In one embodiment, for example, the compensation data may be approximately 376.2 mA, which is the current measured when a second pattern of 248 grayscales for a current horizontal line of 224 grayscale values at a previous horizontal line of 0 grayscale value is displayed on the display device 10. The compensation data may be 248 grayscales, or the compensation data may be (3968, 4464, 3720), which is a combination of the red grayscale value, the green grayscale value, and the blue grayscale value.

[0148] As described above, according to an embodiment of the compensation method of the display device 10 , compensation data may be calculated based on the brightness of the display device 10 and the brightness prediction value.

[0149] In an embodiment, since the brightness of the display device 10 and the current flowing in the first power line ELVDDL correspond to each other, compensation data may be calculated by using the current flowing in the first power line ELVDDL and a predicted value of the current.

[0150] In an alternative embodiment, the compensation method of the display device 10 may include sensing a first current flowing in the first power line ELVDDL of the display device 10 when a first pattern is displayed on the display device 10, and calculating a current prediction value based on the first current when a second pattern different from the first pattern is displayed on the display device 10. Here, the current prediction value may be calculated by Figure 1 The current sensor 15 shown in FIG. 1 is used to sense the first current flowing in the first power line ELVDDL.

[0151] Reference Figure 9 In one embodiment, when the first pattern of 224 grayscales is displayed on the display device 10, the first current may be sensed as 751.9 mA. In this case, the current prediction value corresponding to the case where the second pattern is displayed on the display device 10 may be calculated as approximately 375.9 mA, which corresponds to half of the first current. In other words, the first current may be greater than the current prediction value.

[0152] In such an embodiment, the compensation method of the display device 10 may further include sensing a second current flowing in the first power line ELVDDL when the second pattern is displayed on the display device 10 .

[0153] Reference Figure 10 In an alternative embodiment, when the second pattern of actual 224 grayscales is displayed on the display device 10, the second current of the display device 10 may be sensed to be approximately 300.8 mA. That is, the second current may be less than the current prediction value, and the first current may be greater than both the second current and the current prediction value.

[0154] In such an embodiment, the compensation method of the display device 10 may further include adjusting the second current until the second current reaches the predicted current value.

[0155] Reference Figure 9 In one embodiment, since the second current is about 300.8 mA and the current prediction value is about 375.9 mA, the second current may be continuously increased until the second current reaches the current prediction value. In this case, the current flowing in the first power line ELVDDL may be increased by Figure 9. That is, referring to the grayscale-luminance-current table GLCT, since the current prediction value (approximately 375.9 mA) is very close to the second current (approximately 376.2 mA) when the second pattern of 248 grayscales is displayed on the display device 10, the second current flowing in the first power line ELVDDL can be increased from approximately 300.8 mA to approximately 376.2 mA. Here, the second current flowing in the first power line ELVDDL can be adjusted multiple times or repeatedly until the second current reaches the current prediction value.

[0156] In such an embodiment, the compensation method of the display device 10 may further include storing compensation data corresponding to the second current when the second current reaches the current prediction value in a lookup table. Since the increased second current is approximately 376.2 mA, the compensation data for the current horizontal line with a gray value of 224 at the previous horizontal line with a gray value of 0 is calculated to be 376.2 mA, and this compensation data is the current measured when the second pattern of 248 grays is displayed on the display device 10 and is to be stored in the second lookup table LUT2.

[0157] In an embodiment, as described above, the second current may also be increased by increasing the grayscale value of the first pixel (e.g., PXij) in the second pattern. In this case, the compensation data may be an increased grayscale value relative to the first pixel (e.g., PXij) (e.g., 248 grayscale increased from 224 grayscale).

[0158] By performing the above-described operations for all grayscales (0 grayscale to 255 grayscale), the second lookup table LUT2 can be finally set. That is, the compensation data included in the first high grayscale subgroup HG1 of the second lookup table LUT2 can be determined, and the compensation data included in the second high grayscale subgroup HG2 can also be determined. In such an embodiment, although not shown, the compensation data included in the second low grayscale subgroup LG2 of the second lookup table LUT2 can also be set in a manner similar to that described above.

[0159] In an embodiment, the compensation data for the highest grayscale (white grayscale or 255 grayscale) and the compensation data for the lowest grayscale (black grayscale or 0 grayscale) may be combined with Figure 9 and the remaining compensation data can be determined similarly to Figure 8 The compensation data are determined in the same manner as shown in FIG.

[0160] Reference Figure 10 In an alternative embodiment, the compensation data included in the second high grayscale subgroup HG2 of the third lookup table LUT3 can be as shown in FIG. Figure 9In this case, the compensation data included in the second high grayscale subgroup HG2 can be expressed in grayscale. However, the present invention is not limited thereto. Although not shown, the compensation data included in the second low grayscale subgroup LG2 of the third lookup table LUT3 can also be set to be less than 0 grayscale similarly to the above.

[0161] In an embodiment, when a voltage-current curve defining a relationship between a data voltage to be supplied to the display part 14 and a current flowing in the first power line ELVDDL is previously set according to the image data DATA′, compensation data may be calculated based on the voltage-current curve.

[0162] Reference Figure 11 In one embodiment, when the first pattern is displayed on the display device 10 using the first data voltage V1 and the first current I1, a predicted data voltage Ve is calculated when the second pattern is displayed on the display device 10. The predicted data voltage Ve can be calculated to be less than the first data voltage V1, and the predicted current Ie (or the current prediction value) when the second pattern is displayed on the display device 10 can also be calculated to be less than the first current I1. In such an embodiment, when the second data voltage V2 and the second current I2 measured when the second pattern is displayed on the display device 10 are less than the predicted data voltage Ve and the predicted current Ie, respectively, the second current I2 can be increased to be the same as the predicted current Ie. As the second current I2 increases, the second data voltage V2 can also have the same value as the predicted data voltage Ve.

[0163] In an embodiment, as described above, the compensation method of the display device 10 may effectively calculate compensation data by compensating for the highest grayscale (white grayscale) and the lowest grayscale (black grayscale).

[0164] In an embodiment, the compensation method of the display device 10 can effectively compensate for all grayscales by more accurately setting a lookup table storing compensation data.

[0165] In the embodiment, as described above, since the respective luminous efficiencies of the plurality of display devices may be different from each other, it is desirable to calculate compensation data based on the luminous efficiency of the display section 14. Figure 12 The compensation method of the display device 10 according to the alternative embodiment is described with reference to the table shown in FIG.

[0166] Figure 12 A schematic diagram illustrating a compensation method for a display device according to an alternative embodiment of the present invention is shown.

[0167] Reference Figure 12For a case where multiple display devices have different luminous efficiencies E11, E12, E13, E21, E22, and E23 from each other, an implementation of the compensation method of the display device 10 can calculate compensation data of a target display device for which a lookup table is to be set by using a first reference data voltage Vref_1 and a second reference data voltage Vref_2 of a reference display device having a reference luminous efficiency Eref.

[0168] Here, the target display device can be Figure 1 The display device 10 shown in FIG. 1 is substantially the same as that in FIG. 1 . Therefore, any repetitive detailed description of the target display device will be omitted.

[0169] In an embodiment, the compensation method of the display device 10 may include storing a first reference data voltage Vref_1 of a pixel of the reference display device when a first pattern is displayed on the reference display device with a first brightness; storing a second reference data voltage Vref_2 of a pixel of the reference display device when a second pattern different from the first pattern is displayed on the reference display device with a second brightness; and storing a plurality of first data voltages V11_1, V12_1, V13_1, V21_1, V22_1 and V23_1 of a pixel of the target display device when the first pattern is displayed on the target display device with a first brightness.

[0170] Here, the first pattern can be compared with the above reference Figure 4 and Figure 5 In one embodiment, for example, the first pattern of the first brightness may be a 1% full white pattern of 500 nit. However, the present invention is not limited thereto.

[0171] Here, the second reference data voltage Vref_2 may be greater than the first reference data voltage Vref_1 .

[0172] In such an embodiment, a plurality of first data voltages V11_1, V12_1, V13_1, V21_1, V22_1, and V23_1 may be calculated by using a reference luminous efficiency Eref of a reference display device, a first reference data voltage Vref_1, and a luminous efficiency (one of E11, E12, E13, E21, E22, and E23) of a target display device.

[0173] In one embodiment, for example, the first data voltage V13_1 of a target display device having a light emitting efficiency E13 may be calculated by the following Equation 1.

[0174] [Formula 1]

[0175] V13_1=Vref_1+α(Eref-E13)

[0176] In Formula 1, Vref_1 represents a first reference data voltage, α represents a preset parameter, Eref represents a reference luminous efficiency, and α(Eref−E13) represents a deviation value.

[0177] Similar to the above, we can calculate Figure 12 Each of the plurality of first data voltages V11_1 , V12_1 , V13_1 , V21_1 , V22_1 , and V23_1 included in the table shown in .

[0178] In such an embodiment, the compensation method of the display device 10 may further include calculating a plurality of second data voltages V11_2, V12_2, V13_2, V21_2, V22_2, and V23_2 of pixels of the target display device when the second pattern is displayed on the target display device at the second brightness based on a ratio of the plurality of first data voltages V11_1, V12_1, V13_1, V21_1, V22_1, and V23_1 relative to the first reference data voltage Vref_1.

[0179] Here, the second pattern can be compared with the above reference Figure 6 and Figure 7 The second brightness may be lower than the first brightness. In one embodiment, for example, the second pattern of the second brightness may be a 1% checkered pattern of 250 nit. However, the present invention is not limited thereto.

[0180] In such an embodiment, based on: a plurality of first data voltages V11_1, V12_1, V13_1, V21_1, V22_1 and V23_1; a difference between the first reference data voltage Vref_1 and the second reference data voltage Vref_2 (or a reference compensation value Vref_3); and a ratio of the plurality of first data voltages V11_1, V12_1, V13_1, V21_1, V22_1 and V23_1 relative to the first reference data voltage Vref_1, a plurality of second data voltages V11_2, V12_2, V13_2, V21_2, V22_2 and V23_2 can be calculated.

[0181] In one embodiment, for example, the second data voltage V13_2 of the target display device having the luminous efficiency E13 may be calculated by the following Equation 2.

[0182] [Formula 2]

[0183]

[0184] In such an embodiment, the compensation method of the display device may further include storing compensation data corresponding to the second data voltage in a lookup table.

[0185] In an embodiment, the plurality of compensation data may be equal to the plurality of second data voltages V11_2, V12_2, V13_2, V21_2, V22_2, and V23_2, respectively.

[0186] In an alternative embodiment, the plurality of compensation data may be equal to the plurality of compensation values V11_3, V12_3, V13_3, V21_3, V22_3, and V23_3, respectively.

[0187] Here, the plurality of compensation values V11_3, V12_3, V13_3, V21_3, V22_3 and V23_3 may be, for example, differences between the plurality of first data voltages V11_1, V12_1, V13_1, V21_1, V22_1 and V23_1 and the plurality of second data voltages V11_2, V12_2, V13_2, V21_2, V22_2 and V23_2, respectively.

[0188] In an embodiment, a plurality of compensation values V11_3, V12_3, V13_3, V21_3, V22_3, and V23_3 may be calculated based on ratios of a plurality of first data voltages V11_1, V12_1, V13_1, V21_1, V22_1, and V23_1 relative to a first reference data voltage Vref_1 and a reference compensation value Vref_3. In one embodiment, for example, the compensation value V13_3 for a target display device having a luminous efficiency of E13 may be calculated using the following formula 3.

[0189] [Formula 3]

[0190]

[0191] In an alternative embodiment, the compensation data may be a grayscale value of each of the plurality of second data voltages V11_2, V12_2, V13_2, V21_2, V22_2 and V23_2 and / or a plurality of compensation values V11_3, V12_3, V13_3, V21_3, V22_3 and V23_3, a value of current, a combination of grayscales of three colors determined by an accurate color capture block, or the like.

[0192] In an embodiment, as described above, the compensation method of the display device may efficiently calculate compensation data and set a lookup table by using information on the luminous efficiency of the display device.

[0193] In such an embodiment, the compensation method of the display device can effectively compensate for the highest grayscale and the lowest grayscale by using information on the light emitting efficiency of the display device.

[0194] The present invention should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the present invention to those skilled in the art.

[0195] While the invention has been particularly shown and described with reference to embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit or scope of the disclosure as defined in the following claims.

Claims

1. A compensation method for a display device, comprising: sensing a first brightness of the display device when a first pattern is displayed on the display device; calculating a brightness prediction value corresponding to a second pattern to be displayed on the display device based on the first brightness, wherein the second pattern is different from the first pattern; sensing a second brightness of the display device when the second pattern is displayed on the display device; adjusting a current flowing in a first power line connected to a pixel included in the display device until the second brightness reaches the brightness prediction value; and When the second brightness reaches the brightness prediction value, compensation data corresponding to the adjusted current is stored in a lookup table.

2. The compensation method for a display device according to claim 1, wherein: The first brightness is greater than each of the second brightness and the brightness prediction value, and Adjusting the current includes increasing the current until the second brightness reaches the brightness prediction value.

3. The compensation method for a display device according to claim 2, wherein: The display device includes: a first pixel connected to the first power line, the second power line, the first data line and the first scan line; and a second pixel connected to the first power line, the second power line, the first data line and the second scan line. The first pixel includes a first light emitting diode connected between the first power line and the second power line, The second pixel includes a second light emitting diode connected between the first power line and the second power line, The first pattern is a pattern displayed when both the first light emitting diode and the second light emitting diode emit light, and The second pattern is a pattern displayed when the first light emitting diode emits light and the second light emitting diode does not emit light.

4. The compensation method for a display device according to claim 3, wherein: The first power line of the first pixel and the first power line of the second pixel are connected to each other at the same node.

5. The compensation method for a display device according to claim 3, wherein: When at least one of the first pattern and the second pattern is displayed, a period during which an on-level scan signal is supplied to the first scan line and a period during which an on-level scan signal is supplied to the second scan line partially overlap with each other.

6. The compensation method for a display device according to claim 3, wherein: The first pixel includes three sub-pixels of different colors.

7. The compensation method for a display device according to claim 6, wherein: A combination of light emitted from the three sub-pixels in the first pattern is white light.

8. The compensation method for a display device according to claim 3, wherein: Adjusting the current includes increasing the current by increasing the grayscale value for the first pixel in the second pattern until the second brightness reaches the brightness prediction value.

9. The compensation method for a display device according to claim 8, wherein: The compensation data stored in the lookup table includes an increased grayscale value relative to the first pixel.

10. The compensation method for a display device according to claim 9, wherein: The compensation data stored in the lookup table includes a magnitude of the current corresponding to the increased grayscale value.

11. A compensation method for a display device, comprising: sensing a first current flowing in a first power line connected to a pixel included in the display device when a first pattern is displayed on the display device; calculating a current prediction value corresponding to a second pattern to be displayed on the display device based on the first current, wherein the second pattern is different from the first pattern; sensing a second current flowing in the first power line when the second pattern is displayed on the display device; adjusting the second current until the second current reaches the current prediction value; and When the second current reaches the current prediction value, compensation data corresponding to the adjusted second current is stored in a lookup table.

12. The compensation method for a display device according to claim 11, wherein: The magnitude of the first current is greater than each of the magnitude of the second current and the current prediction value; and Adjusting the second current includes increasing the second current until the magnitude of the second current reaches the current prediction value.

13. The compensation method for a display device according to claim 12, wherein: The display device includes: a first pixel connected to the first power line, the second power line, the first data line and the first scan line; and a second pixel connected to the first power line, the second power line, the first data line and the second scan line. The first pixel includes a first light emitting diode connected between the first power line and the second power line, The second pixel includes a second light emitting diode connected between the first power line and the second power line, The first pattern is a pattern displayed when both the first light emitting diode and the second light emitting diode emit light, and The second pattern is a pattern displayed when the first light emitting diode emits light and the second light emitting diode does not emit light.

14. The compensation method for a display device according to claim 13, wherein: The first power line of the first pixel and the first power line of the second pixel are connected to each other at the same node.

15. The compensation method for a display device according to claim 13, wherein: When at least one of the first pattern and the second pattern is displayed, a period during which an on-level scan signal is supplied to the first scan line and a period during which an on-level scan signal is supplied to the second scan line partially overlap with each other.

16. The compensation method for a display device according to claim 13, wherein: The first pixel includes three sub-pixels of different colors.

17. The compensation method for a display device according to claim 16, wherein: A combination of light emitted from the three sub-pixels in the first pattern is white light.

18. The compensation method for a display device according to claim 13, wherein: Adjusting the second current includes increasing the second current by increasing grayscale values for the first pixel in the second pattern until the magnitude of the second current reaches the current prediction value.

19. The compensation method for a display device according to claim 18, wherein: The compensation data stored in the lookup table includes an increased grayscale value relative to the first pixel.

20. The compensation method for a display device according to claim 19, wherein: The compensation data stored in the lookup table includes the magnitude of the second current corresponding to the increased grayscale value.

21. A compensation method for a display device, comprising: storing a first reference data voltage of a pixel of the reference display device when a first pattern is displayed on the reference display device at a first brightness; storing a second reference data voltage of the pixel of the reference display device when a second pattern different from the first pattern is displayed on the reference display device at a second brightness; storing a first data voltage of a pixel of the display device when the first pattern is displayed on the display device at the first brightness; calculating a second data voltage to be provided to the pixel of the display device when the second pattern is displayed on the display device at the second brightness based on a ratio of the first data voltage to the first reference data voltage; as well as Compensation data corresponding to the second data voltage is stored in a lookup table.

22. The compensation method for a display device according to claim 21, wherein: The display device includes: a first pixel connected to a first power line, a second power line, a first data line, and a first scan line; and a second pixel connected to the first power line, the second power line, the first data line, and a second scan line. The first pixel includes a first light emitting diode connected between the first power line and the second power line, The second pixel includes a second light emitting diode connected between the first power line and the second power line, The first pattern is a pattern displayed when both the first light emitting diode and the second light emitting diode emit light, and The second pattern is a pattern displayed when the first light emitting diode emits light and the second light emitting diode does not emit light.

23. The compensation method for a display device according to claim 21, wherein: The second data voltage is calculated based on a difference between the first reference data voltage and the second reference data voltage and the ratio of the first data voltage to the first reference data voltage.

24. The compensation method for a display device according to claim 23, wherein: The first brightness is greater than the second brightness, and The second reference data voltage is greater than the first reference data voltage.

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