Method of driving a display panel and display device for performing the method

Abstract

A method of driving a display panel and a display apparatus for performing the same are provided. The method of driving a display panel includes dividing an input image into a plurality of segments, generating a flicker value of a segment of the plurality of segments, determining whether to compensate for the flicker value of the segment according to a segment size, compensating for the flicker value of the segment based on the segment size, determining a frame rate of the display panel based on the flicker value of the segment, and outputting a data voltage to the display panel at the frame rate. The flicker value of the segment is compensated for based on the flicker value of the segment and a flicker value of a segment adjacent to the segment.

Description

TECHNICAL FIELD

[0001] The technical field relates to a method of driving a display panel and a display apparatus for performing the same, such as a method of driving a display panel for reducing power consumption and enhancing display quality. BACKGROUND

[0002] Recently, a method for minimizing power consumption of an electronic device such as a tablet PC and a notebook computer has been researched.

[0003] In order to minimize power consumption of an electronic device including a display panel, power consumption of the display panel can be minimized. That is, when the display panel displays a static image, the display panel can be driven at a relatively low frequency, so that power consumption of the display panel can be reduced.

[0004] When the display panel is driven at a relatively low frequency, flicker can occur, so that display quality is reduced. SUMMARY

[0005] An exemplary embodiment of the inventive concept provides a method of driving a display panel capable of reducing power consumption and enhancing display quality.

[0006] An exemplary embodiment of the inventive concept also provides a display apparatus for performing the above-described method.

[0007] In an exemplary embodiment of the method of driving a display panel according to the inventive concept, the method includes dividing an input image into a plurality of segments, generating a flicker value of a segment of the plurality of segments, compensating for the flicker value of the segment based on a segment size, the flicker value of the segment, and a plurality of flicker values of a plurality of neighboring segments located around the segment, determining a frame rate of the display panel based on the flicker value of the segment, and outputting a data voltage to the display panel at the frame rate.

[0008] In an exemplary embodiment, compensating for the flicker value of the segment can include determining not to compensate for the flicker value of the segment when the segment size is equal to or greater than a compensation threshold, and determining to compensate for the flicker value of the segment when the segment size is less than the compensation threshold.

[0009] In an exemplary embodiment, the method can further include determining a compensation size, wherein the compensation size indicates a number of the flicker value of a compensation target segment and a plurality of flicker values of a plurality of segments adjacent to the compensation target segment, and wherein the compensation size is used for compensation of the compensation target segment when the segment size is less than the compensation threshold.

[0010] In an exemplary embodiment, the compensation size can be determined such that a product of the segment size and the compensation size is equal to or greater than the compensation threshold.

[0011] In an example embodiment, the compensation size can be determined as a minimum integer satisfying a product of the segment size and the compensation size is equal to or greater than a compensation threshold.

[0012] In an example embodiment, determining the compensation size can include determining a first compensation size representing a number of the flicker value of the compensation target segment and a plurality of flicker values of a plurality of segments adjacent to the compensation target segment in a first direction, and determining a second compensation size representing a number of the flicker value of the compensation target segment and a plurality of flicker values of a plurality of segments adjacent to the compensation target segment in a second direction different from the first direction, wherein the first compensation size and the second compensation size are each used for the compensation of the compensation target segment.

[0013] In an example embodiment, the method can further include determining the compensation size. The compensation size can be determined by dividing the compensation threshold by the segment size. Compensating the flicker value of the segment can include determining not to compensate the flicker value of the segment when the segment size is equal to or smaller than 1, and compensating the flicker value of the segment when the segment size is greater than 1.

[0014] In an example embodiment, determining the compensation size can include determining a first compensation size representing a number of the flicker value of the compensation target segment and a plurality of flicker values of a plurality of segments adjacent to the compensation target segment in a first direction, and determining a second compensation size representing a number of the flicker value of the compensation target segment and a plurality of flicker values of a plurality of segments adjacent to the compensation target segment in a second direction different from the first direction, wherein the first compensation size and the second compensation size are used for the compensation of the compensation target segment.

[0015] In an example embodiment, the method can further include determining whether the input image represents a still image or a video image. When the input image represents a still image, a frame rate of the display panel can be determined based on the flicker value of the segment.

[0016] In an example embodiment, generating the flicker value of the segment can include converting luminance of a plurality of pixels into a plurality of flicker values of the plurality of pixels, and operating the plurality of flicker values of the plurality of pixels in the segment.

[0017] In an example embodiment, operating the plurality of flicker values of the plurality of pixels in the segment can include summing the plurality of flicker values of the plurality of pixels in the segment.

[0018] In an example embodiment, operating the plurality of flicker values of the plurality of pixels in the segment can include setting a plurality of weights of the plurality of pixels according to a plurality of positions of the plurality of pixels, and operating a weighted sum of the plurality of flicker values of the plurality of pixels by using the plurality of weights of the plurality of pixels.

[0019] In an exemplary embodiment, determining the frame rate of the display panel can include comparing a maximum of the plurality of flicker values of the plurality of segments to a threshold value.

[0020] In an exemplary embodiment, determining the frame rate of the display panel can include comparing an average of the plurality of flicker values of the plurality of segments to a threshold value, the average being greater than a predetermined flicker value.

[0021] In an exemplary embodiment of a display apparatus according to the inventive concept, the display apparatus includes a display panel, a low frequency driver, and a data driver. The display panel is configured to display an image. The low frequency driver is connected to the display panel and is configured to divide an input image into a plurality of segments, generate a flicker value of a segment of the plurality of segments, determine whether to compensate for the flicker value of the segment depending on a segment size, compensate for the flicker value of the segment depending on the segment size, and determine a frame rate of the display panel based on the flicker value of the segment. The data driver is connected to the display panel and is configured to output a data voltage to the display panel at the frame rate.

[0022] In an exemplary embodiment, the low frequency driver can be configured to determine not to compensate for the flicker value of the segment when the segment size is equal to or greater than a compensation threshold value. The low frequency driver can be configured to determine to compensate for the flicker value of the segment when the segment size is less than the compensation threshold value.

[0023] In an exemplary embodiment, the low frequency driver can be configured to determine a compensation size, the compensation size indicating a number of flicker values of a plurality of segments adjacent to a compensation target segment, the compensation size being used for compensation of the compensation target segment when the segment size is less than a compensation threshold value.

[0024] In an exemplary embodiment, the compensation size can be determined such that a product of the segment size and the compensation size is equal to or greater than the compensation threshold value.

[0025] In an exemplary embodiment, the low frequency driver can be configured to determine a compensation size. The compensation size can be determined based on a number of flicker values of a plurality of segments adjacent to a compensation target segment, the compensation size being used for compensation of the compensation target segment. The compensation size can be determined by dividing the compensation threshold value by the segment size. The low frequency driver can be configured to determine not to compensate for the flicker value of the segment when the segment size is equal to or less than 1. The low frequency driver can be configured to determine to compensate for the flicker value of the segment when the segment size is greater than 1.

[0026] In an exemplary embodiment, the low frequency driver can include a still image determiner, wherein the still image determiner is configured to determine whether the input image represents a still image or a video image. The low frequency driver can be configured to determine the frame rate of the display panel based on the flicker value of the segment when the input image represents the still image.

[0027] According to the method of driving a display panel and a display apparatus for performing the same, a frame rate is determined according to an image displayed on the display panel, thereby enabling reduction of power consumption of the display apparatus. In addition, the frame rate is determined by using a flicker value of a segment of the image on the display panel, thereby enabling prevention of flicker of the image and enhancement of display quality of the display panel. In addition, the flicker value of the segment is compensated for by using a plurality of flicker values of a plurality of adjacent segments, thereby enabling further enhancement of the display quality of the display panel. BRIEF DESCRIPTION OF DRAWINGS

[0028] The above and other features and advantages of the inventive concept will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:

[0029] Figure 1 is a block diagram illustrating a display apparatus according to an exemplary embodiment of the inventive concept;

[0030] Figure 2 is a block diagram illustrating a driving controller of Figure 1 ;

[0031] Figure 3 is a block diagram illustrating a low frequency driver of Figure 2 ;

[0032] Figure 4 is a conceptual diagram illustrating a segment defined by a segment determiner of Figure 3 ;

[0033] Figure 5A and Figure 5B illustrate a flicker value of a segment according to a first image;

[0034] Figure 6A and Figure 6B illustrate a flicker value of a segment according to a second image;

[0035] Figure 7A and Figure 7B illustrate a method of compensating for a flicker value of a segment according to a first image;

[0036] Figure 8A and Figure 8B illustrate a method of compensating for a flicker value of a segment according to a second image;

[0037] Figure 9A , Figure 9B and Figure 9C illustrate a method of compensating for a flicker value of a segment without considering a segment size;

[0038] Figure 10 is a block diagram illustrating a display apparatus according to an exemplary embodiment of the inventive concept; Figure 3a flowchart showing operations of the compensation determiner, the compensation size determiner, the flicker value compensator, and the frame rate determiner of the display apparatus of FIG. 1;

[0039] Figure 11 is a block diagram illustrating a low frequency driver of a display apparatus according to an exemplary embodiment of the inventive concept;

[0040] Figure 12 is a block diagram illustrating Figure 11 a flowchart showing operations of the compensation size and compensation determiner, the flicker value compensator, and the frame rate determiner of the display apparatus of FIG. 1;

[0041] Figure 13 is a block diagram illustrating a display apparatus according to an exemplary embodiment of the inventive concept;

[0042] Figure 14 is a block diagram illustrating Figure 13 a circuit diagram of a pixel of a display panel of the display apparatus of FIG. 1; and

[0043] Figure 15 is a timing diagram illustrating an input signal applied to a pixel of the display apparatus of FIG. 1. Figure 14 DETAILED DESCRIPTION

[0044] Hereinafter, embodiments of the inventive concept will be explained in detail with reference to the accompanying drawings. Each of the plurality of components mentioned in the present specification including, but not limited to, for example, a "generator", a "driver", a "converter", a "determiner", a "compensator", a "controller" can be a hardware component such as, for example, an integrated circuit, a microprocessor, and the like. Alternatively, at least some of the components can be implemented with software.

[0045] Exemplary embodiments are described herein with reference to the accompanying drawings. The described embodiments can be modified in various ways, all without departing from the spirit or scope of the present disclosure.

[0046] In the present disclosure, like reference numerals can refer to like elements.

[0047] In the drawings, the size of elements can be exaggerated for clarity.

[0048] Although the terms "first", "second", etc. can be used to describe various elements, these elements should not be limited by these terms. These terms can be used to distinguish one element from another. A first element can be termed a second element without departing from the teachings of one or more embodiments. Descriptions of an element as "first" or "second" can not require or imply the presence of a second or a first element, respectively. The terms "first", "second", etc. can be used to distinguish different categories or groups of elements. For brevity, the terms "first", "second", etc. can be used to indicate "first type (or first group)", "second type (or second group)", etc. respectively.​

[0049] When a first element is referred to as being "on" a second element, the first element can be directly on the second element, or one or more intervening elements can be present between the first element and the second element. When a first element is referred to as being "directly on" a second element, there are no intervening elements present (other than environmental elements such as air) between the first element and the second element. When a first element is referred to as being "connected to" a second element, the first element can be directly (physically and / or electrically) connected and / or attached to the second element, or one or more intervening elements can be connected between the first element and the second element.

[0050] In this specification, unless explicitly described to the contrary, the word "comprise" and variations such as "comprises" or "comprising" will imply the inclusion of stated elements but not the exclusion of any other elements.

[0051] The term "connected" can mean "electrically connected". The term "insulated" can mean "electrically insulated".

[0052] Figure 1 is a block diagram of a display apparatus showing an exemplary embodiment according to the inventive concept.

[0053] Referring to Figure 1 , the display apparatus includes a display panel 100 and a display panel driver. The display panel driver includes a driving controller 200, a gate driver 300, a gamma reference voltage generator 400, and a data driver 500, each of which can be a hardware component such as, for example, an integrated circuit, a microprocessor, and the like. In alternative embodiments, at least some of these components can be implemented in software.

[0054] In some exemplary embodiments, the driving controller 200 and the data driver 500 can be integrally formed (e.g., formed as a single component). In some exemplary embodiments, the driving controller 200, the gamma reference voltage generator 400, and the data driver 500 can be integrally formed. A driving module including at least the integrally formed driving controller 200 and data driver 500 can be referred to as a timing controller embedded data driver (TED).

[0055] The display panel 100 has a display area displaying an image and a peripheral area adjacent to the display area.

[0056] The display panel 100 includes a plurality of gate lines GL, a plurality of data lines DL, and a plurality of pixels connected with the plurality of gate lines GL and the plurality of data lines DL. The gate lines GL extend in a first direction D1, and the data lines DL extend in a second direction D2 intersecting the first direction D1.

[0057] The driving controller 200 receives input image data IMG and input control signals CONT from an external device (not shown). The input image data IMG can include red image data, green image data, and blue image data. The input image data IMG can also include white image data. The input image data IMG can include magenta image data, yellow image data, and cyan image data. The input control signals CONT can include a main clock signal and a data enable signal. The input control signals CONT can also include a vertical synchronization signal and a horizontal synchronization signal.

[0058] The driving controller 200 generates a first control signal CONT1, a second control signal CONT2, and a third control signal CONT3, each based on the input control signals CONT. The driving controller 200 also generates a data signal DATA based on the input image data IMG.

[0059] The driving controller 200 generates the first control signal CONT1 based on the input control signals CONT, and outputs the first control signal CONT1 to the gate driver 300. The first control signal CONT1 can also include a vertical start signal and a gate clock signal. The first control signal CONT1 is used to control the operation of the gate driver 300.

[0060] The driving controller 200 generates the second control signal CONT2 based on the input control signals CONT, and outputs the second control signal CONT2 to the data driver 500. The second control signal CONT2 includes a horizontal start signal and a load signal. The second control signal CONT2 is used to control the operation of the data driver 500.

[0061] The driving controller 200 generates the data signal DATA based on the input image data IMG. The driving controller 200 outputs the data signal DATA to the data driver 500.

[0062] In an exemplary embodiment, the driving controller 200 can adjust the frame rate of the display panel 100 based on the input image data IMG.

[0063] The driving controller 200 generates the third control signal CONT3 based on the input control signals CONT, and outputs the third control signal CONT3 to the gamma reference voltage generator 400. The third control signal CONT3 is used to control the operation of the gamma reference voltage generator 400.

[0064] The structure and operation of the driving controller 200 will be explained in detail with reference to Figures 2-10 The structure and operation of the driving controller 200 will be explained in detail with reference to

[0065] The gate driver 300 generates a gate signal that drives the gate line GL in response to a first control signal CONT1 received from the driving controller 200. The gate driver 300 outputs the gate signal to the gate line GL. For example, the gate driver 300 can sequentially output a plurality of gate signals to a plurality of gate lines GL. The gate driver 300 can be mounted on the display panel 100, or the gate driver 300 can be integrated on the display panel 100.

[0066] The gamma reference voltage generator 400 generates a gamma reference voltage VGREF in response to a third control signal CONT3 received from the driving controller 200. The gamma reference voltage generator 400 provides the gamma reference voltage VGREF to the data driver 500. The gamma reference voltage VGREF has a value corresponding to a level of the data signal DATA.

[0067] In an exemplary embodiment, the gamma reference voltage generator 400 can be disposed in the driving controller 200 or in the data driver 500.

[0068] The data driver 500 receives the second control signal CONT2 and the data signal DATA from the driving controller 200, and receives the gamma reference voltage VGREF from the gamma reference voltage generator 400. The data driver 500 converts the data signal DATA into a data voltage having an analog type by using the gamma reference voltage VGREF. The data driver 500 outputs the data voltage to the data line DL.

[0069] Figure 2 is a block diagram of the driving controller 200 of Figure 1 . Figure 3 is a block diagram of the low frequency driver 240 of Figure 2 . Figure 4 is a diagram illustrating a segment defined by the segment determiner 242 of Figure 3 .

[0070] Referring to Figures 1-4 , the driving controller 200 includes the image converter 220, the low frequency driver 240, and the signal generator 260.

[0071] The image converter 220 compensates for gradation data of input image data IMG and rearranges the input image data IMG to generate a data signal DATA. The data signal DATA can correspond to a data type of the data driver 500 and can have a digital type. The image converter 220 outputs the data signal DATA to the data driver 500.

[0072] For example, the image converter 220 can include an adaptive color correction part (not shown) and a dynamic capacitance compensation part (not shown). The adaptive color correction part receives grayscale data of the input image data IMG, and operates adaptive color correction ("ACC"). The adaptive color correction part can compensate the grayscale data by using a gamma curve. The dynamic capacitance compensation part applies dynamic capacitance compensation ("DCC") that compensates grayscale data of a current frame data by using previous frame data and the current frame data.

[0073] The low frequency driver 240 receives the input image data IMG. The low frequency driver 240 determines a frame rate FR of the display panel 100 based on the input image data IMG. The low frequency driver 240 can output the frame rate FR to the signal generator 260. The low frequency driver 240 can output the frame rate FR to the image converter 220.

[0074] The signal generator 260 receives the input control signal CONT. The signal generator 260 generates a first control signal CONT1 to control a driving timing of the gate driver 300 based on the input control signal CONT and the frame rate FR. The signal generator 260 generates a second control signal CONT2 to control a driving timing of the data driver 500 based on the input control signal CONT and the frame rate FR. The signal generator 260 generates a third control signal CONT3 to control a driving timing of the gamma reference voltage generator 400 based on the input control signal CONT and the frame rate FR.

[0075] The signal generator 260 outputs the first control signal CONT1 to the gate driver 300. The signal generator 260 outputs the second control signal CONT2 to the data driver 500. The signal generator 260 outputs the third control signal CONT3 to the gamma reference voltage generator 400.

[0076] The low frequency driver 240 includes a static image determiner 241, a segment determiner 242, a pixel flicker determiner 243, a segment flicker determiner 244, a compensation determiner 245, a compensation size determiner 246, a flicker value compensator 247, and a frame rate determiner 248, each of which can be a hardware part such as, for example, an integrated circuit, a microprocessor, and the like.

[0077] The static image determiner 241 receives the input image data IMG. The static image determiner 241 determines whether the input image data IMG represents a static image or a video image. The video image can also be referred to as a dynamic image, and can refer to an image that depicts movement and / or motion.

[0078] The segment determiner 242 divides the input image data IMG into a plurality of segments S1 to S100. Although in the embodiment of FIG. 1, the input image data IMG is divided into 100 segments S1 to S100, the number of segments is not limited to 100. For example, the input image data IMG can be divided into 50 segments, 200 segments, or the like. Figure 4The input image data IMG is divided into one hundred segments of ten rows and ten columns, but the inventive concept is not limited to the number of segments.

[0079] Each of the plurality of segments S1 to S100 can have a rectangular shape. Flicker included in a rectangular shape including a long side extending in a horizontal direction is more perceived by human vision than flicker included in a rectangular shape including a long side extending in a vertical direction. Accordingly, each of the plurality of segments S1 to S100 can have a rectangular shape including a long side extending in a horizontal direction to effectively prevent flicker included in a rectangular shape including a long side extending in a horizontal direction. Alternatively, in other exemplary embodiments, each of the plurality of segments S1 to S100 can have a square shape. A segment size can mean a size of one of the plurality of segments S1 to S100. The segment size can be expressed as a number of pixels in a horizontal direction and a number of pixels in a vertical direction.

[0080] The pixel flicker determiner 243 determines a flicker value according to the luminance of the pixel. The flicker value indicates a degree of flicker perceived by a user. The flicker value of the pixel can vary according to the luminance of the pixel and the frame rate FR of the display panel 100. For example, the flicker value can be generated by visual inspection by changing the luminance of the pixel and / or the frame rate FR of the display panel being tested. In general, the flicker value can be relatively high in a low luminance region. In addition, the flicker value can be relatively high when the frame rate FR is low. Furthermore, the flicker value can vary according to the characteristics of the display panel 100.

[0081] The pixel flicker determiner 243 can determine the flicker value of the pixel by using a plurality of flicker values according to a plurality of luminances of the pixel and a plurality of frame rates FR.

[0082] For example, the pixel flicker determiner 243 can include a lookup table including a plurality of flicker values according to a plurality of luminances of the pixel and a plurality of frame rates FR.

[0083] The input image data IMG can include a red gray scale R, a green gray scale G, and a blue gray scale B. The input image data IMG can be determined in an RGB color space. The low frequency driver 240 can extract the luminance of the pixel from the input image data IMG in the RGB color space. For example, the low frequency driver 240 can include an RGB to Y converter to extract the luminance of the pixel from the input image data IMG in the RGB color space.

[0084] The segment flicker determiner 244 generates a flicker value of a segment. The segment flicker determiner 244 generates the flicker value of the segment by using the flicker value of the pixel.

[0085] For example, the segment flicker determiner 244 can sum a plurality of flicker values of a plurality of pixels in a segment.

[0086] When the segment includes one hundred pixels, the pixel flicker determiner 243 can determine one hundred flicker values of the one hundred pixels, respectively, and the segment flicker determiner 244 can sum the one hundred flicker values of the one hundred pixels to generate a flicker value of the segment.

[0087] Alternatively, the segment flicker determiner 244 can set a plurality of weights of a plurality of pixels according to a plurality of positions of the plurality of pixels. The segment flicker determiner 244 can operate a weighted sum of a plurality of flicker values of the plurality of pixels to generate a flicker value of the segment.

[0088] For example, an outer side portion of the display panel 100 is generally weak to flicker, such that pixels in the outer side portion can have a relatively high weight.

[0089] Alternatively, the segment flicker determiner 244 can variously operate a plurality of flicker values of a plurality of pixels to generate a flicker value of a segment.

[0090] For example, when the display panel 100 has one hundred segments, the segment flicker determiner 244 generates one hundred flicker values of the first segment S1 to the one hundredth segment S100.

[0091] In an exemplary embodiment, the segment determiner 242, the pixel flicker determiner 243, and the segment flicker determiner 244 can operate when the input image data IMG represents a still image.

[0092] In an exemplary embodiment, positions of the segment determiner 242 and the pixel flicker determiner 243 can be switched with each other.

[0093] The compensation determiner 245 can determine whether a flicker value of a segment is compensated according to a segment size.

[0094] For example, when the segment size is equal to or greater than a minimum size TH, the flicker value is not compensated, whereas below the minimum size TH, the flicker is perceptible to a user. The minimum size TH at which the flicker is perceived by the user can be referred to as a compensation threshold TH.

[0095] In contrast, when the segment size is less than the minimum size TH, the flicker value of the segment can be compensated based on the flicker value of the segment and the flicker values of adjacent segments, whereas below the minimum size TH, the flicker is perceptible to a user.

[0096] When the segment size is less than the compensation threshold TH, the compensation size determiner 246 can determine a mask size (filter size) to compensate for the flicker value. The mask size (filter size) can mean a number of a compensation target segment and a plurality of segments adjacent to the compensation target segment and can be used for compensation. The mask size (filter size) can mean a number of a flicker value of a compensation target segment and a plurality of flicker values of a plurality of segments adjacent to the compensation target segment and can be used for compensation. The mask size (filter size) can be referred to as a compensation size.

[0097] The flicker value compensator 247 can compensate the flicker value of the segment based on the flicker value of the segment and the plurality of flicker values of the plurality of adjacent segments. The flicker value compensator 247 can compensate the flicker value of the segment based on the flicker value of the segment corresponding to the compensation size and the plurality of flicker values of the plurality of adjacent segments.

[0098] The frame rate determiner 248 determines the frame rate FR of the display panel 100 based on the flicker value of the segment.

[0099] The frame rate determiner 248 can compare the maximum flicker value of the plurality of segments with the threshold value to determine the frame rate FR.

[0100] The frame rate determiner 248 can compare the average value of the plurality of flicker values of the plurality of segments with the threshold value to determine the frame rate FR of the display panel 100, while the plurality of segments have a plurality of relatively high flicker values. For example, the plurality of relatively high flicker values can be greater than a predetermined flicker value.

[0101] Alternatively, the frame rate determiner 248 can perform various operations on the plurality of flicker values of the plurality of segments to determine the frame rate FR.

[0102] In an exemplary embodiment, when the input image data IMG represents a video image, the frame rate determiner 248 can determine the frame rate FR as a high frequency regardless of the flicker value of the segment. When the input image data IMG represents a still image, the frame rate determiner 248 can determine the frame rate FR as one of a plurality of low frequencies based on the flicker value of the segment.

[0103] Figure 5A and Figure 5B The flicker value of the segment according to the first image is shown. Figure 6A and Figure 6B The flicker value of the segment according to the second image is shown. Figure 7A and Figure 7B A method of compensating the flicker value of the segment according to the first image is shown. Figure 8A and Figure 8B A method of compensating the flicker value of the segment according to the second image is shown.

[0104] Hereinafter, referring to Figures 5A-8B A method of determining the flicker value of the segment and the frame rate FR corresponding to the flicker value is explained.

[0105] In Figure 5A , the input image of the display panel 100 is a first image. In the first image, the plurality of segments S32 to S35, S42 to S45, and S52 to S55 of three rows and four columns have a flicker value corresponding to 60 Hz, and the segments other than the plurality of segments S32 to S35, S42 to S45, and S52 to S55 of three rows and four columns have a flicker value corresponding to 1 Hz.

[0106] The plurality of flicker values of the plurality of segments can be represented as shown in Figure 5B The frame rate determiner 248 can determine the frame rate FR of the display panel 100 as 60 Hz based on the maximum value of the plurality of flicker values of the plurality of segments. The "maximum value" as used herein refers to the maximum flicker value of a segment.

[0107] In Figure 6A , the input image of the display panel 100 is the second image. In the second image, the segment S43 has a flicker value corresponding to 60 Hz, and the segments other than the segment S43 have a flicker value corresponding to 1 Hz.

[0108] The plurality of flicker values of the plurality of segments can be represented as shown in Figure 6B The frame rate determiner 248 can determine the frame rate FR of the display panel 100 as 60 Hz based on the maximum value of the plurality of flicker values of the plurality of segments.

[0109] For example, when the segment size is relatively small and the plurality of segments S32 to S35, S42 to S45, and S52 to S55 of three rows and four columns have high flicker values (as shown in Figure 5A ), a high frame rate driving can be required to prevent the user from perceiving flicker. In contrast, when the segment size is relatively small and the single segment S43 has a high flicker value (as shown in Figure 6A ), the flicker of the single segment S43 can not be perceived by the user. In the latter case, a high frame rate driving can not be required. The avoidance of the perception of flicker by using the plurality of high flicker values of the plurality of adjacent segments (e.g., by adjusting the frame rate driving speed) is referred to herein as "compensation".

[0110] When the flicker value of a segment is not compensated based on the plurality of flicker values of the plurality of adjacent segments, the display panel in Figure 5A is driven at a high frame rate of 60 Hz, and the display panel in Figure 6A is driven at a frame rate less than 60 Hz. In contrast, when the flicker value of a segment is compensated based on the plurality of flicker values of the plurality of adjacent segments, the display panel in Figure 5A is driven at a high frame rate of 60 Hz, and the display panel in Figure 6A is driven at a frame rate less than 60 Hz.

[0111] In Figure 7A , the input image of the display panel 100 is a first image similar to the first image of Figure 5A . In Figure 7B , the flicker value of a segment can be compensated by using the plurality of flicker values of the plurality of adjacent segments.

[0112] When the compensation size is 3*3, the flicker value of the forty-second segment S42 can be compensated by using multiple flicker values ​​from multiple segments S31, S32, S33, S41, S42, S43, S51, S52, and S53. For example, the flicker value of the forty-second segment S42 can be compensated by using the average of the flicker values ​​from multiple segments S31, S32, S33, S41, S42, S43, S51, S52, and S53. Alternatively, the flicker value of the forty-second segment S42 can be compensated by using a weighted sum of the flicker values ​​from multiple segments S31, S32, S33, S41, S42, S43, S51, S52, and S53. For example, the flicker value of the forty-second segment S42 can have the highest weight, and the weight can decrease as the distance from the forty-second segment S42 increases.

[0113] When the compensation size is 3*3, the flicker value of segment S43 (segment 43) can be compensated by using multiple flicker values ​​from segments S32, S33, S34, S42, S43, S44, S52, S53, and S54. Similarly, when the compensation size is 3*3, the flicker value of segment S44 (segment 44) can be compensated by using multiple flicker values ​​from segments S33, S34, S35, S43, S44, S45, S53, S54, and S55.

[0114] When the compensation size is 5*5, the flicker value of the forty-third segment S43 can be compensated by using multiple flicker values ​​of multiple segments S21, S22, S23, S24, S25, S31, S32, S33, S34, S35, S41, S42, S43, S44, S45, S51, S52, S53, S54, S55, S61, S62, S63, S64 and S65. When the compensation size is 5*5, the flicker value of the forty-fourth segment S44 can be compensated by using multiple flicker values ​​of multiple segments S22, S23, S24, S25, S26, S32, S33, S34, S35, S36, S42, S43, S44, S45, S46, S52, S53, S54, S55, S56, S62, S63, S64, S65 and S66.

[0115] The flicker value of the segment compensated by flicker value compensator 247 can be as follows: Figure 7B As shown in the diagram. The frame rate determiner 248 can determine the frame rate FR of the display panel 100 to be 60Hz based on the maximum value of multiple flicker values ​​of multiple segments.

[0116] exist Figure 8A In the middle, the input image of the display panel 100 is the same as... Figure 6A The second image is similar to the second image. Figure 8BIn the case of the method of FIG. 6, the flicker value of the segment can be compensated for by using the plurality of flicker values of the plurality of adjacent segments.

[0117] The flicker value of the segment compensated for by the flicker value compensator 247 can be expressed as shown in Figure 8B The frame rate determiner 248 can determine the frame rate FR of the display panel 100 as 15 Hz based on the maximum value of the plurality of flicker values of the plurality of segments.

[0118] In Figure 8B the case where the flicker value of the forty-third segment S43 is the maximum value, the frame rate determiner 248 can compare the flicker value of the forty-third segment S43 with the threshold values of the plurality of frame rates. The flicker value of the forty-third segment S43 is greater than the threshold value of 1 Hz and is equal to or less than the threshold value of 15 Hz, so that the frame rate FR of the display panel 100 can be determined as 15 Hz.

[0119] In Figure 6B the case where the segment size is relatively small, the flicker can not be shown to the user. However, the frame rate FR is determined only by using the flicker value of the segment in Figure 6B , and the display panel 100 can be driven at a frame rate higher than the required frame rate. In contrast, in Figure 8B , the flicker value of the segment is compensated for by using the plurality of flicker values of the plurality of adjacent segments, so that the frame rate of the display panel 100 can be reduced without unnecessary degradation of the display quality of the display panel 100.

[0120] When the flicker value of the segment is compensated for by using the plurality of flicker values of the plurality of adjacent segments regardless of the segment size, the display panel 100 can be driven at an inappropriate frame rate FR.

[0121] Figures 9A-9C A method of compensating for the flicker value of a segment regardless of the segment size is shown.

[0122] Figure 9A In , the plurality of segments S35, S44, S45, S46, S54, S55, S56, S67, S68, S77, and S78 can express the gray value of 19, and the plurality of segments S34, S36, S37, S38, S47, S48, S57, S58, S64, S65, S66, S74, S75, and S76 can express the gray value of 255.

[0123] Figure 9B As shown in Figure 9B and Figure 9C , the frame rate FR corresponding to the gray value of 19 can be 30 Hz. As shown in Figure 9B , the flicker value of the gray value of 255 can be 0, and as shown in Figure 9B andFigure 9C The frame rate FR corresponding to the gray scale value of 255 can be 1 Hz as shown in FIG. 2.

[0124] In Figures 9A-9C In this case, when the display panel 100 is driven at the frame rate FR of 30 Hz corresponding to the gray scale value of 19, the flicker can not be perceived by the user.

[0125] When the flicker values of the segments are compensated by the flicker value compensator 247 using the compensation size CS of 5*5 without considering the segment size, the flicker value corresponding to the compensation size CS of 5*5 can be an average value of the segments S34, S35, S36, S37, S38, S44, S45, S46, S47, S48, S54, S55, S56, S57, S58, S64, S65, S66, S67, S68, S74, S75, S76, S77, and S78. The average value is 89.8. According to Figure 9C The frame rate FR corresponding to the flicker value of 89.8 can be 2 Hz. When the display panel 100 is driven at the frame rate FR of 2 Hz, the flicker of the display panel 100 can not be perceived by the user.

[0126] Figure 10 is a flowchart illustrating operations of the compensation determiner 245, the compensation size determiner 246, the flicker value compensator 247, and the frame rate determiner 248 of Figure 3 Referring to

[0127] According to the present exemplary embodiment, the low frequency driver 240 can include the compensation determiner 245 to determine whether to compensate for the flicker value of the segment according to the segment size (step S100). Figures 1-10 When the segment size is equal to or greater than the compensation threshold TH, the compensation determiner 245 can determine not to compensate for the flicker value of the segment. When the segment size is less than the compensation threshold TH, the compensation determiner 245 can determine to compensate for the flicker value of the segment.

[0128] When the segment size is sufficiently large so that the flicker of the single segment is perceived by the user, the steps S200 and S300 of compensating for the flicker value of the segment can be skipped. Accordingly, the frame rate FR can be determined by using the flicker value of the segment which is not compensated (step S400).

[0129] On the contrary, when the segment size is small so that the flicker of the single segment is not perceived by the user, the flicker value of the segment can be compensated by the steps S200 and S300. Accordingly, the frame rate FR can be determined by using the compensated flicker value of the segment (step S400).

[0130]

[0131] ​When the segment size is smaller than the compensation threshold TH, the compensation size determiner 246 can determine a compensation size CS, and the compensation size CS indicates the number of the flicker value of the segment and the number of the flicker values of a plurality of adjacent segments for compensating for the flicker value of the segment (step S200).

[0132] The compensation size CS can be determined such that the product of the segment size and the compensation size CS is equal to or greater than the compensation threshold TH. For example, the compensation size CS can be determined as the smallest integer satisfying the product of the segment size and the compensation size CS being equal to or greater than the compensation threshold TH.

[0133] For example, when the compensation threshold TH (meaning the segment size in which flicker is perceived by a user) is 300*300 and the actual segment size is 512*512, the steps S200 and S300 of compensating for the flicker value of the segment can be skipped, and the frame rate FR can be determined by using the flicker value of the segment which is not compensated.

[0134] For example, when the compensation threshold TH (meaning the segment size in which flicker is perceived by a user) is 300*300 and the actual segment size is 64*64, the flicker value of the segment can be compensated for by the steps S200 and S300, and the frame rate FR can be determined by using the compensated flicker value of the segment.

[0135] In this document, the compensation size CS can be determined as a value greater than 4.6875*4.6875. The compensation size CS can be determined from among values 5*5, 6*6, 7*7, and 8*8, etc. For example, the compensation size CS can be determined as a value of 5*5.

[0136] The compensation size determiner 246 can independently determine a first compensation size and a second compensation size. The first compensation size means the number of the flicker value of the segment and a plurality of adjacent segments in a first direction D1 (a row direction) for compensating for the flicker value of the segment. The second compensation size means the number of the flicker value of the segment and an adjacent segment in a second direction D2 (a column direction) for compensating for the flicker value of the segment.

[0137] As explained above, the first compensation size and the second compensation size having values such as 5*5, 6*6, 7*7, and 8*8, etc. can be equal to each other. Alternatively, according to the characteristics of the display panel 100, when the degree of flicker in the first direction D1 is different from the degree of flicker in the second direction D2, the first compensation size and the second compensation size can be different from each other.

[0138] The flicker value compensator 247 can compensate for the flicker value of the segment based on the compensation size CS (step S300).

[0139] The frame rate determiner 248 can determine the frame rate FR based on the compensated flicker value or the uncompensated flicker value (step S400).

[0140] According to the present exemplary embodiment, the frame rate FR is determined according to the image displayed on the display panel 100, so that the power consumption of the display apparatus can be reduced. In addition, the frame rate FR is determined by using the flicker value of the segment of the image displayed on the display panel 100, so that the flicker of the image (e.g., the flicker perceived by the user) can be prevented, and the display quality of the display panel 100 can be enhanced. In addition, the flicker value of the segment is compensated by using the flicker value of the adjacent segment, so that the display quality of the display panel 100 can be further enhanced.

[0141] Figure 11 is a block diagram illustrating a low frequency driver 240A of a display apparatus according to an exemplary embodiment of the present inventive concept. Figure 12 is a block diagram illustrating Figure 11 a compensation size and a compensation determiner 245A, a flicker value compensator 247, and a frame rate determiner 248 of the display apparatus 100 according to the present exemplary embodiment.

[0142] The method of driving a display panel and the display apparatus according to the present exemplary embodiment are substantially the same as the method of driving a display panel and the display apparatus of the previous exemplary embodiment explained with reference to Figures 1-10 , except for the structure and operation of the low frequency driver. Therefore, the same reference numerals will be used to refer to the parts same as or similar to those described in the previous exemplary embodiment, and any repeated explanation about the above elements will be omitted. Figures 1-10

[0143] Referring to Figure 1 , Figure 2 , Figures 4-9C , Figure 11 and Figure 12 , the display apparatus includes a display panel 100 and a display panel driver. The display panel driver includes a driving controller 200, a gate driver 300, a gamma reference voltage generator 400, and a data driver 500.

[0144] The driving controller 200 includes an image converter 220, a low frequency driver 240A, and a signal generator 260.

[0145] The low frequency driver 240A receives input image data IMG. The low frequency driver 240A determines a frame rate FR of the display panel 100 based on the input image data IMG. The low frequency driver 240A can output the frame rate FR to the signal generator 260. The low frequency driver 240A can output the frame rate FR to the image converter 220.

[0146] ​The low frequency driver 240A includes a static image determiner 241, a segment determiner 242, a pixel flicker determiner 243, a segment flicker determiner 244, a compensation size and compensation determiner 245A, a flicker value compensator 247, and a frame rate determiner 248.

[0147] In the present exemplary embodiment, the compensation size CS can be determined before determining whether to operate compensation based on the segment size.

[0148] The compensation size and compensation determiner 245A determines the compensation size CS by dividing the compensation threshold TH by the segment size (step S500). The compensation size and compensation determiner 245A determines whether to compensate the flicker value of the segment based on the determined compensation size CS (step S600).

[0149] When the determined compensation size CS is equal to or less than 1, the flicker value of the segment can not need to be compensated. Accordingly, when the determined compensation size CS is equal to or less than 1, the step S700 of compensating the flicker value of the segment can be skipped, and the frame rate FR can be determined based on the flicker value of the segment without compensation (step S800).

[0150] When the determined compensation size CS is greater than 1, the flicker value of the segment can need to be compensated. Accordingly, when the determined compensation size CS is greater than 1, the flicker value of the segment can be compensated (step S700), and the frame rate FR can be determined based on the compensated flicker value of the segment (step S800).

[0151] For example, when the compensation threshold TH (meaning the segment size in which flicker is perceived by a user) is 300*300, and the actual segment size is 512*512, the compensation size CS can be (300*300) / (512*512), such that the compensation size CS can be less than 1. Accordingly, the step S700 of compensating the flicker value of the segment can be skipped, and the frame rate FR can be determined based on the flicker value of the segment without compensation.

[0152] For example, when the compensation threshold TH (meaning the segment size in which flicker is perceived by a user) is 300*300, and the actual segment size is 64*64, the compensation size CS can be (300*300) / (64*64), such that the compensation size CS can be greater than 1. Accordingly, the flicker value of the segment can be compensated (step S700), and the frame rate FR can be determined based on the compensated flicker value of the segment.

[0153] The compensation size and compensation determiner 245A can independently determine a first compensation size and a second compensation size. The first compensation size can mean a number of the flicker value of the segment and a number of the flicker values of a plurality of neighboring segments in the first direction D1 (row direction) for compensating for the flicker value of the segment. The second compensation size can mean a number of the flicker value of the segment and a number of the flicker values of a plurality of neighboring segments in the second direction D2 (column direction) for compensating for the flicker value of the segment.

[0154] The flicker value compensator 247 can compensate for the flicker value of the segment based on the compensation size CS (step S700).

[0155] The frame rate determiner 248 can determine the frame rate FR based on the compensated flicker value or the uncompensated flicker value (step S800).

[0156] According to the present exemplary embodiment, the frame rate FR is determined according to the image displayed on the display panel 100, so that the power consumption of the display apparatus can be reduced. In addition, the frame rate FR is determined by using the flicker value of the segment of the image displayed on the display panel 100, so that the flicker of the image can be prevented, and the display quality of the display panel 100 can be enhanced. In addition, the flicker value of the segment is compensated for by using a plurality of flicker values of a plurality of neighboring segments, so that the display quality of the display panel 100 can be further enhanced.

[0157] Figure 13 is a block diagram illustrating a display apparatus according to an exemplary embodiment of the present inventive concept. Figure 14 is a block diagram illustrating a display apparatus according to an exemplary embodiment of the present inventive concept. Figure 13 is a circuit diagram of a pixel of the display panel 100. Figure 15 is a timing diagram illustrating an input signal applied to a pixel of the display panel 100. Figure 14

[0158] The method of driving a display panel and the display apparatus according to the present exemplary embodiment are substantially the same as the method of driving a display panel and the display apparatus of the previous exemplary embodiment explained with reference to Figures 1-10 , except for some of the structures of the display panel. Therefore, the same reference numerals will be used to refer to parts which are the same as or similar to those described in the previous exemplary embodiment of Figures 1-10 , and any repetitive explanation regarding the above-described elements will be omitted.

[0159] With reference to Figures 2-10 and Figures 13-15 , the display apparatus includes a display panel 100 and a display panel driver. The display panel driver includes a driving controller 200, a gate driver 300, a gamma reference voltage generator 400, a data driver 500, and an emission driver 600.

[0160] ​The display panel 100 has a display area that displays an image and a peripheral area adjacent to the display area.

[0161] The display panel 100 includes a plurality of gate lines GWPL, GWNL, GIL, and GBL, a plurality of data lines DL, a plurality of emission lines EL, and a plurality of pixels electrically connected to the plurality of gate lines GWPL, GWNL, GIL, and GBL, the plurality of data lines DL, and the plurality of emission lines EL. The plurality of gate lines GWPL, GWNL, GIL, and GBL can extend in a first direction D1, the data lines DL can extend in a second direction D2 intersecting the first direction D1, and the emission lines EL can extend in the first direction D1.

[0162] The drive controller 200 receives input image data IMG and an input control signal CONT from an external device (not shown).

[0163] The drive controller 200 generates a first control signal CONT1, a second control signal CONT2, a third control signal CONT3, and a fourth control signal CONT4 based on the input control signal CONT. The drive controller 200 also generates a data signal DATA3 based on the input image data IMG.

[0164] The emission driver 600 generates an emission signal to drive the emission lines EL in response to the fourth control signal CONT4 received from the drive controller 200. The emission driver 600 can output the emission signal to the emission lines EL.

[0165] The display panel 100 includes a plurality of pixels. Each pixel includes an organic light emitting element OLED.

[0166] The pixel receives a plurality of data write gate signals GWP and GWN, a data initialization gate signal GI, an organic light emitting element initialization signal GB, a data voltage VDATA, and an emission signal EM, and the organic light emitting element OLED of the pixel emits light corresponding to a level of the data voltage VDATA to display an image.

[0167] In the present exemplary embodiment, the pixel can include a first type of switching element and a second type of switching element different from the first type. The first type of switching element can be a polysilicon thin film transistor. The first type of switching element can be a low temperature polysilicon (LTPS) thin film transistor. The second type of switching element can be an oxide thin film transistor. The first type of switching element can be a P-type transistor, and the second type of switching element can be an N-type transistor.

[0168] The plurality of data write gate signals GWP and GWN can include a first data write gate signal GWP and a second data write gate signal GWN. The first data write gate signal GWP can be applied to the P-type transistor such that the first data write gate signal GWP has an active signal of a low level corresponding to a data write timing. The second data write gate signal GWN can be applied to the N-type transistor such that the second data write gate signal GWN has an active signal of a high level corresponding to the data write timing.

[0169] At least one of the plurality of pixels can include a first to seventh pixel switching element T1 to T7, a storage capacitor CST, and an organic light emitting element OLED.

[0170] The first pixel switching element T1 includes a control electrode connected to the first node N1, an input electrode connected to the second node N2, and an output electrode connected to the third node N3.

[0171] The first pixel switching element T1 can be a polysilicon thin film transistor. The first pixel switching element T1 can be a P-type thin film transistor. The control electrode of the first pixel switching element T1 can be a gate electrode, the input electrode of the first pixel switching element T1 can be a source electrode, and the output electrode of the first pixel switching element T1 can be a drain electrode.

[0172] The second pixel switching element T2 includes a control electrode to which the first data write gate signal GWP is applied, an input electrode to which the data voltage VDATA is applied, and an output electrode connected to the second node N2.

[0173] The second pixel switching element T2 can be a polysilicon thin film transistor. The second pixel switching element T2 can be a P-type thin film transistor. The control electrode of the second pixel switching element T2 can be a gate electrode, the input electrode of the second pixel switching element T2 can be a source electrode, and the output electrode of the second pixel switching element T2 can be a drain electrode.

[0174] The third pixel switching element T3 includes a control electrode to which the second data write gate signal GWN is applied, an input electrode connected to the first node N1, and an output electrode connected to the third node N3.

[0175] The third pixel switching element T3 can be an oxide thin film transistor. The third pixel switching element T3 can be an N-type thin film transistor. The control electrode of the third pixel switching element T3 can be a gate electrode, the input electrode of the third pixel switching element T3 can be a source electrode, and the output electrode of the third pixel switching element T3 can be a drain electrode.

[0176] The fourth pixel switching element T4 includes a control electrode to which a data initialization gate signal GI is applied, an input electrode to which an initialization voltage VI is applied, and an output electrode connected to the first node N1.

[0177] The fourth pixel switching element T4 can be an oxide thin film transistor. The fourth pixel switching element T4 can be an N-type thin film transistor. The control electrode of the fourth pixel switching element T4 can be a gate electrode, the input electrode of the fourth pixel switching element T4 can be a source electrode, and the output electrode of the fourth pixel switching element T4 can be a drain electrode.

[0178] The fifth pixel switching element T5 includes a control electrode to which an emission signal EM is applied, an input electrode to which a high power voltage ELVDD is applied, and an output electrode connected to the second node N2.

[0179] The fifth pixel switching element T5 can be a polysilicon thin film transistor. The fifth pixel switching element T5 can be a P-type thin film transistor. The control electrode of the fifth pixel switching element T5 can be a gate electrode, the input electrode of the fifth pixel switching element T5 can be a source electrode, and the output electrode of the fifth pixel switching element T5 can be a drain electrode.

[0180] The sixth pixel switching element T6 includes a control electrode to which an emission signal EM is applied, an input electrode connected to the third node N3, and an output electrode connected to the anode of the organic light emitting element OLED.

[0181] The sixth pixel switching element T6 can be a polysilicon thin film transistor. The sixth pixel switching element T6 can be a P-type thin film transistor. The control electrode of the sixth pixel switching element T6 can be a gate electrode, the input electrode of the sixth pixel switching element T6 can be a source electrode, and the output electrode of the sixth pixel switching element T6 can be a drain electrode.

[0182] The seventh pixel switching element T7 includes a control electrode to which an organic light emitting element initialization signal GB is applied, an input electrode to which an initialization voltage VI is applied, and an output electrode connected to the anode of the organic light emitting element OLED.

[0183] The seventh pixel switching element T7 can be an oxide thin film transistor. The seventh pixel switching element T7 can be an N-type thin film transistor. The control electrode of the seventh pixel switching element T7 can be a gate electrode, the input electrode of the seventh pixel switching element T7 can be a source electrode, and the output electrode of the seventh pixel switching element T7 can be a drain electrode.

[0184] The storage capacitor CST includes a first electrode to which a high power voltage ELVDD is applied, and a second electrode connected to the first node N1.

[0185] The organic light emitting element OLED includes an anode electrode connected to the output electrode of the sixth pixel switching element T6 and a cathode electrode to which a low power voltage ELVSS is applied.

[0186] As shown in FIG. 1, the display panel 100 includes a plurality of pixel switching elements T1, T2, T3, T4, T5, T6, and T7, a plurality of storage capacitors CST, a plurality of organic light emitting elements OLED, and a plurality of data lines D1, D2, D3, D4, D5, and D6. Figure 15 As shown in FIG. 1, the display panel 100 includes a plurality of pixel switching elements T1, T2, T3, T4, T5, T6, and T7, a plurality of storage capacitors CST, a plurality of organic light emitting elements OLED, and a plurality of data lines D1, D2, D3, D4, D5, and D6.

[0187] In the present exemplary embodiment, some of the plurality of pixel switching elements can be designed by using oxide thin film transistors. In the present exemplary embodiment, the third pixel switching element T3, the fourth pixel switching element T4, and the seventh pixel switching element T7 can be oxide thin film transistors. The first pixel switching element T1, the second pixel switching element T2, the fifth pixel switching element T5, and the sixth pixel switching element T6 can be polysilicon thin film transistors.

[0188] The display panel 100 can be driven in a normal driving mode in which the display panel 100 is driven at a normal driving frequency and in a low frequency driving mode in which the display panel 100 is driven at a low frequency. The low frequency can be lower than the normal driving frequency.

[0189] For example, when the input image data represents a video image, the display panel 100 can be driven in the normal driving mode. When the input image data represents a still image, the display panel can be driven in the low frequency driving mode. When the display apparatus is operated in an always-on mode, the display panel can be driven in the low frequency driving mode.

[0190] The display panel 100 can be driven in units of frames. In the normal driving mode, the display panel 100 can be refreshed in each frame. Thus, the normal driving mode includes only a write frame in which data is written into the pixels.

[0191] In the low frequency driving mode, the display panel 100 can be refreshed at a low frequency. Thus, the low frequency driving mode includes a write frame in which data is written into the pixels and a hold frame in which the written data is maintained without writing data into the pixels.

[0192] For example, when the frequency of the normal driving mode is 60 Hz and the frequency of the low frequency driving mode is 1 Hz, the low frequency driving mode includes one write frame and fifty-nine hold frames per second. For example, when the frequency of the normal driving mode is 60 Hz and the frequency of the low frequency driving mode is 1 Hz, fifty-nine consecutive hold frames are arranged between two adjacent write frames.

[0193] For example, when the frequency of the normal driving mode is 60 Hz and the frequency of the low frequency driving mode is 10 Hz, the low frequency driving mode includes ten write frames and fifty hold frames per second. For example, when the frequency of the normal driving mode is 60 Hz and the frequency of the low frequency driving mode is 10 Hz, five consecutive hold frames are arranged between two adjacent write frames.

[0194] In the present exemplary embodiment, the second data write gate signal GWN and the data initialization gate signal GI can have a first frequency in the low frequency driving mode. The first frequency can be the frequency of the low frequency driving mode. In contrast, the first data write gate signal GWP, the emission signal EM, and the organic light emitting element initialization signal GB can have a second frequency greater than the first frequency. The second frequency can be the normal frequency of the normal driving mode.

[0195] Figure 3 The low frequency driver 240 in the low frequency driver 240 in FIG. 1 can be applied to the structure of the display panel 100 of the present exemplary embodiment. In addition, Figure 11 The low frequency driver 240A in the low frequency driver 240A in FIG. 1 can be applied to the structure of the display panel 100 of the present exemplary embodiment.

[0196] According to the present exemplary embodiment, the frame rate FR is determined according to the image displayed on the display panel 100, so that the power consumption of the display apparatus can be reduced. In addition, the frame rate FR is determined by using the flicker value of the segment of the image displayed on the display panel 100, so that the flicker of the image can be prevented, and the display quality of the display panel 100 can be improved. In addition, the flicker value of the segment is compensated by using the plurality of flicker values of the plurality of adjacent segments, so that the display quality of the display panel 100 can be further improved.

[0197] According to the present exemplary embodiment, the power consumption of the display apparatus can be reduced, and the display quality of the display panel can be enhanced.

[0198] The foregoing is a summary of the present inventive concept and is not to be construed as limiting. While some example embodiments of the inventive concept have been described, those skilled in the art will readily understand that there are a number of modifications that can be made thereto without departing from the essential characteristics of the present inventive concept. Accordingly, all such modifications are intended to be included within the scope of the present inventive concept as defined in the claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Accordingly, although the inventive concept has been described in detail with reference to particular embodiments, it is not intended that the inventive concept be limited to such embodiments. It is therefore evident that there are many alternatives that fall within the scope of the present inventive concept as claimed. The present inventive concept is defined by the following claims and their equivalents.

Claims

1. A method of driving a display panel, the method comprising: dividing an input image into a plurality of segments; generating a flicker value of a segment among the plurality of segments; compensating the flicker value of the segment based on a segment size, the flicker value of the segment, and a plurality of flicker values of a plurality of neighboring segments located around the segment; determining a frame rate of the display panel based on the flicker value of the segment; and outputting a data voltage to the display panel at the frame rate, wherein the compensating the flicker value of the segment comprises: determining not to compensate the flicker value of the segment when the segment size is equal to or greater than a compensation threshold; and determining to compensate the flicker value of the segment when the segment size is less than the compensation threshold. 2.The method of claim 1, further comprising: determining a compensation size, wherein the compensation size indicates a number of a flicker value of a compensation target segment and a plurality of flicker values of a plurality of segments adjacent to the compensation target segment; and wherein the compensation size is used for compensation of the compensation target segment when the segment size is less than the compensation threshold. determining the compensation size such that a product of the segment size and the compensation size is equal to or greater than the compensation threshold.

3. The method of claim 2, wherein, the compensation size is determined to be a minimum integer satisfying the product of the segment size and the compensation size being equal to or greater than the compensation threshold.

4. The method of claim 3, wherein, determining the compensation size comprises:

5. The method of claim 2, wherein, determining a first compensation size indicating a number of the flicker value of the compensation target segment and the plurality of flicker values of the plurality of segments adjacent to the compensation target segment in a first direction; and determining a second compensation size indicating a number of the flicker value of the compensation target segment and the plurality of flicker values of the plurality of segments adjacent to the compensation target segment in a second direction different from the first direction, wherein the first compensation size and the second compensation size are each used for compensation of the compensation target segment. 6.The method of claim 1, further comprising: determining whether the input image represents a still image or a video image, wherein the frame rate of the display panel is determined based on the flicker value of the segment when the input image represents the still image. generating the flicker value of the segment comprises:

7. The method of claim 1, wherein, converting luminance of a plurality of pixels into a plurality of flicker values of the plurality of pixels; and operating the plurality of flicker values of the plurality of pixels in the segment. determining the frame rate of the display panel comprises:

8. The method of claim 1, wherein, comparing a maximum value of a plurality of flicker values of the plurality of segments with a threshold value. determining the frame rate of the display panel comprises:

9. The method of claim 1, wherein, comparing an average value of a plurality of flicker values of the plurality of segments with a threshold value, the average value being greater than a predetermined flicker value. 10.A method of driving a display panel, the method comprising: dividing an input image into a plurality of segments; generating a flicker value of a segment among the plurality of segments; compensating the flicker value of the segment based on a segment size, the flicker value of the segment, and a plurality of flicker values of a plurality of neighboring segments located around the segment; determining a frame rate of the display panel based on the flicker value of the segment; and outputting a data voltage to the display panel at the frame rate. outputting a data voltage to the display panel at the frame rate; and determining a compensation size, wherein the compensation size is determined by dividing a compensation threshold by the segment size, wherein compensating the flicker value of the segment comprises: when the compensation size is equal to or less than 1, determining not to compensate the flicker value of the segment; and when the compensation size is greater than 1, compensating the flicker value of the segment.

11. The method of claim 10, wherein, determining the compensation size comprises: determining a first compensation size representing a number of flicker values of the compensation target segment and the plurality of segments adjacent to the compensation target segment in a first direction; and determining a second compensation size representing a number of flicker values of the compensation target segment and the plurality of segments adjacent to the compensation target segment in a second direction different from the first direction, wherein the first compensation size and the second compensation size are used for compensation of the compensation target segment.

12. The method of claim 10, further comprising: determining whether the input image represents a still image or a video image, wherein when the input image represents the still image, determining the frame rate of the display panel based on the flicker value of the segment.

13. The method of claim 10, wherein, generating the flicker value of the segment comprises: converting luminance of a plurality of pixels to a plurality of flicker values of the plurality of pixels; and operating the plurality of flicker values of the plurality of pixels in the segment.

14. The method of claim 13, wherein, operating the plurality of flicker values of the plurality of pixels in the segment comprises: summing the plurality of flicker values of the plurality of pixels in the segment.

15. The method of claim 13, wherein, operating the plurality of flicker values of the plurality of pixels in the segment comprises: setting a plurality of weights of the plurality of pixels according to a plurality of positions of the plurality of pixels; and operating a weighted sum of the plurality of flicker values of the plurality of pixels by using the plurality of weights of the plurality of pixels.

16. The method of claim 10, wherein, determining the frame rate of the display panel comprises: comparing a maximum value of a plurality of flicker values of the plurality of segments with a threshold value.

17. The method of claim 10, wherein, determining the frame rate of the display panel comprises: comparing an average value of a plurality of flicker values of the plurality of segments with a threshold value, the average value being greater than a predetermined flicker value.

18. A display apparatus comprising: a display panel configured to display an image; a low frequency driver connected to the display panel and configured to divide an input image into a plurality of segments, generate a flicker value of a segment of the plurality of segments, compensate the flicker value of the segment in accordance with a segment size, and determine a frame rate of the display panel based on the flicker value of the segment; and a data driver connected to the display panel and configured to output a data voltage to the display panel at the frame rate, wherein the low frequency driver is configured to determine not to compensate the flicker value of the segment when the segment size is equal to or greater than a compensation threshold; and wherein the low frequency driver is configured to determine to compensate the flicker value of the segment when the segment size is smaller than the compensation threshold.

19. The display device of claim 18, wherein, The low frequency driver is configured to determine a compensation size, the compensation size representing a number of a flicker value of a compensation target segment and a plurality of flicker values of a plurality of segments adjacent to the compensation target segment, the compensation size being used for compensation of the compensation target segment when the segment size is smaller than the compensation threshold.

20. The display device of claim 19, wherein, The compensation size is determined such that a product of the segment size and the compensation size is equal to or greater than the compensation threshold.

21. The display device of claim 18, wherein, The low frequency driver includes: a still image determiner configured to determine whether the input image represents a still image or a video image; and wherein the low frequency driver is configured to determine the frame rate of the display panel based on the flicker value of the segment when the input image represents the still image.

22. A display apparatus comprising: a display panel configured to display an image; a low frequency driver connected to the display panel and configured to divide an input image into a plurality of segments, generate a flicker value of a segment of the plurality of segments, compensate the flicker value of the segment depending on a segment size, and determine a frame rate of the display panel based on the flicker value of the segment; and a data driver connected to the display panel and configured to output a data voltage to the display panel at the frame rate, wherein the low frequency driver is configured to determine a compensation size; wherein the compensation size is determined based on a number of a flicker value of a compensation target segment and a plurality of flicker values of a plurality of segments adjacent to the compensation target segment, the compensation size being used for compensation of the compensation target segment; wherein the compensation size is determined by dividing a compensation threshold by the segment size; wherein the low frequency driver is configured to determine not to compensate the flicker value of the segment when the compensation size is equal to or smaller than 1; and wherein the low frequency driver is configured to determine to compensate the flicker value of the segment when the compensation size is greater than 1.

23. The display device of claim 22, wherein, The low frequency driver includes: a still image determiner configured to determine whether the input image represents a still image or a video image; and wherein the low frequency driver is configured to determine the frame rate of the display panel based on the flicker value of the segment when the input image represents the still image.

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