Display device for performing static image detection and method of operating the display device

Abstract

A display device for performing static image detection and a method for operating the display device are provided. The display device includes a display panel including a plurality of pixels and a driver configured to drive the display panel. The driver includes: a ditherer configured to perform a dithering operation on image data including a plurality of pixel data for a plurality of pixels to generate dithered image data including a plurality of dithered pixel data respectively corresponding to the plurality of pixel data; and a static image detector configured to receive the dithered image data, detect dither-independent pixel data among the plurality of dithered pixel data that is not changed from the plurality of pixel data by the dithering operation, and determine whether the dithered image data represents a static image by using the dither-independent pixel data.

Description

Technical Field

[0001] Exemplary embodiments of the invention relate generally to a display device, and more particularly to a display device that performs still image detection and a method of operating the display device. Background Art

[0002] It is desirable to reduce power consumption in a display device employed in a portable device such as a smart phone, a tablet computer, etc. Recently, in order to reduce power consumption of the display device, a technology for distinguishing a driving method for a static image that does not change in consecutive frames from a driving method for a dynamic image that changes every frame has been developed. In addition, in order to distinguish a driving method for a static image from a driving method for a dynamic image, a technology for detecting a static image is required.

[0003] Conventional static image detection techniques detect static images by comparing image data in consecutive frames. However, in the case where a dithering technique is applied to increase the grayscale resolution of an image, the dithered image data of the static image may be changed for each frame in each dithering cycle. Therefore, in order to detect a static image in a display device to which the dithering technique is applied, a time period corresponding to at least two dithering cycles is required.

[0004] The above information disclosed in this Background section is only for understanding the background of the inventive concept and therefore it may contain information that does not constitute the prior art. Summary of the invention

[0005] Exemplary embodiments of the present invention provide a display device capable of quickly detecting a static image even if a dithering technique is applied.

[0006] Exemplary embodiments of the present invention also provide a method of operating a display device capable of quickly detecting a static image even if a dithering technique is applied.

[0007] Additional features of the inventive concepts will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the inventive concepts.

[0008] An exemplary embodiment of the present invention provides a display device, which includes a display panel including a plurality of pixels and a driver configured to drive the display panel. The driver includes: a ditherer configured to perform a dithering operation on image data to generate dithered image data, the image data including a plurality of pixel data for a plurality of pixels, the dithered image data including a plurality of dithered pixel data respectively corresponding to the plurality of pixel data; and a static image detector configured to receive the dithered image data, detect dither-independent pixel data among the plurality of dithered pixel data that is not changed from the plurality of pixel data by the dithering operation, and determine whether the dithered image data represents a static image by using the dither-independent pixel data.

[0009] The still image detector may be configured to determine whether the dithered image data represents a still image by comparing the dither-independent pixel data in a first frame with dither-independent pixel data in a second frame directly following the first frame.

[0010] The static image detector may include a comparison pixel ratio determiner, which is configured to detect jitter-independent pixel data among multiple jitter pixel data, calculate a ratio of the number of jitter-independent pixel data to the number of multiple jitter pixel data as a comparison pixel ratio, and compare the comparison pixel ratio with a reference pixel ratio.

[0011] The static image detector may further include a data comparator configured to determine whether the jittered image data represents a static image by comparing jitter-independent pixel data in a first frame with jitter-independent pixel data in a second frame directly following the first frame when the comparison pixel ratio is greater than or equal to the reference pixel ratio.

[0012] When the comparison pixel ratio is less than the reference pixel ratio, the comparison pixel ratio determiner may detect, based on the dithering pattern of the dithering operation, jitter-related pixel data that is unchanged in the first frame and in the second frame directly following the first frame among the jitter-related pixel data except the jitter-irrelevant pixel data in the multiple jitter pixel data, to recalculate the number of jitter-irrelevant pixel data and the ratio of the sum of the numbers of jitter-related pixel data that is unchanged in the first frame and the second frame to the numbers of the multiple jitter pixel data as the comparison pixel ratio, and compare the recalculated comparison pixel ratio with the reference pixel ratio.

[0013] The static image detector may further include a data comparator configured to determine whether the jittered image data represents a static image by using jitter-independent pixel data and jitter-dependent pixel data that is unchanged in the first frame and the second frame when the recalculated comparison pixel ratio is greater than or equal to the reference pixel ratio.

[0014] When the recalculated comparison pixel ratio is less than the reference pixel ratio, the comparison pixel ratio determiner further detects unchanged jitter-related pixel data in the first frame and in at least one frame after the second frame based on the jitter pattern until the comparison pixel ratio using the number of further detected jitter-related pixel data becomes greater than or equal to the reference pixel ratio. The static image detector may further include a data comparator configured to determine whether the jittered image data represents a static image by using the jitter-independent pixel data, the unchanged jitter-related pixel data in the first frame and the second frame, and the unchanged jitter-related pixel data in the first frame and in the at least one frame after the second frame.

[0015] The comparison pixel ratio determiner may add the jitter-related pixel data unchanged in the first frame and at least one subsequent frame to the comparison pixel data used to determine whether the jitter image data represents a static image until the comparison pixel ratio becomes greater than or equal to the reference pixel ratio. The static image detector may further include a data comparator configured to determine whether the jitter image data represents a static image by using the jitter-independent pixel data and the jitter-related pixel data unchanged in the first frame and the at least one subsequent frame. The subsequent frames may be sequentially selected from the second frame to the (2^M+1)th frame, where M is the number of bits corresponding to the jitter period of the jitterer.

[0016] The static image detector may further include: a data storage configured to store representative values ​​of jitter-independent pixel data in a first frame; and a data comparator configured to determine whether the jittered image data represents a static image by comparing the representative values ​​stored in the data storage with representative values ​​of jitter-independent pixel data in a second frame directly following the first frame.

[0017] When the dithering image data represents a static image, the driver may perform low-frequency driving that drives the display panel at a low frame rate that is less than a normal frame rate.

[0018] Another exemplary embodiment provides a method of operating a display device including a plurality of pixels. In the method, image data including a plurality of pixel data for the plurality of pixels may be received, dithered image data including a plurality of dithered pixel data respectively corresponding to the plurality of pixel data may be generated by performing a dithering operation on the image data, dither-independent pixel data that is not changed from the plurality of pixel data by the dithering operation may be detected among the plurality of dithered pixel data, and whether the dithered image data represents a static image may be determined by using the dither-independent pixel data.

[0019] To determine whether the dithered image data represents a static image, it may be determined by comparing dither-independent pixel data in a first frame with dither-independent pixel data in a second frame directly following the first frame.

[0020] In an exemplary embodiment, a ratio of the number of dithering irrelevant pixel data to the number of a plurality of dithering pixel data may be calculated as a comparison pixel ratio, and the comparison pixel ratio may be compared with a reference pixel ratio.

[0021] In order to determine whether the jittered image data represents a static image, when the comparison pixel ratio is greater than or equal to the reference pixel ratio, it can be determined whether the jittered image data represents a static image by comparing the jitter-independent pixel data in a first frame with the jitter-independent pixel data in a second frame directly after the first frame.

[0022] Among the jitter-related pixel data other than the jitter-independent pixel data in the multiple jitter pixel data, when the comparison pixel ratio is smaller than the reference pixel ratio, the jitter-related pixel data that is unchanged in the first frame and the second frame directly after the first frame can be detected based on the jitter pattern of the jitter operation, the number of the jitter-independent pixel data and the ratio of the sum of the numbers of the jitter-related pixel data that is unchanged in the first frame and the second frame to the number of the multiple jitter pixel data can be recalculated as the comparison pixel ratio, and the recalculated comparison pixel ratio can be compared with the reference pixel ratio.

[0023] In order to determine whether the jittered image data represents a static image, when the recalculated comparison pixel ratio is greater than or equal to the reference pixel ratio, it can be determined whether the jittered image data represents a static image by using the jitter-independent pixel data and the jitter-related pixel data that has not changed in the first frame and the second frame.

[0024] When the recalculated comparison pixel ratio is less than the reference pixel ratio, the jitter-related pixel data unchanged in the first frame and in at least one frame after the second frame may be further detected based on the jitter pattern until the comparison pixel ratio using the number of further detected jitter-related pixel data becomes greater than or equal to the reference pixel ratio. In order to determine whether the jittered image data represents a static image, it may be determined whether the jittered image data represents a static image by using the jitter-independent pixel data, the jitter-related pixel data unchanged in the first frame and the second frame, and the jitter-related pixel data unchanged in the first frame and in the at least one frame after the second frame.

[0025] The jitter-related pixel data that is unchanged in the first frame and at least one subsequent frame may be added to the comparison pixel data used to determine whether the jittered image data represents a static image until the comparison pixel ratio becomes greater than or equal to the reference pixel ratio. In order to determine whether the jittered image data represents a static image, the jittered image data may be determined by using the jitter-independent pixel data and the jitter-related pixel data that is unchanged in the first frame and the at least one subsequent frame. The subsequent frames may be sequentially selected from the second frame to the 2^M+1th frame, where M is the number of bits corresponding to the jitter period of the jitterer that performs the jittering operation.

[0026] A representative value of the jitter-independent pixel data in the first frame may be stored. To determine whether the jittered image data represents a static image, the stored representative value may be compared with a representative value of the jitter-independent pixel data in a second frame directly following the first frame to determine whether the jittered image data represents a static image.

[0027] When the dithering image data represents a static image, low-frequency driving of driving a display panel including a plurality of pixels at a low frame rate lower than a normal frame rate may be performed.

[0028] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings illustrate exemplary embodiments of the invention and together with the description serve to explain the inventive concept. The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification.

[0030] Figure 1 is a block diagram illustrating a display device according to an exemplary embodiment.

[0031] Figure 2 is used to describe the Figure 1 A diagram of an example of a spatial dithering operation performed by a ditherer in a display device.

[0032] Figure 3 is used to describe the Figure 1 FIG. 1 is a diagram of an example of a time dithering operation performed by a ditherer in a display device.

[0033] Figure 4 It is shown that the Figure 1 A block diagram of a static image detector in a display device.

[0034] Figure 5 is a flowchart illustrating a method of operating a display apparatus according to an exemplary embodiment.

[0035] Figure 6 is a diagram for describing a still image detection period required in a conventional still image detection method and a still image detection period required in a still image detection method according to an exemplary embodiment.

[0036] Figure 7 is a flowchart illustrating a method of operating a display apparatus according to an exemplary embodiment.

[0037] Figure 8 is a diagram for describing an example of adding dither-related pixel data that is unchanged in a first frame and subsequent frames to comparison pixel data when a spatial dithering operation is performed.

[0038] Fig. 9 is a diagram for describing an example of adding dithering-related pixel data that is unchanged in a first frame and subsequent frames to comparison pixel data when a temporal dithering operation is performed.

[0039] Fig.10 An electronic device including the display device according to the exemplary embodiment. DETAILED DESCRIPTION

[0040] In the following description, for the purpose of explanation, many specific details are set forth to provide a thorough understanding of various exemplary embodiments of the invention. "Embodiment" as used herein is a non-limiting example of a device or method using one or more inventive concepts disclosed herein. However, it is apparent that various exemplary embodiments can be practiced without these specific details or with one or more equivalent arrangements. In other cases, known structures and devices are shown in block diagram form to avoid making various exemplary embodiments unnecessarily obscure. In addition, various exemplary embodiments may be different, but not necessarily exclusive. For example, without departing from the inventive concept, the specific shape, configuration (construction) and characteristics of the exemplary embodiment may be used or implemented in another exemplary embodiment.

[0041] Unless otherwise specified, the exemplary embodiments shown will be understood as providing exemplary features of the details of the variations of some ways in which the inventive concept can be implemented in practice. Therefore, unless otherwise specified, the features, components, modules, layers, films, panels, regions and / or aspects, etc. (hereinafter, individually or collectively referred to as "elements") of the various embodiments may be further combined, separated, interchanged and / or rearranged without departing from the inventive concept.

[0042] In the accompanying drawings, the size and relative size of the elements may be exaggerated for clarity and / or descriptive purposes. When the exemplary embodiments may be implemented differently, the specific process sequence may be performed in a different order than described. For example, two processes described in succession may be performed substantially simultaneously or in an order opposite to the described order. In addition, the same reference numerals represent the same elements.

[0043] When an element or layer is referred to as being "on" another element or layer, "connected to" or "bonded to" another element or layer, the element or layer may be directly on, directly connected to or directly bonded to the other element or layer, or there may be an intermediate element or intermediate layer. However, when an element or layer is referred to as being "directly on" another element or layer, "directly connected to" or "directly bonded to" another element or layer, there is no intermediate element or intermediate layer. For this reason, the term "connection" may refer to a physical connection, electrical connection and / or fluid connection with or without an intermediate element. In addition, the D1 axis, the D2 axis and the D3 axis are not limited to the three axes (such as the x-axis, the y-axis and the z-axis) of a rectangular coordinate system, but may be interpreted in a wider sense. For example, the D1 axis, the D2 axis and the D3 axis may be perpendicular to each other, or may represent different directions that are not perpendicular to each other. In addition, the first cross direction CDR1 and the second cross direction CDR2 may be perpendicular to each other, or may represent different directions that are not perpendicular to each other. For the purpose of this disclosure, "at least one of X, Y, and Z" and "at least one selected from the group consisting of X, Y, and Z" may be interpreted as any combination of only X, only Y, only Z, or two or more of X, Y, and Z, such as, for example, XYZ, XYY, YZ, and ZZ. As used herein, the term "and / or" includes any and all combinations of one or more of the relevant listed items.

[0044] Although the terms "first", "second", etc. may be used herein to describe various types of elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another element. Therefore, the first element discussed below may be named as the second element without departing from the disclosed teachings.

[0045] For descriptive purposes, spatially relative terms such as "below," "beneath," "under," "down," "above," "upper," "above," "higher," "side" (e.g., as in "sidewall"), etc., may be used herein to describe the relationship of one element to other elements as shown in the accompanying drawings. Spatially relative terms are intended to encompass different orientations of the device in use, operation, and / or manufacture in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as "below" or "beneath" other elements or features would subsequently be positioned as "above" the other elements or features. Thus, the exemplary term "below" can include both above and below orientations. In addition, the device can be positioned otherwise (e.g., rotated 90 degrees or at other orientations), and as such, the spatially relative descriptors used herein are interpreted accordingly.

[0046] The term used herein is for the purpose of describing a particular embodiment, and is not intended to be limited. As used herein, unless the context clearly indicates otherwise, the singular form "one", "one (kind / person)" and "said (the)" are also intended to include plural forms. In addition, when the terms "comprise", "include" and / or their variations are used in this specification, it is explained that there are stated features, integral bodies, steps, operations, elements, components and / or their groups, but it is not excluded that there are or add one or more other features, integral bodies, steps, operations, elements, components and / or their groups. It should also be noted that, as used herein, the terms "substantially (roughly)", "approximately (about)" and other similar terms are used as approximate terms and are not used as degree terms, so that they are used to explain the inherent deviations of measured values, calculated values ​​and / or provided values ​​that will be recognized by those of ordinary skill in the art.

[0047] As is customary in the art, in terms of functional blocks, units and / or modules, some exemplary embodiments are described and shown in the accompanying drawings. It will be appreciated by those skilled in the art that these blocks, units and / or modules are physically implemented by electronic (or optical) circuits (such as logic circuits, discrete components, microprocessors, hard-wired circuits, storage elements, wiring connections, etc.) that can be formed using semiconductor-based manufacturing techniques or other manufacturing techniques. In the case of implementing blocks, units and / or modules by microprocessors or other similar hardware, they can be programmed and controlled using software (e.g., microcode) that performs the various functions discussed herein, and they can be optionally driven by firmware and / or software. It is also contemplated that each block, unit and / or module can be implemented by dedicated hardware, or can be implemented as a combination of dedicated hardware that performs certain functions and processors that perform other functions (e.g., one or more programmed microprocessors and related circuits). In addition, without departing from the scope of the inventive concept, each block, unit and / or module of some exemplary embodiments can be physically separated into two or more interactive and discrete blocks, units and / or modules. Furthermore, the blocks, units and / or modules of some exemplary embodiments may be physically combined into more complex blocks, units and / or modules without departing from the scope of the inventive concept.

[0048] 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 this disclosure is a part. Terms (such as those defined in general dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0049] Hereinafter, exemplary embodiments of the inventive concept will be explained in detail with reference to the accompanying drawings.

[0050] Figure 1 is a block diagram illustrating a display device according to an exemplary embodiment; Figure 2 is used to describe the Figure 1 FIG. 1 is a diagram showing an example of a spatial dithering operation performed by a ditherer in a display device of FIG. 1 ; Figure 3 is used to describe the Figure 1 FIG. 1 is a diagram showing an example of a time dithering operation performed by a ditherer in a display device of FIG. 1 ; Figure 4 It is shown that the Figure 1 A block diagram of a static image detector in a display device.

[0051] Reference Figure 1According to an exemplary embodiment, the display device 100 may include: a display panel 110 including a plurality of pixels PX; and a driver driving the display panel 110. In some exemplary embodiments, the driver may include a data driver 180 providing a data signal DS to the plurality of pixels PX, a gate driver 190 providing a gate signal GS to the plurality of pixels PX, and a controller 120 controlling the operation of the display device 100.

[0052] The display panel 110 may include a plurality of data lines, a plurality of gate lines, and a plurality of pixels PX coupled to the plurality of data lines and the plurality of gate lines. In some exemplary embodiments, each pixel PX may include a switching transistor and a liquid crystal capacitor coupled to the switching transistor, and the display panel 110 may be a liquid crystal display (LCD) panel. In other exemplary embodiments, each pixel PX may include an organic light emitting diode (OLED), at least one capacitor, and at least two transistors, and the display panel 110 may be an OLED display panel. However, the display panel 110 is not limited to an LCD panel and an OLED display panel, but may be any suitable display panel.

[0053] The controller (e.g., timing controller; TCON) 120 may receive image data IDAT and a control signal CTRL from an external host processor (e.g., a graphics processing unit (GPU) or a graphics card). In some exemplary embodiments, the control signal CTRL may include, but is not limited to, a vertical synchronization signal, a horizontal synchronization signal, an input data enable signal, a main clock signal, etc. The controller 120 may generate a gate control signal GCTRL and a data control signal DCTRL based on the control signal CTRL. In addition, the controller 120 may generate a jittered image data DIDAT by performing a jitter operation on the image data IDAT.

[0054] The data driver 180 may generate a data signal DS based on the jitter image data DIDAT and the data control signal DCTRL output from the controller 120, and may provide the data signal DS corresponding to the jitter image data DIDAT to a plurality of pixels PX. For example, the data control signal DCTRL may include, but is not limited to, an output data enable signal, a horizontal start signal, and a load signal. In some exemplary embodiments, the data driver 180 may be implemented using one or more data integrated circuits (ICs). In addition, according to some exemplary embodiments, the data driver 180 may be directly mounted on the display panel 110, or may be coupled to the display panel 110 in the form of a chip on film (COF) or a tape carrier package (TCP). In other exemplary embodiments, the data driver 180 may be integrated in the peripheral portion of the display panel 110.

[0055] The gate driver 190 may generate a gate signal GS based on a gate control signal GCTRL from the controller 120, and may provide the gate signal GS to a plurality of pixels PX. In some exemplary embodiments, the gate control signal GCTRL may include, but is not limited to, a frame start signal and a gate clock signal. In some exemplary embodiments, the gate driver 190 may be implemented as an amorphous silicon gate (ASG) driver integrated in the peripheral portion of the display panel 110. In other exemplary embodiments, the gate driver 190 may be implemented using one or more gate ICs. In addition, according to some exemplary embodiments, the gate driver 190 may be directly mounted on the display panel 110, or may be coupled to the display panel 110 in the form of a COF or TCP.

[0056] The driver of the display device 100 according to an exemplary embodiment may include a ditherer 130 that performs a dithering operation to increase the grayscale resolution of an image. The ditherer 130 may perform a dithering operation on the image data IDAT including the plurality of pixel data for the plurality of pixels PX to generate dithered image data DIDAT, the dithered image data DIDAT including a plurality of dithered pixel data respectively corresponding to the plurality of pixel data. In some exemplary embodiments, the ditherer 130 may be configured as follows: Figure 1 1 and 120. In other exemplary embodiments, the ditherer 130 may be located outside the controller 120, between the controller 120 and the data driver 180, or inside the data driver 180.

[0057] In some exemplary embodiments, the ditherer 130 may perform a spatial dithering operation representing a grayscale having a greater number of bits than the number of bits of each pixel data by adjusting pixel data for spatially adjacent pixels PX. Figure 2 An example of expressing grayscale with a higher number of bits (eg, 10 bits) than the number of bits of each pixel data (eg, 8 bits) through a spatial dithering operation is shown.

[0058] In the case where a grayscale having a value VALUE “N.00” is represented at each of the adjacent four pixels PX, or in the case where the lower bit LSB [1:0] represents “00”, all the jittered pixel data 210 for the adjacent four pixels PX may have a value “N”. In addition, the jittered pixel data 210 for the adjacent four pixels PX may not change within a jitter period (or 2^2 frames FRAME1 to FRAME4) corresponding to a jitter bit of 2.

[0059] In the case where a grayscale having a value VALUE “N.25” is represented at each of the adjacent four pixels PX, or in the case where the lower bits LSB [1:0] represent “01”, three of the jittered pixel data 220 for the adjacent four pixels PX may have a value “N”, and one of the jittered pixel data 220 for the adjacent four pixels PX may have a value “N+1”. In addition, in order to improve image quality, the position of the pixel PX corresponding to the value “N” and the position of the pixel PX corresponding to the value “N+1” may be changed according to the frames FRAME1 to FRAME4 within the jittering period.

[0060] In the case where a grayscale having a value VALUE "N.50" is represented at each of the adjacent four pixels PX, or in the case where the lower bits LSB [1:0] represent "10", two of the jittered pixel data 230 for the adjacent four pixels PX may have a value "N", and two of the jittered pixel data 230 for the adjacent four pixels PX may have a value "N+1". In addition, in order to improve image quality, the position of the pixel PX corresponding to the value "N" and the position of the pixel PX corresponding to the value "N+1" may be changed according to the frames FRAME1 to FRAME4 within the jitter period.

[0061] In the case where a grayscale having a value VALUE “N.75” is represented at each of the adjacent four pixels PX, or in the case where the lower bits LSB [1:0] represent “11”, one of the jittered pixel data 240 for the adjacent four pixels PX may have a value “N”, and three of the jittered pixel data 240 for the adjacent four pixels PX may have a value “N+1”. In addition, in order to improve image quality, the position of the pixel PX corresponding to the value “N” and the position of the pixel PX corresponding to the value “N+1” may be changed according to the frames FRAME1 to FRAME4 within the jittering period.

[0062] In other exemplary embodiments, the ditherer 130 may perform a time dithering operation representing a grayscale having a larger number of bits than the number of bits of each pixel data by adjusting pixel data in adjacent frames. Figure 3 An example of expressing a grayscale having a larger number of bits (eg, 10 bits) than the number of bits of each pixel data (eg, 8 bits) through a time dithering operation is shown.

[0063] In the case of representing a gray level having a value VALUE “N.00” at each pixel PX, or in the case of the lower bits LSB [1:0] representing “00”, all the jittered pixel data 310 for the pixel PX in the jittering period or in the 2^2 frames FRAME1 to FRAME4 may have a value “N”.

[0064] In the case of representing a gray level having a value VALUE “N.25” at each pixel PX, or in the case of the lower bits LSB [1:0] representing “01”, the jittered pixel data 320 for the pixel PX may have a value “N” in three of the four frames FRAME1 to FRAME4 corresponding to the jittering period, and may have a value “N+1” in one of the four frames FRAME1 to FRAME4.

[0065] In the case of representing a gray level having a value VALUE “N.50” at each pixel PX, or in the case of the lower bits LSB [1:0] representing “10”, the jittered pixel data 330 for the pixel PX may have a value “N” in two frames of the four frames FRAME1 to FRAME4, and may have a value “N+1” in the other two frames of the four frames FRAME1 to FRAME4.

[0066] In the case of representing a gray level having a value VALUE “N.75” at each pixel PX, or in the case of the lower bits LSB [1:0] representing “11”, the jittered pixel data 340 for the pixel PX may have a value “N” in one of the four frames FRAME1 to FRAME4, and may have a value “N+1” in three of the four frames FRAME1 to FRAME4.

[0067] Although in Figure 2 An example of spatial dithering operation is shown in Figure 3 An example of a time dithering operation is shown in FIG. 1 , but the dithering operation of the ditherer 130 according to an exemplary embodiment is not limited to Figure 2 and Figure 3 .

[0068] The display device 100 according to an exemplary embodiment may further include a static image detector 140 that detects a static image based on the dithered image data DIDAT generated by the ditherer 130. In some exemplary embodiments, the static image detector 140 may be configured as follows. Figure 1 1 and 120. In other exemplary embodiments, the still image detector 140 may be located outside the controller 120, between the controller 120 and the data driver 180, or inside the data driver 180.

[0069] The static image detector 140 may receive the dithered image data DIDAT from the ditherer 130, and may detect dither-independent pixel data that is not changed from the plurality of pixel data by the dithering operation among the plurality of dithered pixel data. Figure 2 and Figure 3In the example of , the dithering pixel data 210 and 310 representing the lower bits LSB [1:0] of “00” may be detected as dithering-independent pixel data among the plurality of dithering pixel data of the dithering image data DIDAT.

[0070] In some exemplary embodiments, the static image detector 140 may detect jitter-independent pixel data among a plurality of jitter pixel data based on the jitter information DTI received by the jitterer 130. In an example, for each jitter pixel data, the jitter information DTI may include one bit of data indicating whether a jitter operation is performed. For example, for the jitter pixel data 210 and 310 representing the lower LSB [1:0] of "00", the jitter information DTI may have a value of "1", and for the jitter pixel data 220, 230, 240, 320, 330 and 340 representing the lower LSB [1:0] of "01", "10" or "11", the jitter information DTI may have a value of "0". In this case, the static image detector 140 may detect the jitter pixel data 210 and 310 corresponding to the jitter information DTI having a value of "1" as jitter-independent pixel data. In another example, for each jitter pixel data, the jitter information DTI may include the lower bits LSB [1:0] represented by the jitter pixel data. In this case, for example, the static image detector 140 may detect the jitter pixel data 210 and 310 corresponding to the jitter information DTI having a value of "00" as jitter-independent pixel data.

[0071] In other exemplary embodiments, the static image detector 140 may detect the jitter-independent pixel data among the plurality of jitter pixel data by analyzing the jitter image data DIDAT. Figure 2 In the example of , all the dithered pixel data 210 for adjacent four pixels PX may have a value of “N”, and the still image detector 140 may detect all the dithered pixel data 210 having a value of “N” as dither-independent pixel data.

[0072] Furthermore, the still image detector 140 may determine whether the dithered image data DIDAT represents a still image by using the dither-independent pixel data.

[0073] In some exemplary embodiments, the static image detector 140 may determine whether the jittered image data DIDAT represents a static image by comparing the jitter-independent pixel data in the first frame with the jitter-independent pixel data in the second frame directly following the first frame. In an example, when all jitter-independent pixel data in the first frame are the same as all jitter-independent pixel data in the second frame, the static image detector 140 may determine that the jittered image data DIDAT represents a static image, and when any one of the jitter-independent pixel data in the first frame is different from the corresponding jitter-independent pixel data in the second frame, the static image detector 140 may determine that the jittered image data DIDAT represents a dynamic image. In another example, when the representative value (e.g., the sum or average value) of the jitter-independent pixel data in the first frame is the same as the representative value of the jitter-independent pixel data in the second frame, the static image detector 140 may determine that the jittered image data DIDAT represents a static image. Therefore, although the jittering operation is performed, the static image detector 140 may detect a static image only in two frames of the first frame and the second frame.

[0074] In other exemplary embodiments, the static image detector 140 may calculate a ratio of the number of jitter-independent pixel data to the number of multiple jitter pixel data, may determine whether the jitter image data DIDAT represents a static image by using the jitter-independent pixel data when the calculated ratio is greater than or equal to the reference pixel ratio, and may add the jitter-dependent pixel data to the comparison pixel data used to determine whether the jitter image data DIDAT represents a static image when the calculated ratio is less than the reference pixel ratio. In some exemplary embodiments, in order to perform this operation, as Figure 4 As shown in , the still image detector 140 may include a comparison pixel ratio determiner 150 and a data comparator 160 .

[0075] The comparison pixel ratio determiner 150 may divide a plurality of dither pixel data included in the dither image data DIDAT into dither-related pixel data (eg, Figure 2 220, 230 and 240 or Figure 3 320, 330 and 340) and jitter-independent pixel data (e.g., Figure 2 210 or Figure 3 310 in the dithering period), the dithering-related pixel data changes due to the dithering operation within the dithering period, and the dithering-independent pixel data does not change due to the dithering operation within the dithering period. The comparison pixel ratio determiner 150 can detect the dithering-independent pixel data among the plurality of dithering pixel data, can calculate the ratio of the number of the dithering-independent pixel data to the number of the plurality of dithering pixel data (for example, the number of all pixels PX of the display panel 110) as the comparison pixel ratio, and can compare the comparison pixel ratio with the reference pixel ratio.

[0076] For example, the comparison pixel ratio determiner 150 may include a comparison pixel ratio calculator 152 and a comparison pixel ratio comparator 154. The comparison pixel ratio calculator 152 may set the jitter-independent pixel data as the comparison pixel data to be compared between the two frames to determine whether the jitter image data DIDAT represents a static image, and may calculate the ratio of the number of the comparison pixel data to the number of the plurality of jitter pixel data as the comparison pixel ratio. The comparison pixel ratio comparator 154 may compare the comparison pixel ratio with a reference pixel ratio. In some exemplary embodiments, the reference pixel ratio may be set or changed by a host processor.

[0077] When the comparison pixel ratio comparator 154 determines that the comparison pixel ratio is greater than or equal to the reference pixel ratio, the data comparator 160 can determine whether the jitter image data DIDAT represents a static image by comparing the jitter-independent pixel data in the first frame with the jitter-independent pixel data in the second frame directly after the first frame.

[0078] In the case where the comparison pixel ratio comparator 154 determines that the comparison pixel ratio is less than the reference pixel ratio, the comparison pixel ratio calculator 152 may add the jitter-related pixel data that has not changed in the first frame and at least one subsequent frame to the comparison pixel data used to determine whether the jitter image data DIDAT represents a static image until the comparison pixel ratio becomes greater than or equal to the reference pixel ratio. Once the comparison pixel ratio becomes greater than or equal to the reference pixel ratio, the data comparator 160 may determine whether the jitter image data DIDAT represents a static image by using the jitter-independent pixel data and the jitter-related pixel data that has not changed in the first frame and the at least one subsequent frame. Here, in the case where the jitter bit of the jitter 130 is M, or in the case where the jitter period of the jitter 130 corresponds to a 2^M frame, the subsequent frames may be sequentially selected from the second frame to the 2^M+1 frame.

[0079] For example, when the comparison pixel ratio is less than the reference pixel ratio, the comparison pixel ratio calculator 152 may detect the jitter-related pixel data that is unchanged in the first frame and the second frame among the jitter-related pixel data other than the jitter-independent pixel data among the plurality of jitter pixel data based on the jitter mode of the jitter operation, and may add the jitter-related pixel data that is unchanged in the first frame and the second frame to the comparison pixel data. In addition, the comparison pixel ratio calculator 152 may recalculate the ratio of the number of the comparison pixel data to the number of the plurality of jitter pixel data as the comparison pixel ratio, or may recalculate the ratio of the sum of the number of the jitter-independent pixel data and the number of the jitter-related pixel data that is unchanged in the first frame and the second frame to the number of the plurality of jitter pixel data as the comparison pixel ratio. The comparison pixel ratio comparator 154 may compare the recalculated comparison pixel ratio with the reference pixel ratio. When the recalculated comparison pixel ratio is greater than or equal to the reference pixel ratio, the data comparator 160 may determine whether the jitter image data DIDAT represents a static image by using the jitter-independent pixel data and the jitter-related pixel data that is unchanged in the first frame and the second frame.

[0080] When the recalculated comparison pixel ratio is less than the reference pixel ratio, the comparison pixel ratio calculator 152 may further detect the jitter-related pixel data that has not changed in the first frame and the third frame after the second frame based on the jitter pattern, and may further add the jitter-related pixel data that has not changed in the first frame and the third frame to the comparison pixel data. In addition, the comparison pixel ratio calculator 152 may recalculate the ratio of the number of comparison pixel data to the number of multiple jitter pixel data as the comparison pixel ratio, or may recalculate the ratio of the sum of the number of jitter-independent pixel data, the number of jitter-related pixel data that has not changed in the first frame and the second frame, and the number of jitter-related pixel data that has not changed in the first frame and the third frame to the number of multiple jitter pixel data as the comparison pixel ratio. The data comparator 160 may determine whether the jitter image data DIDAT represents a static image by using the jitter-independent pixel data, the jitter-related pixel data that has not changed in the first frame and the second frame, and the jitter-related pixel data that has not changed in the first frame and the third frame. The jitter-related pixel data that is unchanged in the first frame and the subsequent frames may be repeatedly added to the comparison pixel data until the comparison pixel ratio becomes greater than or equal to the reference pixel ratio. In addition, even if the reference pixel ratio has a maximum value or is approximately 100%, when the subsequent frames up to the 2^M+1 frame are selected, all jitter pixel data (or all jitter-independent pixel data and all jitter-related pixel data) are selected as the comparison pixel data, so the static image detection operation of the static image detector 140 can be completed within a maximum of 2^M+1 frames.

[0081] In some exemplary embodiments, the data comparator 160 may compare corresponding comparison pixel data (e.g., jitter-independent pixel data, or jitter-independent pixel data and at least a portion of jitter-related pixel data) in at least two frames of the comparison pixel data, and when any pair of the comparison pixel data is different from each other, the data comparator 160 may determine that the jitter image data DIDAT represents a dynamic image. In order to compare the comparison pixel data in two frames by the data comparator 160, in some exemplary embodiments, the static image detector 140 may further include a data storage 170 that stores the comparison pixel data in the previous frame as data PDAT of the previous frame (e.g., the first frame).

[0082] In other exemplary embodiments, the data comparator 160 may compare representative values ​​of the comparison pixel data in at least two frames, and when the representative values ​​are different from each other, it may be determined that the jittered image data DIDAT represents a dynamic image. For example, the representative value may be, but is not limited to, the sum of all the comparison pixel data in each frame. In this case, the data storage 170 may store the representative value of the comparison pixel data in the previous frame as the data PDAT of the previous frame. For example, in the second frame, the data comparator 160 may calculate the representative value of the jitter-independent pixel data included in the jittered image data DIDAT received from the jitter 130, and may determine whether the jittered image data DIDAT represents a static image by comparing the representative value of the first frame stored in the data storage 170 with the calculated representative value.

[0083] When it is determined that the jitter image data DIDAT represents a static image, the static image detector 140 may output a static image detection signal SSTILL indicating that a static image is detected. The controller 120 may perform a low-frequency drive of driving the display panel 110 at a low frame rate lower than a normal frame rate in response to the static image detection signal SSTILL indicating that a static image is detected. For example, when a static image is detected, the controller 120 may control the data driver 180 and the gate driver 190 to drive the display panel 110 at a low frame rate (e.g., about 1 Hz) lower than a normal frame rate (e.g., about 60 Hz). Therefore, when a static image is displayed, the power consumption of the display device 100 may be reduced.

[0084] As described above, the display device 100 according to an exemplary embodiment can detect the dither-independent pixel data that is not changed from the multiple pixel data by the dithering operation among the multiple dithering pixel data, and can determine whether the dithering image data DIDAT represents a static image by using the dither-independent pixel data, thereby quickly detecting the static image even if the dithering operation is performed.

[0085] Figure 5is a flowchart illustrating a method of operating a display device according to an exemplary embodiment, Figure 6 is a diagram for describing a still image detection period required in a conventional still image detection method and a still image detection period required in a still image detection method according to an exemplary embodiment of the present invention.

[0086] Reference Figure 1 and Figure 5 In a method of operating a display device 100 including a plurality of pixels PX, the display device 100 may receive image data IDAT including a plurality of pixel data for the plurality of pixels PX (S410). The ditherer 130 of the display device 100 may generate dithered image data DIDAT including a plurality of dithered pixel data respectively corresponding to the plurality of pixel data by performing a dithering operation (e.g., a spatial dithering operation and / or a temporal dithering operation) on the image data IDAT (S420).

[0087] The static image detector 140 may detect jitter-independent pixel data that is not changed from the plurality of pixel data by the jitter operation among the plurality of jitter pixel data of the jitter image data DIDAT (S430), and may determine whether the jitter image data DIDAT represents a static image by using the jitter-independent pixel data (S440). When it is determined that the jitter image data DIDAT represents a static image, the display device 100 may perform low-frequency driving that drives the display panel 110 including the plurality of pixels PX at a low frame rate lower than a normal frame rate.

[0088] In a display device that uses the dithering technology, even when displaying a static image, the dithered image data will change for each frame within the dithering period. Figure 6 As shown in 510 of FIG. 5 , a conventional display device that applies the dithering technology may perform a static image detection operation for two dithering cycles, or perform a static image detection operation for 2^(M+1) frames in the case of a dithering operation with a dithering bit of M. For example, the conventional display device may perform a static image detection operation for 2^(M+1) frames by combining the dithered image data in the first frame FRAME1 and the 2^M+1 frame FRAME2. M +1, and compare the jitter image data in the second frame FRAME2 with the jitter image data in the 2^M+2 frame FRAME2 M +2, ... and by comparing the 2^Mth frame FRAME2 M The jittered image data and the 2^(M+1)th frame FRAME2 M+1 Therefore, the conventional display device will perform low-frequency driving 2^(M+1) frames after the time point of displaying the static image.

[0089] However, in the method of operating the display device 100 according to the exemplary embodiment, the jitter-independent pixel data that is not changed from the plurality of pixel data by the jitter operation among the plurality of jitter pixel data may be detected, and whether the jitter image data DIDAT represents a static image may be determined by comparing the jitter-independent pixel data in the first frame FRAME1 with the jitter-independent pixel data in the second frame FRAME2. Figure 6 As shown in 520, low-frequency driving can be performed two frames after the time point of displaying the static image. That is, in the method of operating the display device 100 according to the exemplary embodiment, even if the shaking operation is performed, the static image can be detected quickly, and the low-frequency driving can be performed quickly, thereby reducing the power consumption of the display device 100.

[0090] Figure 7 is a flowchart illustrating a method of operating a display device according to an exemplary embodiment; Figure 8 is a diagram for describing an example in which dither-related pixel data that is unchanged in a first frame and subsequent frames is added to comparison pixel data when a spatial dithering operation is performed; Fig. 9 is a diagram for describing an example of adding dithering-related pixel data that is unchanged in a first frame and subsequent frames to comparison pixel data when a temporal dithering operation is performed.

[0091] Reference Figure 1 and Figure 7 In a method of operating a display device 100 including a plurality of pixels PX, the display device 100 may receive image data IDAT including a plurality of pixel data for the plurality of pixels PX (S610). The ditherer 130 of the display device 100 may generate dithered image data DIDAT including a plurality of dithered pixel data respectively corresponding to the plurality of pixel data by performing a dithering operation (e.g., a spatial dithering operation and / or a temporal dithering operation) on the image data IDAT (S620).

[0092] The static image detector 140 may detect the jitter-independent pixel data, which is not changed from the plurality of pixel data by the jitter operation, among the plurality of jitter pixel data as the comparison pixel data to be compared in two frames to detect the static image (S630). Figure 8 The jitter pixel data 710 representing the low bit LSB [1:0] of "00" or Fig. 9 The dither pixel data 810 of the lower bits LSB [1:0] representing "00" is used as dither-independent pixel data.

[0093] The static image detector 140 may calculate a ratio of the number of comparison pixel data to the number of multiple jitter pixel data as a comparison pixel ratio, or may calculate a ratio of the number of jitter-independent pixel data to the number of multiple jitter pixel data as a comparison pixel ratio, and may compare the comparison pixel ratio with a reference pixel ratio (S640). When the comparison pixel ratio is greater than or equal to the reference pixel ratio (S640: Yes), the static image detector 140 may determine whether the jitter image data DIDAT represents a static image by comparing the jitter-independent pixel data in the first frame (the representative value of the jitter-independent pixel data in the first frame) and the jitter-independent pixel data in the second frame directly after the first frame (the representative value of the jitter-independent pixel data in the second frame) (S660).

[0094] When the comparison pixel ratio is less than the reference pixel ratio (S640: No), the static image detector 140 may add the jitter-related pixel data that has not changed in the first frame and at least one subsequent frame to the comparison pixel data for determining whether the jitter image data DIDAT represents a static image (S650) until the comparison pixel ratio becomes greater than or equal to the reference pixel ratio. Here, in the case where the jitter operation is performed with the jitter bit M, the subsequent frames may be sequentially selected from the second frame to the 2^M+1th frame until the comparison pixel ratio becomes greater than or equal to the reference pixel ratio. Once the comparison pixel ratio becomes greater than or equal to the reference pixel ratio (S640: Yes), the static image detector 140 may determine whether the jitter image data DIDAT represents a static image by using the comparison pixel data, or may determine whether the jitter image data DIDAT represents a static image by using the jitter-independent pixel data and the jitter-related pixel data that has not changed in the first frame and the at least one subsequent frame (S660).

[0095] For example, when the comparison pixel ratio using only the number of jitter-independent pixel data is less than the reference pixel ratio (S640: No), the static image detector 140 can detect jitter-related pixel data that is unchanged in the first frame and the second frame among the jitter-related pixel data other than the jitter-independent pixel data in the multiple jitter pixel data based on the jitter pattern of the jitter operation, and can add the jitter-related pixel data that is unchanged in the first frame and the second frame to the comparison pixel data including only the jitter-independent pixel data (S650).

[0096] exist Figure 8In the example of , the static image detector 140 may add two dithering-related pixel data of the lower left pixel PX and the lower right pixel PX that are unchanged in the first frame FRAME1 and the second frame FRAME2, among the four dithering-related pixel data 720 of the low-bit LSB [1:0] representing “01”, to the comparison pixel data. In addition, the static image detector 140 may add two dithering-related pixel data of the lower left pixel PX and the upper right pixel PX that are unchanged in the first frame FRAME1 and the second frame FRAME2, among the four dithering-related pixel data 730 of the low-bit LSB [1:0] representing “10”, to the comparison pixel data. In addition, the static image detector 140 may add two dithering-related pixel data of the upper right pixel PX and the lower right pixel PX that are unchanged in the first frame FRAME1 and the second frame FRAME2, among the four dithering-related pixel data 740 of the low-bit LSB [1:0] representing “11”, to the comparison pixel data.

[0097] exist Fig. 9 In the example of , the static image detector 140 can add the jitter-related pixel data 820 and 840 that are unchanged in the first frame FRAME1 and the second frame FRAME2 to the comparison pixel data. That is, the static image detector 140 can add the jitter-related pixel data 820 of the low-order LSB[1:0] representing "01" and the jitter-related pixel data 840 of the low-order LSB[1:0] representing "11" to the comparison pixel data. Figure 8 and Fig. 9 1 and 12 show examples of a plurality of jittered pixel data, but the jitter-related pixel data that is unchanged in the first frame FRAME1 and subsequent frames may be different depending on the jittering pattern of the jittering operation performed by the jitterer 130. Figure 8 and Fig. 9 .

[0098] The static image detector 140 may recalculate the ratio of the number of comparison pixel data (or the sum of the number of jitter-independent pixel data and the number of jitter-related pixel data that is unchanged in the first frame and the second frame) to the number of multiple jitter pixel data as the comparison pixel ratio, and may compare the recalculated comparison pixel ratio with the reference pixel ratio (S640). When the recalculated comparison pixel ratio is greater than or equal to the reference pixel ratio (S640: Yes), the static image detector 140 may determine whether the jittered image data represents a static image by using the comparison pixel data or by using the jitter-independent pixel data and the jitter-related pixel data that is unchanged in the first frame and the second frame (S660).

[0099] When the recalculated comparison pixel ratio (or the comparison pixel ratio using the number of jitter-independent pixel data and the number of jitter-related pixel data that are unchanged in the first frame and the second frame) is less than the reference pixel ratio (S640: No), the static image detector 140 may further detect jitter-related pixel data that are unchanged in the first frame and at least one frame after the second frame based on the jitter pattern, and may add the further detected jitter-related pixel data to the comparison pixel data (S650). Subsequent frames may be sequentially selected in the order of the third frame, the fourth frame, the fifth frame, and the like, and in the case where a jitter operation is performed with a jitter bit M, selection of subsequent frames may be performed until the 2^M+1th frame. For example, as Figure 8 As shown in , the dithering pixel data of the upper right pixel PX among the four dithering pixel data 720 representing the low-bit LSB [1:0] of "01" and the dithering pixel data of the upper left pixel PX among the four dithering pixel data 740 representing the low-bit LSB [1:0] of "11" can be detected as the dithering pixel data that does not change in the first frame FRAME1 and the third frame FRAME3. In addition, the dithering pixel data of the upper left pixel PX and the lower right pixel PX among the four dithering pixel data 730 representing the low-bit LSB [1:0] of "10" can be detected as the dithering pixel data that does not change in the first frame FRAME1 and the fourth frame FRAME4. In addition, the dithering pixel data of the upper left pixel PX among the four dithering pixel data 720 representing the low bit LSB [1:0] of "01" and the dithering pixel data of the lower left pixel PX among the four dithering pixel data 740 representing the low bit LSB [1:0] of "11" can be detected as the dithering pixel data that does not change in the first frame FRAME1 and the fifth frame FRAME5. Figure 8 In the example of , once the jitter-related pixel data unchanged in the first frame FRAME1 and the fifth frame FRAME5 are added to the comparison pixel data, the number of the comparison pixel data may become the same as the number of the plurality of jitter pixel data, and thus further addition of the jitter-related pixel data may be unnecessary. Fig. 9 As shown in FIG. 8 , as dithering-related pixel data unchanged in the first frame FRAME1 and the third frame FRAME3 , dithering-related pixel data 830 of lower bits LSB[1:0] representing “10” may be added to the comparison pixel data.

[0100] The static image detector 140 may determine whether the jitter image data DIDAT represents a static image by using the comparison pixel data or by using the jitter-independent pixel data, the jitter-related pixel data unchanged in the first frame and the second frame, and the jitter-related pixel data unchanged in the first frame and the at least one subsequent frame (S660).

[0101] When it is determined that the dithered image data DIDAT represents a static image, the display device 100 can perform low-frequency driving that drives the display panel 110 including the plurality of pixels PX at a low frame rate lower than a normal frame rate. Therefore, when displaying a static image, power consumption of the display device 100 can be reduced.

[0102] As described above, in the method of operating the display device 100 according to the exemplary embodiment, the jitter-related pixel data may be added to the comparison pixel data so that the comparison pixel ratio becomes greater than or equal to the reference pixel ratio, and whether the jitter image data DIDAT represents a static image may be determined by using the comparison pixel data including the jitter-independent pixel data and the jitter-related pixel data. Therefore, the static image may be detected quickly, and the power consumption of the display device 100 may be reduced.

[0103] Fig.10 An electronic device including the display device according to the exemplary embodiment.

[0104] Reference Fig.10 , the electronic device 1100 may include a processor 1110, a memory device 1120, a storage device 1130, an input / output (I / O) device 1140, a power supply 1150, and a display device 1160. The electronic device 1100 may also include a plurality of ports for communication video cards, sound cards, memory cards, universal serial bus (USB) devices, other electrical devices, and the like.

[0105] The processor 1110 may perform various computing functions or tasks. The processor 1110 may be an application processor (AP), a microprocessor, a central processing unit (CPU), etc. The processor 1110 may be coupled to other components via an address bus, a control bus, a data bus, etc. In addition, in some exemplary embodiments, the processor 1110 may be further coupled to an expansion bus such as a peripheral component interconnect (PCI) bus.

[0106] The memory device 1120 may store data used for the operation of the electronic device 1100. For example, the memory device 1120 may include at least one nonvolatile memory device (such as an erasable programmable read-only memory (EPROM) device, an electrically erasable programmable read-only memory (EEPROM) device, a flash memory device, a phase change random access memory (PRAM) device, a resistive random access memory (RRAM) device, a nano floating gate memory (NFGM) device, a polymer random access memory (PoRAM) device, a magnetic random access memory (MRAM) device, a ferroelectric random access memory (FRAM) device, etc.) and / or at least one volatile memory device (such as a dynamic random access memory (DRAM) device, a static random access memory (SRAM) device, a mobile dynamic random access memory (mobile DRAM) device, etc.).

[0107] The storage device 1130 may be a solid state drive (SSD) device, a hard disk drive (HDD) device, a CD-ROM device, etc. The I / O device 1140 may be an input device such as a keyboard, a keypad, a mouse, a touch screen, etc. and an output device such as a printer, a speaker, etc. The power supply 1150 may supply power for the operation of the electronic device 1100. The display device 1160 may be coupled to other components through a bus or other communication links.

[0108] The display device 1160 can detect the jitter-independent pixel data that is unchanged by the jitter operation among the plurality of jitter pixel data, and can determine whether the jitter image data represents a static image by using the jitter-independent pixel data. Therefore, even if the jitter operation is performed, the static image can be detected quickly, and the power consumption of the display device 1160 can be reduced.

[0109] The inventive concept can be applied to any display device 1160 and any electronic device 1100 including the display device 1160. For example, the inventive concept can be applied to a television (TV), a digital TV, a 3D TV, a smart phone, a wearable electronic device, a tablet computer, a mobile phone, a personal computer (PC), a home appliance, a laptop computer, a personal digital assistant (PDA), a portable multimedia player (PMP), a digital camera, a music player, a portable game console, a navigation device, etc.

[0110] As described above, a display device and a method for operating a display device according to an exemplary embodiment can detect jitter-independent pixel data that is not changed from multiple pixel data by a jittering operation among multiple jittering pixel data, and can determine whether jittered image data represents a static image by using the jitter-independent pixel data, thereby quickly detecting a static image even if a jittering operation is performed.

[0111] Although certain exemplary embodiments have been described herein, other embodiments and modifications will be apparent from this description. Therefore, the inventive concept is not limited to such embodiments, but is limited to the broader scope of the appended claims and various obvious modifications and equivalent arrangements as will be apparent to those of ordinary skill in the art.

Claims

1. A display device, comprising: A display panel including a plurality of pixels; as well as a driver configured to drive the display panel, the driver comprising: a ditherer configured to perform a dithering operation on image data to generate dithered image data, the image data comprising a plurality of pixel data for the plurality of pixels, the dithered image data comprising a plurality of dithered pixel data respectively corresponding to the plurality of pixel data; and a static image detector configured to receive the dithered image data, to detect dither-independent pixel data among the plurality of dithered pixel data that is not changed from the plurality of pixel data by the dithering operation, and to determine whether the dithered image data represents a static image by comparing the dither-independent pixel data in a first frame with the dither-independent pixel data in a second frame directly following the first frame, Wherein, the static image detector includes a comparison pixel ratio determiner, which is configured to: detect the jitter-independent pixel data among the multiple jitter pixel data; calculate the ratio of the number of the jitter-independent pixel data to the number of the multiple jitter pixel data as a comparison pixel ratio; and compare the comparison pixel ratio with a reference pixel ratio.

2. The display device according to claim 1, wherein: The static image detector also includes: A data comparator is configured to determine whether the jittered image data represents a static image by comparing the jitter-independent pixel data in the first frame with the jitter-independent pixel data in the second frame when the comparison pixel ratio is greater than or equal to the reference pixel ratio.

3. The display device according to claim 1, wherein: When the comparison pixel ratio is less than the reference pixel ratio, the comparison pixel ratio determiner is configured to: detecting, based on a dithering pattern of the dithering operation, dither-related pixel data that is unchanged in the first frame and in the second frame among dither-related pixel data other than the dither-independent pixel data in the plurality of dithered pixel data; recalculating a ratio of a sum of the number of the jitter-independent pixel data and the number of the jitter-dependent pixel data that is unchanged in the first frame and the second frame to the number of the plurality of jitter pixel data as a comparison pixel ratio; and comparing the recalculated comparison pixel ratio with the reference pixel ratio.

4. The display device according to claim 3, wherein: The static image detector also includes a data comparator configured to determine whether the jittered image data represents a static image by using jitter-independent pixel data and jitter-dependent pixel data that is unchanged in the first frame and the second frame when the recalculated comparison pixel ratio is greater than or equal to the reference pixel ratio.

5. The display device according to claim 3, wherein: When the recalculated comparison pixel ratio is less than the reference pixel ratio, the comparison pixel ratio determiner is configured to: further detect jitter-related pixel data that is unchanged in the first frame and in at least one frame after the second frame based on the jitter pattern until the comparison pixel ratio using the number of further detected jitter-related pixel data becomes greater than or equal to the reference pixel ratio; and The static image detector also includes a data comparator configured to determine whether the jittered image data represents a static image by using the jitter-independent pixel data, the jitter-dependent pixel data that is unchanged in the first frame and the second frame, and the jitter-dependent pixel data that is unchanged in the first frame and in the at least one frame after the second frame.

6. The display device according to claim 1, wherein: the comparison pixel ratio determiner being configured to: add the jitter-related pixel data unchanged in the first frame and at least one subsequent frame to the comparison pixel data used to determine whether the jittered image data represents a static image until the comparison pixel ratio becomes greater than or equal to the reference pixel ratio; The static image detector further includes a data comparator configured to: determine whether the dithered image data represents a static image by using the dither-independent pixel data and the dither-dependent pixel data that is unchanged in the first frame and the at least one subsequent frame; and The subsequent frames are sequentially selected from the second frame to the 2^M+1th frame, wherein M is the number of bits corresponding to the jitter period of the jitterer.

7. The display device according to claim 1, wherein: The static image detector also includes: A data storage device configured to store representative values ​​of jitter-independent pixel data in a first frame; and A data comparator is configured to determine whether the jittered image data represents a static image by comparing the representative value stored in the data storage with a representative value of the jitter-independent pixel data in the second frame.

8. The display device according to claim 1, wherein: The driver is configured to perform low-frequency driving on the display panel at a low frame rate lower than a normal frame rate when the dithering image data represents a static image.

9. A method for operating a display device, the display device comprising a plurality of pixels, the method comprising the following steps: receiving image data, the image data comprising a plurality of pixel data for the plurality of pixels; Generating dithered image data by performing a dithering operation on the image data, the dithered image data comprising a plurality of dithered pixel data respectively corresponding to the plurality of pixel data; detecting dither-independent pixel data among the plurality of dithered pixel data that is not changed from the plurality of pixel data by the dithering operation; as well as determining whether the dithered image data represents a static image by comparing dither-independent pixel data in a first frame with dither-independent pixel data in a second frame that directly follows the first frame, The method further includes the following steps: calculating a ratio of the number of jitter-independent pixel data to the number of the plurality of jitter pixel data as a comparison pixel ratio; and comparing the comparison pixel ratio with a reference pixel ratio.

10. The method according to claim 9, wherein: The step of determining whether the jittered image data represents a static image includes: when the comparison pixel ratio is greater than or equal to the reference pixel ratio, determining whether the jittered image data represents a static image by comparing the jitter-independent pixel data in the first frame with the jitter-independent pixel data in the second frame.

11. The method according to claim 9, further comprising the steps of: when the comparison pixel ratio is less than the reference pixel ratio, detecting, based on a dithering pattern of the dithering operation, dither-related pixel data that is unchanged between the first frame and the second frame among the dither-related pixel data other than the dither-independent pixel data among the plurality of dithering pixel data; recalculating a ratio of a sum of the number of the jitter-independent pixel data and the number of the jitter-dependent pixel data that is unchanged in the first frame and the second frame to the number of the plurality of jitter pixel data as a comparison pixel ratio; as well as The recalculated comparison pixel ratio is compared with the reference pixel ratio.

12. The method according to claim 11, wherein: The step of determining whether the jittered image data represents a static image includes: when the recalculated comparison pixel ratio is greater than or equal to the reference pixel ratio, determining whether the jittered image data represents a static image by using the jitter-independent pixel data and the jitter-dependent pixel data that is unchanged in the first frame and the second frame.

13. The method according to claim 11, further comprising the steps of: When the recalculated comparison pixel ratio is smaller than the reference pixel ratio, further detecting jitter-related pixel data unchanged in the first frame and in at least one frame after the second frame based on the jitter pattern until the comparison pixel ratio using the number of further detected jitter-related pixel data becomes greater than or equal to the reference pixel ratio, The step of determining whether the shaking image data represents a static image comprises: Whether the jittered image data represents a static image is determined by using the jitter-independent pixel data, jitter-dependent pixel data unchanged in the first frame and the second frame, and jitter-dependent pixel data unchanged in the first frame and in the at least one frame after the second frame.

14. The method according to claim 9, further comprising the steps of: adding the jitter-related pixel data unchanged in the first frame and in at least one subsequent frame to the comparison pixel data used to determine whether the jittered image data represents a static image until the comparison pixel ratio becomes greater than or equal to the reference pixel ratio, in: The step of determining whether the jittered image data represents a static image comprises: using the jitter-independent pixel data and jitter-dependent pixel data that is unchanged in the first frame and the at least one subsequent frame; and The subsequent frames are sequentially selected from the second frame to the 2^M+1th frame, where M is the number of bits corresponding to the dithering period of the ditherer performing the dithering operation.

15. The method according to claim 9, further comprising storing representative values ​​of jitter-independent pixel data in the first frame, in, The step of determining whether the jitter image data represents a static image includes comparing the stored representative value with a representative value of the jitter-independent pixel data in the second frame.

16. The method according to claim 9, further comprising the steps of: When the dithering image data represents a static image, a low frequency driving is performed, the low frequency driving driving the display panel including the plurality of pixels at a low frame rate lower than a normal frame rate.

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